SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a high-voltage semiconductor device which can suppress concentration of electric field and obtain stable withstanding voltage; and provide a manufacturing method of the semiconductor device.SOLUTION: A semiconductor device manufacturing method comprises: forming a second conductivity type semiconductor region 13 near a surface of a semiconductor epitaxial layer 12 on one side in a thickness direction of the semiconductor epitaxial layer 12 on a semiconductor substrate 11; forming a plurality of field limiting ring(FLR) regions 15 on an outer periphery end side of the semiconductor epitaxial layer 12 than the second conductivity type semiconductor region 13 in which the plurality of FLR regions 15 are formed annularly at intervals from each other and have the second conductivity type; forming a second conductivity type field relaxation region 16 on an inward side and an outward side of each FLR region 15 in a radial direction of the FLR region 15 in contact with each FLR region 15, in which a concentration of a second conductivity type impurity in the field relaxation region 16 is determined to be not more than 1/10 of a concentration of a second conductivity type impurity in the FLR region 15.