Semiconductor device and the method of producing the same
AssigneeHitachi, Ltd.
InventorsKazuhiro Mochizuki, Tohru Oka, Isao Ohbu, Kiichi Yamashita
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Abstract
In the case of a semiconductor device where a base electrode 11 in a collector top heterojunction bipolar transistor is disposed so as to contact with the side face of a base layer 5 in which no ion is implanted and the surface of a high resistance extrinsic emitter area 14 in which ion is implanted, the dependence of the current gain in the collector top HBT on the collector size can be diminished.
Claims17
A semiconductor device, characterized in that it has a collector top heterojunction bipolar transistor, the base layer does not cover the whole of high resistance extrinsic emitter area, and the base electrode is present on the high resistance extrinsic emitter area and electrically connected to a side face of the base layer.
A semiconductor device using a collector top heterojunction bipolar transistor which has a single crystal semiconductor substrate, a sub-emitter layer formed on the substrate and comprising an n-type compound semiconductor, an emitter layer formed on the sub-emitter layer and comprising an n-type compound semiconductor larger in forbidden band width than the compound semiconductor constituting the sub-emitter layer, a base layer formed on the emitter layer and comprising a p-type compound semiconductor smaller in forbidden band width than the compound semiconductor constituting the emitter layer, a collector layer formed on the base layer and comprising an n-type compound semiconductor having a forbidden band width equal to or larger than that of the compound semiconductor constituting the base layer, a cap layer formed on the collector layer and comprising an n-type compound semiconductor higher in impurity concentration than the collector layer, and a collector electrode, a base electrode and an emitter electrode electrically connected to the cap layer, the base layer and the sub-emitter layer, respectively, characterized in that the base electrode is formed in contact with a side face of the base layer and the surface of the emitter layer, and the area of the emitter layer which contacts with at least the base electrode contains at least one element of hydrogen, helium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon.
A method for producing a collector top heterojunction bipolar transistor which comprises a step of growing an emitter layer comprising an n-type compound semiconductor on a single crystal semiconductor substrate, a step of growing on the emitter layer a base layer comprising a p-type compound semiconductor smaller in forbidden band width than the compound semiconductor constituting the emitter layer, a step of processing the base layer into a desired shape, and a step of forming by ion implantation a high resistance extrinsic emitter area in the area of the emitter layer which is not covered with the base layer.
Dependencies are inferred from the claim text.