| 摘要 |
PURPOSE:To inhibit the generation of a defect on the electrical conduction of a thermal oxide film in a process, in which the thermal oxide film is formed onto the surface of the semiconductor wafer after a phosphorus diffusion layer having not less than 10<19>cm<-3> high concentration is formed, by previously forming the phosphorus diffusion layer onto the back of the semiconductor wafer. CONSTITUTION:The (100) Si wafer 1 in 5-20OMEGAcm through a CZ method is hydrogen-combustion oxidized for 100min at 1,000 deg.C, and thermal oxide films 2a, 2b with approximately 5,000Angstrom are formed onto both surfaces (a). The thermal oxide film 2b of the back is etched, and the phosphorus diffusion layer 3 with not less than 10<19>cm<-3> high concentration is formed onto the back through the diffusion of PoCl3 for thirty min at 1,000 deg.C while using the thermal oxide film 2a as a mask for diffusing phosphorus onto the surface (b). Field oxide films 4a, 4b are shaped through hydrogen combustion oxidation, the thermal oxide film as a gate oxide film is formed, and the pattern of a gate electrode 6 is formed (e). |
