International Business Machines Corporation

S Noor Mohammad

Robert B Renbeck

A vertical Triple Heterojunction Bipolar Transistor (THBT) and method of fabrication therefor. The THBT collector has a substrate layer of N.sup.+ silicon, an N.sup.- silicon layer grown on the substrate and a Si/SiGe superlattice grown on the N.sup.- silicon layer. The THBT base is layer of P.sup.+ SiGe grown on the superlattice. The THBT Emitter is a second Si/SiGe Superlattice grown on the base layer. An N.sup.- silicon layer is grown on the emitter superlattice. A layer of N.sup.+ GaP grown on that N.sup.- Si layer. The base is formed, first, by etching a rectangular groove through the emitter, ion implanting dopant into the base layer to form an extrinsic base, etching a V shaped groove into the extrinsic base and, then, filling the grooved base with doped polysilicon.

Method of fabricating a triple heterojunction bipolar transistor

A vertical Metal Oxide Semiconductor Heterojunction Field Effect Transistor (MOSHFET) and method of fabrication therefor. The MOSHFET is in a layered wafer made by successively growing an N.sup.+ silicon layer, and a N.sup.- silicon layer, a P.sup.- Si.sub.1-x Gex layer, a P.sup.- Silicon layer and then, an N.sup.- silicon layer, one on top of the other. Trenches are etched through the top 3 layers to form islands that are the MOSHFETs heterojunction channel. A gate deposited or grown in a trench extends vertically from the drain at the bottom of the trench to the source in the layer near the top of the trench.

Metal oxide semiconductor heterojunction field effect transistor

Triple heterojunction bipolar transistor

A superheterojunction Field Effect Transistor (FET) with a multi-region channel on a Silicon (Si) substrate. The FET is a Metal Semiconductor FET (MESFET) or, alternatively, a Junction FET (JFET). The multi-region channel has: A first region of Si extending from the FET's source to a point under the FET's gate, beyond the gate's midpoint; a second region extending from the first region to the FET's drain, comprised of a superlattice of alternating Si and SiGe layers; and, a third region of Si extending under the first two regions from the source to the drain. The first region has a laterally graded dopant that creates an accelerating electric field. The superlattice structure increases electron mobility and transit velocity.

Method of making a high performance MESFET with multiple quantum wells

A Double Heterojunction Bipolar Transistor (DHBT) and the method of fabrication therefor. First a layered wafer is prepared on a semi-insulating GaAs substrate. The bottom wafer layer is n.sup.+ GaAs, followed by n.sub.- AlGaAs, a thin layer of n AlGaAs (which form the DHBT's collector) and a base layer of p.sup.+ GaAS. A layered plug fills a trench etched in the base layer. The bottom two plug layers are AlGaAs and the top plug layer is GaAs. Next, an emitter is ion-implanted into the plug core and an extrinsic base region is ion-implanted. Finally, base, emitter and collector contacts are formed.

Double heterojunction bipolar transistor and the method of manufacture

A Metal Insulator Semiconductor (MIS) heterojunction transistor. The MIS transistor is in a layered wafer having a n.sup.+ Si substrate, n Si collector layer, and a p Si/SiGe base. The base Si/SiGe interface may be vertical or horizontal. A thin oxide layer separates the base from the emitter, which is of a low work function metal such as Al, Mg, Mn, or Ti.

High-gain Si/SiGe MIS heterojunction bipolar transistors

Method of fabricating a vertical Metal Oxide Semiconductor Heterojunction Field Effect Transistor (MOSHFET) which is in a layered wafer made by successively growing an N.sup.+ silicon layer, and a N.sup.- silicon layer, a P.sup.- Si.sub.1-x Gex layer, a P.sup.- Silicon layer and then, an N.sup.- silicon layer, one on top of the other. Trenches are etched through the top 3 layers to form islands that are the MOSHFETs heterojunction channel. A gate deposited or grown in a trench extends vertically from the drain at the bottom of the trench to the source in the layer near the top of the trench.

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Hopewell Junction, NY, United States of America

S Noor Mohammad