Wolfspeed, Inc.

Cree Gmbh

Simon Bubel

John Adam Edmond

Matthew Donofrio

Valeri Fedorovich Tsvetkov

Robert Tyler Leonard

Yuri Khlebnikov

Elif Balkas

Ian Currier

Adrian Powell

Matthew David Conrad

Caleb A Kent

Steven Griffiths

Michael J Paisley

Oleksandr Kramarenko

Eugene Deyneka

Varad R Sakhalkar

Jeffrey C Seaman

Alexander Kevin Shveyd

Curt Progl

Michael Fusco

Lukas Nattermann

Kathy Doverspike

David P Malta

Josephus Daniel Ferguson

Kathryn A O'Hara

Silicon carbide (SiC) wafers and related methods are disclosed that include large diameter SiC wafers with wafer shape characteristics suitable for semiconductor manufacturing. Large diameter SiC wafers are disclosed that have reduced deformation related to stress and strain effects associated with forming such SiC wafers. As described herein, wafer shape and flatness characteristics may be improved by reducing crystallographic stress profiles during growth of SiC crystal boules or ingots. Wafer shape and flatness characteristics may also be improved after individual SiC wafers have been separated from corresponding SiC crystal boules. In this regard, SiC wafers and related methods are disclosed that include large diameter SiC wafers with suitable crystal quality and wafer shape characteristics including low values for wafer bow, warp, and thickness variation.

Large diameter silicon carbide wafers

Systems and methods for laser-based surface processing operations on a semiconductor wafer, such as a silicon carbide semiconductor wafer, are provided. In one example, a method includes providing a semiconductor workpiece having a surface. The method includes providing emission of one or more lasers to the surface of a semiconductor workpiece at a non-perpendicular incidence angle relative to the surface. The method includes imparting relative motion between the one or more lasers and the semiconductor workpiece while providing emission of the one or more lasers to the surface of the semiconductor workpiece at the non-perpendicular incidence angle.

Off axis laser-based surface processing operations for semiconductor wafers

Systems and methods for laser-based surface processing operations on a wide bandgap semiconductor wafer, such as a silicon carbide semiconductor wafer, are provided. In one example, a method includes providing a semiconductor workpiece having a surface, the semiconductor workpiece including silicon carbide. The method includes providing a filler material on at least a portion of the surface. The method includes, subsequent to providing the filler material, performing a surface processing operation on the surface.

Fill-in planarization system and method

Silicon carbide (SiC) materials including SiC wafers and SiC boules and related methods are disclosed that provide large dimension SiC wafers with reduced crystallographic stress. Growth conditions for SiC materials include maintaining a generally convex growth surface of SiC crystals, adjusting differences in front-side to back-side thermal profiles of growing SiC crystals, supplying sufficient source flux to allow commercially viable growth rates for SiC crystals, and reducing the inclusion of contaminants or non-SiC particles in SiC source materials and corresponding SiC crystals. By forming larger dimension SiC crystals that exhibit lower crystallographic stress, overall dislocation densities that are associated with missing or additional planes of atoms may be reduced, thereby improving crystal quality and usable SiC crystal growth heights.

Large dimension silicon carbide single crystalline materials with reduced crystallographic stress

Silicon carbide (SiC) wafers and related methods are disclosed that include intentional or imposed wafer shapes that are configured to reduce manufacturing problems associated with deformation, bowing, or sagging of such wafers due to gravitational forces or from preexisting crystal stress. Intentional or imposed wafer shapes may comprise SiC wafers with a relaxed positive bow from silicon faces thereof. In this manner, effects associated with deformation, bowing, or sagging for SiC wafers, and in particular for large area SiC wafers, may be reduced. Related methods for providing SiC wafers with relaxed positive bow are disclosed that provide reduced kerf losses of bulk crystalline material. Such methods may include laser-assisted separation of SiC wafers from bulk crystalline material.

Silicon carbide wafers with relaxed positive bow and related methods

Silicon carbide (SiC) crystalline materials and related methods are disclosed that provide SiC crystalline materials with reduced optical absorption. In certain aspects, SiC crystalline materials with reduced absorption coefficients for wavelengths of light within the visible spectrum are disclosed. Various peaks in absorption over a wavelength spectrum may be reduced in SiC crystalline materials to improve overall absorption coefficient uniformity across the visible spectrum. By providing such improvements in absorption coefficients for SiC crystalline materials, reduced reflection and transmission losses of light in corresponding devices may be realized. Related methods are disclosed that include various combinations of crystalline growth, with and without various post-growth thermal conditioning steps.

Reduced optical absorption for silicon carbide crystalline materials

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Carrboro, NC, United States of America

Simon Bubel