| 摘要 |
PURPOSE:To further enable the formation of inactive region without introducing into patterned active region and high integration of an MOSLSI by forming a polysilicon layer on the overall surface of a patterned silicon wafer and heat treating it. CONSTITUTION:A silicon oxide layer 2 and a nitrided silicon layer 3 are formed on a silicon wafer 1. In order to form the same conductive type impurity as a silicon substrate in the inactive region higher in density than the silicon substrate, boron ions are implanted. A polysilicon layer 6 is formed on the overall surface. Then, a heat treatment is performed. As a result, phosphorus is supplied into polysilicon layer 6 adjacent to a silicon oxide layer 5 containing the resulting phosphorus, and the layer 6 of this part is formed in N type. The layer 6 is etched until the layer 6 of the N type is completely eliminated. The layer 5 containing phosphorus is removed. Thermal oxidation is performed until the remaining polysilicon 7 is completely converted into silicon oxide. The layer 3 is removed. |
