| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which can prevent a surface high-withstanding structure to voltage on surface from reaching a critical electric field causing a breakdown prior to an active region, and can reduce a ratio in surface area of the surface high-breakdown-voltage structure to the entire surface area of a chip. <P>SOLUTION: A semiconductor substrate in the semiconductor device comprises an n-type high-concentration layer and an n-type low-concentration drift layer for suppressing at least spread of a depletion layer, and a p-type high-concentration layer laminated in this order to form a pn main junction with the drift layer. Further, the substrate has an active region through which an effective current flows in the thickness direction of the substrate; and a separating tilted groove by cutting the pn main junction from the surface of the semiconductor substrate on the side of the n-type high-concentration layer at a positive bevel angle, through the entire substrate at the outer periphery of the active region and to separate the substrate. An n-type surface region lower in impurity concentration than the n-type drift layer is formed along the side wall surface of the tilted groove of the n-type drift layer. <P>COPYRIGHT: (C)2007,JPO&INPIT |
