Browse Prior Art Database

BARRIER HEIGHT ENHANCEMENT IN GaAs MOS DEVICES USING A METAL OXIDE

IP.com Disclosure Number: IPCOM000046548D
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Hovel, HJ: AUTHOR

Abstract

The barrier height of a Schottky barrier contact to n-GaAs is achieved by the use of a metal oxide where the oxide dopes the GaAs with acceptors. The metal is deposited followed by diffusion and oxidation. The band diagrams for the oxide is shown in Fig. 1, and the enhancement by diffusion is shown in Fig. 2. A Mg layer is deposited on nGaAs. The sample is then annealed at 300-500ŒC. The Mg partly diffuses into and partly alloys with the GaAs. The introduction of O2 or another oxidizing gas causes the Mg to oxidize, producing both a thin insulating oxide and a doping enhanced barrier. Mg layers 25-50 ˜ thick will result in 50-100 ˜ thick oxide layers, and the doping enhanced region thickness can be controlled to produce doping regions of a similar thickness so that the acceptor-doped region is fully depleted.

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

BARRIER HEIGHT ENHANCEMENT IN GaAs MOS DEVICES USING A METAL OXIDE

The barrier height of a Schottky barrier contact to n-GaAs is achieved by the use of a metal oxide where the oxide dopes the GaAs with acceptors. The metal is deposited followed by diffusion and oxidation. The band diagrams for the oxide is shown in Fig. 1, and the enhancement by diffusion is shown in Fig. 2. A Mg layer is deposited on nGaAs. The sample is then annealed at 300-500OEC. The Mg partly diffuses into and partly alloys with the GaAs. The introduction of O2 or another oxidizing gas causes the Mg to oxidize, producing both a thin insulating oxide and a doping enhanced barrier. Mg layers 25-50 ~ thick will result in 50-100 ~ thick oxide layers, and the doping enhanced region thickness can be controlled to produce doping regions of a similar thickness so that the acceptor-doped region is fully depleted. Thicker acceptor-doped regions produced by longer times and/or higher temperatures form a pn junction in the GaAs rather than an enhanced Schottky barrier. Thicker MgO layers using thicker Mg starting layers can be used to produce MOS structures on the GaAs.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]