Browse Prior Art Database

Precision Seeding of a Semiconductor Melt

IP.com Disclosure Number: IPCOM000074751D
Original Publication Date: 1971-Jun-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Chicotka, RJ: AUTHOR [+3]

Abstract

In this method the precise location of a solid-liquid interface is detected by a light pipe in order to determine the proper amount of heat to be applied to the recrystallization of GaAs.

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Precision Seeding of a Semiconductor Melt

In this method the precise location of a solid-liquid interface is detected by a light pipe in order to determine the proper amount of heat to be applied to the recrystallization of GaAs.

In order to nucleate and grow single crystals of GaAs it is necessary to seed the melt. The crystallization is normally carried out by placing a container 10 containing GaAs and a single crystal GaAs seed 12 in one end. The container 10 is placed in a furnace and heat applied to melt the GaAs. Care must be taken that the heat input be controlled so as to not melt the seed 12.

This method makes use of the fact that the emissivity of a metal differs substantially from the emissivity of its melt. A sapphire rod light pipe 14 is inserted into the end of the furnace with the viewing end positioned in the location of the desired liquid seed melt interface 16. The liquid Will appear very dull and the solid will appear bright. The change in the emissivity of the material within the viewing area of the pipe 14 can be observed visually or with a suitable detecting apparatus. When a change is noted in the emissivity, the interface 16 has passed the end of the pipe 14 and the heat input to the furnace can be adjusted accordingly to cause recrystallization of the molten GaAs into a single crystal.

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