High-electron-mobility transistor with field plate and sidewall spacers

Patent metadata

Field	Value
Publication number	US-12538550-B2
Application number	US-202218075930-A
Country	US
Kind code	B2
Filing date	Dec 6, 2022
Priority date	Dec 6, 2022
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

The present disclosure relates to semiconductor structures and, more particularly, to a high-electron-mobility transistor (HEMT) and methods of manufacture. The structure includes: a gate structure; a source contact and a drain contact adjacent to the gate structure; and a field plate electrically isolated from the gate structure and abutting the source contact and the drain contact.

First claim

What is claimed:

1 . A structure comprising:
a gate structure comprising semiconductor material and conductive material; a gate contact metal contacting the conductive material; a sidewall spacer above the conductive material and surrounding the gate contact metal; a source contact and a drain contact adjacent to the gate structure; and a field plate electrically isolated from the gate structure by the sidewall spacer surrounding the gate contact metal, and the field plate physically contacting the source contact and the drain contact.

2 . The structure of claim 1 , wherein the gate contact metal is electrically connected to the gate structure, and the field plate is electrically isolated from and below a top surface of the gate contact metal.

3 . The structure of claim 2 , wherein the sidewall spacer is on a sidewall of the gate contact metal, and the gate contact metal comprising an upper portion and a lower portion, the upper being wider than the lower portion and the field plate is electrically isolated from the gate contact by the sidewall spacer at the lower portion, below the upper portion.

4 . The structure of claim 3 , wherein the field plate abuts the sidewall spacer.

5 . The structure of claim 1 , wherein the gate structure comprises pGaN material.

6 . The structure of claim 5 , wherein the source contact and the drain contact connect to a source region and a drain region, respectively, comprising AlGaN/GaN material.

7 . The structure of claim 6 , wherein the field plate is separated from the source region and the drain region by a passivation layer and comprises a stepped feature above the passivation layer.

8 . The structure of claim 1 , wherein the field plate surrounds the source contact and the drain contact.

9 . The structure of claim 1 , wherein the source contact and the drain contact comprise ohmic contacts physically contacting to a source region and a drain region, respectively, and comprising AlGaN/GaN material.

10 . The structure of claim 1 , wherein the field plate is a common patterned field plate contacting the source contact and the drain contact and abutting a sidewall spacer of a gate contact.

11 . A structure comprising:
a gate structure; a gate metal contact electrically connecting to the gate structure; a source contact connecting to a source region of the gate structure; a drain contact connecting to a drain region of the gate structure; and a field plate electrically isolated from the gate metal contact and contacting the source contact and the drain contact by a sidewall spacer surrounding the gate metal contact.

12 . The structure of claim 11 , wherein the sidewall spacer is on sidewalls of the gate metal contact.

13 . The structure of claim 12 , wherein the field plate field plate contacts the sidewall spacer, and the gate metal contact comprises an upper portion and a lower portion, the upper being wider than the lower portion and the field plate is electrically isolated from the gate contact by the sidewall spacer at the lower portion, below the upper portion.

14 . The structure of claim 11 , wherein the gate structure comprises pGaN material, and the source region and the drain region comprise AlGaN/GaN material.

15 . The structure of claim 14 , wherein the field plate is separated from the source region and the drain region by a passivation layer, and the field plate includes a stepped feature above the passivation layer.

16 . The structure of claim 14 , wherein the source contact and the drain contact comprise ohmic contacts physically contacting the source region and the drain region, respectively.

17 . The structure of claim 11 , wherein the field plate surrounds the source contact and the drain contact.

18 . The structure of claim 11 , wherein the field plate is a common patterned field plate contacting the source contact and the drain contact and separated from the gate contact on at least one side.

19 . The structure of claim 11 , wherein a gap is provided in the field plate between the source contact, the drain contact and the gate structure.

20 . A method comprising:
forming a gate structure comprising semiconductor material and conductive material; forming a gate contact metal contacting the conductive material; forming a sidewall spacer above the conductive material and surrounding the gate contact metal; forming a source contact and a drain contact adjacent to the gate structure; and forming a field plate electrically isolated from the gate structure by the sidewall spacer surrounding the gate contact metal, and the field plate physically contacting the source contact and the drain contact.

Assignees

• Globalfoundries Us Inc

Inventors

• Sharma Santosh
• Zierak Michael J
• Bentley Steven J
• Levy Mark D

Classifications

• H10D64/01

  Manufacture or treatment · CPC title

• H10D62/8503

  Nitride Group III-V materials, e.g. AlN or GaN · CPC title

• H10D62/824

  comprising only Group III-V materials heterojunctions, e.g. GaN/AlGaN heterojunctions · CPC title

• H10D30/475 Primary

  having wider bandgap layer formed on top of lower bandgap active layer, e.g. undoped barrier HEMTs such as i-AlGaN/GaN HEMTs · CPC title

• H10D30/015

  of FETs having heterojunction interface channels or heterojunction gate electrodes, e.g. HEMT · CPC title