×

Differential measurements for endpoint signal enhancement

  • US 8,900,470 B2
  • Filed: 10/17/2012
  • Issued: 12/02/2014
  • Est. Priority Date: 10/17/2012
  • Status: Active Grant
First Claim
Patent Images

1. A method for etching a layer, comprising:

  • providing a substrate in a chamber;

    generating an etch plasma for etching a layer on the substrate;

    measuring light from a first region of the chamber to provide a first signal;

    measuring light from a second region of the chamber to provide a second signal; and

    comparing the first signal with the second signal to determine an etch endpoint,wherein the comparing the first signal with the second signal to determine an etch endpoint indicates a spike in nitrogen in the first region.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×