JPS57177577A - Semiconductor device - Google Patents

Abstract

PURPOSE:To avoid a short accident due to the eaves survival, by thickening a layer with smaller area of electrode metallic layers more than a layer with larger area in a semiconductor device with electrode metallic layers having slant peripheral surfaces provided on the back and surface of a semiconductor pellet placed between a pair of heat sinks. CONSTITUTION:The semiconductor pellet 14 is placed between the heat sinks 3 and 4 made from Mo fixed with Cu leads 5 and 6 respectively constituted of slug lead 1 and 2 being sealed by a glass 8 including the side surfaces on the heat sinks 3 and 4. In this constitution, the pellet 14 is constituted of a P type region 141, N<-> type region 142 and N<+> type region 143 with a thick Al electrode layer 146 adhered on the surface of the region 143 and a thin Al electrode layer 145 on the back of the region 141 later to apply mesa etching for a truncated cone shape of the pellet 14. Thus, the electrode layer 146 with smaller area is thickened to prevent a short by the avoidance of the eaves generation on the electrode layer 146 when mesa etching.