| 摘要 |
PURPOSE:To form an isolated region and a well region simultaneously by performing a heat treatment by a method wherein the impurities, which were formed in the second impurity introducing process using the quantity of impurities different from the impurity introducing process for isolated diffusion, are diffused simultaneously. CONSTITUTION:A p type epitaxial layer 2 is formed on an n type silicon substrate 1 and phosphorus is diffused in an isolation forming region 10 using a mask. Then, a resist pattern 13 is formed, phosphours is ion-injected and an impurity region 14 is formed. Then, a silicon nitriding film 8 is formed and impurity regions 10 and 14 are formed by performing a heat treatment. As a diffusing region 3, to be used for substrate isolation, and an n well region 15 can be formed by performing a high- temperature and long-hour heat treatment, the sagging and crystal defect of impurity profile generated in the heat treatment can be prevented. |
