Method of material deposition

Patent metadata

Field	Value
Publication number	US-9978586-B2
Application number	US-201615087968-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Nov 6, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A method and apparatus for material deposition onto a sample to form a protective layer composed of at least two materials that have been formulated and arranged according to the material properties of the sample.

First claim

We claim as follows:

1. A method of charged particle beam processing of a work piece to expose for observation a region of interest, comprising:
providing, in sequence, flail first, second, and third precursor gases at the work piece;
directing a charged particle beam toward the work piece to induce deposition of a first protective layer from the first precursor gas on the work piece surface above the region of interest, the first protective layer in direct contact with the work piece surface having a sputter rate equal to the etch rate of the work piece based on first etch parameters;
directing the charged particle beam toward the work piece to induce deposition of a second protective layer from the second precursor gas, the second protective layer disposed on the first protective layer, and having a sputter rate that is different than the sputter rate of the work piece;
directing the charged particle beam toward the work piece to induce deposition of a third protective layer from the third precursor gas, the third protective layer disposed on the second protective layer, and having a sputter rate equal to the first protective layer; and
directing a second charged particle beam toward the work piece to mill through the protective layers to expose the region of interest below the first protective layer.

2. The method of claim 1 , in which the first third protective layers comprise silicon oxide.

3. The method of claim 1 , in which the second protective layer comprises tungsten, carbon, or platinum.

4. The method of claim 1 , further comprising forming a fourth protective layer on the third protective layer, the fourth protective layer being the same as the second protective layer.

5. The method of claim 1 , in which directing Hall the second charged particle beam toward the work piece to mill through the protective layers to expose the region of interest below the protective layers comprises producing a lamella having a thickness of less than 100 nm.

6. The method of claim 1 , wherein the sputter rate of the second material protective layer is lower than the sputter rate of the work piece.

7. The method of claim 1 , wherein
directing the charged particle beam toward the work piece to induce deposition of the first protective layer from the first precursor gas on the work piece surface above the region of interest comprises directing a focused electron beam toward the work piece; and
directing the charged particle beam toward the work piece to induce deposition of the second protective layer from the second precursor gas comprises directing a focused ion beam toward the work piece.

8. The method of claim 1 in which:
directing the charged particle beam toward the work piece to induce deposition of the first protective layer from the first precursor gas comprises directing an electron beam toward the work piece; and
directing the charged particle beam toward the work piece to induce deposition of the second protective layer from the second precursor gas comprises directing an ion beam toward the work piece.

9. The method of claim 1 , in which the second or third protective layer has a sputter rate that is greater than the sputter rate of the work piece.

10. The method of claim 1 , in which the second or third protective layer has a sputter rate that is less than the sputter rate of the work piece.

11. A method comprising:
providing a first precursor gas to a surface of a work piece;
depositing, in response to a first charged particle beam directed to the surface and interacting with the first precursor gas, a first protective layer on the surface, the first protective layer having an etch rate substantially similar to an etch rate of the work piece based on a first set of etch parameters;
providing a second precursor gas, different from the first precursor gas, to the surface of the work piece;
depositing, in response to a second charged particle beam directed to the surface and interacting with the second precursor gas, a second protective layer on the first protective layer, the second protective layer having an etch rate different than the etch rate of the work piece and the first protective layer based on the first set of etch parameters;
providing the first precursor gas to the surface of the work piece;
depositing, in response to the first charged particle beam directed to the surface and interacting with the first precursor gas, a third protective layer on the second protective layer, the third protective layer having an etch rate substantially similar to the etch rate of the first protective layer based on the first set of etch parameters; and
milling a lamella from the work piece that includes at least a portion of the region of interest and further includes a protective cap on at least one end of the lamella comprising the first, second, and third protective layers.

12. The method of claim 11 , wherein the first and third protective layers are formed from silicon oxide, and the second protective layer is formed from one of tungsten, carbon, and platinum.

13. The method of claim 11 , wherein the first and third protective layers are formed from one of tungsten, carbon, and platinum, and the second protective layer is formed from silicon oxide.

14. The method of claim 11 , wherein the first and third protective layers are tungsten and the second protective layer is carbon.

15. The method of claim 11 , wherein the first set of etch parameters includes a focused ion beam of less than 5 keV, performed at 10 to 45 degrees off glancing angle.

16. The method of claim 11 , wherein the first gas precursor is selected from one of TEOS, TEOS+H 2 O, TEOS+O 2 , HMCHS, HMCHS+O 2 , HMCHS/H 2 O, HMCHS/N 2 O, TMCTS, TMCTS+O 2 , TMCTS/H 2 O, and TMCTS/N 2 O.

Assignees

• Fei Co

Inventors

• Routh Jr Brian Roberts
• Miller Thomas G
• Rue Chad
• Franco Noel Thomas

Classifications

• H10P14/6684

  the compound comprising silicon and oxygen · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6548

  by forming intermediate materials, e.g. capping layers or diffusion barriers · CPC title

• H10P14/6329 Primary

  using physical ablation of a target, e.g. physical vapour deposition or pulsed laser deposition · CPC title

• C23C14/048 Primary

  using irradiation by energy or particles · CPC title