Capacitive distance sensing in semiconductor processing tools
First Claim
Patent Images
1. A non-contact sensor for sensing a distance between a platen and a conductive showerhead of a semiconductor processing chamber, the sensor comprising:
- a housing resting on the platen;
a power source disposed within the housing;
wireless communication circuitry coupled to the power source;
a controller coupled to wireless communication circuitry and to the power source;
a plurality of capacitive plates forming capacitors, each having a capacitance that corresponds to a distance between the platen and the conductive showerhead;
measurement circuitry coupled to the controller and the plurality of capacitive plates, the measurement circuitry applying excitation voltages of substantially equal magnitude, but opposite polarity to the plurality of capacitive plates, measuring the capacitance of each capacitor and providing an indication thereof to the controller; and
wherein the controller provides a distance and parallelism indication relative to the platen and conductive showerhead based at least in part upon the measured capacitances.
2 Assignments
0 Petitions
Accused Products
Abstract
A wireless sensor includes at least one capacitive plate for sensing a distance relative to an object of interest within a semiconductor-processing environment. The sensor includes an internal power source and wireless communication such that distance and/or parallelism measurements effected using the capacitive plate(s) can be provided wirelessly to an external device.
146 Citations
14 Claims
-
1. A non-contact sensor for sensing a distance between a platen and a conductive showerhead of a semiconductor processing chamber, the sensor comprising:
-
a housing resting on the platen; a power source disposed within the housing; wireless communication circuitry coupled to the power source; a controller coupled to wireless communication circuitry and to the power source; a plurality of capacitive plates forming capacitors, each having a capacitance that corresponds to a distance between the platen and the conductive showerhead; measurement circuitry coupled to the controller and the plurality of capacitive plates, the measurement circuitry applying excitation voltages of substantially equal magnitude, but opposite polarity to the plurality of capacitive plates, measuring the capacitance of each capacitor and providing an indication thereof to the controller; and wherein the controller provides a distance and parallelism indication relative to the platen and conductive showerhead based at least in part upon the measured capacitances. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A sensor for sensing a distance to an object of interest within a semiconductor processing chamber, the sensor comprising:
-
a housing; a power source disposed within the housing; wireless communication circuitry coupled to the power source; a controller coupled to wireless communication circuitry and to the power source; an even number of capacitive plates configured to form a capacitor having a capacitance that varies with the distance, wherein a first capacitive plate is coupled to a surface that is extendable to the object of interest, and a second capacitive plate is fixed within the housing, wherein a capacitor is formed between the first and second plates, the capacitor having a capacitance that varies with the degree to which the surface is extended, and wherein the sensor is hermetically sealed and the surface that is extendable to the object of interest is compressed, or expanded, in response to atmospheric pressure, or lack thereof, external to the sensor; and measurement circuitry coupled to the controller and to the at least one capacitive plate, the measurement circuitry being configured to measure the capacitance and provide an indication thereof to the controller, wherein the controller is configured to provide an indication relative to the object based at least in part upon the measured capacitance.
-
-
13. A method of sensing distance and parallelism between a platen and a conductive showerhead within a semiconductor processing chamber, the method comprising:
-
bringing a plurality of capacitive plates into proximity with a first surface of the conductive showerhead while resting on the platen; applying excitation voltages of substantially equal magnitude, but opposite polarity to the plurality of capacitive plates; sensing the effective capacitance between the plurality of capacitive plates and the conductive showerhead; and wirelessly providing an indication relative to the distance and parallelism based at least in part upon the measured capacitance. - View Dependent Claims (14)
-
Specification