Method and Apparatus for Measuring Process Parameters of a Plasma Etch Process
4 Assignments
0 Petitions
Accused Products
Abstract
Method and apparatus for measuring process parameters of a plasma etch process. A method for detecting at least one process parameter of a plasma etch process being performed on a semiconductor wafer. The method comprises the steps of detecting light being generated from the plasma during the etch process, filtering the detected light to extract modulated light; and processing the detected modulated light to determine at least one process parameter of the etch process.
-
Citations
115 Claims
-
1-80. -80. (canceled)
-
81. A method for detecting at least one process parameter of a plasma etch process being performed on a semiconductor wafer, the method comprising the steps of:
-
detecting light being generated from the plasma during the etch process; filtering the detected light to extract modulated light; and processing the detected modulated light to determine at least one process parameter of the etch process. - View Dependent Claims (82, 98)
-
-
83. A method for detecting the etch rate of a plasma etch process being performed on a semiconductor wafer, the method comprising the steps of:
-
detecting light being generated from the plasma during the etch process; filtering the detected light to extract modulated light; and processing the detected modulated light to determine the etch rate of the etch process. - View Dependent Claims (84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 99)
-
-
96. A method to determine the process monitor signals and conversion constant for use in a method of detecting the etch rate of a plasma etch process to be performed on a semiconductor wafer from a particular wafer batch, the method comprising the steps of:
-
placing a test wafer of the wafer batch in a plasma etching tool and initiating the etch process;
detecting modulated light being generated from the plasma of the test wafer over the duration of the etch process;converting the detected modulated light into digital signals; transforming the digital signals into frequency domain signals; determining the main frequencies of the frequency domain signals; selecting those main frequencies which are sensitive to changes in the etch rate as the process monitor signals; establishing the linear relationship between the values of the selected process monitor signals over time and the actual etch rate; and storing the established linear relationship as the conversion constant. - View Dependent Claims (100)
-
-
97. An apparatus for determining the process monitor signals and conversion constant for use in detecting the etch rate of a plasma etch process to be performed on a semiconductor wafer from a particular wafer batch, comprising:
-
a plasma etching tool; a means for detecting modulated light being generated from the plasma of the test wafer over the duration of the etch process; a means for converting the detected modulated light into digital signals; a means for transforming the digital signals into frequency domain signals; a means for determining the main frequencies of the frequency domain signals; a means for selecting those main frequencies which are sensitive to changes in the etch rate as the process monitor signals;
a means for establishing the linear relationship between the values of the selected process monitor signals over time and the actual etch rate; anda means for storing the established linear relationship as the conversion constant.
-
-
101. A method for detecting the endpoint of a plasma etch process being performed on a semiconductor wafer, the method comprising the steps of:
-
detecting light being generated from the plasma; filtering the detected light to extract modulated light; processing the detected modulated light to determine when the endpoint of the etch process has been reached; and generating an indicator when the endpoint has been determined. - View Dependent Claims (102, 103, 104, 105, 106, 107, 108, 109, 114)
-
-
110. A method to determine the process monitor signals and a signal level transition value for use in a method of detecting the endpoint of a plasma etch process to be performed on a semiconductor wafer from a particular wafer batch, the method comprising the steps of:
-
placing a test wafer of the wafer batch in a plasma etching tool and initiating the etch process;
detecting modulated light being generated from the plasma of the test wafer over the duration of the etch process;converting the detected modulated light signals into digital signals; transforming the digital signals into frequency domain signals; determining the main frequencies of the frequency domain signals; generating a plot of the intensity of the main frequencies over the duration of the time of the etch process; selecting those main frequencies which exhibit in the plot a signal level transition when the endpoint of the etch process is reached as the process monitor signals; and selecting the value of this signal level transition as the signal level transition value to be stored. - View Dependent Claims (111, 115)
-
-
112. An apparatus for detecting the endpoint of a plasma etch process to be performed on a semiconductor wafer, comprising:
-
a plasma etching tool; means for detecting light to be generated from the plasma during an etch process; means for filtering the detected light to extract modulated light; means for processing the detected modulated light to determine when the endpoint of the etch process has been reached; and means for generating an indicator when the endpoint has been determined.
-
-
113. An apparatus for determining the process monitor signals and the signal level transition value to be stored for use in detecting the endpoint of a plasma etch process to be performed on a semiconductor wafer from a particular wafer batch, comprising:
-
a plasma etching tool; a means for detecting modulated light to be generated from the plasma of a test wafer of the wafer batch over the duration of an etch process; a means for converting the detected modulated light signals into digital signals; a means for transforming the digital signals into frequency domain signals; a means for determining the main frequencies of the frequency domain signals; a means for selecting those main frequencies which exhibit a signal level transition when the endpoint of the etch process is reached as the process monitor signals; and a means for selecting the value of this signal level transition as the signal level transition value.
-
Specification