End-point detection
First Claim
1. A method of selecting a wavelength of light to monitor for end-point detection during etching, wherein the etching produces discharge which emits light, said method comprising the steps of:
- collecting data during etching, said data characterizing variation of light emitted by discharge produced during the etching;
calculating a principal component of the data, said principal component having variables, each variable having a weight, and each variable corresponding to a wavelength of the light emitted by the discharge; and
determining which variable of the principal component varies during the etching such that end-point of the etch can be detected by monitoring the wavelength corresponding to the variable.
1 Assignment
0 Petitions
Accused Products
Abstract
A wavelength of light is monitored for end-point detection during etching. Spectral data is collected during etching which characterizes variation of light emitted by discharge produced during etching. At least one principal component of the data is calculated. Each principal component has variables, each variable has a weight, and each variable corresponds to a wavelength of the light emitted by the discharge. By examining or analyzing the weights, it is then determined which variable of the principal component varies during etching such that end-point of the etch can be detected by monitoring the wavelength corresponding to the variable.
82 Citations
33 Claims
-
1. A method of selecting a wavelength of light to monitor for end-point detection during etching, wherein the etching produces discharge which emits light, said method comprising the steps of:
-
collecting data during etching, said data characterizing variation of light emitted by discharge produced during the etching; calculating a principal component of the data, said principal component having variables, each variable having a weight, and each variable corresponding to a wavelength of the light emitted by the discharge; and determining which variable of the principal component varies during the etching such that end-point of the etch can be detected by monitoring the wavelength corresponding to the variable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method of etching a wafer, comprising the steps of:
-
etching a wafer such that discharge is produced which emits light; and terminating etching of the wafer when light of a predetermined wavelength emitted by the discharge varies so as to signal end-point of the etch, wherein determining of the predetermined wavelength comprises the steps of; performing an experimental etch; collecting data during the experimental etch, said data characterizing variation of light emitted by the discharge produced during the experimental etch; calculating a principal component of the data, said principal component having variables, each variable having a weight, and each variable corresponding to a wavelength of the light emitted by the discharge; and determining which variable of the principal component varies during the experimental etch such that end-point can be detected by monitoring the wavelength corresponding to the variable, said wavelength being the predetermined wavelength. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. An apparatus for selecting a wavelength of light to monitor for end-point detection during etching, wherein the etching produces discharge which emits light, said apparatus comprising:
-
means for collecting data characterizing variation of light emitted by discharge produced during etching; means for calculating a principal component of the data, said principal component having variables, each variable having a weight, and each variable corresponding to a wavelength of the light emitted by the discharge; and means for determining which variable of the principal component varies during etching such that end-point of the etch can be detected by monitoring the wavelength corresponding to the variable. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
Specification