System of inspecting focus ring and method of inspecting focus ring

Patent metadata

Field	Value
Publication number	US-9841395-B2
Application number	US-201615179306-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Jun 11, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A system of inspecting a focus ring is provided. The system includes a measuring device, a transfer device and an operation unit. The measuring device includes a base substrate, a sensor chip and a circuit board. The sensor chip has a sensor electrode and is provided along an edge of the base substrate. The circuit board is configured to output a high frequency signal to the sensor electrode and acquire a digital value indicating electrostatic capacitance based on a voltage amplitude in the sensor electrode. The transfer device is configured to scan the measuring device. The operation unit is configured to obtain difference values by performing a difference operation with respect to the digital values acquired by the measuring device at multiple positions along a direction which intersects with an inner periphery of the focus ring.

First claim

We claim:

1. A system of inspecting a focus ring,
wherein the focus ring is provided on a mounting table configured to mount thereon a processing target object within a processing vessel of a plasma processing apparatus, and the focus ring has an annular plate-shaped first portion and an annular plate-shaped second portion which is extended on the first portion, and a diameter of an inner periphery of the second portion is larger than a diameter of an inner periphery of the first portion, and
the system comprises:
a measuring device, configured to measure electrostatic capacitance, comprising a base substrate having a disk shape; a sensor chip, having a sensor electrode, provided along an edge of the base substrate; and a circuit board configured to output a high frequency signal to the sensor electrode and acquire a digital value indicating electrostatic capacitance based on a voltage amplitude in the sensor electrode;
a transfer device configured to move the sensor chip on the first portion and within a region surrounded by the inner periphery of the second portion by scanning the measuring device; and
an operation unit configured to receive the digital values acquired by the measuring device at multiple positions along a direction which intersects with the inner periphery of the second portion, and configured to obtain difference values at the multiple positions by performing a difference operation with respect to the digital values.

2. The system of claim 1 ,
wherein the operation unit is configured to calculate a difference between each of the difference values and a preset value corresponding thereto.

3. The system of claim 1 ,
wherein the circuit board comprises a communication device configured to wirelessly transmit the digital value to the operation unit.

4. A system of inspecting a focus ring,
wherein the focus ring is provided on a mounting table configured to mount thereon a processing target object within a processing vessel of a plasma processing apparatus, and the focus ring has an annular plate-shaped first portion and an annular plate-shaped second portion which is extended on the first portion, and a diameter of an inner periphery of the second portion is larger than a diameter of an inner periphery of the first portion, and
the system comprises:
a measuring device, configured to measure electrostatic capacitance, comprising a base substrate having a disk shape; a sensor chip, provided along an edge of the base substrate, having a first sensor electrode facing downwards and a second sensor electrode facing an outside of the edge of the base substrate; and a circuit board configured to output a high frequency signal to the first sensor electrode and the second sensor electrode and acquire a first digital value indicating electrostatic capacitance based on a voltage amplitude in the first sensor electrode and a second digital value indicating electrostatic capacitance based on a voltage amplitude in the second sensor electrode;
a transfer device configured to move the sensor chip on the first portion and within a region surrounded by the inner periphery of the second portion by scanning the measuring device; and
an operation unit configured to receive the first digital values and the second digital values acquired by the measuring device at multiple positions along a direction which intersects with the inner periphery of the second portion, and configured to obtain difference values at the multiple positions by performing a difference operation with respect to the first digital values.

5. The system of claim 4 ,
wherein the sensor chip further comprises a guard electrode provided between the first sensor electrode and the second sensor electrode, and the high frequency signal is sent to the guard electrode.

6. The system of claim 4 ,
wherein the operation unit is configured to calculate a difference between each of the difference values and a preset value corresponding thereto.

7. The system of claim 4 ,
wherein the circuit board comprises a communication device configured to wirelessly transmit the first digital value and the second digital value to the operation unit.

8. A method of inspecting a focus ring with a measuring device configured to measure electrostatic capacitance,
wherein the focus ring is provided on a mounting table configured to mount thereon a processing target object within a processing vessel of a plasma processing apparatus, and the focus ring has an annular plate-shaped first portion and an annular plate-shaped second portion which is extended on the first portion, and a diameter of an inner periphery of the second portion is larger than a diameter of an inner periphery of the first portion,
the measuring device comprises a base substrate having a disk shape; a sensor chip, having a sensor electrode, provided along an edge of the base substrate; and a circuit board configured to output a high frequency signal to the sensor electrode and acquire a digital value indicating electrostatic capacitance based on a voltage amplitude in the sensor electrode, and
the method comprises:
scanning the measuring device such that the sensor chip is moved on the first portion and within a region surrounded by the inner periphery of the second portion; and
obtaining difference values at multiple positions along a direction which intersects with the inner periphery of the second portion by performing a difference operation with respect to the digital values acquired by the measuring device at the multiple positions.

9. The method of claim 8 , further comprising:
calculating a difference between each of the difference values and a preset value corresponding thereto.

10. A method of inspecting a focus ring with a measuring device configured to measure electrostatic capacitance,
wherein the focus ring is provided on a mounting table configured to mount thereon a processing target object within a processing vessel of a plasma processing apparatus, and the focus ring has an annular plate-shaped first portion and an annular plate-shaped second portion which is extended on the first portion, and a diameter of an inner periphery of the second portion is larger than a diameter of an inner periphery of the first portion,
the measuring device comprises a base substrate having a disk shape; a sensor chip, provided along an edge of the base substrate, having a first sensor electrode facing downwards and a second sensor electrode facing an outside of the edge of the base substrate; and a circuit board configured to output a high frequency signal to the first sensor electrode and the second sensor electrode and acquire a first digital value indicating electrostatic capacitance based on a voltage amplitude in the first sensor electrode and a second digital value indicating electrostatic capacitance based on a voltage amplitude in the second sensor electrode, and
the method comprises:
scanning the measuring device such that the sensor chip is moved on the first portion and within a region surrounded by the inner periphery of the second portion; and
obtaining difference values at multiple positions along a direction which intersects with the inner periphery of the second portion by performing a difference operation with respect to the first digital values acquired by the measuring device at the multiple positions.

11. The method of claim 10 , further comprising:
calculating a difference between each of the difference values and a preset value corresponding thereto.

Assignees

• Tokyo Electron Ltd

Inventors

• Sugita Kippei
• Minami Tomohide

Classifications

• H01J37/32009 Primary

  Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources (plasma generation in general H05H1/24) · CPC title

• H01J37/321

  the radio frequency energy being inductively coupled to the plasma · CPC title

• G01R31/318511

  Wafer Test · CPC title

• H01J37/32211

  Means for coupling power to the plasma · CPC title

• G01R31/2831

  Testing of materials or semi-finished products, e.g. semiconductor wafers or substrates (G01R31/318511 takes precedence; testing during manufacture H10P74/00) · CPC title