Method and apparatus for 2-d spatially resolved optical emission and absorption spectroscopy

• US 6,958,484 B2
• Filed: 11/28/2001
• Issued: 10/25/2005
• Est. Priority Date: 11/28/2000
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Mitrovic, Andrej S.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US10/432,713
• Publication Number:
  US 20040026035A1
• Time in Patent Office: 1,427 Days
• Field of Search: 250/559.27, 250/221, 250/216, 250/228, 250/554, 356/72, 356/338, 356/339, 216/67, 216/59, 216/60
• US Class Current: 250/559.27
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: G01N 21/71 thermally excited
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32972 Spectral analysis

Abstract

A multi-point detection method and system for analyzing a composition within an examination area. The system simultaneously acquires multi-dimensional distributions (e.g., two- or three-dimensional distributions) of plasma optical emissions at at least two wavelengths. Such diagnostics are useful for real-time spatially-resolved measurements of plasma electron temperature distributions and/or chemical species concentrations within a plasma processing chamber (50). Generally, the system analyzes/diagnoses the measurement of line-of-sight light emission or absorption in the plasma.

Claims

1. In a plasma processing chamber for processing substrates, wherein the processing chamber includes plural optical viewports, the improvement comprising:

a first optical system for receiving a first series of light beams in a first direction;

a first detector for receiving the first series of light beams from the first optical system;

a second optical system for receiving a second series of light beams in a second direction;

a second detector for receiving the second series of light beams from the second optical system; and

a calculator for calculating two-dimensional distributions of light emissions from substantially simultaneous outputs of the first and second detectors, wherein at least a portion of the first and second series of light beams pass across a common area within the plasma processing chamber.

2. The improvement as claimed in claim 1, wherein the first and second directions are substantially perpendicular.

3. The improvement as claimed in claim 1, wherein the first and second optical systems comprise at least one beam splitter.

4. The improvement as claimed in claim 1, wherein the first and second detectors comprise multi-frequency detectors.

5. The improvement as claimed in claim 1, wherein the first and second detectors comprise CCDs.

6. The improvement as claimed in claim 1, wherein the first and second optical systems comprise at least one filter interposed between the plasma processing chamber and the first and second detectors.

7. The improvement as claimed in claim 1, wherein the substrate comprises a wafer.

8. The improvement as claimed in claim 1, wherein the calculator for calculating two-dimensional distributions of light emissions comprises a computer.