Browse Prior Art Database

Electrochemical Removal of GaAs Substrate

IP.com Disclosure Number: IPCOM000075498D
Original Publication Date: 1971-Sep-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Shang, DC: AUTHOR [+2]

Abstract

In certain applications, a GaAs substrate is used as the basic support structure in the formation processes of certain semiconductor devices. One such example is the formation of GaAlAs light emitting diodes (LED) on a GaAs substrate by an epitaxially growth process.

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Electrochemical Removal of GaAs Substrate

In certain applications, a GaAs substrate is used as the basic support structure in the formation processes of certain semiconductor devices. One such example is the formation of GaAlAs light emitting diodes (LED) on a GaAs substrate by an epitaxially growth process.

The present system employs an electrochemical process to remove the GaAs substrate after the formation of the semiconductor device. One such system is as follows:

A semiconductor body 10, c.f. Fig. 1, consists of a LED portion 11, e. g. GaAlAs, and a GaAs substrate portion 12. Portion 11 is electrically insulated, and the body 10 is affixed to a suitable fixture 13, shown schematically, which includes means for urging an electrical contact against portion 12. Body 10 and the fixture 13 and contact are immersed in a suitable electrolyte, such as a 1:1 solution of methyl alcohol and nitric acid. Substrate 12 acts as the anode. A suitable cathode, such as a platinum sheet 14 is also immersed in the electrolyte.

The cathode 14 is connected to the SCR 15 and portion 12 is connected via the contact 13 to a bias source, e.g. battery 16, through a current-limiting resistor RL.

In operation, a pulse train signal is applied to gate electrode 17 and cyclically turns on SCR 15. As a result current flows in the anode/ cathode circuit 12 and 14 via the electrolyte and the GaAs substrate 12 is removed.

For the particular GaAlAs portion 11 example, the anode 12 is operated a...