| 摘要 |
<p>PURPOSE:To decrease leakage currents in the reverse direction by a method wherein the second mesa grooves are formed at the insides of mesa grooves on the back of a semiconductor substrate, junctions exposed and the intermediate surfaces of the substrate of the grooves at the outside and the inside are protected by an insulator. CONSTITUTION:P Layers 2, 3 are formed at the both sides of an N-type substrate 1, the both sides are coated with SiO2 films, a window is selectively opened, and an N layer 4 is made up. Openings are formed opposing to the surface and the back, openings are further made up at the inside on the back, and mesa grooves 9', 10', 11 are built up by means of etching. The surfaces of the grooves are protected by glass while glass films 13 are formed on the surface of the substrate between the grooves 10' and 11, and the second mesa grooves 12 are completed. And electrodes 6-8 are attached, and the substrate is divited at a central portion between the grooves 9' and 10'. The backs of these pellets are stuck on radiant plates with epoxy resin and sealed. In this case, portions where the second mesa grooves surround can become independent to radiant portions electrically complete. Since stress due to the thermal expansion of resin hardly reaches junctions at the insides, leakage currents are decreased.</p> |
