| 摘要 |
PURPOSE:To prevent the surface contamination by the substance isolated from the reverse side of a substrate by a method wherein, when an FET (field effect transistor), IC (integrated circuit) and the like are formed on a compound semiconductor substrate, an amorphous thin film is coated on the reverse side of the substrate before formation of said FET and IC. CONSTITUTION:When an FET or an IC is formed on a compound semiconductor substrate such as GaAs, InP, GaP, InAs and the like, a substrate having mirror- polished surface and the back side where microscopic recesses and projections are formed by lapping is used as a substrate. Then, before the FET or the IC is formed on the mirror-polished surface, the substrate is placed in a decompression chamber, the chamber is maintained at the temperature of approximately 280 deg.C, plasma is generated by feeding SiH4, NH3 and N2 gas, and an Si3N4 film of approximately 1,200Angstrom in thickness, having the refractive index of approximately 1.9, is grown on the back side only of the substrate. Accordingly, the material constituting the substrate is not adhered to each element even when a heat treatment is performed in the process of manufacture of the FET or IC, and a back side washing process can be unnecessitated. |
