| 摘要 |
In the interior of a semiconductor substrate having a main surface, a first p - epitaxial region is formed, a second p - epitaxial region is formed on the main surface side, and an n-type drift region and a p-type body region are formed on the main surface side. An n + buried region is formed between the first p - epitaxial region and the second p - epitaxial region in order to electrically isolate the regions. A p + buried region having a p-type impurity concentration higher than that of the second p - epitaxial region is formed between the n + buried region and the second p - epitaxial region. The p + buried region is located at least immediately under the junction between the n-type drift region and the p-type body region so as to avoid a site immediately under a drain region which is in contact with the n-type drift region. |
