PROCESS CONTROL USING SIGNAL REPRESENTATIVE OF A THROTTLE VALVE POSITION
First Claim
1. A method, comprising:
- a) conducting at least a step in a fabrication process in a processing chamber by varying a position of a throttle valve with time to thereby maintain a desired pressure within the chamber;
b) generating a signal representative of the position of the throttle valve; and
c) determining when the step in the fabrication process has reached an end point by detecting a change in the signal.
1 Assignment
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Accused Products
Abstract
In accordance with an embodiment of the invention, a step in a fabrication process can be conducted so as to determine when the process has reached an end point. End point detection can be performed by detecting when a operating process condition changes. For example, in one embodiment, a step in a fabrication process (e.g., an etching step) can be conducted in a chamber by varying a position of a throttle valve connected to the chamber so as to maintain a desired pressure within the chamber. In such method, it can be determined when the etching step has reached an end point by detecting when a signal representative of the throttle valve position changes in a particular way which matches an expected signature. In another embodiment, a step in a fabrication process can be conducted in a chamber by maintaining a desired flow within the chamber, such as by controlling a throttle valve, and allowing the pressure within the chamber to vary. In such method, it can be determined when the step has reached an end point by detecting when a signal representative of the pressure changes. In a particular embodiment in which end point detection is based on change in pressure, the throttle valve can be maintained at a particular position when conducting the step in the fabrication process.
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Citations
20 Claims
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1. A method, comprising:
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a) conducting at least a step in a fabrication process in a processing chamber by varying a position of a throttle valve with time to thereby maintain a desired pressure within the chamber; b) generating a signal representative of the position of the throttle valve; and c) determining when the step in the fabrication process has reached an end point by detecting a change in the signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method, comprising:
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a) conducting a step in a fabrication process in a chamber at a pressure subject to variation by setting a throttle valve to a fixed position; b) generating a signal representative of the pressure within the chamber; and c) determining when the step in the fabrication process has reached an end point by detecting a change in the signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification