| 摘要 |
PURPOSE:To ensure the prevention of discharging and rediffusion of impurities having first-conductivity type high concentration even in diffusion in a second- conductivity type impurity region and to obtain a high yield rate, by positioning the first-conductivity type high concentration impurity region in the inside by means of wafer bonding. CONSTITUTION:For example, an N-type substrate 11 is prepared, and an SiO2 film 41 is formed thereon. By the selective diffusion of phosphorus atoms, a high concentration N<+> impurity layer 12 is provided by a specified amount at a specified depth. After the diffusion of the phosphorus atoms is finished, the entire SiO2 film 41 is removed. Then, an N-type substrate 42 is prepared and aligned with the forming surface of the high concentration N<+> impurity layer 12 in the substrate 11. Then, the substrates 11 and 42 are bonded. Then, the high concentration N<+> impurity layer 12 is diffused in conformity with the design of a semiconductor device when it is completed. Thereafter, by selective diffusion, a P-type layer 13 is provided. When a transistor is to be obtained, an N-type impurity layer is provided in the P-type layer 13. The substrate 42 is lapped until the N<+> impurity layer 12 is exposed to meet the requirement of ohmic contact of the N-type layer 11 and the like. |
