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Author Vohra, A.; Khanam, A.; Slotte, J.; Makkonen, I.; Pourtois, G.; Loo, R.; Vandervorst, W.
Title Evolution of phosphorus-vacancy clusters in epitaxial germanium Type A1 Journal article
Year 2019 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 125 Issue 2 Pages 025701
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The E centers (dopant-vacancy pairs) play a significant role in dopant deactivation in semiconductors. In order to gain insight into dopant-defect interactions during epitaxial growth of in situ phosphorus doped Ge, positron annihilation spectroscopy, which is sensitive to open-volume defects, was performed on Ge layers grown by chemical vapor deposition with different concentrations of phosphorus (similar to 1 x 10(18)-1 x 10(20) cm(-3)). Experimental results supported by first-principles calculations based on the two component density-functional theory gave evidence for the existence of mono-vacancies decorated by several phosphorus atoms as the dominant defect type in the epitaxial Ge. The concentration of vacancies increases with the amount of P-doping. The number of P atoms around the vacancy also increases, depending on the P concentration. The evolution of P-n-V clusters in Ge contributes significantly to the dopant deactivation. Published under license by AIP Publishing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000455922100057 Publication Date 2019-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 5 Open Access Not_Open_Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:156722 Serial 5274
Permanent link to this record
 

 
Author Clima, S.; McMitchell, S.R.C.; Florent, K.; Nyns, L.; Popovici, M.; Ronchi, N.; Di Piazza, L.; Van Houdt, J.; Pourtois, G.
Title First-principles perspective on poling mechanisms and ferroelectric/antiferroelectric behavior of Hf1-xZrxO2 for FEFET applications Type P1 Proceeding
Year 2018 Publication 2018 Ieee International Electron Devices Meeting (iedm) Abbreviated Journal
Volume Issue Pages
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We investigate at the atomic level the most probable phase transformations under strain, that are responsible for the ferroelectric/ antiferroelectric behavior in Hf1-xZrxO2 materials. Four different crystalline phase transformations exhibit a polar/non-polar transition: monoclinic-to-orthorhombic requires a gliding strain tensor, orthorhombic-to-orthorhombic transformation does not need strain to polarize the material, whereas tetragonal-to-cubic cell compression and tetragonal-to-orthorhombic cell elongation destabilizes the non-polar tetragonal phase, facilitating the transition towards a polar atomic configuration, therefore changing the polarization-electric field loop from antiferroelectric to ferroelectric. Oxygen vacancies can reduce drastically the polarization reversal barriers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000459882300073 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-72811-987-8; 978-1-72811-987-8 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:158693 Serial 7972
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Author Sankaran, K.; Swerts, J.; Carpenter, R.; Couet, S.; Garello, K.; Evans, R.F.L.; Rao, S.; Kim, W.; Kundu, S.; Crotti, D.; Kar, G.S.; Pourtois, G.
Title Evidence of magnetostrictive effects on STT-MRAM performance by atomistic and spin modeling Type P1 Proceeding
Year 2018 Publication 2018 Ieee International Electron Devices Meeting (iedm) Abbreviated Journal
Volume Issue Pages
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract For the first time, we demonstrate, using an atomistic description of a 30nm diameter spin-transfer-torque magnetic random access memories (STT-MRAM), that the difference in mechanical properties of its sub-nanometer layers induces a high compressive strain in the magnetic tunnel junction (MTJ) and leads to a detrimental magnetostrictive effect. Our model explains the issues met in engineering the electrical and magnetic performances in scaled STT-MRAM devices. The resulting high compressive strain built in the stack, particularly in the MgO tunnel barrier (t-MgO), and its associated non-uniform atomic displacements, impacts on the quality of the MTJ interface and leads to strain relieve mechanisms such as surface roughness and adhesion issues. We illustrate that the strain gradient induced by the different materials and their thicknesses in the stacks has a negative impact on the tunnel magneto-resistance (TMR), on the magnetic nucleation process and on the STT-MRAM performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000459882300147 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-72811-987-8; 978-1-72811-987-8 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:158694 Serial 7942
Permanent link to this record
 

 
Author Dhayalan, S.K.; Nuytten, T.; Pourtois, G.; Simoen, E.; Pezzoli, F.; Cinquanta, E.; Bonera, E.; Loo, R.; Rosseel, E.; Hikavyy, A.; Shimura, Y.; Vandervorst, W.
Title Insights into the C Distribution in Si:C/Si:C:P and the Annealing Behavior of Si:C Layers Type A1 Journal article
Year 2019 Publication ECS journal of solid state science and technology Abbreviated Journal Ecs J Solid State Sc
Volume 8 Issue 4 Pages P209-P216
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Si:C and Si:C:P alloys are potential candidates for source-drain stressor applications in n-type Fin Field Effect Transistors (FinFETs). Increasing the C content to achieve high strain results in the arrangement of C atoms as third nearest neighbors (3nn) in the Si: C lattice. During thermal annealing, the presence of C atoms as 3nn may promote clustering at the interstitial sites, causing loss of stress. The concentration of C atoms as 3nn is reduced by the incorporation of a small amount of Ge atoms during the growth, whereas in-situ P doping does not influence this 3nn distribution [J Solid State Sci. Technol vol 6, p 755, 2017]. Small amounts of Ge are provided during low temperature selective epitaxial growth scheme, which are based on cyclic deposition and etching (CDE). In this work, we aim to provide physical insights into the aforementioned phenomena, to understand the behavior of 3nn C atoms and the types of defects that are formed in the annealed Si: C films. Using ab-initio simulations, the Ge-C interaction in the Si matrix is investigated and this insight is used to explain how the Ge incorporation leads to a reduced 3nn distribution of the C atoms. The interaction between C and P in the Si: C: P films is also investigated to explain why the P incorporation has not led to a reduction in the 3nn distribution. We then report on the Raman characterization of Si: C layers subjected to post epi annealing. As the penetration depth of the laser is dependent on the wavelength, Raman measurements at two different wavelengths enable us to probe the depth distribution of 3nn C atoms after applying different annealing conditions. We observed a homogeneous loss in 3nn C throughout the layer. Whereas in the kinematic modeling of high resolution X-ray diffraction spectra, a gradient in the substitutional C loss was observed close to the epitaxial layer/substrate interface. This gradient can be due to the out diffusion of C atoms into the Si substrate or to the formation of interstitial C clusters, which cannot be distinguished in HR-XRD. Deep Level Transient Spectroscopy indicated that the prominent out-diffusing species was interstitial CO complex while the interstitial C defects were also prevalent in the epi layer. (c) 2019 The Electrochemical Society.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000465069200001 Publication Date 2019-04-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2162-8769; 2162-8777 ISBN Additional Links (up) UA library record; WoS full record
Impact Factor 1.787 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 1.787
Call Number UA @ admin @ c:irua:160399 Serial 5275
Permanent link to this record
 

 
Author Adelmann, C.; Sankaran, K.; Dutta, S.; Gupta, A.; Kundu, S.; Jamieson, G.; Moors, K.; Pinna, N.; Ciofi, I.; Van Elshocht, S.; Bommels, J.; Boccardi, G.; Wilson, C.J.; Pourtois, G.; Tokei, Z.
Title Alternative Metals: from ab initio Screening to Calibrated Narrow Line Models Type P1 Proceeding
Year 2018 Publication Proceedings of the IEEE ... International Interconnect Technology Conference T2 – IEEE International Interconnect Technology Conference (IITC), JUN 04-07, 2018, Santa Clara, CA Abbreviated Journal
Volume Issue Pages 154-156
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We discuss the selection and assessment of alternative metals by a combination of ab initio computation of electronic properties, experimental resistivity assessments, and calibrated line resistance models. Pt-group metals as well as Nb are identified as the most promising elements, with Ru showing the best combination of material properties and process maturity. An experimental assessment of the resistivity of Ru, Ir, and Co lines down to similar to 30 nm(2) is then used to devise compact models for line and via resistance that can be compared to Cu predictions. The main advantage of alternative metals originates from the possibility for barrierless metallization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000468672900051 Publication Date 2018-09-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-5386-4337-2; 978-1-5386-4337-2 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:160473 Serial 7436
Permanent link to this record
 

 
Author Sankaran, K.; Moors, K.; Dutta, S.; Adelmann, C.; Tokei, Z.; Pourtois, G.
Title Metallic ceramics for low resitivity interconnects : an ab initio insight Type P1 Proceeding
Year 2018 Publication Proceedings of the IEEE ... International Interconnect Technology Conference T2 – IEEE International Interconnect Technology Conference (IITC), JUN 04-07, 2018, Santa Clara, CA Abbreviated Journal
Volume Issue Pages 160-162
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The scalability potential of low resistivity ternary metallic alloys (MAX) as an interconnect medium has been benchmarked against copper through first-principle simulations. We report that some carbon and nitrogen MAX phases have the potential to display a reduced sensitivity of their intrinsic resistivity to scaling, while showing improved electromigration properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000468672900053 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-5386-4337-2; 978-1-5386-4337-2 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:160474 Serial 8219
Permanent link to this record
 

 
Author Vohra, A.; Khanam, A.; Slotte, J.; Makkonen, I.; Pourtois, G.; Porret, C.; Loo, R.; Vandervorst, W.
Title Heavily phosphorus doped germanium : strong interaction of phosphorus with vacancies and impact of tin alloying on doping activation Type A1 Journal article
Year 2019 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 125 Issue 22 Pages 225703
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We examined the vacancy trapping proficiency of Sn and P atoms in germanium using positron annihilation spectroscopy measurements, sensitive to the open-volume defects. Epitaxial Ge1 xSnx films were grown by chemical vapor deposition with different P concentrations in the 3: 0 1019-1: 5 1020 cm 3 range. We corroborate our findings with first principles simulations. Codoping of Ge with a Sn concentration of up to 9% is not an efficient method to suppress the free vacancy concentration and the formation of larger phosphorus-vacancy complexes. Experimental results confirm an increase in the number of P atoms around the monovacancy with P-doping, leading to dopant deactivation in epitaxial germanium-tin layers with similar Sn content. Vice versa, no impact on the improvement of maximum achieved P activation in Ge with increasing Sn-doping has been observed. Theoretical calculations also confirm that Pn-V (vacancy) complexes are energetically more stable than the corresponding SnmPn-V and Snm-V defect structures with the same number of alien atoms (Sn or P) around the monovacancy. he strong attraction of vacancies to the phosphorus atoms remains the dominant dopant deactivation mechanism in Ge as well as in Ge1 xSnx. Published under license by AIP Publishing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000471698600044 Publication Date 2019-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 1 Open Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:161333 Serial 6300
Permanent link to this record
 

 
Author Clima, S.; Garbin, D.; Devulder, W.; Keukelier, J.; Opsomer, K.; Goux, L.; Kar, G.S.; Pourtois, G.
Title Material relaxation in chalcogenide OTS SELECTOR materials Type A1 Journal article
Year 2019 Publication Microelectronic engineering Abbreviated Journal Microelectron Eng
Volume 215 Issue 215 Pages 110996
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Nature of the mobility-gap states in amorphous Ge-rich Ge50Se50 was found to be related to homopolar Ge bonds in the chains/clusters of Ge atoms. Threshold switching material suffers Ge-Ge bond concentration drift during material ageing, which can explain the observed reliability of the aGe(50)Se(50) selector devices. Strong Ge-N bonds were introduced to alleviate the observed instability.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000480665600008 Publication Date 2019-05-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-9317 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.806 Times cited 1 Open Access
Notes Approved Most recent IF: 1.806
Call Number UA @ admin @ c:irua:161905 Serial 6308
Permanent link to this record
 

 
Author Yu, H.; Schaekers, M.; Chew, S.A.; Eyeraert, J.-L.; Dabral, A.; Pourtois, G.; Horiguchi, N.; Mocuta, D.; Collaert, N.; De Meyer, K.
Title Titanium (germano-)silicides featuring 10-9 Ω.cm2 contact resistivity and improved compatibility to advanced CMOS technology Type P1 Proceeding
Year 2018 Publication 2018 18th International Workshop On Junction Technology (iwjt) Abbreviated Journal
Volume Issue Pages 80-84 T2 - 18th International Workshop on Junction
Keywords P1 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract uIn this work, we discuss three novel Ti (germano-)silicidation techniques featuring respectively the pre-contact amorphization implantation (PCAI), the TiSi co-deposition, and Ti atomic layer deposition (ALD). All three techniques form TiSix(Ge-y) contacts with ultralow contact resistivity (rho(c)) of (1-3)x10(-9) Omega.cm(2) on both highly doped n-Si and p-SiGe substrates: these techniques meet rho(c) requirement of 5-14 nm CMOS technology and feature unified CMOS contact solutions. We further discuss the compatibility of these techniques to the realistic CMOS transistor fabrication.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000502768600020 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-5386-4511-6; 978-1-5386-4511-6 ISBN Additional Links (up) UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:165190 Serial 8673
Permanent link to this record
 

 
Author Clima, S.; Garbin, D.; Opsomer, K.; Avasarala, N.S.; Devulder, W.; Shlyakhov, I.; Keukelier, J.; Donadio, G.L.; Witters, T.; Kundu, S.; Govoreanu, B.; Goux, L.; Detavernier, C.; Afanas'ev, V.; Kar, G.S.; Pourtois, G.
Title Ovonic threshold-switching GexSey chalcogenide materials : stoichiometry, trap nature, and material relaxation from first principles Type A1 Journal article
Year 2020 Publication Physica Status Solidi-Rapid Research Letters Abbreviated Journal Phys Status Solidi-R
Volume Issue Pages 1900672
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Density functional theory simulations are used to identify the structural factors that define the material properties of ovonic threshold switches (OTS). They show that the nature of mobility-gap trap states in amorphous Ge-rich Ge50Se50 is related to Ge-Ge bonds, whereas in Se-rich Ge30Se70 the Ge valence-alternating-pairs and Se lone-pairs dominate. To obtain a faithful description of the electronic structure and delocalization of states, it is required to combine hybrid exchange-correlation functionals with large unit-cell models. The extent of localization of electronic states depends on the applied external electric field. Hence, OTS materials undergo structural changes during electrical cycling of the device, with a decrease in the population of less exothermic Ge-Ge bonds in favor of more exothermic Ge-Se. This reduces the amount of charge traps, which translates into coordination changes, an increase in mobility-gap, and subsequently changes in the selector-device electrical parameters. The threshold voltage drift process can be explained by natural evolution of the nonpreferred Ge-Ge bonds (or “chains”/clusters thereof) in Ge-rich GexSe1-x. The effect of extrinsic doping is shown for Si and N, which introduce strong covalent bonds into the system, increase both mobility-gap and crystallization temperature, and decrease the leakage current.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000512431100001 Publication Date 2020-01-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6254 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.8 Times cited 3 Open Access
Notes ; This work was carried out in the framework of the imec Core CMOS-Emerging Memory Program. Financial support from EU H2020-NMBPTO-IND-2018 project “INTERSECT” (Grant No. 814487) is acknowledged. ; Approved Most recent IF: 2.8; 2020 IF: 3.032
Call Number UA @ admin @ c:irua:166492 Serial 6575
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Author Mehta, A.N.; Mo, J.; Pourtois, G.; Dabral, A.; Groven, B.; Bender, H.; Favia, P.; Caymax, M.; Vandervorst, W.
Title Grain-boundary-induced strain and distortion in epitaxial bilayer MoS₂ lattice Type A1 Journal article
Year 2020 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 124 Issue 11 Pages 6472-6478
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Grain boundaries between 60 degrees rotated and twinned crystals constitute the dominant type of extended line defects in two-dimensional transition metal dichalcogenides (2D MX2) when grown on a single crystalline template through van der Waals epitaxy. The two most common 60 degrees grain boundaries in MX2 layers, i.e., beta- and gamma-boundaries, introduce distinct distortion and strain into the 2D lattice. They impart a localized tensile or compressive strain on the subsequent layer, respectively, due to van der Waals coupling in bilayer MX2 as determined by combining atomic resolution electron microscopy, geometric phase analysis, and density functional theory. Based on these observations, an alternate route to strain engineering through controlling intrinsic van der Waals forces in homobilayer MX2 is proposed. In contrast to the commonly used external means, this approach enables the localized application of strain to tune the electronic properties of the 2D semiconducting channel in ultra-scaled nanoelectronic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000526396000067 Publication Date 2020-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 2 Open Access
Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 4.536
Call Number UA @ admin @ c:irua:168625 Serial 6528
Permanent link to this record
 

 
Author Vohra, A.; Makkonen, I.; Pourtois, G.; Slotte, J.; Porret, C.; Rosseel, E.; Khanam, A.; Tirrito, M.; Douhard, B.; Loo, R.; Vandervorst, W.
Title Source/drain materials for Ge nMOS devices: phosphorus activation in epitaxial Si, Ge, Ge1-xSnx and SiyGe1-x-ySnx Type A1 Journal article
Year 2020 Publication Ecs Journal Of Solid State Science And Technology Abbreviated Journal Ecs J Solid State Sc
Volume 9 Issue 4 Pages 044010-44012
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract This paper benchmarks various epitaxial growth schemes based on n-type group-IV materials as viable source/drain candidates for Ge nMOS devices. Si:P grown at low temperature on Ge, gives an active carrier concentration as high as 3.5 x 10(20) cm(-3) and a contact resistivity down to 7.5 x 10(-9) Omega.cm(2). However, Si:P growth is highly defective due to large lattice mismatch between Si and Ge. Within the material stacks assessed, one option for Ge nMOS source/drain stressors would be to stack Si:P, deposited at contact level, on top of a selectively grown n-SiyGe1-x-ySnx at source/drain level, in line with the concept of Si passivation of n-Ge surfaces to achieve low contact resistivities as reported in literature (Martens et al. 2011 Appl. Phys. Lett., 98, 013 504). The saturation in active carrier concentration with increasing P (or As)-doping is the major bottleneck in achieving low contact resistivities for as-grown Ge or SiyGe1-x-ySnx. We focus on understanding various dopant deactivation mechanisms in P-doped Ge and Ge1-xSnx alloys. First principles simulation results suggest that P deactivation in Ge and Ge1-xSnx can be explained both by P-clustering and donor-vacancy complexes. Positron annihilation spectroscopy analysis, suggests that dopant deactivation in P-doped Ge and Ge1-xSnx is primarily due to the formation of P-n-V and SnmPn-V clusters. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000531473500002 Publication Date 2020-04-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2162-8769; 2162-8777 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 2.2 Times cited Open Access
Notes ; The imec core CMOS program members, European Commission, the TAKEMI5 ECSEL project, local authorities and the imec pilot line are acknowledged for their support. Air Liquide Advanced Materials is acknowledged for providing advanced precursor gases. A. V. acknowledges his long stay abroad grant and a grant for participation in congress abroad from the Research Foundation-Flanders (Application No. V410518N and K159219N). I. M. acknowledges financial support from Academy of Finland (Project Nos. 285 809, 293 932 and 319 178). CSC-IT Center for Science, Finland is acknowledged for providing the computational resources. ; Approved Most recent IF: 2.2; 2020 IF: 1.787
Call Number UA @ admin @ c:irua:169502 Serial 6607
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Author Khanam, A.; Vohra, A.; Slotte, J.; Makkonen, I.; Loo, R.; Pourtois, G.; Vandervorst, W.
Title A demonstration of donor passivation through direct formation of V-As-i complexes in As-doped Ge1-XSnx Type A1 Journal article
Year 2020 Publication Journal Of Applied Physics Abbreviated Journal J Appl Phys
Volume 127 Issue 19 Pages 195703
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Positron annihilation spectroscopy in the Doppler and coincidence Doppler mode was applied on Ge1 xSnx epitaxial layers, grown by chemical vapor deposition with different total As concentrations (1019-1021 cm3), high active As concentrations (1019 cm3), and similar Sn concentrations (5.9%-6.4%). Positron traps are identified as mono-vacancy complexes. Vacancy-As complexes, V-Asi, formed during the growth were studied to deepen the understanding of the electrical passivation of the Ge1 xSnx:As epilayers. Larger monovacancy complexes, V-Asi (i 2), are formed as the As doping increases. The total As concentration shows a significant impact on the saturation of the number of As atoms (i 1/4 4) around the vacancies in the sample epilayers. The presence of V-Asi complexes decreases the dopant activation in the Ge1 xSnx:As epilayers. Furthermore, the presence of Sn failed to hinder the formation of larger V-Asi complexes and thus failed to reduce the donor-deactivation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000536196000003 Publication Date 2020-05-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.2 Times cited Open Access
Notes ; ; Approved Most recent IF: 3.2; 2020 IF: 2.068
Call Number UA @ admin @ c:irua:170252 Serial 6447
Permanent link to this record
 

 
Author Guo, J.; Clima, S.; Pourtois, G.; Van Houdt, J.
Title Identifying alternative ferroelectric materials beyond Hf(Zr)O-₂ Type A1 Journal article
Year 2020 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 117 Issue 26 Pages 262903
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A database-driven approach combined with ab initio density functional theory (DFT) simulations is used to identify and simulate alternative ferroelectric materials beyond Hf(Zr)O-2. The database-driven screening method identifies a class of wurtzite ferroelectric materials. DFT simulations of wurtzite magnesium chalcogenides, including MgS, MgSe, and MgTe, show their potential to achieve improved ferroelectric (FE) stability, simple atomistic unit cell structure, and large FE polarization. Strain engineering can effectively modulate the FE switching barrier height for facilitating FE switching. The effect of the piezoelectric property on the FE switching barrier heights is also examined.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000608049700003 Publication Date 2020-12-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; 1077-3118 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4 Times cited Open Access
Notes Approved Most recent IF: 4; 2020 IF: 3.411
Call Number UA @ admin @ c:irua:176053 Serial 6766
Permanent link to this record
 

 
Author Clima, S.; O'Sullivan, B.J.; Ronchi, N.; Bardon, M.G.; Banerjee, K.; Van den Bosch, G.; Pourtois, G.; van Houdt, J.
Title Ferroelectric switching in FEFET : physics of the atomic mechanism and switching dynamics in HfZrOx, HfO2 with oxygen vacancies and Si dopants Type P1 Proceeding
Year 2020 Publication Abbreviated Journal
Volume Issue Pages
Keywords P1 Proceeding; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The fine balance between dipole-field energy and anion drift force defines the switching mechanism during polarization reversal: for the first time we show that only Pbcm mechanism obeys the ferroelectric switching physics, whereas P4(2)/nmc (or any other) mechanism does not. However, with lower energy barrier, it represents an important antiferroelectric mechanism. Constraints relaxation can lead to 90 degrees polarization rotation (domain deactivation). Intrinsically, the Si/VO-doping can switch faster than undoped HfO2 or HfZrOx. Theoretical Arrhenius model / intrinsic material switching (DFT) overestimates the switching speed extracted from experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000717011600218 Publication Date 2021-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-7281-8888-1 ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:184730 Serial 7963
Permanent link to this record
 

 
Author Compemolle, S.; Pourtois, G.; Sorée, B.; Magnus, W.; Chibotaru, L.F.; Ceulemans, A.
Title Conductance of a copper-nanotube bundle interface: impact of interface geometry and wave-function interference Type A1 Journal article
Year 2008 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 77 Issue 19 Pages 193406,1-4
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000256971600032 Publication Date 2008-05-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 8 Open Access
Notes Approved Most recent IF: 3.836; 2008 IF: 3.322
Call Number UA @ lucian @ c:irua:70215 Serial 479
Permanent link to this record
 

 
Author Neyts, E.; Maeyens, A.; Pourtois, G.; Bogaerts, A.
Title A density-functional theory simulation of the formation of Ni-doped fullerenes by ion implantation Type A1 Journal article
Year 2011 Publication Carbon Abbreviated Journal Carbon
Volume 49 Issue 3 Pages 1013-1017
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using self-consistent KohnSham density-functional theory molecular dynamics simulations, we demonstrate the theoretical possibility to synthesize NiC60, the incarfullerene Ni@C60 and the heterofullerene C59Ni in an ion implantation setup. The corresponding formation mechanisms of all three complexes are elucidated as a function of the ion implantation energy and impact location, suggesting possible routes for selectively synthesizing these complexes.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000286683500032 Publication Date 2010-11-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 13 Open Access
Notes Approved Most recent IF: 6.337; 2011 IF: 5.378
Call Number UA @ lucian @ c:irua:85139 Serial 639
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Author Sorée, B.; Magnus, W.; Pourtois, G.
Title Analytical and self-consistent quantum mechanical model for a surrounding gate MOS nanowire operated in JFET mode Type A1 Journal article
Year 2008 Publication Journal of computational electronics Abbreviated Journal J Comput Electron
Volume 7 Issue 3 Pages 380-383
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We derive an analytical model for the electrostatics and the drive current in a silicon nanowire operating in JFET mode. We show that there exists a range of nanowire radii and doping densities for which the nanowire JFET satisfies reasonable device characteristics. For thin nanowires we have developed a self-consistent quantum mechanical model to obtain the electronic structure.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000208473800067 Publication Date 2008-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1569-8025;1572-8137; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.526 Times cited 70 Open Access
Notes Approved Most recent IF: 1.526; 2008 IF: NA
Call Number UA @ lucian @ c:irua:89504 Serial 107
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Author Neyts, E.C.; Khalilov, U.; Pourtois, G.; van Duin, A.C.T.
Title Hyperthermal oxygen interacting with silicon surfaces : adsorption, implantation, and damage creation Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 15 Pages 4818-4823
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using reactive molecular dynamics simulations, we have investigated the effect of single-impact, low-energy (thermal-100 eV) bombardment of a Si(100){2 × 1} surface by atomic and molecular oxygen. Penetration probability distributions, as well as defect formation distributions, are presented as a function of the impact energy for both species. It is found that at low impact energy, defects are created chemically due to the chemisorption process in the top layers of the surface, while at high impact energy, additional defects are created by a knock-on displacement of Si. These results are of particular importance for understanding device performances of silica-based microelectronic and photovoltaic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000288401200060 Publication Date 2011-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 28 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:89858 Serial 1543
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Author Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Structural and vibrational properties of amorphous GeO2 from first-principles Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 98 Issue 20 Pages 202110,1-202110,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The structural and vibrational properties of amorphous germanium oxide (a-GeO<sub>2</sub>) are investigated using first-principles calculations based on density functional theory. We first generate an a-GeO<sub>2</sub> structure by first-principles molecular dynamics and analyze its structural properties. The vibrational spectra is then calculated within a density-functional approach. Both static and dynamic properties are in good agreement with experimental data. We next generate defects in our structure (oxygen vacancies with several density and charge states) and consider the most stable atomic configurations, focusing on the vibrational features of threefold coordinated O and divalent Ge centers.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000290812100038 Publication Date 2011-05-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 226 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:90222 Serial 3202
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Author Delabie, A.; Sioncke, S.; Rip, J.; van Elshocht, S.; Caymax, M.; Pourtois, G.; Pierloot, K.
Title Mechanisms for the trimethylaluminum reaction in aluminum oxide atomic layer deposition on sulfur passivated germanium Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 35 Pages 17523-17532
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Germanium combined with high-κ dielectrics is investigated for the next generations of CMOS devices. Therefore, we study reaction mechanisms for Al2O3 atomic layer deposition on sulfur passivated Ge using calculations based on density functional theory and total reflection X-ray fluorescence (TXRF). TXRF indicates 6 S/nm2 and 4 Al/nm2 after the first TMA/H2O reaction cycle, and growth inhibition from the second reaction cycle on. Calculations are performed on molecular clusters representing −GeSH surface sites. The calculations confirm that the TMA reaction does not affect the S content. On fully SH-terminated Ge, TMA favorably reacts with up to three −GeSH sites, resulting in a near tetrahedral Al coordination. Electron deficient structures with a GeS site shared between two Al atoms are proposed. The impact of the cluster size on the structures and reaction energetics is systematically investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000294386000037 Publication Date 2011-08-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 9 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91714 Serial 1980
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Author Nourbakhsh, A.; Cantoro, M.; Klekachev, A.V.; Pourtois, G.; Vosch, T.; Hofkens, J.; van der Veen, M.H.; Heyns, M.M.; de Gendt, S.; Sels, B.F.
Title Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 33 Pages 16619-16624
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract This contribution presents the effects of a mild O2 plasma treatment on the structural, optical, and electrical properties of single-layer (SLG) and bilayer graphene (BLG). Unexpectedly, we observe only photoluminescence in the SLG parts of a graphene flake composed of regions of various thickness upon O2 plasma treatment, whereas the BLG and few-layer graphene (FLG) parts remain optically unchanged. Confirmed with X-ray photoelectron spectroscopy (XPS) that O2 plasma induces epoxide and hydroxyl-like groups in graphene, density functional theory (DFT) calculations are carried out on representative epoxidized and hydroxylated SLG and BLG models to predict density of states (DOS) and band structures. Sufficiently oxidized SLG shows a bandgap and thus loss of semimetallic behavior, while oxidized BLG maintains its semimetallic behavior even at high oxygen density in agreement with the results of the photoluminescence spectroscopy (PL) experiments. DFT calculations confirm that the Fermi velocity in epoxidized BLG is remarkably comparable with that of pristine SLG, pointing to a similarity of electronic band structure. The similarity is also experimentally demonstrated by the electrical characterization of a plasma-treated BLG-FET. As expected from the electronegative oxygen adatoms in the graphene, epoxidized BLG presents conductive features typical of hole doping. Moreover, the electrical characteristics suggest band structures closely related to that of epoxidized graphene while deviating from that of hydroxylated graphene. Finally, upon O2 plasma treatment of BLG, the four-component 2D peak around 2700 cm1 in the Raman spectrum evolves into a single Lorentzian line, very like the 2D peak of pristine SLG. Summarizing, the data in this contribution recommend that a controlled O2 plasma treatment, which is compatible with CMOS process flow in contrast to wet chemical oxidation methods, provides an efficient and valuable technique to exploit the transport properties of the bottom layer of BLG.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000294077000047 Publication Date 2011-06-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 46 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91715 Serial 3024
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Author Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Electronic properties of two-dimensional hexagonal germanium Type A1 Journal article
Year 2010 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 96 Issue 8 Pages 082111,1-082111,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electronic properties of two-dimensional hexagonal germanium, so called germanene, are investigated using first-principles simulations. Consistent with previous reports, the surface is predicted to have a poor metallic behavior, i.e., being metallic with a low density of states at the Fermi level. It is found that biaxial compressively strained germanene is a gapless semiconductor with linear energy dispersions near the K pointslike graphene. The calculated Fermi velocity of germanene is almost independent of the strain and is about 1.7×10<sup>6</sup> m/s, quite comparable to the value in graphene.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000275027200044 Publication Date 2010-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 86 Open Access
Notes Approved Most recent IF: 3.411; 2010 IF: 3.841
Call Number UA @ lucian @ c:irua:91716 Serial 1004
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Author Pham, A.-T.; Zhao, Q.-T.; Jungemann, C.; Meinerzhagen, B.; Mantl, S.; Sorée, B.; Pourtois, G.
Title Comparison of strained SiGe heterostructure-on-insulator (0 0 1) and (1 1 0) PMOSFETs : CV characteristics, mobility, and ON current Type A1 Journal article
Year 2011 Publication Solid state electronics Abbreviated Journal Solid State Electron
Volume 65-66 Issue Pages 64-71
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Strained SiGe heterostructure-on-insulator (0 0 1) and (1 1 0) PMOSFETs are investigated including important aspects like CV characteristics, mobility, and ON current. The simulations are based on the self-consistent solution of 6 × 6 k · p Schrödinger Equation, multi subband Boltzmann Transport Equation and Poisson Equation, and capture size quantization, strain, crystallographic orientation, and SiGe alloy effects on a solid physical basis. The simulation results are validated by comparison with different experimental data sources. The simulation results show that the strained SiGe HOI PMOSFET with (1 1 0) surface orientation has a higher gate capacitance and a much higher mobility and ON current compared to a similar device with the traditional (0 0 1) surface orientation.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000297182700012 Publication Date 2011-07-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1101; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.58 Times cited 2 Open Access
Notes ; ; Approved Most recent IF: 1.58; 2011 IF: 1.397
Call Number UA @ lucian @ c:irua:92866 Serial 433
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Author Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Inelastic electron tunneling spectroscopy of HfO2 gate stacks : a study based on first-principles modeling Type A1 Journal article
Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 99 Issue 13 Pages 132101,1-132101,3
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract A first-principles modeling approach is used to investigate the vibrational properties of HfO2. The calculated phonon density of states is compared to experimental results obtained from inelastic electron tunneling spectroscopy (IETS) of various metal-oxide-semiconductor devices with HfO2 gate stacks. This comparison provides deep insights into the nature of the signatures of the complicated IETS spectra and provides valuable structural information about the gate stack, such as the possible presence of oxygen vacancies in jet-vapour deposited HfO2. Important structural differences between the interface of atomic-layer or molecular-beam deposited HfO2 and the Si substrate are also revealed.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000295618000036 Publication Date 2011-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 1 Open Access
Notes Approved Most recent IF: 3.411; 2011 IF: 3.844
Call Number UA @ lucian @ c:irua:93611 Serial 1606
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Author Khalilov, U.; Neyts, E.C.; Pourtois, G.; van Duin, A.C.T.
Title Can we control the thickness of ultrathin silica layers by hyperthermal silicon oxidation at room temperature? Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 50 Pages 24839-24848
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using reactive molecular dynamics simulations by means of the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation at room temperature. Oxidation of Si(100){2 × 1} surfaces by both atomic and molecular oxygen was investigated in the energy range 15 eV. The oxidation mechanism, which differs from thermal oxidation, is discussed. In the case of oxidation by molecular O2, silica is quickly formed and the thickness of the formed layers remains limited compared to oxidation by atomic oxygen. The Si/SiO2 interfaces are analyzed in terms of partial charges and angle distributions. The obtained structures of the ultrathin SiO2 films are amorphous, including some intrinsic defects. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry, and more specifically for the fabrication of metal oxide semiconductor devices.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000297947700050 Publication Date 2011-11-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 36 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:94303 Serial 273
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Author Pourtois, G.; Lauwers, A.; Kittl, J.; Pantisano, L.; Sorée, B.; De Gendt, S.; Magnus, W.; Heyns, A.; Maex, K.
Title First-principle calculations on gate/dielectric interfaces : on the origin of work function shifts Type A1 Journal article
Year 2005 Publication Microelectronic engineering Abbreviated Journal Microelectron Eng
Volume 80 Issue Pages 272-279
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The impact of interfacial chemistry occurring at dielectric/gate interface of P-MOS and N-MOS devices is reviewed through a quick literature survey. A specific emphasis is put on the way the bond polarization that occurs between a dielectric and a metal substrate impacts on the gate work function. First-principle simulations are then used to study the work function changes induced by dopant aggregation in nickel monosilicide metal gates. It is shown that the changes are a natural consequence of the variation of the interface polarization.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000231517000062 Publication Date 2005-06-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-9317; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.806 Times cited 31 Open Access
Notes Approved Most recent IF: 1.806; 2005 IF: 1.347
Call Number UA @ lucian @ c:irua:95095 Serial 1199
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Author Delabie, A.; Sioncke, S.; Rip, J.; Van Elshocht, S.; Pourtois, G.; Mueller, M.; Beckhoff, B.; Pierloot, K.
Title Reaction mechanisms for atomic layer deposition of aluminum oxide on semiconductor substrates Type A1 Journal article
Year 2012 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A
Volume 30 Issue 1 Pages 01a127-01a127,10
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract In this work, we have studied the TMA/H(2)O (TMA Al(CH(3))(3)) atomic layer deposition (ALD) of Al(2)O(3) on hydroxyl (OH) and thiol (SH) terminated semiconductor substrates. Total reflection x-ray fluorescence reveals a complex growth-per-cycle evolution during the early ALD reaction cycles. OH and SH terminated surfaces demonstrate growth inhibition from the second reaction cycle on. Theoretical calculations, based on density functional theory, are performed on cluster models to investigate the first TMA/H(2)O reaction cycle. Based on the theoretical results, we discuss possible mechanisms for the growth inhibition from the second reaction cycle on. In addition, our calculations show that AlCH(3) groups are hydrolyzed by a H(2)O molecule adsorbed on a neighboring Al atom, independent of the type of backbonds (Si-O, Ge-O, or Ge-S) of AlCH(3). The coordination of Al remains four-fold after the first TMA/H(2)O reaction cycle. (C) 2012 American Vacuum Society. [DOI: 10.1116/1.3664090]
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000298992800027 Publication Date 2011-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0734-2101; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 1.374 Times cited 41 Open Access
Notes Approved Most recent IF: 1.374; 2012 IF: 1.432
Call Number UA @ lucian @ c:irua:96253 Serial 2818
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Author Scalise, E.; Houssa, M.; Pourtois, G.; Afanas'ev, V.; Stesmans, A.
Title Strain-induced semiconductor to metal transition in the two-dimensional honeycomb structure of MoS2 Type A1 Journal article
Year 2012 Publication Nano Research Abbreviated Journal Nano Res
Volume 5 Issue 1 Pages 43-48
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The electronic properties of two-dimensional honeycomb structures of molybdenum disulfide (MoS(2)) subjected to biaxial strain have been investigated using first-principles calculations based on density functional theory. On applying compressive or tensile bi-axial strain on bi-layer and mono-layer MoS(2), the electronic properties are predicted to change from semiconducting to metallic. These changes present very interesting possibilities for engineering the electronic properties of two-dimensional structures of MoS(2).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000299085200006 Publication Date 2011-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1998-0124;1998-0000; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 7.354 Times cited 407 Open Access
Notes Approved Most recent IF: 7.354; 2012 IF: 7.392
Call Number UA @ lucian @ c:irua:96262 Serial 3169
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Author Mees, M.J.; Pourtois, G.; Neyts, E.C.; Thijsse, B.J.; Stesmans, A.
Title Uniform-acceptance force-bias Monte Carlo method with time scale to study solid-state diffusion Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 85 Issue 13 Pages 134301-134301,9
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Monte Carlo (MC) methods have a long-standing history as partners of molecular dynamics (MD) to simulate the evolution of materials at the atomic scale. Among these techniques, the uniform-acceptance force-bias Monte Carlo (UFMC) method [ G. Dereli Mol. Simul. 8 351 (1992)] has recently attracted attention [ M. Timonova et al. Phys. Rev. B 81 144107 (2010)] thanks to its apparent capacity of being able to simulate physical processes in a reduced number of iterations compared to classical MD methods. The origin of this efficiency remains, however, unclear. In this work we derive a UFMC method starting from basic thermodynamic principles, which leads to an intuitive and unambiguous formalism. The approach includes a statistically relevant time step per Monte Carlo iteration, showing a significant speed-up compared to MD simulations. This time-stamped force-bias Monte Carlo (tfMC) formalism is tested on both simple one-dimensional and three-dimensional systems. Both test-cases give excellent results in agreement with analytical solutions and literature reports. The inclusion of a time scale, the simplicity of the method, and the enhancement of the time step compared to classical MD methods make this method very appealing for studying the dynamics of many-particle systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000302290500001 Publication Date 2012-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links (up) UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 31 Open Access
Notes Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:97160 Serial 3809
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