Method and apparatus for monitoring processes using multiple parameters of a semiconductor wafer processing system

• US 5,910,011 A
• Filed: 05/12/1997
• Issued: 06/08/1999
• Est. Priority Date: 05/12/1997
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Cruse, James P.
• Primary Examiner(s): Picardat, Kevin M.
• Assistant Examiner(s): COLLINS, DEVEN M
• Application Number:
  US08/854,508
• Time in Patent Office: 757 Days
• Field of Search: 438/16, 438/14, 438/17
• US Class Current: 438/16
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B81C 1/00587 Processes for avoiding or controlling over-etching not provided for in B81C1/00571 - B81C1/00579
• CPC Class Codes: B81C 2201/0132 Dry etching, i.e. plasma etching, barrel etching, reactive ion etching [RIE], sputter etching or ion milling
• CPC Class Codes: B81C 2201/0138 Monitoring physical parameters in the etching chamber, e.g. pressure, temperature or gas composition
• CPC Class Codes: B81C 99/0065 Process control; Yield prediction
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• 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 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

A method and apparatus that provides process monitoring within a semiconductor wafer processing system using multiple process parameters. Specifically, the apparatus analyzes multiple process parameters and statistically correlates these parameters to detect a change in process characteristics such that the endpoint of an etch process may be accurately detected, as well as detecting other characteristics within the chamber. The multiple parameters may include optical emissia, environmental parameters such as pressure and temperature within the reaction chamber, RF power parameters such as reflected power or tuning voltage, and system parameters such as particular system configurations and control voltages.

Claims

1. A method for monitoring semiconductor wafer processing system parameters during operation of the system comprising the steps of:

acquiring parametric data indicative of system characteristics by a plurality of sensors connected to the system;

correlating said data from said plurality of sources of parametric data to form a correlation signal;

defining a trigger criterion corresponding to a particular value of said correlation signal resulting from a simultaneous chance in two or more of said wafer processing system parameters to form a trigger point;

comparing said correlation signal to said trigger point to determine the existence of a specific characteristic within the system; and

reacting to said comparison.

2. The method of claim 1 wherein one of the sensors detects optical emissia of plasma in the semiconductor wafer processing system.

3. The method of claim 1 wherein one of the sensors detects RF reflected power or tuning voltage.

4. The method of claim 1 wherein one of the sensors detects temperature in the semiconductor wafer processing system.

5. The method of claim 1 wherein one of the sensors detects pressure in the semiconductor wafer processing system.

6. The method of claim 1 wherein one of the sensors detects semiconductor wafer processing system configuration parameters.

7. The method of claim 1 wherein one of the sensors detects foreline pressure in the wafer processing system.

8. The method of claim 1 wherein one of the sensors detects reactive gas analyzer signals in the wafer processing system.

9. The method of claim 1 wherein the step of correlating data is accomplished by a signal analyzer that accepts input of the parametric data and provides output of control signals to a wafer processing system controller.

10. The method of claim 9 wherein the signal analyzer is a general purpose computer.