scholarly journals Titanium Silicide Formation in Presence of Oxygen

1992 ◽  
Vol 15 (1) ◽  
pp. 9-26 ◽  
Author(s):  
C. Nobili ◽  
F. Nava ◽  
G. Ottaviani ◽  
M. Costato ◽  
G. De Santi ◽  
...  
Keyword(s):  
Electron Spectroscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Titanium Silicide ◽  
Silicide Formation ◽  
Metal Oxidation ◽  
X Ray Diffraction ◽  
Amorphous Films ◽  
Titanium Disilicide ◽  
X Ray

In-situ resistivity vs. temperature, Rutherford backscattering spectrometry, Auger electron spectroscopy and X-ray diffraction measurements have been performed in order to study the effects arising from the presence of oxygen in the annealing ambient on the integrity of amorphous films of TiSix, with x ranging from 1.45 to 2.1. Crystalisation occurs around 400 C. The presence of oxygen produces the formation of silicon and titanium oxide around 500 C. Critical analysis of the experimental results have indicated that metal oxidation is inhibited when an excess of silicon is present, which suggests the use of a sputtered Si coating cap as a medium capable of effectively decoupling the silicide film from oxygen. This avoids unwanted Ti oxidation even in heavily oxygen contaminated ambients up to the highest temperatures used for the formation of low resistivity titanium disilicide.

In Situ Rapid Thermal Hydrogenation Pretreatment of Ti for Salicide RTA

1996 ◽  
Vol 429 ◽  
Author(s):  
K. Ando ◽  
T. Ishigami ◽  
Y. Matsubara ◽  
T. Horiuchi ◽  
S. Nishimoto
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Diffraction Analysis ◽  
Sheet Resistance ◽  
Rapid Thermal Annealing ◽  
Titanium Silicide ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray

AbstractAn in situ rapid thermal hydrogenation (RTH) pretreatment of titanium prior to rapid thermal annealing (RTA), or RTH/RTA, is proposed as a silicide formation annealing in a CMOS self-aligned silicide (salicide) process. The in situ RTH is found to enhance silicidation, to reduce nitridation, and even to lower the resultant sheet resistance of titanium silicide.During in situ RTH (e.g., at 550°C), amorphous Ti silicide (e.g., 15-nm thick) grows selectively on Si. Furthermore, Ti nitridation during subsequent RTA (690°C, N2, 10 Torr, 30 s) is reduced depending on RTH (H2, 10 Torr, 30 s) temperature. Accordingly, for 550°C RTH and an initial Ti thickness of 15 nm, the sheet resistance obtained at the 0.27-μm-wide n+ poly-Si gate after a phase transition annealing (800°C, Ar, 10 s) was lower (11.7 Ω /□, st. dev. = 6%) than that of conventional Ti silicide (15.8 Ω/□, st. dev. = 10%). The silicidation enhancement and nitridation reduction are related to crystal structure metamorphosis or to hydrogen interstitial incorporation in the Ti layer during RTH as observed by x-ray diffraction analysis. It is concluded that in situ RTH pretreatment before RTA is very promising as a sub-quarter-micron CMOS salicide process.

Silicide Formation in High-Dose Fe-Implanted Silicon

1991 ◽  
Vol 235 ◽  
Author(s):  
Z. Tan ◽  
F. Namavar ◽  
S. M. Heald ◽  
J. I. Budnick ◽  
F. H. Sanchez
Keyword(s):  
Fine Structure ◽  
Single Phase ◽  
Rutherford Backscattering Spectrometry ◽  
High Dose ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Implantation Damage ◽  
X Ray Absorption ◽  
Post Implantation

ABSTRACTWe have studied the silicide formation in Fe-implanted Si(100), with 1×1017-1×1018 Fe/cm2, using extended x-ray-absorption fine structure (EXAFS), x-ray diffraction and Rutherford backscattering spectrometry (RBS) methods. In the samples as-implanted at 350 °C, no silicide was observed at doses below 3×1017 Fe/cm2. At 5×1017 Fe/cm2, both α-FeSi2 and (β-FeSi2 form but α-FeSi2 appears to be the majority phase. As the dose increases to 7×1017 and above, ordered FeSi forms, but implantation damage is severe and a large number of Fe atoms are in very disordered environments. In addition to FeSi, Fe5Si3 was also observed in the 1×1018 Fe/cm2 sample. Upon post-implantation annealing at 700 °C or 900 °C, single phase P-FeSi2 was obtained independent of the dosage.

Forkation and Oxidation of Titanium Silicide

1986 ◽  
Vol 77 ◽  
Author(s):  
Tzuen-Luh Huang ◽  
Shuit-Tong Lee
Keyword(s):  
High Temperature ◽  
Refractory Metal ◽  
Electron Spectroscopy ◽  
Polycrystalline Silicon ◽  
Auger Electron ◽  
Titanium Silicide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selective Etch ◽  
Furnace Sintering

ABSTRACTRefractory metal suicides have been used widely in VLSI fabrication, owing to their low resistivity, high-temperature compatibility, and oxidiz-ability. In this work, we have studied the titanium suicide formation, using a rapid thermal processor (RTP). Isothermal and isochronal sintering experiments were carried out to determine the appropriate process steps. The selective etch of the unreacted Ti was characterized. The sintered films were characterized by four-point probe, X-ray diffraction, and Auger electron spectroscopy. We also studied the oxidation at 800–1000°C of Ti suicide formed by sintering Ti and polycrystalline silicon using a RTP in N2 ambient. The oxidation results of Ti suicide formed using RTP in N2 ambient are compared with those formed using furnace sintering in vacuum/argon ambient and those deposited by cosputtering.

In situ x‐ray diffraction analysis of the C49–C54 titanium silicide phase transformation in narrow lines

1995 ◽  
Vol 66 (14) ◽  
pp. 1732-1734 ◽  
Author(s):  
R. A. Roy ◽  
L. A. Clevenger ◽  
C. Cabral ◽  
K. L. Saenger ◽  
S. Brauer ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Diffraction Analysis ◽  
Titanium Silicide ◽  
Silicide Phase ◽  
X Ray Diffraction ◽  
X Ray

Investigation of titanium silicide formation in Ti+Si reactions using infrared spectroscopy and x‐ray diffraction

1995 ◽  
Vol 77 (10) ◽  
pp. 5156-5159 ◽  
Author(s):  
K. L. Saenger ◽  
C. Cabral ◽  
L. A. Clevenger ◽  
R. A. Roy
Keyword(s):  
Infrared Spectroscopy ◽  
Titanium Silicide ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray

IS Selective CVD an Improvement for the Titanium Silicide Process in Sub-Quarter Micron Technology? A Phase Formation Study Using X-ray Diffraction

1998 ◽  
Vol 514 ◽  
Author(s):  
Ronnen Roy ◽  
Cryil Cabral ◽  
Christian Lavoie ◽  
Jean Jordan-Sweet ◽  
R. Viswanathan ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Phase Formation ◽  
Chemical Vapor ◽  
Titanium Silicide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silicon Chips ◽  
In Situ Xrd ◽  
Silicon Structures

ABSTRACTThe C54 phase formation process of titanium silicide was studied after selective chemical vapor despostion (CVD) onto very small silicon structures, to ascertain the efficacy of CVD to form low resistance contacts in sub-quarter micron technology. Because the selective CVD process forms silicide on any exposed silicon in a CMOS device, the process was studied on both polysilicon and Si (100) chips. The structures consisted of arrays of about 106 identical lines, 0.1 2.0 μm in width, depending on the chip. The CVD process employed TiCl4 and SiH4 for the most part as process gases and the depostion temperature ranged from 730–825°C. X-ray diffraction (XRD) was used to document the amount of C54 phase present after deposition. In some cases samples were annealed after deposition and the phase transformation behavior studied by in-situ XRD. The latter technique employed a synchrotron radiation source providng for rapid XRD spectra collection, so that the C49-C54 phase transformation could be examined with great precision in real time during rapid thermal annealing. The results of CVD depositions were compared to titanium silicide formed by sputter deposition of Ti on identical silicon chips, followed by a typical salicide protocol. Although the phase formation is affected by both film thickness and substrate temperature during CVD, the general result is that the C54 formation is more facile using the CVD process, especially for the smallest line dimensions. The findings are discussed with respect to nucleation processes occurring during growth and post-deposition thermal processing.

Silicide Formation By High Dose Transition Metal Implants Into Si.

1985 ◽  
Vol 51 ◽  
Author(s):  
F. H. Sanchez ◽  
F. Namavar ◽  
J. I. Budnick ◽  
A. Fasihudin ◽  
H. C. Hayden
Keyword(s):  
Transition Metal ◽  
Rutherford Backscattering Spectrometry ◽  
Atomic Diffusion ◽  
High Dose ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Implants ◽  
Metal Silicides ◽  
Suitable Technique

ABSTRACTWe report preliminary results of a study on silicide formation by means of high dose transition metal implants into Si (100) single crystals.100 keV Cr+, Fe+, Co+ and Ni+ were implanted at room temperature. For the Cr+, Fe+ and Ni+ implants, no silicide formation was observed after implantation. However, both Rutherford Backscattering Spectrometry (RBS) and X-Ray Diffraction (XRD) results clearly indicated the existence of CrSi2 after the Cr-Si samples were annealed 4 hours at 550°C. In the case of the Fe+ and Ni+ implants, FeSi2 and NiSi2 were identified by XRD after annealing the implanted samples half an hour at 400°C. A layer of CoSi of about 1000 Å was observed in the as implanted Co-Si samples by both RBS and XRD.Ni+ ions accelerated to 150 keV were implanted at 350°C. A much broader distribution and higher retention of Ni was obtained in this case, showing evidence of long range atomic diffusion. NiSi and polycrystalline silicon were observed by XRD in the as implanted samples.The possibility of high dose ion implantation as a suitable technique for producing transition metal silicides is discussed.

In situ and Ex situ Measurements of Stress Evolution in the Cobalt-Silicon System

2000 ◽  
Vol 611 ◽  
Author(s):  
G. Lucadamo ◽  
C. Lavoie ◽  
C. Cabral ◽  
R. A. Carruthers ◽  
J.M.E. Harper
Keyword(s):  
Room Temperature ◽  
Biaxial Stress ◽  
Ex Situ ◽  
Silicide Formation ◽  
Stress Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bending Force ◽  
Constant Heating

ABSTRACTThe biaxial stress in Co thin-films has been investigated in situ by measuring changes in substrate curvature that occurred during deposition and annealing.Films of Co, 35 to 500 nm in thickness, were deposited by UHV magnetron sputtering at room temperature on Si (100) and poly-Si substrates.Results show that during Co deposition the bending force increased linearly with film thickness; a signature of constant stress.In addition, the stress evolution during silicide formation was measured under constant heating rate conditions from room temperature up to 700°C. The stress-temperature curve was correlated with Co2Si, CoSi, and CoSi2 phase formation using in situ synchrotron X-ray diffraction measurements.The room temperature stress for the CoSi2 phase was found to be ∼0.8 GPa (tensile) in the films deposited on Si (100) and ∼1 GPa (tensile) on the films deposited on poly-Si.The higher tensile stress in the poly-Si sample could be a result of Si grain growth during annealing.

In-Situ Studies of Silicide Formation in Ti-Ta Bilayer Thin Films on Poly-Si

2002 ◽  
Vol 721 ◽  
Author(s):  
A. S. Özcan ◽  
K. F. Ludwig ◽  
C. Lavoie ◽  
C. Cabral ◽  
J. M. E. Harper
Keyword(s):  
Volume Fraction ◽  
Formation Temperature ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
Template Effect ◽  
Elastic Light Scattering ◽  
Time Resolved ◽  
X Ray ◽  
Si Substrates

AbstractWe have studied the formation of titanium silicides in the presence of an ultra-thin layer of Ta, interposed between Ti and Si. In-situ x-ray diffraction (XRD), resistance measurements and elastic light scattering were used to study the thin film reactions in real time during ramp anneals to 1000°C. On poly-Si substrates the Ta thickness was varied from 0 to 1.5 nm while the Ti thickness was held constant at ∼27 nm. The time-resolved XRD shows that the volume fraction of C40 and metal-rich silicide phases grows with increasing Ta layer thickness. Increased Ta layer thicknesses also delay the growth of the C49 disilicide phase to higher temperatures. Among the Ta thicknesses we examined, 0.3 nm is the most effective in lowering the C49-C54 transformation temperature. Films with Ta layers thicker than 0.5 nm do not completely transform into the C54 phase. The texture of the C54 phase is also sensitive to the Ta thickness. The C54 disilicide film is predominantly (010) textured for the Ti / 0.3 nm Ta sample. The final C54 texture is significantly different for Ta layers thinner or thicker than the optimal 0.3 nm. This suggests that the most effective thickness for lowering the C54 formation temperature is related to the development of a strong (010) texture. The possibility of a template effect by the C40 or metal-rich Ti5Si3 phases is also discussed on the basis of texture considerations.

In situ X-ray diffraction measurements of silicide formation in the CoSi system

1994 ◽  
Vol 249 (2) ◽  
pp. 187-194 ◽  
Author(s):  
S Zalkind ◽  
Joshua Pellag ◽  
L Zevin ◽  
B.M Ditchek
Keyword(s):  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray
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