SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device which exhibits a high performance at the time of reverse recovery and can be used as a high-withstand-voltage power diode in addition and to provide its manufacturing method. SOLUTION: A drift layer of a diode is composed of three regions. When the impurity concentration of a region adjoining an anode layer is expressed by n1, the impurity concentration of a region adjoining a cathode layer is expressed by n2 and the impurity concentration of a region sandwiched between these two regions is expressed by n3, the impurity concentration of the cathode layer is adjusted so that the following inequality may be satisfied: n2