Scott Mitchell Allen

US Patent:

6486502, Nov 26, 2002

Filed:

Feb 16, 2001

Appl. No.:

09/701951

Inventors:

Scott Thomas Sheppard - Chapel Hill NC
Scott Thomas Allen - Apex NC
John Williams Palmour - Raleigh NC

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 2976

US Classification:

257194, 257195

Abstract:

A high electron mobility transistor (HEMT) ( ) is disclosed that includes a semi-insulating silicon carbide substrate ( ), an aluminum nitride buffer layer ( ) on the substrate, an insulating gallium nitride layer ( ) on the buffer layer, an active structure of aluminum gallium nitride ( ) on the gallium nitride layer, a passivation layer ( ) on the aluminum gallium nitride active structure, and respective source, drain and gate contacts ( ) to the aluminum gallium nitride active structure.

US Patent:

6583454, Jun 24, 2003

Filed:

Mar 29, 2001

Appl. No.:

09/821360

Inventors:

Scott Thomas Sheppard - Chapel Hill NC
Scott Thomas Allen - Apex NC
John Williams Palmour - Raleigh NC

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 310328

US Classification:

257194, 257190, 257192

Abstract:

A high electron mobility transistor (HEMT) is disclosed that includes a semi-insulating silicon carbide substrate, an aluminum nitride buffer layer on the substrate, an insulating gallium nitride layer on the buffer layer, an active structure of aluminum gallium nitride on the gallium nitride layer, a passivation layer on the aluminum gallium nitride active structure, and respective source, drain and gate contacts to the aluminum gallium nitride active structure.

US Patent:

7592211, Sep 22, 2009

Filed:

Jan 17, 2006

Appl. No.:

11/333726

Inventors:

Scott T. Sheppard - Chapel Hill NC, US
Scott Allen - Apex NC, US

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 21/338

US Classification:

438172, 438182, 257E21403

Abstract:

Transistors are fabricated by forming a protective layer having an opening extending therethrough on a substrate, and forming a gate electrode in the opening. A first portion of the gate electrode laterally extends on surface portions of the protective layer outside the opening, and a second portion of the gate electrode is spaced apart from the protective layer and laterally extends beyond the first portion. Related devices and fabrication methods are also discussed.

US Patent:

7858460, Dec 28, 2010

Filed:

Mar 16, 2009

Appl. No.:

12/404557

Inventors:

Zoltan Ring - Chapel Hill NC, US
Helmut Hagleitner - Zebulon NC, US
Jason Patrick Henning - Carrboro NC, US
Andrew Mackenzie - Cary NC, US
Scott Allen - Apex NC, US
Scott Thomas Sheppard - Chapel Hill NC, US
Richard Peter Smith - Carrboro NC, US
Saptharishi Sriram - Cary NC, US
Allan Ward, III - Durham NC, US

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 21/336
H01L 21/8234

US Classification:

438197, 257E21177

Abstract:

A passivated semiconductor structure and associated method are disclosed. The structure includes a silicon carbide substrate or layer; an oxidation layer on the silicon carbide substrate for lowering the interface density between the silicon carbide substrate and the thermal oxidation layer; a first sputtered non-stoichiometric silicon nitride layer on the thermal oxidation layer for reducing parasitic capacitance and minimizing device trapping; a second sputtered non-stoichiometric silicon nitride layer on the first layer for positioning subsequent passivation layers further from the substrate without encapsulating the structure; a sputtered stoichiometric silicon nitride layer on the second sputtered layer for encapsulating the structure and for enhancing the hydrogen barrier properties of the passivation layers; and a chemical vapor deposited environmental barrier layer of stoichiometric silicon nitride for step coverage and crack prevention on the encapsulant layer.

US Patent:

7960756, Jun 14, 2011

Filed:

May 19, 2009

Appl. No.:

12/468537

Inventors:

Scott T. Sheppard - Chapel Hill NC, US
Scott Allen - Apex NC, US

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 29/778

US Classification:

257192, 257194, 257284, 257E29246

Abstract:

A transistor includes a protective layer having an opening extending therethrough on a substrate, and a gate electrode in the opening. First portions of the gate electrode laterally extend on surface portions of the protective layer outside the opening on opposite sides thereof, and second portions of the gate electrode are spaced apart from the protective layer and laterally extend beyond the first portions. Related devices are also discussed.

US Patent:

8618582, Dec 31, 2013

Filed:

Sep 11, 2011

Appl. No.:

13/229750

Inventors:

Jason Patrick Henning - Carrboro NC, US
Qingchun Zhang - Cary NC, US
Anant Agarwal - Chapel Hill NC, US
John Williams Palmour - Cary NC, US
Scott Allen - Apex NC, US

Assignee:

Cree, Inc. - Durham NC

International Classification:

H01L 29/66

US Classification:

257267, 257155, 257454, 257E33051, 257E27068

Abstract:

Elements of an edge termination structure, such as multiple concentric guard rings, are effectively doped regions in a drift layer. To increase the depth of these doped regions, individual recesses may be formed in a surface of the drift layer where the elements of the edge termination structure are to be formed. Once the recesses are formed in the drift layer, these areas about and at the bottom of the recesses are doped to form the respective edge termination elements.

US Patent:

20030201459, Oct 30, 2003

Filed:

May 19, 2003

Appl. No.:

10/440727

Inventors:

Scott Sheppard - Chapel Hill NC, US
Scott Allen - Apex NC, US
John Palmour - Raleigh NC, US

International Classification:

H01L031/0328
H01L031/0336

US Classification:

257/194000

Abstract:

A high electron mobility transistor (HEMT) is disclosed that includes a semi-insulating silicon carbide substrate, an aluminum nitride buffer layer on the substrate, an insulating gallium nitride layer on the buffer layer, an active structure of aluminum gallium nitride on the gallium nitride layer, a passivation layer on the aluminum gallium nitride active structure, and respective source, drain and gate contacts to the aluminum gallium nitride active structure.

US Patent:

20070018199, Jan 25, 2007

Filed:

Jul 20, 2005

Appl. No.:

11/185398

Inventors:

Scott Sheppard - Chapel Hill NC, US
Andrew Mackenzie - Cary NC, US
Scott Allen - Apex NC, US
Richard Smith - Carrboro NC, US

International Classification:

H01L 31/00

US Classification:

257200000

Abstract:

A III-Nitride field-effect transistor, specifically a HEMT, comprises a channel layer, a barrier layer on the channel layer, an etch stop layer on the cap layer, a dielectric layer on the etch stop layer, a gate recess that extends to the barrier layer, and a gate contact in the gate recess. The etch stop layer may reduce damage associated with forming the recessed gate by not exposing the barrier layer to dry etching. The etch stop layer in the recess is removed and the remaining etch stop layer serves as a passivation layer.