SEMICONDUCTOR DEVICE

PURPOSE:To obtain a larger cathode area and, moreover, facilitate working of a beveled plane by a method wherein a negative bevel is so formed as to have a shape limited to a depletion layer part formed above a 2nd P-N junction. CONSTITUTION:When a forward voltage is applied, most of a depletion layer width in a bulk is spread to the side of an NB layer 2, which is at a low concentration side, and only a little part of it is spread to the side of a PB layer 3, which is high concentration side. Even if the bending phenomenon of the depletion layer created by bevel angle formation is taken into account, it is ten and several mum at most near the surface of a mesa part. Therefore, a negative bevel 8 with a minute angle is formed only at that part. With this constitution, an electric field intensity can be alleviated to the same extent as in the case of conventional negative bevel formation and, although the negative bevel angle theta- is the same, the bevel width L1 is approximately 1mm, which is about 1/5 the width of the conventional bevel, so that the part L2, which used to belong to the conventional negative bevel, can be utilized as a cathode 6.