A DEVELOPMENT OF SINGLE-WAFER TYPE APCVD EQUIPMENT FOR SIO2 FILM DEPOSITION

Based on the deposition mechanism and fine particle behavior, single w afer-type atmospheric pressure chemical vapor deposition (APCVD) equip ment has been developed for boro-phospo-silicate glass (BPSG) depositi on on 8- inch Si wafers.The gas composition near the wafer and the ste p coverage characteristic suggest that the deposition rate of the BPSG film is controlled by the SiH4 diffusion rate. Therefore, the uniform ity of the source-gas injection velocity from the gas head as the hold er temperature. is the key to achieving good film-thickness uniformity . Furthermore, it has been found that the behavior of fine particles p roduced in the reaction chamber is significantly affected by thermal m igration, so particle deposition on the exhaust side wall was prevente d by wall heating. The APCVD equipment can deposit 10,000 angstrom BPS G film for more than 1000 wafers without chamber cleaning, while keepi ng film thickness uniformity within +/- 3%.