The kinetics of titanium monosilicide growth studied by three-wavelength ellipsometry

✍ Scribed by J.M.M. de Nijs; A. van Silfhout

• Book ID: 103952835
• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 417 KB
• Volume: 5
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(90)90075-m

✦ Synopsis

Thin titanium layers" (approximately 10 nm) have been grown on top of a clean Si(lll) substrate. Heating these layers initiates a solid state reaction, yielding an amorphous monosilicide phase at about 350 °C. The kinetics of the solid state reaction has been followed using three-wavelength ellipsometry (340, 450 and 550 nm). A very coarse two-layer model has been applied in the analyses of the measured data: a top layer of pure titanium is consumed by a second layer of TiSi. The dielectric constants of titanium and TiSi are known and the layer thicknesses d I and ~ have been fitted to the six ellipsometrical angles measured. These analyses reveal a diffusionlimited growth mechanism exhibiting two growth rates: a rapid initial rate followed by a slower final rate. The diffusion coefficient D of the rapid process and its activation energy E, could be obtained." D=2× 10 -l' cm 2 s I at T = 370 °C and E. =0.62 eV. The two growth rates have been attributed to silicon diffusion along the grains and diffusion into the grains.