David M Jewett

US Patent:

42895715, Sep 15, 1981

Filed:

Jun 25, 1979

Appl. No.:

6/051998

Inventors:

David N. Jewett - Harvard MA

Assignee:

Energy Materials Corporation - Ayer MA

International Classification:

C30B 1506
C30B 3500

US Classification:

156617H

Abstract:

A method and associated apparatus are disclosed for the continuous formation of single crystal silicon ribbons. A seed crystal is placed on the surface of a pool of molten silicon and pulled at a slight angle above the horizontal over the edge of a meniscus attachment member at a rate commensurate with the rate of growth of the ribbon. The formation of the ribbon is controlled in part by a submerged stabilizer disposed under the molten silicon below the advancing edge of the ribbon at the surface of the silicon. A thermal impedance is provided below the surface of the molten silicon to provide stability in the formation of the ribbon and to provide the proper temperature gradients conducive to the efficient formation of the ribbon from the molten material.

US Patent:

42486459, Feb 3, 1981

Filed:

Sep 5, 1978

Appl. No.:

5/939808

Inventors:

David N. Jewett - Harvard MA

Assignee:

Mobil Tyco Solar Energy Corporation - Waltham MA

International Classification:

C30B 1534

US Classification:

156601

Abstract:

A temperature profile controller is provided for cooling a crystal as it is pulled from a melt so that a substantially linear temperature gradient is established and maintained along the length of the crystal as it is cooled, whereby to prevent or reduce the occurrence of residual stresses in the crystal.

US Patent:

46594213, Apr 21, 1987

Filed:

Apr 16, 1985

Appl. No.:

6/723942

Inventors:

David N. Jewett - Harvard MA

Assignee:

Energy Materials Corporation - So. Lancaster MA

International Classification:

C30B 1310
C30B 1502
C30B 2702

US Classification:

156617SP

Abstract:

A system and process for growing extremely high quality single crystal materials, particularly silicon and other semiconductor materials, containing a generally uniform distribution of dopants, impurities, and oxygen, both axially and radially, wherein the concentration of impurities and oxygen and the number of defects are minimized. A significant feature is the use of a shallow tray-like crucible consisting of a replenishment zone and at least one crystal growth zone independently heated by one or more heating elements through the bottom of the crucible. In the preferred embodiment, an oval shaped crucible is used which consists of one replenishment zone and one growth zone. In one embodiment, a spiral shaped heater is centered underneath the feed rod and growing crystal and a "picture frame" shaped heater is located underneath the outer edges of the replenishment and growth zones to provide a more controlled thermal gradient. Mechanical pumping produces a controlled, directed, three-dimensional flow within the melt from the replenishment zone to the growth zone. The pumping is achieved either by rotation of a solid feed rod in the replenishment zone or by a strong directed flow of an inert gas onto the surface of the melt.

US Patent:

41239890, Nov 7, 1978

Filed:

Sep 12, 1977

Appl. No.:

5/832728

Inventors:

David N. Jewett - Harvard MA

Assignee:

Mobil Tyco Solar Energy Corp. - Waltham MA

International Classification:

C23C 1308

US Classification:

118 495

Abstract:

A new method and apparatus for producing silicon are disclosed which are characterized by using a silicon tube as the reaction chamber and disproportionating a gaseous silicon compound so as to produce silicon and deposit the same on the inner surface of the reaction chamber.

US Patent:

52661512, Nov 30, 1993

Filed:

Mar 4, 1992

Appl. No.:

7/846533

Inventors:

David N. Jewett - Harvard MA

Assignee:

Advanced Crystal Products Corporation - Woburn MA

International Classification:

B01D 900

US Classification:

156608

Abstract:

A method and system for growing elongated crystalline materials. Crystalline melt rises through a capillary. At the upper end of the capillary is a die having a die tip. A seed crystal engages and draws the melt through the die tip. The die tip is characterized by a top surface and an aperture therein. The top surface is non-wetting with reference to the crystalline melt. The geometry of the aperture or inner edge defines the geometry of the crystalline filament formed.

US Patent:

41580389, Jun 12, 1979

Filed:

Jan 24, 1977

Appl. No.:

5/761949

Inventors:

David N. Jewett - Harvard MA

Assignee:

Mobil Tyco Solar Energy Corporation - Waltham MA

International Classification:

B01J 1718

US Classification:

422249

Abstract:

A temperature profile controller is provided for cooling a crystal as it is pulled from a melt so that a substantially linear temperature gradient is established and maintained along the length of the crystal as it is cooled, whereby to prevent or reduce the occurrence of residual stresses in the crystal.

US Patent:

45991324, Jul 8, 1986

Filed:

Jan 18, 1985

Appl. No.:

6/692844

Inventors:

David N. Jewett - Harvard MA
Herbert E. Bates - Ashby MA
Joseph B. Milstein - Denver CO

Assignee:

Energy Materials Corporation - So. Lancaster MA

International Classification:

C30B 1506

US Classification:

156617H

Abstract:

In a low angle silicon sheet growth process, a puller mechanism advances a seed crystal and solidified ribbon from a cooled growth zone in a melt at a low angle with respect to the horizontal. The ribbon is supported on a ramp adjacent the puller mechanism. Variations in the vertical position of the ribbon with respect to the ramp are isolated from the growth end of the ribbon by (1) growing the ribbon so that it is extremely thin, preferably less than 0. 7 mm, (2) maintaining a large growth zone, preferably one whose length is at least 5. 0 cm, and (3) spacing the ramp from the growth zone by at least 15 cm.

US Patent:

42658594, May 5, 1981

Filed:

Oct 26, 1979

Appl. No.:

6/088366

Inventors:

David N. Jewett - Harvard MA

Assignee:

Energy Materials Corporation - Harvard MA

International Classification:

B01J 1202
B01J 1902
C01B 3302

US Classification:

422199

Abstract:

A method and related apparatus are provided for producing on a semi-continuous basis polycrystalline silicon and melt replenishment for a crystal growth crucible. The silicon is deposited in low density form on the inner walls of a multi-walled reaction chamber by delivering gaseous HSiCL. sub. 3, SiH. sub. 4, or the like, and reducing gas if needed, through the chamber which is heated to the reaction temperature of the feed gas. After a certain amount of silicon has been produced, the chamber temperature is raised sufficiently to melt down the silicon which is then used to replenish a crystal growth crucible. The operations are then cyclically repeated. The apparatus includes a reaction chamber having a multi-walled configuration to maximize the interior surface area on which the silicon is deposited. A drain trap such as a U-shaped tube, or the like, is connected to the bottom of the reaction chamber and provided with heating elements. Silicon collected on the walls of the reaction chamber, when periodically melted, flows through the drain trap and a delivery tube to a crystal growth system.