Semiconductor device prodn. by etching deep groove around device - except under lead to minimise leakage current

摘要

Prodn. of a semiconductor device involves growing planar monocrystalline semiconductor layer(s) on a prestructurised substrate and providing contact(s) and lead(s) on the surface. The novel features are that a structurised masking layer (5,51) is produced on the planar surface, covering the monocrystalline device zone (3,31, 32,33) and the lead; and a deep groove (6) is egched around the device, except at the position of the lead. Etching is carried out so that the edge of the masked area is etched more strongly than the zones further from the edge, pref. by a wet process. Grooves pref. are etched along the edge of the lead at the same time. The structurised masking layer consists of metallic conductor, which remains on the planar surface of the finished device as lead and/or contact. In the area around the device, the surface layer consists of low ohmic material and the layer under this of high ohmic material. The low ohmic laye is removed in the unmasked areas, pref. in another etching stage; and another passive device is produced on the exposed high ohmic material. After etching the groove, it is also possible to coat other semiconductor layer(s) on the exposed high ohmic material, opt. after growing on oxide layer. The lead and/or contact are produced from silicides. The semiconductor layer(s) of the device and surrounding material are grown by differential epitaxy, pref. mol. beam epitaxy. ADVANTAGE - Leakage currents are very small.