Fabricating a gallium nitride device with a diamond layer

• US 7,989,261 B2
• Filed: 12/22/2008
• Issued: 08/02/2011
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Bernstein, Steven D., Korenstein, Ralph, Pereira, Stephen J.
• Primary Examiner(s): Le; Dung A.
• Application Number:
  US12/341,115
• Publication Number:
  US 20100155900A1
• Time in Patent Office: 953 Days
• Field of Search: 438/105, 257/40, 257 77- 78, 257191-194, 257/280, 257/613
• US Class Current: 438/105
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02527 Carbon, e.g. diamond-like carbon
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/1602 Diamond
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/267 in different semiconductor regions , e.g. heterojunctions H01L29/263 takes precedence
• CPC Class Codes: H01L 29/66431 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT with an active layer made of a group 13/15 material H01L29/66462
• CPC Class Codes: H01L 29/66462 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 29/7786 with direct single heterostructure, i.e. with wide bandgap layer formed on top of active layer, e.g. direct single heterostructure MIS-like HEMT

Abstract

In one aspect, a method includes fabricating a device. The device includes a gallium nitride (GaN) layer, a diamond layer disposed on the GaN layer and a gate structure disposed in contact with the GaN layer and the diamond layer.

In another aspect, a device includes a gallium nitride (GaN) layer, a diamond layer disposed on the GaN layer and a gate structure disposed in contact with the GaN layer and the diamond layer.

Claims

1. A method, comprising:

fabricating a device comprising;

a gallium nitride (GaN) layer;

a first diamond layer disposed on the GaN layer; and

a gate structure disposed in contact with the GaN layer and the first diamond layer,

wherein the fabricating comprises;

depositing a first diamond layer onto a first surface of the GaN; and

disposing a second diamond layer onto a second surface of the GaN layer opposite the first surface of the GaN layer.

2. The method of claim 1 wherein the depositing comprises depositing the diamond layer onto the GaN layer using a microwave plasma chemical vapor deposition (CVD).

3. The method of claim 1 wherein the depositing comprises depositing a diamond layer that is greater than 1,000 Angstroms.

4. The method of claim 1 wherein disposing a second diamond layer onto a second surface of the GaN layer opposite the first surface of the GaN layer comprises attaching to the second surface of the GaN layer a second diamond layer having a first thermal conductivity and a third diamond layer disposed thereto having a second thermal conductivity greater than the first thermal conductivity.

5. The method of claim 1 wherein fabricating a device comprising the GaN layer comprises fabricating a device comprising a GaN layer comprising at least one of undoped GaN, doped GaN or GaN combined with another element.

6. The method of claim 1 wherein fabricating a device comprises fabricating one of a high frequency device, a high electron mobility transistor (HEMT) or a microwave device.

7. A method comprising:

disposing a diamond layer onto a first surface of gallium nitride (GaN);

removing a portion of the diamond layer exposing the first surface of the GaN;

forming a gate structure in contact with the first surface of the GaN and the diamond layer; and

attaching a second diamond layer to a second surface of the GaN opposite the first surface of the GaN.

8. The method of claim 7, further comprising fabricating at least one of a high frequency device, a high electron mobility transistor (HEMT) or a microwave device from the diamond/GaN structure.

9. The method of claim 7 wherein removing a portion of the diamond layer exposing the GaN surface comprises removing a portion of the diamond layer using oxygen plasma.

10. The method of claim 7 wherein disposing a diamond layer comprises depositing a diamond layer.

11. The method of claim 10, further comprising performing an ultrasound on the GaN immersed in a solution comprising nano-diamond particles prior to depositing the diamond layer.

12. The method of claim 7, further comprising:

growing GaN on a first substrate;

disposing a layer of material onto the GaN; and

removing the first substrate.

13. The method of claim 12 wherein growing GaN on a first substrate comprises growing GaN on one of silicon carbide, silicon or sapphire.

14. The method of claim 12 wherein disposing a layer of material onto the GaN comprises disposing one of a silicon layer or a glass layer.

15. The method of claim 12, further comprising removing the layer of material to form a diamond/GaN structure.