| 摘要 |
PURPOSE:To improve the blocking effect of impurity ions and humidity resistance and to enhance reliability, by using two or more layers for passivation films, diffusing ions in another layer of an amorphous film into the grain boundary of one layer of a crystalline film of said two layers, and enhancing the potential barrier of the grain boundary. CONSTITUTION:An amorphous thin film 1 and a crystalline thin film 3 are provided at adjacent positions. As the crystalline thin film 3, an insulating film, which has a grain boundary comprising polysilicon, SiO2, SiN and other oxide and fluoride and the like, is used. As the amorphous film 1, As doped phospho-silicate glass is used. As a crystalline film 2, silicon nitride film 2 is used. Both thin films are bonded and then undergo heat treatment at 500 deg.C for 15 minutes. Thus As is diffused into the grain boundary 2. As a result, the potential barrier of the grain boundary 2 after the As diffusion can be improved to about 0.75 eV in comparison with the low potential barrier of 0.2 eV in the grain boundary of ordinary silicon nitride. Since the movement of impurity ions in the crystal grain boundary 2 is suppressed in this way, the characteristics of a semiconductor element at high temperature and high humidity can be enhanced by about two-three times, thereby the passivation for a highly reliable super LSI can be obtained.
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