Browse Prior Art Database

Production of Semiconductor Single Crystals

IP.com Disclosure Number: IPCOM000095320D
Original Publication Date: 1965-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Kampschulte, G: AUTHOR [+2]

Abstract

For producing single crystals of the III/V Group, the Czochralski method is used. By that method, a seed crystal is dipped into the melt and then withdrawn slowly. However, those compounds tend to decompose at the melting point. They form a congruent melt only at a certain vapor pressure of the more volatile component. One such compound is gallium arsenide. In order to prevent a contamination of the arsenic, this element is placed in the apparatus in a sealed quartz storage bulb. This is not opened until after the reaction tube has been sealed.

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Production of Semiconductor Single Crystals

For producing single crystals of the III/V Group, the Czochralski method is used. By that method, a seed crystal is dipped into the melt and then withdrawn slowly. However, those compounds tend to decompose at the melting point. They form a congruent melt only at a certain vapor pressure of the more volatile component. One such compound is gallium arsenide. In order to prevent a contamination of the arsenic, this element is placed in the apparatus in a sealed quartz storage bulb. This is not opened until after the reaction tube has been sealed.

Quartz tube 1 is surrounded by a furnace 2. In its bottom part, tube 1 contains a crucible with melt 4. This is heated by RF heating system 3. Seed crystal 5, on which single crystal 6 grows out of melt 4, is fastened to a crystal holder. This consists of quartz rings 8 and 9 connected by quartz tubes 7. These contain iron rods so that the crystal holder is guided by magnets 10 and
11. These are mounted to be displaceable and rotatable.

The sealed quartz storage bulb 12 containing the arsenic is placed on ring 9. After the apparatus is degassed by baking out and tube 1 is sealed, bulb 12 is opened through impact with quartz enclosed steel hammer 13. The latter is manipulated from outside tube 1 with the aid of magnet 14.

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