公开(公告)号：US20220189768A1

公开(公告)日：2022-06-16

申请号：US17121863

申请日：2020-12-15

Applicant: Cree, Inc.

Inventor： Yuri Khlebnikov ,  Varad R. Sakhalkar ,  Caleb A. Kent ,  Valeri F. Tsvetkov ,  Michael J. Paisley ,  Oleksandr Kramarenko ,  Matthew David Conrad ,  Eugene Deyneka ,  Steven Griffiths ,  Simon Bubel ,  Adrian R. Powell ,  Robert Tyler Leonard ,  Elif Balkas ,  Curt Progl ,  Michael Fusco ,  Alexander Shveyd ,  Kathy Doverspike ,  Lukas Nattermann

IPC: H01L21/02 ,  C30B29/36

Abstract: 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.

公开(公告)号：US20210230769A1

公开(公告)日：2021-07-29

申请号：US16775407

申请日：2020-01-29

Applicant: Cree, Inc.

Inventor： Yuri Khlebnikov ,  Robert T. Leonard ,  Elif Balkas ,  Steven Griffiths ,  Valeri Tsvetkov ,  Michael Paisley

IPC: C30B29/36 ,  H01L29/32 ,  H01L29/16 ,  C30B23/02

Abstract: Silicon carbide (SiC) wafers, SiC boules, and related methods are disclosed that provide improved dislocation distributions. SiC boules are provided that demonstrate reduced dislocation densities and improved dislocation uniformity across longer boule lengths. Corresponding SiC wafers include reduced total dislocation density (TDD) values and improved TDD radial uniformity. Growth conditions for SiC crystalline materials include providing source materials in oversaturated quantities where amounts of the source materials present during growth are significantly higher than what would typically be required. Such SiC crystalline materials and related methods are suitable for providing large diameter SiC boules and corresponding SiC wafers with improved crystalline quality.

公开(公告)号：US20210225652A1

公开(公告)日：2021-07-22

申请号：US17225384

申请日：2021-04-08

Applicant: Cree, Inc.

Inventor： Matthew Donofrio ,  John Edmond ,  Hua-Shuang Kong ,  Elif Balkas

IPC: H01L21/18 ,  H01L21/20 ,  B23K26/00 ,  H01L21/02

Abstract: A method for removing a portion of a crystalline material (e.g., SiC) substrate includes joining a surface of the substrate to a rigid carrier (e.g., >800 μm thick), with a subsurface laser damage region provided within the substrate at a depth relative to the surface. Adhesive material having a glass transition temperature above 25° C. may bond the substrate to the carrier. The crystalline material is fractured along the subsurface laser damage region to produce a bonded assembly including the carrier and a portion of the crystalline material. Fracturing of the crystalline material may be promoted by (i) application of a mechanical force proximate to at least one carrier edge to impart a bending moment in the carrier; (ii) cooling the carrier when the carrier has a greater coefficient of thermal expansion than the crystalline material; and/or (iii) applying ultrasonic energy to the crystalline material.

公开(公告)号：US11024501B2

公开(公告)日：2021-06-01

申请号：US16274045

申请日：2019-02-12

Applicant: Cree, Inc.

Inventor： Matthew Donofrio ,  John Edmond ,  Hua-Shuang Kong ,  Elif Balkas

IPC: C30B33/02 ,  H01L21/18 ,  H01L21/20 ,  B23K26/00 ,  H01L21/02

Abstract: A method for removing a portion of a crystalline material (e.g., SiC) substrate includes joining a surface of the substrate to a rigid carrier (e.g., >800 μm thick), with a subsurface laser damage region provided within the substrate at a depth relative to the surface. Adhesive material having a glass transition temperature above 25° C. may bond the substrate to the carrier. The crystalline material is fractured along the subsurface laser damage region to produce a bonded assembly including the carrier and a portion of the crystalline material. Fracturing of the crystalline material may be promoted by (i) application of a mechanical force proximate to at least one carrier edge to impart a bending moment in the carrier; (ii) cooling the carrier when the carrier has a greater coefficient of thermal expansion than the crystalline material; and/or (iii) applying ultrasonic energy to the crystalline material.

公开(公告)号：US20210198804A1

公开(公告)日：2021-07-01

申请号：US17124810

申请日：2020-12-17

Applicant: Cree, Inc.

Inventor： Yuri Khlebnikov ,  Varad R. Sakhalkar ,  Caleb A. Kent ,  Valeri F. Tsvetkov ,  Michael J. Paisley ,  Oleksandr Kramarenko ,  Matthew David Conrad ,  Eugene Deyneka ,  Steven Griffiths ,  Simon Bubel ,  Adrian R. Powell ,  Robert Tyler Leonard ,  Elif Balkas ,  Jeffrey C. Seaman

IPC: C30B29/36 ,  H01L29/16 ,  H01L29/34 ,  H01L29/36 ,  H01L21/04 ,  C30B23/02 ,  C30B31/22 ,  C30B33/02

Abstract: 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.

公开(公告)号：US20200211850A1

公开(公告)日：2020-07-02

申请号：US16274045

申请日：2019-02-12

Applicant: Cree, Inc.

Inventor： Matthew Donofrio ,  John Edmond ,  Hua-Shuang Kong ,  Elif Balkas

IPC: H01L21/18 ,  H01L21/02 ,  B23K26/00 ,  H01L21/20

Abstract: A method for removing a portion of a crystalline material (e.g., SiC) substrate includes joining a surface of the substrate to a rigid carrier (e.g., >800 μm thick), with a subsurface laser damage region provided within the substrate at a depth relative to the surface. Adhesive material having a glass transition temperature above 25° C. may bond the substrate to the carrier. The crystalline material is fractured along the subsurface laser damage region to produce a bonded assembly including the carrier and a portion of the crystalline material. Fracturing of the crystalline material may be promoted by (i) application of a mechanical force proximate to at least one carrier edge to impart a bending moment in the carrier; (ii) cooling the carrier when the carrier has a greater coefficient of thermal expansion than the crystalline material; and/or (iii) applying ultrasonic energy to the crystalline material.