Browse Prior Art Database

Graded Base Heterostructure Hot Electron Transistor

IP.com Disclosure Number: IPCOM000062176D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Jackson, TN: AUTHOR [+3]

Abstract

A hot electron-type transistor structure is constructed with a semiconductor (e.g., nGaAs) for the emitter and collector, and with an epitaxial n++ semiconductor with a smaller band gap (e.g., InGaAs) for the base layer. This will minimize base losses associated with scattering at the metal/semiconductor (base/collector) interface. Further, the emitter/base barrier is made larger than the base/collector barrier to improve the current gain. This is accomplished by grading the In concentration in the ternary semiconductor base layer. The figure illustrates the energy bands for the case of a GaAs/InGaAs/GaAs device, in which a larger In fraction at the emitter/base interface than at the collector/base interface results in a higher emitter/base barrier.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Graded Base Heterostructure Hot Electron Transistor

A hot electron-type transistor structure is constructed with a semiconductor (e.g., nGaAs) for the emitter and collector, and with an epitaxial n++ semiconductor with a smaller band gap (e.g., InGaAs) for the base layer. This will minimize base losses associated with scattering at the metal/semiconductor (base/collector) interface. Further, the emitter/base barrier is made larger than the base/collector barrier to improve the current gain. This is accomplished by grading the In concentration in the ternary semiconductor base layer. The figure illustrates the energy bands for the case of a GaAs/InGaAs/GaAs device, in which a larger In fraction at the emitter/base interface than at the collector/base interface results in a higher emitter/base barrier. The composition is thus graded so that the In concentration decreases across the base from emitter to collector.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]