Patent ID: 6198126
Filing Date: 2001-03-06
Classification: H01L

Abstract:
A power converter comprising:a pair of direct current terminals;alternating current terminals in a number equal to the number of phases; anda semiconductor switching element connected between the direct current terminals and the alternating current terminals, said semiconductor switching element including:a pair of main surfaces;a first semiconductor region of a first conductivity type having a surface which is in contact with one main surface;a second semiconductor region of a second conductivity type extending from the one main surface into the first semiconductor region;a plurality of third semiconductor regions of the second conductivity type formed so as to surround the second semiconductor region and extending from the one main surface into the first semiconductor region;a first main electrode formed on the other main surface;a second main electrode which is in ohmic-contact with the second semiconductor region and which covers the surface of the first semiconductor region through an insulating film; anda plurality of auxiliary electrodes which are respectively in ohmic-contact with the third semiconductor regions and which cover the surface of the first semiconductor region through an insulating film on the second semiconductor region side and on the side opposite thereto;wherein at the surface of the first semiconductor region which is in contact with the one main surface between adjacent ones of the third semiconductor regions, the total length of the auxiliary electrodes which cover the surface of the first semiconductor region is not less than one half of the distance between the adjacent third semiconductor regions;wherein the distance between one of the third semiconductor regions and a second one of the third semiconductor regions adjacent to said one of the third semiconductor regions on a peripheral side of the semiconductor device is wider than the distance between said one of the third semiconductor regions and a third one of the third semiconductor regions adjacent to said one of the third semiconductor regions on an inner side of the semiconductor device; andwherein between the adjacent third semiconductor regions, the length of one of the auxiliary electrodes which covers the surface of the first semiconductor region on the peripheral side of the semiconductor device is longer than the length of an adjacent one of the auxiliary electrodes which covers the surface of the first semiconductor region on the inner side.