Fabrication of Silicon Nano-Crystal Dots on SiO2 by Ultrahigh-Vacuum Chemical Vapor Deposition

Autor: Bruce E. White, Bich-Yen Nguyen, Sucharita Madhukar, Junro Sakai, Supika Mashiro, Masato Oishi, Takayuki Kawashima
Rok vydání: 2000
Předmět:
Zdroj: MRS Proceedings. 638
ISSN: 1946-4274
0272-9172
Popis: We report a process for Silicon (Si) nano-crystal dots fabrication using a cold-wall Ultrahigh-Vacuum Chemical Vapor Deposition (UHV-CVD) system. Si2H6 gas was used as the pre-curser and irradiated upon SiO2 film on Si wafer to form Si nano-crystal dots.In our system, nucleation, growth, and coalescence phases of nano-crystal dots on SiO2 were found to be related with the optical pyro-meter's read-out curve.At first, the optimum gas irradiation time which gives the highest dot density without coalescence was decided for every gas irradiation condition by using an optical pyro-meter. Then, the dependence of optimum gas irradiation time, dot diameter and dot density on gas flow rate and wafer temperature were investigated. A decrease of wafer temperature or an increase of gas flow rate during the nucleation and growth phase results in a decrease of dot diameter and an increase of dot density. The optimum gas irradiation time was prolonged by decreasing wafer temperature or gas flow rate.Finally, a reproducible process of forming non-coalesced, small size, and high-density Si nano-crystal dots of about 5.5nm in diameter with density of 1x1012 dots/cm2 were obtained. Typical process time to get such dot formation characteristics was about 10 minutes, which were long enough for ensuring reproducibility.
Databáze: OpenAIRE
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