| 摘要 |
PURPOSE:To form a thermal oxide film with no defect simply and effectively by executing a process, in which a semiconductor wafer is thermally treated at the high temperature of 1,050 deg.C or more, and a process, in which a phosphorus diffusion layer having not less than 10<19>cm<-3> high concentration is formed onto the back of the semiconductor wafer, to the semiconductor wafer. CONSTITUTION:The P type (100) Si wafer 1 in 5-20OMEGAcm is hydrogen-combustion oxidized for 50min at 1,150 deg.C, and thermal oxide films 21, 22 with approximately 5,000Angstrom are formed onto both surfaces (a). The silicon oxide film 22 of the back is removed through etching, and the phosphorus diffusion layer 3 having not less than 10<19>cm<-3> high concentration is formed through the diffusion of POCl3 for 30min at 1,000 deg.C (b). The oxide films formed onto both the surface and the back are etched, and the thermal oxide film 4 as a gate oxide film is formed through oxidation fir 15min at 1,000 deg.C in dried oxygen (c). A phosphorus added polycrystalline silicon film is patterned, and a gate electrode 5 is formed. |
