Remote plasma processing of interface surfaces

• US 8,084,339 B2
• Filed: 06/12/2009
• Issued: 12/27/2011
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Original Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Inventors: Antonelli, George Andrew, O'Loughlin, Jennifer, Xavier, Tony, Sriram, Mandyam, Van Schravendijk, Bart, Rangarajan, Vishwanathan, Varadarajan, Seshasayee, Buckalew, Bryan L.
• Primary Examiner(s): Nhu, David
• Application Number:
  US12/484,047
• Publication Number:
  US 20100317178A1
• Time in Patent Office: 928 Days
• Field of Search: 438/512, 438/513, 438/514, 438/463, 438/535, 438/679, 438/681, 438/687, 438/692, 438/740, 438/931, 257/E21.17, 257/E21.006, 257/E21.027, 257/E21.054, 257/E21.134, 257/E21.267, 257/E21.304, 257/E21.311, 257/E21.329
• US Class Current: 438/512
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/54 Apparatus specially adapted for continuous coating
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/0206 during, before or after processing of insulating layers
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/02315 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/67201 characterized by the construction of the load-lock chamber
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Embodiments related to the cleaning of interface surfaces in a semiconductor wafer fabrication process via remote plasma processing are disclosed herein. For example, in one disclosed embodiment, a semiconductor processing apparatus includes a processing chamber, a load lock coupled to the processing chamber via a transfer port, a wafer pedestal disposed in the load lock and configured to support a wafer in the load lock, a remote plasma source configured to provide a remote plasma to the load lock, and an ion filter disposed between the remote plasma source and the wafer pedestal.

Claims

1. In a semiconductor processing apparatus, a method of forming an etch stop layer over a wafer with a surface comprising a metal region and a dielectric material region, the method comprising:

inserting the wafer into an inbound load lock that is coupled to a plasma enhanced chemical vapor deposition chamber;

heating the wafer in the inbound load lock;

flowing a remote plasma over the surface of the wafer while the wafer is in the inbound load lock;

transferring the wafer from the inbound load lock into the plasma enhanced chemical vapor deposition chamber; and

forming an etch stop layer over the surface of the wafer.

2. The method of claim 1, wherein flowing the remote plasma over the surface of the wafer comprises reducing a metal oxide on a metal portion of the surface.

3. The method of claim 1, wherein flowing the remote plasma over the surface of the wafer comprises introducing a flow of the remote plasma over the wafer in a flow direction substantially normal to the surface of the wafer.

4. The method of claim 3, wherein flowing the remote plasma over the surface of the wafer in the flow direction substantially normal to the surface of the wafer comprises introducing a remote plasma flow via a remote plasma source with an outlet diameter equal to or greater than a diameter of the wafer.

5. The method of claim 1, further comprising flowing the remote plasma through an ion filter comprising a plate with a plurality of through-holes each having a length to diameter ratio of three or more.

6. The method of claim 1, wherein the remote plasma comprises one or more of a reducing gas and an oxidizing gas, and wherein flowing the remote plasma over the surface of the wafer comprises one or more of reducing metal oxides and oxidizing carbon residues on the surface of the wafer.

7. In a semiconductor processing apparatus, a method of forming an interface between two layers of different material compositions, the method comprising:

forming a layer of a first material composition on a substrate;

positioning the substrate in a remote plasma processing apparatus;

generating a remote plasma and filtering ions from the remote plasma;

flowing the remote plasma over a surface of the layer of the first material composition; and

forming a layer of a second material composition on the surface of the layer of the first material composition to thereby form the interface between the layer of the first material composition and the layer of the second material composition of different material compositions.

8. The method of claim 7, wherein the layer of the first material composition comprises a metal region and a dielectric region, wherein the layer of the second material composition comprises a layer of an etch stop material, and wherein forming the layer of the second material composition comprises forming the layer of the second material composition by plasma enhanced chemical vapor deposition.

9. The method of claim 8, further comprising forming the surface of the first material via chemical mechanical polishing before flowing the remote plasma over the surface of the first material.

10. The method of claim 7, wherein positioning the substrate in a remote plasma processing apparatus comprises positioning the substrate in an inbound load lock for a plasma enhanced CVD system.

11. The method of claim 7, wherein the layer of the first material composition comprises tungsten, and wherein the layer of the second material composition comprises a hard mask layer.

12. The method of claim 7, wherein flowing the remote plasma over the surface of the layer of the first material composition, in a direction normal to the surface of the layer of the first material comprises introducing a remote plasma flow via a remote plasma source with an outlet diameter equal to or greater than a diameter of the substrate.

13. The method of claim 7, wherein the remote plasma processing apparatus comprises a load lock coupled to a remote plasma source.

14. The method of claim 7, wherein the remote plasma processing apparatus comprises a processing station in a multi-station processing tool.

15. The method of claim 7, wherein the layer of the first material composition comprises a low-k dielectric material, and wherein positioning the substrate in a remote plasma processing apparatus comprises positioning the substrate in an outbound load lock coupled to a low-k dielectric material deposition chamber.

16. The method of claim 7, further comprising exposing the substrate to ultraviolet light while the substrate is positioned in the remote plasma processing apparatus.