Passivated germanium-on-insulator lateral bipolar transistors
AssigneeInternational Business Machines Corporation
InventorsKevin K. Chan, Tak H. Ning, Jeng-Bang Yau
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Abstract
After forming an epitaxial germanium layer over a germanium-on-insulator substrate including an insulator layer and a doped germanium layer overlying the insulator layer, the doped germanium layer is selectively removed and a passivation layer is formed within a space between the epitaxial germanium layer and the insulator layer that is formed by removal of the doped germanium layer. A lateral bipolar transistor is subsequently formed in the epitaxial germanium layer.
Claims19
A semiconductor structure comprising:
- a passivation layer located on an insulator layer;
- an epitaxial germanium portion located on the passivation layer and including an intrinsic base region comprising dopants of a first conductivity type, an emitter region laterally contacting a first side of the intrinsic base region and comprising dopants of a second conductivity type that is the opposite type of the first conductivity type, and a collector region laterally contacting a second side of the intrinsic base region opposite the first side and comprising dopants of the second conductivity type;
- an extrinsic base region vertically contacting the intrinsic base region and comprising dopants of the first conductivity type;
- and
- a trench isolation structure laterally surrounding the passivation layer and the doped epitaxial germanium portion.
A semiconductor structure comprising:
- a passivation layer located on an insulator layer;
- an epitaxial germanium portion located on the passivation layer and including an intrinsic base region comprising dopants of a first conductivity type, an emitter region laterally contacting a first side of the intrinsic base region and comprising dopants of a second conductivity type that is the opposite type of the first conductivity type, and a collector region laterally contacting a second side of the intrinsic base region opposite the first side and comprising dopants of the second conductivity type;
- and
- an extrinsic base region vertically contacting the intrinsic base region and comprising dopants of the first conductivity type,
- wherein the passivation layer contacts sidewalls and a bottom surface of the epitaxial germanium portion.
A method of forming a semiconductor structure comprising:
- providing a germanium-on-insulator (GOI) substrate comprising, from bottom to top, a handle substrate, a buried insulator layer and a doped germanium layer;
- forming an epitaxial germanium layer on the doped germanium layer;
- forming a trench extending through the epitaxial germanium layer and the doped germanium layer, the trench exposing sidewalls of a doped germanium portion and an epitaxial germanium portion;
- removing the doped germanium portion, wherein a space is formed between the epitaxial germanium portion and the buried insulator layer;
- and
- forming a passivation layer to fill the space.
Dependencies are inferred from the claim text.