Westinghouse Electric Corporation

The United States of America as Represented by the United States

Raymond G Seidensticker

James P McHugh

Charles S Duncan

Edgar L Kochka

Paul A Piotrowski

Richard J Ravas

Rolv Hundal

George V Hall

John A Spitznagel

Lynd R McCormick

Frank L Przywarty

A melt replenishment system for dendritic web growth having a pellet feed arrangement, which distributes equal amounts of feed material to a pair of feed tubes in communication with opposite ends of a crucible to maintain a melt pool at a constant level and a cover gas system, which keeps the feed tubes flowing and helps maintain thermal consistency within the melt.

Melt replenishment system for dendritic web growth

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.

Lid for improved dendritic web growth

A method of tailoring the heat balance of the outer edge of the dendrites adjacent the meniscus to produce thinner, smoother dendrites, which have substantially less dislocation sources contiguous with the dendrites, by changing the view factor to reduce radiation cooling or by irradiating the dendrites with light from a quartz lamp or a laser to raise the temperature of the dendrites.

Method of inhibiting dislocation generation in silicon dendritic webs

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.

Barrier design for crucibles for silicon dendritic web growth

A method and apparatus for growing dendritic web crystals at increased growth rates is disclosed in which a sublid is used to maintain a sufficiently hot silicon melt surface temperature to insure stable web growth, while simultaneously permitting more efficient heat transfer from the growing dendritic web to the cooler susceptor lid.

Apparatus for dendritic web growth systems

The concept of this invention is to provide a thermal geometry which produces web growth at a constant width by balancing the heat loss pattern from the growing dendrites in such a manner that the outer requirements for stable web growth are simultaneously met. This is accomplished by configuring the geometry of the growth system such that the heat loss pattern from the growing web, the heat loss pattern from the growing dendrites, and the temperature profile in the melt can each be controlled independently and simultaneously optimized.

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Forest Hills, PA, United States of America

Raymond G Seidensticker