SELECTIVE GROWTH OF GE IN GEF4-SI2H6 SYSTEM

Selective growth of Ge in GeF4-Si2H6 system was investigated on SiO2 p atterned Si substrates and its characteristics were discussed in compa rison with those of W chemical vapor deposition in WF6-SiH4 system whi ch is similar in terms of a combination of redox materials including a fluorinated substance. The selectivity was governed primarily by the growth temperature. The selective growth on a SiO2 patterned Si substr ate was achieved at a wide range of the gas flow ratios (Si2H6/GeF4) a t 375-degrees-C, where the characteristics of film growth were disting uished clearly from those at the temperatures over-400-degrees-C large r quality degraded. The experimental results indicated that the select ivity was deeply rooted in the growth mechanisms of the film themselve s which were separated around 400-degrees-C.