SOS Bipolar transistor
AssigneeRCA Corporation
InventorsCharles William Mueller, Edward Curtis Douglas
Life of this patent
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Abstract
A planar bipolar transistor is made by the successive ion implantations of selected atoms into selected regions of a layer of doped single-crystal silicon on an insulating substrate, such as sapphire or spinel. The silicon layer is epitaxially grown, has a thickness of between 0.5 and 5 .mu.m, and is formed in two strata of different resistivities. A collector contact well is ion implanted into the upper stratum and annealed to diffuse it into the lower stratum of lower resistivity. The transistor is isolated, as a mesa, on the substrate; and an edge-guard region is ion implanted through the periphery of the mesa, except in the region of the emitter-base junction.
Claims3
A bipolar transistor comprising:
- an electrically insulating substrate,
- a mesa comprising a layer of single-crystal semiconductor material of one type conductivity on a surface of said substrate, said layer having a planar surface and a thickness of between about 0.5 .mu.m and about 5 .mu.m,
- a base region of an opposite type conductivity disposed in a portion of said layer, said layer comprising a collector region,
- an emitter region of said one type conductivity disposed in a portion of said base region and defining with said base region an emitter-base junction,
- each of said regions having a planar surface coplanar with said planar surface of said layer, said mesa having a periphery in which a portion of said emitter-base junction terminates, and
- an edge-guard region of said one type conductivity disposed in said periphery of said mesa, except in said emitter region and said emitter-base junction.
Dependencies are inferred from the claim text.