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Wide Ribbon Growth Through Thermal Geometry Control by Gaseous Means

IP.com Disclosure Number: IPCOM000089237D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 71K

Publishing Venue

IBM

Related People

Ciszek, TF: AUTHOR [+2]

Abstract

This article describes a technique for growing wide ribbons through thermal profile control which is continuously variable, inert, and capable of heat extraction. The apparatus employs multiple inert gas jets directed at various parts of the hot zone of the crystal puller, each with an individually controlled flow adjustment (manual or automatic). A system using four port-jets and flow-meters in a ribbon growth apparatus may be used. The two end ports impinge on the ribbon growth region at points 38 mm apart, corresponding to the edge positions of a 38 mm wide ribbon. The two middle ports are directed so as to be at either side of a ribbon being grown and pulled upward through the large central draw tube. The draw tube also serves as the exit tube for the inert gas.

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Wide Ribbon Growth Through Thermal Geometry Control by Gaseous Means

This article describes a technique for growing wide ribbons through thermal profile control which is continuously variable, inert, and capable of heat extraction. The apparatus employs multiple inert gas jets directed at various parts of the hot zone of the crystal puller, each with an individually controlled flow adjustment (manual or automatic). A system using four port-jets and flow-meters in a ribbon growth apparatus may be used. The two end ports impinge on the ribbon growth region at points 38 mm apart, corresponding to the edge positions of a 38 mm wide ribbon. The two middle ports are directed so as to be at either side of a ribbon being grown and pulled upward through the large central draw tube. The draw tube also serves as the exit tube for the inert gas. To use the system, more argon is directed to those parts of the system where the temperature is locally higher than desired.

Examples of use of the system are best understood with reference to Figs. 1 and 2. Three thermocouples (T.C.) were placed in a graphite block as shown in Fig. 1. The spacing was 19 mm. The T.C. junctions were approximately at the growth region of a 38 mm wide ribbon (edges and middle). The system was heated to approximately 1200 Degrees C by an external RF coil. Example 1 (Fig.
1). Flows to the four ports were each adjusted to 10 cubic feet per hour (CFH) - gauge (uncorrected for flow differences between air ga...