| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor device which is manufactured into a a structure, wherein the resistance of a substrate with a silicon epitaxially grown layer formed thereon is increased, capable of obtaining high breakdown voltage, and moreover is low in on-resistance. SOLUTION: In this semiconductor device, a one conductivity-type silicon substrate 1 is a heavily-doped substrate and an lightly-doped epitaxially grown layer 2 with lower impurity concentration than that of the substrate 1 is formed on the substrate. The impurity concentration of this lightly-doped silicon epitaxially grown layer (N-) 2 is set in the concentration range of 1×1014 to 1×1015 cm-3 and extremely lightly-doped silicon epitaxially grown layers (N--) 21, which are formed into an insular regions and are set in the concentration range of 1×1012 to 1×1013 cm-3, are provided in the layer (N-) 2.
|
