InPSb/InAs BJT device and method of making
US6482711B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1999 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Oct 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/852
Abstract
Bipolar junction transistor (BJT) devices, particularly heterojunction bipolar transistor (HBT) devices, and methods of making same are described. A combination of InPSb and p-type InAs is used to create extremely high speed bipolar devices which, due to reduced turn-on voltages, lend themselves to circuits having drastically reduced power dissipation. The described HBTs are fabricated on InAs or GaSb substrates, and include an InPSb emitter. The base includes In and As, in the form of InAs when on an InAs substrate, and as InAsSb when on a GaSb substrate. The collector may be the same as the base to form a single heterojunction bipolar transistor (SHBT) or may be the same as the emitter to form a double heterojunction bipolar transistor (DHBT). Heterojunctions preferably include a grading layer, which may be implemented by continuously changing the bulk material composition, or by forming a chirped superlattice of alternating materials. The grading layer preferably has delta doping planes near its ends to form an electrostatic gradient offsetting the quasi-electric field variation due to the changes in material composition, whereby effective conduction band offset may be substanti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.