Browse Prior Art Database

Ge Channel High Electron Mobility Transistor

IP.com Disclosure Number: IPCOM000062803D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Freeouf, JL: AUTHOR [+2]

Abstract

The problems of doping, load devices and contacts are simplified in a high electron mobility transistor by providing a channel of germanium with GaAs as shown as an example in the figure. (Image Omitted)

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Ge Channel High Electron Mobility Transistor

The problems of doping, load devices and contacts are simplified in a high electron mobility transistor by providing a channel of germanium with GaAs as shown as an example in the figure.

(Image Omitted)

Band offsets for Ge/GaAs and Ge/AlGaAs heterojunctions are cummutative for the (100) orientation.

Bulk Ge has relatively high mobilities for both electrons and holes, especially at LN temperatures. High quality Ge/AlGaAs heterojunctions exhibit the same mobility enhancements observed at GaAs/AlGaAs heterojunctions. The hole mobilities are also impressive, making "load" devices possibly as fast as drivers. The capabilities of complementary device structures are enhanced.

There are very good contact resistances to both degenerate Ge and to Ge epitaxially grown onto GaAs. Since high-dose implants in Ge can be annealed at relatively low temperatures, formation of self-aligned FETs with low contact resistivity is facilitated.

Gate leakage current is strongly reduced from that of a normal GaAs-gate FET structure since the conduction band offset for Ge/GaAs is about 0.2V larger than that of GaAs/AlGaAs, and the valence band offset increases by about 0.55V. This extends the acceptable temperature range for Ge channel FETs to beyond 300OEK.

Disclosed anonymously.

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