Methods of and apparatuses for maintenance, diagnosis, and optimization of processes

• US 8,698,037 B2
• Filed: 06/13/2011
• Issued: 04/15/2014
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: KLA-Tencor Corporation
• Inventors: Mundt, Randall S., MacDonald, Paul Douglas, Beers, Andrew, Freed, Mason L., Spanos, Costas J.
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US13/159,266
• Publication Number:
  US 20110240610A1
• Time in Patent Office: 1,037 Days
• Field of Search: 219/121.54, 219/121.57, 219/121.43, 156/345.24, 156/345.25, 156/345.27, 156/345.28, 118/723.R
• US Class Current: 219/121.54
• CPC Class Codes: G01K 7/25 for modifying the output characteristic, e.g. linearising
• CPC Class Codes: G01N 27/60 by investigating electrostatic variables , e.g. electrographic flaw testing G01N27/007 takes precedence
• CPC Class Codes: G01N 33/0004 Gaseous mixtures, e.g. polluted air gaseous biological material G01N33/497; exhaust gas of internal combustion engines G01M15/102
• CPC Class Codes: G01R 15/24 using light-modulating devices
• CPC Class Codes: G01R 29/12 Measuring electrostatic fields or voltage-potential
• CPC Class Codes: H01L 21/67248 Temperature monitoring
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A sensor apparatus for measuring a plasma process parameter for processing a workpiece. The sensor apparatus includes a base, an information processor supported on or in the base, and at least one sensor supported on or in the base. The at least one sensor includes at least one sensing element configured for measuring an electrical property of a plasma and may include a transducer coupled to the at least one sensing element. The transducer can be configured to receive a signal from the sensing element and convert the signal into a second signal for input to the information processor.

Claims

1. A sensor apparatus for measuring a plasma process parameter for processing a workpiece, the sensor apparatus comprising:

a base;

an information processor supported by the base; and

a sensor supported by the base, the sensor comprising a sensing element configured for measuring an electrical property of a plasma and a transducer coupled to the sensing element, wherein the transducer is selected from a group consisting of;

a) a transducer configured so as to receive a signal from the sensing element and convert the signal into a second signal for input to the information processor,

b) a power transducer having a resistive load for receiving a current and a voltage from the sensing element and a thermometer arranged so as to measure changes in temperature of the resistive load, and

c) an optical transducer configured so as to receive a signal from the sensing element and convert the signal into a second signal for input to the information processor, wherein the optical transducer is configured to convert an electrical signal from the sensor element to a light output and a light sensor configured to produce the second signal in proportion to an intensity of the light output that falls on the light sensor.

2. The sensor apparatus of claim 1, wherein the transducer comprises a diode rectification circuit comprising a semiconductor junction diode for rectifying an applied radio frequency voltage or current and a low pass filter so as to produce a DC voltage or current proportional to the applied RF voltage or current.

3. The sensor apparatus of claim 1 wherein the sensor includes

a capacitive sensor supported on or in by the base and coupled to the information processor, the sensor having a capacitive sensing element configured so as to provide an output that represents a plasma process parameter measurement,

an inductive sensor supported by the base and coupled to the information processor, the sensor having an inductive sensing element configured so as to provide an output that represents a plasma process parameter measurement, and

an electrostatic charge sensor supported by the base and coupled to the information processor, the sensor having an electrostatic charge sensing element configured so as to provide an output that represents a plasma process parameter measurement,

wherein the capacitive sensor, inductive sensor, or electrostatic sensor further comprise a a diode rectification transducer comprising a semiconductor junction diode for rectifying an applied radio frequency voltage or current and a low pass filter so as to produce a DC voltage or current proportional to the applied RF voltage or current.

4. The sensor apparatus of claim 2, wherein, in the diode rectification circuit, radio frequency voltages or radio frequency current induced in a capacitive or inductive sensing element are connected through the diode to a high impedance load to provide a measure of the peak to peak radio frequency potential.

5. The sensor apparatus of claim 4, wherein the radio frequency voltages or radio frequency current are induced in a capacitive or an inductive sensing element and the capacitive or inductive sensing element is connected to a low impedance load to provide a measure of the local radio frequency current.

6. The sensor apparatus of claim 4, wherein identical sensor elements are connected to impedances of different values so as to be capable of measuring nonlinear plasma current-voltage characteristics.

7. The sensor apparatus of claim 4, wherein a signal from the sensing element is applied to a complex load having resistive, inductive, and capacitive properties so as to be capable of making frequency sensitive measurements.