Integrated Materials, Incorporated

Other

Ferrotec (usa) Corporation

Tom L Cadwell

James E Boyle

Reese Reynolds

Robert W Mytton

Raanan Y Zehavi

Ranaan Y Zehavi

Michael Sklyar

Doris Mytton, Legal Representative

Non-production wafers of polycrystalline silicon are placed in non-production slots of a support tower for thermal processing monocrystalline silicon wafers. They may have thicknesses of 0.725 to 2 mm and be roughened on both sides. Nitride may be grown on the non-production wafers to a thickness of over 2 &#x3bc;m without flaking. The polycrystalline silicon is preferably randomly oriented Czochralski polysilicon grown using a randomly oriented seed, for example, CVD grown silicon. Both sides are ground to introduce sub-surface damage and then oxidized and etch cleaned. An all-silicon hot zone of a thermal furnace, for example, depositing a nitride layer, may include a silicon support tower placed within a silicon liner and supporting the polysilicon non-production wafers with silicon injector tube providing processing gas within the liner.

Czochralski growth of randomly oriented polysilicon and use of randomly oriented polysilicon dummy wafers

Baffle wafers of polycrystalline silicon are placed in non-production slots of a support tower for thermal processing monocrystalline silicon wafers. The polycrystalline silicon is preferably randomly oriented Czochralski polysilicon grown using a randomly oriented seed, for example, CVD grown silicon. An all-silicon hot zone of a thermal furnace may include a silicon support tower placed within a silicon liner and supporting the polysilicon baffle wafers with silicon injector tube providing processing gas within the liner. The randomly oriented polysilicon may be used for other parts requiring a rugged member, for example, within a silicon processing chamber and for structural members.

Baffle wafers and randomly oriented polycrystalline silicon used therefor

A baffled liner cover supported at the top of a liner surrounding a wafer support tower for semiconductor thermal processing. The cover may present a continuous horizontal surface for preventing particles from falling within the liner but present horizontal extending gas passageways in a baffle assembly to allow the flow of processing gas through the cover. In one embodiment, the baffle assembly includes a cup-shaped member disposed in a central aperture of a top plate having an open top, a continuous bottom, horizontal holes through the sides, and a flange around sides defining a convolute annular passage. Alternatively, the planar top plate may included slanted holes therethrough or vertical holes occupying a small fraction of the surface area. The liner and cover may be composed of quartz, silicon carbide, or preferably silicon.

Baffled liner cover

An edge ring for use in batch thermal processing of wafers supported on a vertical tower within a furnace. The edge rings are have a width approximately overlapping the periphery of the wafers and are detachably supported on the towers equally spaced between the wafer to reduce thermal edge effects. The edge rings have may have internal or external recesses to interlock with structures on or adjacent the fingers of the tower legs supporting the wafers or one or more steps formed on the lateral sides of the edge ring may slide over and then fall below a locking ledge associated with the support fingers. Preferably, the tower and edge ring and other parts of the furnace adjacent the hot zone are composed of silicon.

Detachable edge ring for thermal processing support towers

Polysilicon dummy wafers and process used therewith

Growing community of inventors

Los Altos, CA, United States of America

Tom L Cadwell