Methods and arrangements for determining an endpoint for an in-situ local interconnect etching process
First Claim
Patent Images
1. A method for determining at least one endpoint in an etching process, the method comprising:
- measuring a first intensity of optical emissions having a first wavelength from a semiconductor wafer in a plasma chamber during a first etching process;
measuring a second intensity of optical emissions having a second wavelength from the semiconductor wafer in the plasma chamber during the first etching process; and
determining an endpoint for the first etching process based on at least one of the first and second measured intensities.
3 Assignments
0 Petitions
Accused Products
Abstract
An arrangement is provided for collecting, measuring and analyzing at least two specific wavelengths of optical emissions produced while etching a semiconductor wafer in a plasma chamber to determine an optimal endpoint for the etching process. The arrangement includes a sensor for gathering optical emissions, an interface for converting the intensity of optical emissions into corresponding electrical signals, and a controller for determining an optimal endpoint based on the corresponding electrical signals for the two specific wavelengths and other predetermined threshold data.
31 Citations
20 Claims
-
1. A method for determining at least one endpoint in an etching process, the method comprising:
-
measuring a first intensity of optical emissions having a first wavelength from a semiconductor wafer in a plasma chamber during a first etching process; measuring a second intensity of optical emissions having a second wavelength from the semiconductor wafer in the plasma chamber during the first etching process; and determining an endpoint for the first etching process based on at least one of the first and second measured intensities. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for controlling in-situ local interconnect etching of a semiconductor wafer, the method comprising:
-
etching a semiconductor wafer in a plasma chamber with a first etching process; monitoring optical emissions from the plasma chamber while etching with the etching process, wherein the monitoring includes determining an intensity of at least two wavelengths of the optical emissions; stopping the etching with the first etching process based on the intensity of at least one of the two wavelengths; etching the semiconductor wafer in the plasma chamber with a second etching process; and stopping the etching with the second etching process based on the intensity of at least one of the two wavelengths. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. A method for determining at least one endpoint in an etching process, the method comprising:
-
measuring a first intensity of optical emissions having a first wavelength from a semiconductor wafer in a plasma chamber during a first etching process; measuring a second intensity of optical emissions having a second wavelength from the semiconductor wafer in the plasma chamber during the first etching process; and determining an endpoint for the first etching process based on a change in a ratio of the first and second measured intensities; wherein the first wavelength is selected from a set of wavelengths including approximately 386 nm and 520 nm wavelengths, and wherein the second wavelength is approximately 439 nm.
-
-
19. A method for controlling in-situ local interconnect etching of a semiconductor wafer, the method comprising:
-
etching a semiconductor wafer in a plasma chamber with a first etching process; monitoring optical emissions from the plasma chamber while etching with the etching process, said monitoring including determining an intensity of two wavelengths of the optical emissions; stopping the etching with the first etching process based on a first change in a ratio of the intensities of the two wavelengths; etching the semiconductor wafer in the plasma chamber with a second etching process; and stopping the etching with the second etching process based on a second change in the ratio of the intensities of the two wavelengths. - View Dependent Claims (20)
-
Specification