Methods of and apparatuses for measuring electrical parameters of a plasma process

• US 9,029,728 B2
• Filed: 04/14/2014
• Issued: 05/12/2015
• Est. Priority Date: 04/19/2001
• Status: Expired due to Fees

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Mundt, Randall S., MacDonald, Paul Douglas, Beers, Andrew, Freed, Mason L., Spanos, Costas J.
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US14/252,505
• Publication Number:
  US 20140312916A1
• Time in Patent Office: 393 Days
• Field of Search: 219/121.43, 219/121.44, 219/121.54, 219/121.57, 156/345.28, 156/345.24, 156/345.25, 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
• 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 on or in the base;

an electrostatic charge sensor supported on or in the base and coupled to the information processor, the sensor having an electrostatic charge sensing element and a transducer coupled to the sensing element, wherein the sensing element is configured so as to provide a signal that represents a plasma process parameter measurement and wherein the transducer is configured so as to receive the signal from the sensing element and convert the signal into a second signal for input to the information processor.

2. The sensor apparatus of claim 1 wherein the base comprises a silicon wafer with a diameter of between 100 mm and 450 mm and the sensor apparatus has a thickness of 0.3 mm to 10 mm.

3. The sensor apparatus of claim 1 wherein the base comprises a substantially whole semiconductor wafer, a substantially whole flat panel display substrate, or a substantially whole lithography mask.

4. The sensor apparatus of claim 1 wherein the transducer comprises a diode rectification circuit.

5. 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.

6. The sensor apparatus of claim 1 wherein the transducer comprises a power detection circuit that includes:

a resistive load having a resistance between 1 ohm and 1000000 ohms and

a temperature measuring device disposed so as to measure the temperature of the resistive load.

7. The sensor apparatus of claim 1 wherein the transducer comprises a power detection circuit that includes:

a resistive load having a resistance between 1 ohm and 1000000 ohms and

a thermistor or a thermocouple disposed so as to measure the temperature of the resistive load.

8. The sensor apparatus of claim 1 wherein the transducer comprises an optical transducer.

9. The sensor apparatus of claim 1 wherein the transducer comprises an optical transducer comprising a light emitting device configured so as to provide light emissions proportional to the signal from the sensing element and an optical detector configured so as to measure the light emissions from the light emitting device.

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

a base;

an information processor supported on or in the base; and

a sensor supported on or in 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 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, wherein the sensing element is configured to provide an output of a current and a voltage that represent a process parameter measurement to the transducer.

11. The sensor apparatus of claim 10, wherein the transducer comprises a power detection circuit that includes:

a resistive load having a resistance between 1 ohm and 1000000 ohms and

a thermistor or a thermocouple disposed so as to measure the temperature of the resistive load.

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

a base;

an information processor supported on or in the base; and

a sensor supported on or in 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 an optical transducer coupled to the at least one sensing element, the transducer being 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.

13. The sensor apparatus of claim 12 wherein the optical transducer comprises a light emitting device configured so as to provide light emissions proportional to the signal from the sensing element and an optical detector configured so as to measure the light emissions from the light emitting device.

14. The sensor apparatus of claim 12 wherein the sensor has an optical sensing element configured for measuring an optical property of the plasma related to an electrical property of the plasma and the transducer is selected from the group consisting of a diode transducer, a power transducer, and an optical transducer.