Effects of Rapid Thermal Annealing on W/Si1−xGex Contacts

1993 ◽  
Vol 320 ◽  
Author(s):  
V. Aubry ◽  
F. Meyer ◽  
R. Laval ◽  
C. Clerc ◽  
P. Warren ◽  
...  

ABSTRACTThermal reaction of W with Si1−xGex films epitaxially grown by Rapid Thermal Chemical Vapor Deposition was investigated in the temperature range 500°C - 1000°C. The samples were annealed either in a Rapid Thermal Annealing (RTA) system or in a conventional furnace, both in flowing nitrogen. The reaction products were investigated by Rutherford Backscattering Spectroscopy (RBS), Energy Dispersive Spectrometry (EDS) and X-ray diffraction (XRD). Sheet resistance measurements were also performed to follow the progress of the reaction. The reaction of W with Si0.67Ge0.33 is similar to that of W with silicon. W reacts with silicon to form tetragonal WSi2. The Ge-content in the silicide is lower than that of the asdeposited alloy. It is shown that an oxygen contamination occurs during conventional annealing and leads to the formation of non homogeneous Si1−x Gex unreacted alloy below the silicide film. Rapid thermal annealing prevents this parasitic effect and the unreacted film remains homogeneous although a slight decrease in the Ge-content is observed. These results are correlated with Schottky barrier height measurements on p-Si0.83Ge0.17 partially strained films. We observed an increase of the barrier height with increasing the temperature for annealing from 500°C to 1000°C. This trend may be explained either by strain relaxation or (and) Ge-content decrease in the unreacted alloy.

1995 ◽  
Vol 379 ◽  
Author(s):  
M. Mamnor ◽  
C. Guedj ◽  
P. Boucaud ◽  
F. Meyer ◽  
D. Bouchier ◽  
...  

ABSTRACTWe have recently investigated the properties of W/Si1-xGex films prepared by rapid thermal chemical vapor deposition (RTCVD). The barrier height on p-type, ΦBp, varies as the band gap with the germanium content for totally relaxed films, and increases with strain relaxation, while that on n-type remains rather constant. These results suggest that the Fermi level is pinned relative to the conduction band at the interface of the binary alloy and that the measurement of Schottky barriers is a suitable tool to follow band gap variations. In this work, the effects of carbon incorporation on Schottky barriers have been investigated. The study has been performed on Si1-x-yGexCy films (0≤y≤1.35% with x=10%). The strain retained in the films was determined by X-ray diffraction. Infrared absorption measurements have shown that the carbon is incorporated on substitutional sites. The electrical results indicate the same trends than those observed on the binary alloys, the barrier height on n-type remains rather constant while the barrier height on p-type varies. Adding C leads to an increase of ΦBp, but this increase is too large to be explained in terms of variation of the band gap. The influence of other parameters, such as the doping level and the hole effective mass is discussed.


1995 ◽  
Vol 379 ◽  
Author(s):  
D.Y.C. Lie ◽  
J.H. Song ◽  
M.-A. Nicolet ◽  
N.D. Theodore ◽  
J. Candelaria ◽  
...  

ABSTRACTMetastable pseudomorphic GexSi1−x (x=8%,16%) films were deposited on p-Si(100) substrates by chemical-vapor-deposition and then implanted at room temperature with 90 keV arsenic ions to a dose of 1.5×1015/cm2. The implantation amorphizes approximately the top 125 nm of the 145 nm-thick GeSi layers. The Si-GeSi interfaces remain sharp after implantation. Implanted and non-implanted GeSi samples, together with implanted Si control samples, were subsequently annealed simultaneously by rapid thermal annealing in a nitrogen ambient at 600,700,800 × for 10,20,40s at each temperature. The implanted samples undergo layer-by-layer solid-phase epitaxial regrowth during annealing at or above 600 ×C. The amorphized and regrown GeSi layers are always fully relaxed with a very high density of dislocations (1010-1011/cm2). At a fixed annealing temperature, strain relaxation of an implanted GeSi film is substantially more extensive than that of a non-implanted one. About 50-90% of the implanted arsenic ions become electrically active after the completion of solid-phase epitaxy. The percentages of arsenic ions that are activated in the Si control samples are generally higher than those in GeSi. The room-temperature sheet electron mobility in GeSi is roughly 30% lower than that in Si for a given sheet electron concentration. We conclude that metastable GeSi on Si(100) amorphized by arsenic ions and recrystallized by solid-phase epitaxy cannot recover both its crystallinity and its pseudomorphic strain under rapid thermal annealing.


1995 ◽  
Vol 403 ◽  
Author(s):  
J. J. Pedroviejo ◽  
B. Garrido ◽  
J. C. Ferrer ◽  
A. Cornet ◽  
E. Scheid ◽  
...  

AbstractConventional and Rapid Thermal Annealing of Semi-Insulating Polycrystalline Silicon layers obtained by Low Pressure Chemical Vapor Deposition (LPCVD) from disilane Si2H6 have been performed in order to determine the structural modifications induced on the layers by these thermal treatments. The study of these modifications has been carried out by several analysis methods like FTIR, XPS, TEM, RAMAN and ellipsometry. The results obtained are presented, contrasted and discussed in this work.


1987 ◽  
Vol 92 ◽  
Author(s):  
E. Ma ◽  
M. Natan ◽  
B.S. Lim ◽  
M-A. Nicolet

ABSTRACTSilicide formation induced by rapid thermal annealing (RTA) and conventional furnace annealing (CFA) in bilayers of sequentially deposited films of amorphous silicon and polycrystalline Co or Ni is studied with RBS, X-ray diffraction and TEM. Particular attention is paid to the reliability of the RTA temperature measurements in the study of the growth kinetics of the first interfacial compound, Co2Si and Ni2Si, for both RTA and CFA. It is found that the same diffusion-controlled kinetics applies for the silicide formation by RTA in argon and CFA in vacuum with a common activation energy of 2.1+0.2eV for Co2Si and 1.3+0.2eV for Ni Si. Co and Ni atoms are the dominant diffusing species; during silicide formation by both RTA and CFA. The microstructures of the Ni-silicide formed by the two annealing techniques, however, differs considerably from each other, as revealed by cross-sectional TEM studies.


2013 ◽  
Vol 40 (1) ◽  
pp. 0106003
Author(s):  
王健 Wang Jian ◽  
谢自力 Xie Zili ◽  
张韵 Zhang Yun ◽  
滕龙 Teng Long ◽  
李烨操 Li Yecao ◽  
...  

1997 ◽  
Vol 470 ◽  
Author(s):  
Patricia Warren ◽  
Stephane Retzmanick ◽  
Martin Gotza ◽  
Marc Begems

ABSTRACTSi / Si1-x-yGexCy / Si heterostructures containing up to 17 at.% Ge and 1.9 at.% C were grown on (001) silicon by low pressure Rapid Thermal Chemical Vapor Deposition, using a mixture of silane, germane and methylsilane, diluted in hydrogen. The samples were then annealed in a Rapid Thermal Processing furnace, under an atmospheric pressure of nitrogen, at temperatures ranging from 900 to 1130 °C.The samples were characterized using infrared spectroscopy and x-ray diffraction. SIMS profiling and TEM observation were performed on some of the samples.Substitutional C gradually disappeared, either precipitating out to form cubic silicon carbide (β-SiC), or simply vanishing into interstitial positions. In any case, the in-plane lattice constant remained constant after annealing, indicating that there was no mechanical strain relaxation by formation of misfit dislocations. The perpendicular lattice constant increased due to the decrease in substitutional C concentration, as well as it decreased due to the germanium out-diffusion. This variation of the strain during annealing was modeled, and allowed the determination of the kinetics of the substitutional carbon disappearance. The same behavior was observed for all samples. Indeed, the Cs disappearance rate was always increased for samples with higher initial Ge and C concentrations. The kinetics of this precipitation was found in very good agreement with previous published results.


1995 ◽  
Vol 34 (Part 1, No. 12A) ◽  
pp. 6321-6325 ◽  
Author(s):  
Chien-Jen Wang ◽  
Ming-Shiann Feng ◽  
ShihHsiungChan ◽  
Janne-Wha Wu ◽  
Chun-Yen Chang ◽  
...  

1991 ◽  
Vol 70 (4) ◽  
pp. 2366-2369 ◽  
Author(s):  
Jong‐Sung Hong ◽  
Yong Tae Kim ◽  
Suk‐Ki Min ◽  
Tae Won Kang ◽  
Chi Yhou Hong

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