| 摘要 |
PURPOSE:To prevent an electrode from generation of thermal fatigue even when it is pressure-welded by a method wherein the short-circuit generating between a base and an emitter is prevented by providing an emitter electrode on the first semiconductor layer, which becomes a base, through the intermediary of a polycrystalline silicon layer. CONSTITUTION:An emitter electrode 28 is connected to a second semiconductor layer 24 through the intermediary of a flat-surfaced polycrystalline silicon layer 27. Said polycrystalline silicon layer 27 is extended to a first semiconductor layer 23, it forms a low resistance layer 27a on the second semiconductor layer 24, and also it forms a high resistance layer 27b on the first semiconductor layer 23. As a result, no thermal fatigue is generated on the layer 27 when the emitter electrode 28 is pressure-welded, and a high reliability can be displayed. Also, as the polycrystalline silicon layer 27 has the resistance value of 1-100OMEGA between the first semiconductor layer 23 and the second semiconductor layer 24, an external resistor can be unnecessitated.
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