| 摘要 |
PURPOSE:To form a P<+> channel cut with a desired profile by a method wherein an oxide film is formed on the inside surface of an isolating groove, the groove is filled with SOG and the SOG is allowed to dry, and the heat treatment is accomplished for the formation of a P<+> diffusion region in the vicinity of the groove. CONSTITUTION:An oxide film 2 and then a nitride film 3 is provided on a P-type substrate 1, and the oxide film 2 and nitride film 3 are subjected to etching for the formation of an opening in the region for an isolating groove. Next, by means of anisotropic etching method (RIE method), a U-shaped groove 5 is created in the region for an isolating groove. In the surface of the groove 5, a 200Angstrom -thick oxide film 8 is formed by means of thermal oxidation. Next, SOG 10 containing B2O3 is applied, to be annealed dry and solid in N2 gas at about 450 deg.. Another process of annealing in N2 gas is accomplished at about 950 deg. for the formation of an oxide film 11. Next, SOG 12 that contains B2O3 and P2O5 is applied to completely fill the groove 5, which is subjected to annealing for hardening.
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