公开(公告)号：US11837657B2

公开(公告)日：2023-12-05

申请号：US18109933

申请日：2023-02-15

Applicant: Wolfspeed, Inc.

Inventor： Naeem Islam ,  Woongsun Kim ,  Daniel J. Lichtenwalner ,  Sei-Hyung Ryu

IPC: H01L29/78 ,  H01L29/66 ,  H01L29/16

CPC classification number: H01L29/7813 ,  H01L29/1608 ,  H01L29/66727 ,  H01L29/66734

Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.

公开(公告)号：US20240429323A1

公开(公告)日：2024-12-26

申请号：US18340418

申请日：2023-06-23

Applicant: Wolfspeed, Inc.

Inventor： Jae-Hyung Park ,  In-Hwan Ji ,  Daniel J. Lichtenwalner ,  Edward Robert Van Brunt

IPC: H01L29/872 ,  H01L29/16 ,  H01L29/36

Abstract: A Schottky diode includes a semiconductor layer structure that is interposed between first and second contacts. The semiconductor layer structure comprises a current spreading layer having a first conductivity type, a drift region between the second contact and the current spreading layer, the drift region having the first conductivity type, and a first blocking junction having a second conductivity type that is opposite the first conductivity type, the first blocking junction extending downwardly from an upper surface of the semiconductor layer structure. The current spreading layer has a first conductivity type dopant concentration that is at least 1.5 times greater than a first conductivity type dopant concentration of the drift region and the current spreading layer vertically overlaps at least a portion of a lower half of the first blocking junction.

公开(公告)号：US20230207686A1

公开(公告)日：2023-06-29

申请号：US18109933

申请日：2023-02-15

Applicant: Wolfspeed, Inc.

Inventor： Naeem Islam ,  Woongsun Kim ,  Daniel J. Lichtenwalner ,  Sei-Hyung Ryu

IPC: H01L29/78 ,  H01L29/66 ,  H01L29/16

CPC classification number: H01L29/7813 ,  H01L29/66734 ,  H01L29/1608 ,  H01L29/66727

Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.

公开(公告)号：US20220165862A1

公开(公告)日：2022-05-26

申请号：US17668448

申请日：2022-02-10

Applicant: Wolfspeed, Inc.

Inventor： Daniel J. Lichtenwalner

IPC: H01L29/51 ,  H01L29/78 ,  H01L29/16 ,  H01L29/40

Abstract: A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.

公开(公告)号：US11837629B2

公开(公告)日：2023-12-05

申请号：US16952757

申请日：2020-11-19

Applicant: Wolfspeed, Inc.

Inventor： Daniel J. Lichtenwalner ,  Edward R. Van Brunt ,  Brett Hull

IPC: H01L29/06 ,  H01L29/10 ,  H01L29/78 ,  H01L21/04 ,  H01L29/66 ,  H01L29/739 ,  H01L29/16 ,  H01L29/08

CPC classification number: H01L29/063 ,  H01L21/046 ,  H01L29/0623 ,  H01L29/1095 ,  H01L29/66068 ,  H01L29/66734 ,  H01L29/7397 ,  H01L29/7811 ,  H01L29/7813 ,  H01L29/0615 ,  H01L29/0619 ,  H01L29/0696 ,  H01L29/0878 ,  H01L29/1037 ,  H01L29/1608

Abstract: Semiconductor devices include a semiconductor layer structure comprising a drift region that includes a wide band-gap semiconductor material. A shielding pattern is provided in an upper portion of the drift region in an active region of the device and a termination structure is provided in the upper portion of the drift region in a termination region of the device. A gate trench extends into an upper surface of the semiconductor layer structure. The semiconductor layer structure includes a semiconductor layer that extends above and at least partially covers the termination structure.

公开(公告)号：US11355630B2

公开(公告)日：2022-06-07

申请号：US17018305

申请日：2020-09-11

Applicant: Wolfspeed, Inc.

Inventor： Woongsun Kim ,  Daniel J. Lichtenwalner ,  Naeem Islam ,  Sei-Hyung Ryu

IPC: H01L29/78 ,  H01L29/66 ,  H01L29/423 ,  H01L29/417

Abstract: Semiconductor devices and methods of forming a semiconductor device that includes a polysilicon layer that may improve device reliability and/or a functioning of the device. An example device may include a wide band-gap semiconductor layer structure including a drift region that has a first conductivity type; a plurality of gate trenches in an upper portion of the semiconductor layer structure, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; and a plurality of polysilicon layers, each polysilicon layer on the second sidewall of a respective gate trench.

公开(公告)号：US20240413197A1

公开(公告)日：2024-12-12

申请号：US18813208

申请日：2024-08-23

Applicant: Wolfspeed, Inc.

Inventor： Daniel J. Lichtenwalner ,  Naeem Islam ,  Woongsun Kim ,  Sei-Hyung Ryu

IPC: H01L29/06 ,  H01L21/04 ,  H01L29/10 ,  H01L29/16 ,  H01L29/66 ,  H01L29/78

Abstract: devices and methods of forming a semiconductor device that includes a deep shielding pattern that may improve a reliability and/or a functioning of the device. An example method may include forming a wide band-gap semiconductor layer structure on a substrate, the semiconductor layer structure including a drift region that has a first conductivity type; forming a plurality of gate trenches in an upper portion of the semiconductor layer structure, the gate trenches spaced apart from each other, each gate trench having a bottom surface, a first sidewall, a second sidewall, and an upper opening; forming an obstruction over a portion of each gate trench that partially obscures the upper opening; and implanting dopants having a second conductivity type that is opposite the first conductivity type into the bottom surfaces of the gate trenches, where the dopants implanted into the bottom surface of the gate trenches form deep shielding patterns.

公开(公告)号：US11929420B2

公开(公告)日：2024-03-12

申请号：US17668448

申请日：2022-02-10

Applicant: Wolfspeed, Inc.

Inventor： Daniel J. Lichtenwalner

IPC: H01L29/51 ,  H01L29/16 ,  H01L29/40 ,  H01L29/78

CPC classification number: H01L29/513 ,  H01L29/1608 ,  H01L29/401 ,  H01L29/7803 ,  H01L29/7813 ,  H01L29/517

Abstract: A semiconductor device includes a semiconductor layer structure that comprises silicon carbide, a gate dielectric layer on the semiconductor layer structure, the gate dielectric layer including a base gate dielectric layer that is on the semiconductor layer structure and a capping gate dielectric layer on the base gate dielectric layer opposite the semiconductor layer structure, and a gate electrode on the gate dielectric layer opposite the semiconductor layer structure. A dielectric constant of the capping gate dielectric layer is higher than a dielectric constant of the base gate dielectric layer.

公开(公告)号：US11791378B2

公开(公告)日：2023-10-17

申请号：US17371514

申请日：2021-07-09

Applicant: Wolfspeed, Inc.

Inventor： Edward Robert Van Brunt ,  Alexander V. Suvorov ,  Vipindas Pala ,  Daniel J. Lichtenwalner ,  Qingchun Zhang

IPC: H01L29/06 ,  H01L29/16 ,  H01L29/04 ,  H01L29/66 ,  H01L29/872 ,  H01L21/04 ,  H01L29/78 ,  H01L29/10

CPC classification number: H01L29/0634 ,  H01L21/047 ,  H01L29/045 ,  H01L29/0619 ,  H01L29/1608 ,  H01L29/6606 ,  H01L29/7802 ,  H01L29/872 ,  H01L29/0692 ,  H01L29/1095

Abstract: Semiconductor devices include a silicon carbide drift region having an upper portion and a lower portion. A first contact is on the upper portion of the drift region and a second contact is on the lower portion of the drift region. The drift region includes a superjunction structure that includes a p-n junction that is formed at an angle of between 10° and 30° from a plane that is normal to a top surface of the drift region. The p-n junction extends within +/−1.5° of a crystallographic axis of the silicon carbide material forming the drift region.

公开(公告)号：US11610991B2

公开(公告)日：2023-03-21

申请号：US17082647

申请日：2020-10-28

Applicant: Wolfspeed, Inc.

Inventor： Naeem Islam ,  Woongsun Kim ,  Daniel J. Lichtenwalner ,  Sei-Hyung Ryu

IPC: H01L29/78 ,  H01L29/66 ,  H01L29/16

Abstract: A power semiconductor device comprises a semiconductor layer structure having a wide band-gap drift region having a first conductivity type, a gate trench having first and second opposed sidewalls that extend in a first direction in an upper portion of the semiconductor layer structure, first and second well regions having a second conductivity type in the upper portion of the semiconductor layer structure, the first well region comprising part of the first sidewall and the second well region comprising part of the second sidewall. A deep shielding region having the second conductivity type is provided underneath the gate trench, and a plurality of deep shielding connection patterns that have the second conductivity type are provided that electrically connect the deep shielding region to the first and second well regions. The deep shielding connection patterns are spaced apart from each other along the first direction.