| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of the N channel MOS transistor in a high breakdown voltage semiconductor element that although it has a heavily doped and deeply diffused drain structure, a desired breakdown voltage cannot be attained because of a parasitic NPN transistor being formed across the drain, the well and a semiconductor substrate. <P>SOLUTION: The semiconductor element comprises a semiconductor substrate, an epitaxial layer formed on the semiconductor substrate and having an electric polarity identical to that of the semiconductor substrate, a buried diffusion layer formed between the semiconductor substrate and the epitaxial layer and having an electric polarity different from that of the semiconductor substrate, and an MOS transistor formed on the buried diffusion layer and having an electric polarity identical to that of the buried diffusion layer connected electrically with the well region. Its fabricating method is also provided. <P>COPYRIGHT: (C)2003,JPO |
