Method and System of Creating a Symmetrical FIB Deposition

• US 20150369710A1
• Filed: 10/27/2014
• Published: 12/24/2015
• Est. Priority Date: 06/24/2014
• Status: Abandoned Application

• Current Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Original Assignee: FEI Company (Thermo Fisher Scientific Incorporated)
• Inventors: Fuller, Scott Edward, Sidorov, Oleg
• Application Number:
  US14/524,315
• Publication Number:
  US 20150369710A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 16/486 using ion beam radiation
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: G01N 1/32 Polishing; Etching
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: H01J 2237/3109 Cutting
• CPC Class Codes: H01J 2237/31732 Depositing thin layers on selected microareas
• CPC Class Codes: H01J 2237/31749 Focused ion beam
• CPC Class Codes: H01J 37/3056 for microworking, e. g. etching of gratings or trimming of electrical components
• CPC Class Codes: H01J 37/317 for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation H01J37/36 takes precedence
• CPC Class Codes: H01J 37/3178 for applying thin layers on objects

Abstract

A system is provided to produce symmetric depositions using a charged-particle beam deposition with an angled beam. In the past, the use of an FIB with non-orthogonal incidence angles produced depositions that grew toward the FIB beam path making it difficult to produce uniformity of the deposit. With the current invention, a symmetrical deposition is made even with the use of a non-orthogonal FIB.

Claims

1. A method of forming a TEM sample lamella having a uniform deposition using a focused ion beam comprising

directing a focused ion beam toward a work piece surface at an angle of greater than 30 degrees from a surface normal, the charged particles having a landing energy of 10 keV or less;

providing a carbon precursor gas at the impact point of the charged particle beam, the carbon precursor gas decomposing in the presence of the ion beam to deposit carbon onto the work piece; and

directing a focused ion beam toward the deposited material on the work piece to remove material from both sides of a region of interest to leave a thin lamella containing the region of interest, the deposited carbon protecting the thin lamella during formation.

2. The method of claim 1 in which directing a focused ion beam toward a work piece surface comprises scanning the focused ion beam in a direction along a normal projection of the beam onto the work piece.

3. The method of claim 1 in which providing a precursor gas at the impact point of the charged particle beam comprises providing a metallo-organic compound.

4. The method of claim 1 in which directing a focused ion beam toward a work piece surface comprises directing a focused ion beam toward the work piece surface at an incident angle of greater than 40 degrees from a surface normal, the ions in the beam having landing energies of 8 keV or less.

5. The method of claim 1 in which directing a focused ion beam toward a work piece surface comprises directing a focused ion beam toward the work piece surface at an incident angle of 45 degrees+/−

5 degrees from a surface normal, the ions in the beam having landing energies of between 3 keV and 7 keV.

13. A charged particle beam system for processing a work piece, comprising:

an ion beam column oriented at least 30 degrees from the vertical;

an electron beam column oriented at least 30 degrees from the vertical;

a gas injection system for directing a precursor gas to be decomposed by the ion beam or the electron beam;

a sample stage, the sample stage capable of moving in at least two dimensions and of rotating about a vertical axis, but incapable of tilting;

a controller for controlling the operation of the charged particle beam system in accordance with stored instructions; and

a memory for storing computer instructions for performing the method of claim 1.

14. The apparatus of claim 13 in which the ion beam column is oriented at least 45 degrees plus or minus 10% from the vertical.

15. The apparatus of claim 13 in which the ion beam column includes a liquid metal ion source.

16. The apparatus of claim 13 in which the ion beam column includes a plasma ion source.

6. A method of ion beam-induced deposition, comprising:

directing an ion beam toward a work piece surface at an angle of greater than 30 degrees from a surface normal, the ions in the beam having landing energies of 10 keV or less; and

providing a precursor gas at the impact point of the ion beam, the precursor gas decomposing in the presence of the ion beam to deposit material onto the work piece.

7. The method of claim 6 in which directing an ion beam toward a work piece surface comprises scanning the ion beam primarily in a direction along a normal projection of the ion beam onto the work piece.

8. The method of claim 6 in which providing a precursor gas at the impact point of the ion beam comprises providing a precursor gas that does not contain metal and that deposits carbon onto the work piece surface in the presence of the ion beam.

9. The method of claim 6 in which providing a precursor gas at the impact point of the ion beam comprises providing a metallo-organic compound.

10. The method of claim 6 in which directing an ion beam toward a work piece surface comprises directing the ion toward the work piece surface at an incident angle of greater than 40 degrees from a surface normal, the ion having landing energies of 8 keV or less.

11. The method of claim 6 in which directing an ion beam toward a work piece surface comprises directing an ion beam toward the work piece surface at an incident angle of 45 degrees+/−

5 degrees from a surface normal, the ions having landing energies of between 3 keV and 7 keV.

12. The method of claim 6 in which directing an ion beam toward a work piece surface comprises directing an ion beam that is focused above or below the work piece surface.