| 摘要 |
PURPOSE:To improve the waterproofness of a protective film consisting of Si nitride on the surface of the semiconductor device of a MOS transistor and the like. CONSTITUTION:In a MOS transistor having a field insulating film 2, a gate insulating film 5, a gate electrode formed on a semiconductor substrate 1, after forming electrode wirings 8, 9 and a posphate silicate glass film 7, NH3 gas, and SiH4 gas diluted to 1% with N2 gas plasmified under a pressure of 0.16 Torr. and 0.8 Torr. respectively and an Si nitride film 21 is formed on the substrate. Next, an Si nitride film 22 is similarly formed by decreasing the NH3 gas to 0.12 Torr. With the films 21, 22 expressed in SiXNY, although the film 21 has high electrical resistance under X/Y=0.75 and refractive index 2.0, waterproofness is poor. On the other hand, although the film 22 has low electrical resistance under X/Y>0.75 and a refractive index of 2.1 or over, waterproofness is good. Therefore, as a whole, the waterproofness of an Si nitride protective film is improved owing to two layers of the films 21, 22. |
