SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME

摘要

A field buffer layer (13) is formed from an outer circumferential end portion of an active region (12) toward an outer circumferential end portion of a semiconductor substrate (11) so as to surround the active region (12). The field buffer layer (13) is provided with a plurality of P-type impurity layers (21-25). The P-type impurity layers (21-25) are respectively provided with P-type injection layers (21a-25a), and P-type diffusion layers (21b-25b), which are formed to surround the P-type injection layers (21a-25a), and which have P-type impurity concentration lower than that of the P-type injection layers (21a-25a). A first P-type injection layer (21a) is formed such that the first P-type injection layer is in contact with the active region (12) or the first P-type injection layer partially overlaps the active region. The P-type diffusion layers (21b-25b) are formed to extend to an extent wherein the first P-type diffusion layer (21b) and the second P-type diffusion layer (22b) are in contact with each other or overlap each other. Intervals (s2-s5) among the P-type injection layers (21a-25a) are increased toward the outer circumferential end portion of the semiconductor substrate (11) from the active region (12).