[13p-1E-1~17] 15.8 Crystal evaluation, impurities and crystal defects

▲ [13p-1E-16] Numerical analysis of SiC and SiO₂ deposition processes by gas-solid interaction in Czochralski silicon crystal growth

〇(P)Xin Liu¹, Bing Gao¹, Satoshi Nakano¹, Hirofumi Harada¹, Yoshiji Miyamura¹, Koichi Kakimoto¹ (1.RIAM, Kyushu Univ.)

Keywords:Czochralski method,impurity effect,simulation

Depositions of Si, SiO, SiO₂ and SiC in CZ-Si system are undesirable owing to their negative effects on the crystal growth process, such as poly Si growth, degradation of heater and obstruction of gas flow. Therefore, mechanisms of the gas-solid interaction and the deposition process are critical for the active control of impurity transport in CZ-Si crystal growth. To investigate the dynamic deposition processes, transient global simulations of heat and mass transport were conducted for melting process of CZ-Si crystal growth. An extended chemical model, which accounts for the gas-solid interactions, was developed to predict the deposition rate of SiO₂ and SiC on furnace elements. The SiC deposition on the inner side of the heater is remarkable due to the SiO absorption by graphite. The removal of SiO must be reinforced to reduce the depositions of SiO₂ and SiC by the enhancement of gas flow in CZ-Si crystal growth.