| 摘要 |
PURPOSE:To realize the high accuracy etching of a selective oxidation mask, the shortening of selective oxidation time and the reduction of bird beaks, by performing a pre-treatment before a selective oxidation. CONSTITUTION:An SiO2 film 2 is formed on a semiconductor substrate 1, thereafter an Si3N4 film 3 is formed, and then a photoresist pattern 4 is formed at a fixed region. Next, neutral ions such as Ar are implanted into the substrate 1 at the energy whereby they reach the substrate 1. Where, the numeral 5 represents the Ar implanted Si3N4 film, and the numeral 6 represents the Ar implanted substrate. Then, the film 5 is etched. Since this film 5 gets the etching rate increased by a neutral ion implantation, a good etching with small side etch is performed. While P is introduced into a P channel region, and B is introduced into an N channel, thus a channel stopper 7 is introduced into the part wherein the Si3N4 film is etched. After removing the resist, an oxide film 8 is formed. Thereat, the oxidation rate of the Ar implanted part becomes larger than that of a normal substrate by several times, and accordingly the shortening, etc. of oxidation time are enabled. |
