Making bipolar element e.g. transistor operating in high gigahertz region, involves forming base layer, masking layer and second base semiconductor layer carrying ohmic electrode in metallic material

摘要

Bipolar device is manufactured by forming base layer with an active base layer and a first base semiconductor electrode layer, from a semiconductor material of second type, on collector, forming a masking layer on active base layer, forming a second base semiconductor layer on first base semiconductor layer, and forming ohmic base electrode constructed in metallic material. A collector (111) is constructed in semiconductor material of a first type. A base layer is formed with an active base layer and a first base semiconductor electrode (123a) layer, from a semiconductor material of a second type, on the collector. A masking layer (191) is formed, covering the active base layer. A second base semiconductor layer is formed selectively on the first base semiconductor layer. An ohmic base electrode (129) is constructed in metallic material, selectively on the second base semiconductor electrode (123b). An Independent claim is included for the corresponding bipolar device.