IP Library › Granted Patent US 12,484,244
Granted Patent B2
US 12,484,244 · App. 17/172,669 · Granted Nov 25, 2025

Group III-nitride high-electron mobility transistors with gate connected buried p-type layers and process for making the same

Inventors: Saptharishi Sriram (Cary, NC); Jia Guo (Apex, NC)
Assignee: Wolfspeed, Inc.
H10D30/475H10D30/015H10D30/4732H10D30/4755H10D62/357H10D62/8503H10D64/111H10D64/251H10D64/411H10D62/343H10D64/256
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Quick Facts
Patent No.
US 12,484,244
App. No.
17/172,669
Granted
Nov 25, 2025
Kind
B2
Abstract

An apparatus to address gate lag effect and/or other negative performance includes a substrate; a group III-Nitride buffer layer on the substrate; a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer may include a higher bandgap than a bandgap of the group III-Nitride buffer layer; a source electrically coupled to the group III-Nitride barrier layer; a gate electrically coupled to the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; and a p-region being arranged at least in the substrate. In particular, the p-region extends toward a source side of the substrate; and the p-region extends toward a drain side of the substrate.

Claims (104)

1 . An apparatus, comprising:

a substrate;

a group III-Nitride buffer layer on the substrate;

a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

a source electrically coupled to the group III-Nitride barrier layer;

a gate coupled to the group III-Nitride barrier layer;

a drain electrically coupled to the group III-Nitride barrier layer; and

a p-region being arranged at least in the substrate,

wherein the p-region extends toward a source side of the substrate;

wherein the p-region extends toward a drain side of the substrate;

wherein a portion of the substrate includes the p-region located along a vertical axis below the source; and

wherein another portion of the substrate does not include the p-region located along another vertical axis below the source.

2 . The apparatus of claim 1 , wherein:

a part of the source side of the substrate is free of the p-region; and

a part of the drain side of the substrate is free of the p-region.

3 . An apparatus, comprising:

a substrate;

a group III-Nitride buffer layer on the substrate;

a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

a source electrically coupled to the group III-Nitride barrier layer;

a gate coupled to the group III-Nitride barrier layer;

a drain electrically coupled to the group III-Nitride barrier layer;

a p-region being arranged at least in the substrate; and

a connection to the p-region that is electrically connected to the gate,

wherein the p-region extends toward a source side of the substrate; and

wherein the p-region extends toward a drain side of the substrate.

4 . The apparatus of claim 1 , further comprising a connection to the p-region that is electrically connected to a contact separate from the gate, the source, and the drain to receive an external signal or bias.

5 . The apparatus of claim 1 , further comprising a connection to the p-region that is electrically connected to a contact separate from the gate, the source, and the drain that is electrically connected to a radiofrequency circuit.

6 . The apparatus of claim 1 wherein:

a distance LGD is a distance from a lower corner of the gate on the drain side to a lower corner of the drain on a gate side;

a distance LGS is a distance from a lower corner of the gate on the source side to a lower corner of the source on a gate side; and

the distance LGD greater than the distance LGS.

7 . A method of making a device comprising:

providing a substrate;

providing a group III-Nitride buffer layer on the substrate;

providing a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

electrically coupling a source to the group III-Nitride barrier layer;

coupling a gate to the group III-Nitride barrier layer;

electrically coupling a drain to the group III-Nitride barrier layer; and

providing a p-region being arranged at least in the substrate,

wherein the p-region extends toward a source side of the substrate;

wherein the p-region extends toward a drain side of the substrate;

wherein a portion of the substrate includes the p-region located along a vertical axis below the source; and

wherein another portion of the substrate does not include the p-region located along another vertical axis below the source.

8 . The method of making the device of claim 7 , wherein:

a part of the source side of the substrate is free of the p-region; and

a part of the drain side of the substrate is free of the p-region.

9 . A method of making a device comprising:

providing a substrate;

providing a group III-Nitride buffer layer on the substrate;

providing a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

electrically coupling a source to the group III-Nitride barrier layer;

coupling a gate to the group III-Nitride barrier layer;

electrically coupling a drain to the group III-Nitride barrier layer;

providing a p-region being arranged at least in the substrate; and

forming a connection to the p-region that is electrically connected to the gate,

wherein the p-region extends toward a source side of the substrate; and

wherein the p-region extends toward a drain side of the substrate.

10 . The method of making the device of claim 7 , further comprising forming a connection to the p-region that is electrically connected to a contact separate from the gate, the source, and the drain to receive an external signal or bias.

11 . The method of making the device of claim 7 , further comprising forming a connection to the p-region that is electrically connected to a contact separate from the gate, the source, and the drain that is electrically connected to a radiofrequency circuit.

12 . The method of making the device of claim 7 wherein:

a distance LGD is a distance from a lower corner of the gate on the drain side to a lower corner of the drain on a gate side;

a distance LGS is a distance from a lower corner of the gate on the source side to a lower corner of the source on a gate side; and

the distance LGD greater than the distance LGS.

13 . An apparatus, comprising:

a substrate;

a group III-Nitride buffer layer on the substrate;

a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

a source electrically coupled to the group III-Nitride barrier layer;

a gate coupled to the group III-Nitride barrier layer;

a drain electrically coupled to the group III-Nitride barrier layer;

a p-region being arranged at least in the substrate; and

a connection to the p-region that is electrically connected to a contact separate from the gate, the source, and the drain to receive an external signal or bias,

wherein a part of a source side of the substrate is free of the p-region;

wherein a part of a drain side of the substrate is free of the p-region;

wherein the substrate does not include the p-region located within the substrate vertically below the source; and

wherein the substrate does not include the p-region located vertically below the drain.

14 . The apparatus of claim 13 , wherein the p-region is structured and arranged such that no portion of the p-region is located vertically below the drain.

15 . An apparatus, comprising:

a substrate;

a group III-Nitride buffer layer on the substrate;

a group III-Nitride barrier layer on the group III-Nitride buffer layer, the group III-Nitride barrier layer comprising a higher bandgap than a bandgap of the group III-Nitride buffer layer;

a source electrically coupled to the group III-Nitride barrier layer;

a gate coupled to the group III-Nitride barrier layer;

a drain electrically coupled to the group III-Nitride barrier layer; and

a p-region being arranged at least in the substrate; and

a connection to the p-region that is electrically connected to the gate,

wherein a part of a source side of the substrate is free of the p-region; and

wherein a part of a drain side of the substrate is free of the p-region.

16 . The apparatus of claim 13 , wherein the contact is electrically connected to a radiofrequency circuit.

17 . The apparatus of claim 13 wherein:

a distance LGD is a distance from a lower corner of the gate on the drain side to a lower corner of the drain on a gate side;

a distance LGS is a distance from a lower corner of the gate on the source side to a lower corner of the source on a gate side; and

the distance LGD greater than the distance LGS.

18 . The apparatus of claim 13 wherein:

a distance LGPS defines a length of a portion of the p-region from a lower corner of the gate on the source side to a lower corner of the source;

a distance LGPD defines a length of a portion of the p-region from a lower corner of the gate on the drain side to a lower corner of the drain; and

the distance LGPS being equal to the distance LGPD.

19 . The apparatus of claim 13 wherein:

a distance LGPS defines a length of a portion of the p-region from a lower corner of the gate on the source side to a lower corner of the source;

a distance LGPD defines a length of a portion of the p-region from a lower corner of the gate on the drain side to a lower corner of the drain; and

the distance LGPS greater than the distance LGPD.

20 . The apparatus of claim 1 , wherein the p-region is partially under the source.

21 . The method of making the device of claim 7 , wherein the p-region is partially under the source.

Assignments (9)
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Mar 26, 2026
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 075280/0919 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0113 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0381 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0467 →
NOTICE OF GRANT OF SECURITY INTEREST IN INTELLECTUAL PROPERTY Recorded Sep 30, 2025
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 072992/0588 →
RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY COLLATERAL AT REEL/FRAME NO. 64185/0755 Recorded Sep 30, 2025
From: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: WOLFSPEED, INC.
Reel/Frame 072989/0001 →
SECURITY INTEREST Recorded Jun 30, 2023
From: WOLFSPEED, INC.
To: U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 064185/0755 →
CHANGE OF NAME Recorded Feb 14, 2022
From: CREE, INC.
To: WOLFSPEED, INC.
Reel/Frame 059085/0667 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 19, 2021
From: SRIRAM, SAPTHARISHI; GUO, JIA
To: CREE, INC.
Reel/Frame 055649/0251 →
Continuity (6)
Continuation In Part 17123727 · Dec 16, 2020
Division 16376596 · Apr 5, 2019
Continuation In Part 16260095 · Jan 28, 2019
Continuation In Part 15424209 · Feb 3, 2017
Continuation In Part 15192545 · Jun 24, 2016
Related Publication 20210167199A1 · Jun 3, 2021
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