Method of fabricating electrically isolated diamond nanowires and its application for nanowire MOSFET

Patent metadata

Field	Value
Publication number	US-10636880-B2
Application number	US-201816198274-A
Country	US
Kind code	B2
Filing date	Nov 21, 2018
Priority date	Jan 31, 2018
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

A method for fabricating an electrically isolated diamond nanowire includes forming a diamond nanowire on a diamond substrate, depositing a dielectric or a polymer on the diamond nanowire and on the diamond substrate, planarizing the dielectric or the polymer, etching a portion of the planarized dielectric or polymer to expose a first portion of the diamond nanowire, depositing a metal layer to conformably cover the first portion of the diamond nanowire, and implanting ions into a second portion of the diamond nanowire between the first portion of the diamond nanowire and the diamond substrate or at an intersection of the diamond nanowire and the diamond substrate, wherein the ions are implanted at an oblique angle from a first side of the diamond nanowire.

First claim

What is claimed is:

1. A method for fabricating an electrically isolated diamond nanowire comprising:
forming a diamond nanowire on a diamond substrate;
depositing a dielectric or a polymer on the diamond nanowire and on the diamond substrate;
planarizing the dielectric or the polymer;
etching a portion of the planarized dielectric or polymer to expose a top portion of the diamond nanowire;
depositing a metal layer to conformably cover the top portion of the diamond nanowire; and
implanting ions into the diamond substrate below an intersection of the diamond nanowire and the diamond substrate;
wherein the ions are implanted at an oblique angle from a side of the diamond nanowire;
wherein the top portion of the diamond nanowire covered by the metal layer is not implanted with the ions; and
wherein the ions implanted into the diamond substrate electrically isolate the diamond nanowire from the diamond substrate.

2. The method of claim 1 further comprising:
removing the dielectric or polymer before implanting ions.

3. The method of claim 1 further comprising:
depositing by atomic layer deposition (ALD), chemical vapor deposition (CVD), or physical vapor deposition (PVD), a second dielectric on the diamond nanowire to protect a surface of the diamond nanowire before depositing the dielectric or the polymer on the diamond nanowire and on the diamond substrate.

4. The method of claim 1 further comprising:
patterning and etching the metal layer.

5. The method of claim 1 wherein the dielectric or the polymer is a polydimethylglutarimide resist coating or a spin on glass coating.

6. The method of claim 1 wherein planarizing the dielectric or the polymer comprises chemical mechanical polishing, or dry etching.

7. The method of claim 2 wherein removing the dielectric or polymer comprises an isotropic etch so that no dielectric or polymer material remains underneath the metal layer.

8. The method of claim 1 :
wherein the metal layer comprises a tungsten layer, bismuth, molybdenum, or tin.

9. The method of claim 8 wherein the tungsten layer is at least 200 nm thick.

10. The method of claim 1 :
wherein the implanted ions comprise N 2 , argon, hydrogen, helium or another inert gases.

11. The method of claim 1 further comprising removing the metal layer.

12. The method of claim 1 wherein the ions are implanted at an oblique angle from a first side and a second side of the diamond nanowire.

13. The method of claim 1 wherein the diamond nanowire is a channel for a field effect transistor.

14. The method of claim 13 further comprising:
depositing a third dielectric over the channel;
forming a gate over the third dielectric;
forming a drain for the field effect transistor on the diamond substrate and coupled to a first end of the diamond nanowire; and
forming a source for the field effect transistor on the diamond substrate and coupled to a second end of the diamond nanowire;
wherein the third dielectric insulates the gate from the channel.

15. A method for fabricating an electrically isolated diamond nanowire comprising:
providing a diamond substrate;
forming a diamond nanowire on the diamond substrate;
depositing a metal layer to conformally cover a top portion of the diamond nanowire; and
implanting ions in the diamond nanowire below an intersection of the diamond nanowire and the diamond substrate;
wherein the ions are implanted at an oblique angle from a side of the diamond nanowire;
wherein the top portion of the diamond nanowire covered by the metal layer is not implanted with the ions; and
wherein the ions implanted into the diamond substrate electrically isolate the diamond nanowire from the diamond substrate.

16. The method of claim 15 :
wherein the metal layer comprises a tungsten layer, bismuth, molybdenum, or tin.

Assignees

• Hrl Lab Llc

Inventors

• Huang Biqin
• Bai Xiwei

Classifications

• H10P30/2044

  into semiconducting carbon, e.g. diamond or semiconducting diamond-like carbon · CPC title

• H10P30/222

  characterised by the angle between the ion beam and the crystal planes or the main crystal surface (characterised by the angle between the ion beam and the mask H10P30/221) · CPC title

• H10P30/22

  using masks · CPC title

• H10P14/3462

  Nanowires · CPC title

• H10P14/2903

  Carbon, e.g. diamond-like carbon · CPC title