CHARLES L DUNCAN
Vehicle Board in Pittsburgh, PA

4828808, May 9, 1989

Sep 2, 1987

7/092796

Charles S. Duncan - Penn Hills PA
Paul A. Piotrowski - Monroeville PA

The United States of America as represented by the United States
Department of Energy - Washington DC

C30B 2702

422249

This disclosure describes an apparatus to improve the web growth attainable from prior web growth configurations. This apparatus modifies the heat loss at the growth interface in a manner that minimizes thickness variations across the web, especially regions of the web adjacent to the two bounding dendrites. In the unmodified configuration, thinned regions of web, adjacent to the dendrites, were found to be the origin of crystal degradation which ultimately led to termination of the web growth. According to the present invention, thinning adjacent to the dendrites is reduced and the incidence of crystal degradation is similarly reduced.

4389377, Jun 21, 1983

Jul 10, 1981

6/282334

Charles S. Duncan - Pittsburgh PA
Paul A. Piotrowski - Monroeville PA
Maria E. Skutch - Trafford PA
James P. McHugh - Pittsburgh PA

The United States of America as represented by the United States
Department of Energy - Washington DC

C30B 1510

422246

A melt system including a susceptor-crucible assembly having improved gradient control when melt replenishment is used during dendritic web growth. The improvement lies in the formation of a thermal barrier in the base of the receptor which is in the form of a vertical slot in the region of the susceptor underlying the crucible at the location of a compartmental separator dividing the crucible into a growth compartment and a melt replenishment compartment. The result achieved is a step change in temperature gradient in the melt thereby providing a more uniform temperature in the growth compartment from which the dendritic web is drawn.

4919901, Apr 24, 1990

Dec 31, 1987

7/140071

Raymond G. Seidensticker - Forest Hills PA
Edgar L. Kochka - Greentree PA
Charles S. Duncan - Penn Hills PA

Westinghouse Electric Corp. - Pittsburgh PA

C30B 3500

422249

This invention delineates a multiple barrier design for separating the feed compartment (12) from the growth compartment (13) in crucibles (10) used for silicon dendritic web growth. The use of the barrier design greatly reduces the thermal interaction between the two compartments permitting larger replenishment rates without adverse effect on crystal growth. Its novelty lies in having a primary and secondary barrier (15,16) spaced apart from one another such that there exists a space (22) between the barriers (15,16) which is devoid of liquid silicon thus reducing the thermal conductance of the combination.

4747774, May 31, 1988

Feb 9, 1987

7/012779

Paul A. Piotrowski - Monroeville PA
Edgar L. Kochka - Greentree PA
Charles S. Duncan - Penn Hills PA

Westinghouse Electric Corp. - Pittsburgh PA

F27B 1400

432156

A crucible/susceptor system is described in which the walls of the crucible and the susceptor cavity are sloped outward in an angle sufficient for the force of gravity to exceed the inward pulling forces created by the high surface tension of molten silicon allowing the softened quartz crucible walls to settle into and form to the sloped walls of the susceptor thereby improving heat transfer from the susceptor to the molten silicon and improving the reproducibility of the system.

5098287, Mar 24, 1992

Mar 16, 1990

7/525205

Charles S. Duncan - Penn Hills PA
Edgar L. Kochka - Greentree PA
Paul A. Piotrowski - Monroeville PA
Raymond G. Seidensticker - Forest Hills PA

Westinghouse Electric Corp. - Pittsburgh PA

F27B 1410

432262

A lid for a susceptor in which a crystalline material is melted by induction heating to form a pool or melt of molten material from which a dendritic web of essentially a single crystal of the material is pulled through an elongated slot in the lid and the lid has a pair of generally round openings adjacent the ends of the slot and a groove extends between each opening and the end of the slot. The grooves extend from the outboard surface of the lid to adjacent the inboard surface providing a strip contiguous with the inboard surface of the lid to produce generally uniform radiational heat loss across the width of the dendritic web adjacent the inboard surface of the lid to reduce thermal stresses in the web and facilitate the growth of wider webs at a greater withdrawal rate.