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Ge Inlays in a GaAs Matrix by Solvent Evaporation

IP.com Disclosure Number: IPCOM000096565D
Original Publication Date: 1963-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 18K

Publishing Venue

IBM

Related People

Marinace, JC: AUTHOR [+2]

Abstract

A small amount of solid Ge with a low doping is placed in each of the pyramidal depressions of a high-resistivity GaAs substrate. Such is positioned with the depressions opening upwardly, as shown in the drawing. This is then sealed in a quartz tube with a measured amount of arsenic in the tube. Typical values for the dimensions of the tube are 10 mm for the diameter and 7. 5 cm for the length. Approximately 6 mg of arsenic is used in a tube this size.

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Ge Inlays in a GaAs Matrix by Solvent Evaporation

A small amount of solid Ge with a low doping is placed in each of the pyramidal depressions of a high-resistivity GaAs substrate. Such is positioned with the depressions opening upwardly, as shown in the drawing. This is then sealed in a quartz tube with a measured amount of arsenic in the tube. Typical values for the dimensions of the tube are 10 mm for the diameter and 7. 5 cm for the length. Approximately 6 mg of arsenic is used in a tube this size.

The tube is placed in a furnace at 800 degrees C. At this temperature, the As and Ge form a liquid solution in each of the depressions. Equilibrium is established in about thirty minutes. After this time, a part of the tube remote from the substrate is started to cool and some of the As starts to condense out there. As soon as the Ge:As solutions are supersaturated with Ge, Ge starts to crystallize out epitaxially upon the GaAs walls of the depressions. As the cooling continues, more As is evaporated from the solutions. The crystallization of the Ge continues until finally only solid Ge remains. This solid Ge is, of course, doped with the maximum solid solubility of As for the temperature at which it was grown. The temperature, at least initially, is 800 degrees C.

The cooling cycle can be carried out in several ways. First, the tube can be pulled slowly from the hottest region of the furnace. Second, the furnace power can be turned off. If the substrate is in the m...