| 摘要 |
PURPOSE:To enable accurate and easy control of etching shape, improve reliability of a device,and improve production yield by performing plasma vapor growth under the condition that an appropriate amount of oxygen is added to a reaction gas, thereby forming an oxygen-added silicon nitride film on the substrate. CONSTITUTION:After a substrate 1 is set in the reaction chamber of a plasma CVD apparatus, a reaction gas and additive oxygen are allowed to flow in. At this time, growth is performed under the condition that the gas flow ratio of monosilane and pure ammonia in the reaction gas is 1:0.8-1:1, the gas flow ratio of monosilane and oxygen is 1:0-1:0.8, the gas pressure of the reaction chamber is 0.4-1 Torr, the substrate temperatuer is as low as 250-300 deg.C, and the high frequency output power is 0.1-1W/cm<2>. An oxygen-added silicon nitride film 2 formed in this way can be applied with dry etching, so that etching control becomes accurate and easy. By this, the diffusion window can be formed as designed, and simultaneously the sectional shape of a diffusion layer area obtained by diffusion, particularly by thermal diffusion of impurities through the diffusion window becomes accurate and clean. |
