Method and apparatus for determining process rate

• US 9,735,069 B2
• Filed: 09/23/2015
• Issued: 08/15/2017
• Est. Priority Date: 09/23/2015
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Bailey, III, Andrew D., Lee, Seonkyung, Kabouzi, Yassine, Luque, Jorge, Albarede, Luc, Lill, Thorsten
• Primary Examiner(s): DUCLAIR, STEPHANIE P.
• Application Number:
  US14/862,983
• Publication Number:
  US 20170084503A1
• Time in Patent Office: 692 Days
• Field of Search: None
• CPC Class Codes: H01J 37/32834 Exhausting
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32981 Gas analysis
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: H01L 21/3083 characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane
• CPC Class Codes: H01L 21/31056 the removal being a selective chemical etching step, e.g. selective dry etching through a mask
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: H01L 28/00 Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor testing or measuring during manufacture H01L22/00; integration methods H01L21/70; integrated circuits H01L27/00; two-terminal components with a potential-jump or surface barrier H01L29/00; resistors in general H01C; inductors in general H01F; capacitors in general H01G

Abstract

A method for dry processing a substrate in a processing chamber is provided. The substrate is placed in the processing chamber. The substrate is dry processed, wherein the dry processing creates at least one gas byproduct. A concentration of the at least one gas byproduct is measured. The concentration of the at least one gas byproduct is used to determine processing rate of the substrate.

Claims

1. A method for dry processing a substrate in a processing chamber, comprising:

creating a plurality of concentration models related to processing rate and processing uniformity;

placing the substrate in the processing chamber;

dry processing the substrate, wherein the dry processing creates at least one gas byproduct;

measuring a concentration of the at least one gas byproduct;

fitting the measured concentration of the at least one gas byproduct over time to at least one of the plurality of concentration models;

using the concentration of the at least one gas byproduct to determine processing rate of the substrate;

creating process parameters from the fitted at least one of the plurality of concentration models and the measured concentration of the at least one gas byproduct;

using the created process parameters to determine run-to-run and chamber-to-chamber performance; and

using the concentration of the at least one gas byproduct to determine processing uniformity.

2. The method, as recited in claim 1, further comprising using the concentration of the at least one gas byproduct to determine process endpoint.

3. The method, as recited in claim 2, wherein the process is plasma etching, and further comprising using the concentration of the at least one gas byproduct to determine aspect ratio dependent ER.

4. The method, as recited in claim 3, wherein the process is plasma etching alternating layers, and further comprising using the concentration of the at least one gas byproduct to determine aspect ratio dependent selectivity.

5. The method, as recited in claim 1, further comprising changing a chamber setting based on the measured concentration of the at least one gas byproduct.

6. The method, as recited in claim 1, wherein the dry processing the substrate comprises plasma etching the substrate or a stack over the substrate.

7. The method, as recited in claim 1, wherein the dry processing the substrate comprises etching a silicon containing layer.

8. The method, as recited in claim 1, wherein the byproducts comprise at least one of SiF₄, SiCl₄, SiBr₄, COF₂, CO₂, CO and CF₄.

9. The method, as recited in claim 1, wherein the using the concentration of the at least one gas byproduct to determine etch selectivity.

10. The method, as recited in claim 1, wherein the measuring a concentration of the at least one gas byproduct comprises using IR absorption with a multi-pass gas cell to measure the concentration of at least one gas byproduct.

11. The method, as recited in claim 10, wherein the IR absorption measures the concentration of at least one gas byproduct after the at least one gas byproduct is pumped through an exhaust pump.

12. The method, as recited in claim 1, wherein the byproducts comprises SiF₄.

13. A method for dry etching at least eight alternating layers over a substrate in a processing chamber, comprising

creating a plurality of concentration models related to processing rate and processing uniformity;

placing the substrate in the processing chamber;

dry etching the at least eight alternating layers, wherein the dry etching creates at least one gas byproduct;

measuring a concentration of the at least one gas byproduct;

fitting the measured concentration of the at least one gas byproduct over time to at least one of the plurality of concentration models;

using the concentration of the at least one gas byproduct to determine etching rate of the substrate, etch selectivity, and etch uniformity;

creating process parameters from the fitted at least one of the plurality of concentration models and the measured concentration of the at least one gas byproduct;

using the created process parameters to determine run-to-run and chamber-to-chamber performance; and

changing a chamber parameter based on the measured concentration.