| 摘要 |
PURPOSE:To form a thick polycrystal silicon oxide film having high dielectric breakdown strength by conducting high-temperature oxygen oxidation and conducting low-temperature steam oxidation. CONSTITUTION:The first polycrystal silicon film 5 is deposited onto a silicon single crystal substrate 1 through a silicon oxide film, and an impurity, such as arsenic, phosphorboron, etc. is diffused to the film 5. The first polycrystal silicon film 5 is thermally treated at the high temperature of 950-1,100 deg.C and in a dried oxygen atmosphere, a polycrystal silicon oxide film with predetermined film thickness is formed, and thermally treated at the low temperature of 700- 900 deg.C in a steam atmosphere, and the polycrystal silicon oxide film 6 is shaped. Patterns are formed by using the deposition of the second polycrystal silicon film 8, the diffusion of the impurity and photolithography technique in the same manner as the first polycrystal silicon film 5. The impurity is diffused into a silicon single crystal and a diffusion layer 9 is shaped, an oxide film for protection and metallic wiring are formed, and the semiconductor device can be obtained. |
