| 摘要 |
PURPOSE:To stabilize element performance characteristics by a method wherein a high-concentration n type semiconductor region containing arsenic atoms as impurity atoms is provided, between an element isolating silicon dioxide region and a base region, along the entire outer circumference of the base region. CONSTITUTION:Between an element isolating silicon dioxide region 1 and a base region 2, a high-concentration n type semiconductor region 5 is provided containing arsenic atoms as impurity atoms. In this design, the threshold voltage, whereat the surface of an epitaxial region 4 is reversed into a p type layer, may be set high even when the silicon dioxide film 3 of the epitaxial region 4 is thin. A high threshold voltage makes it difficult for the reversion to take place of said surface into a p type layer. Use of low-diffusivity arsenic atoms as impurity atoms reduces, in the manufacturing process, the diffusion of impurity atoms as well as the resultant lower concentration. |
