| 摘要 |
PROBLEM TO BE SOLVED: To provide a specified breakdown strength to a semiconductor device by improving a breakdown voltage value in a depletion layer, without increasing the film thickness of an electrically insulating film on a semiconductor substrate. SOLUTION: This device is provided with a conductive layer 18, which is extended to the side of a first impurity region 12 in an electrically insulating film 14 on a semiconductor substrate 11 as a field relaxing means and is placed at approximately the same potential as that of the semiconductor board 11, and a third impurity region 19 which is formed in a surface of the semiconductor substrate 11, shows conductivity equal to that of the semiconductor board 11, has an impurity concentration which is higher is than the impurity concentration of the semiconductor substrate and is lower than an impurity concentration of a second impurity region 13, and is extended towards the first impurity region 12 and is formed apart from the first impurity region. In addition, an extended end 18a of a layer 18 to the side of the first impurity region 12 is placed closer to the side of the second impurity region 13 than an extended end 19a of the third impurity region 19 placed to the side of the firs impurity region 12. |
