In-situ deposition thickness monitoring

Patent metadata

Field	Value
Publication number	US-12098918-B2
Application number	US-202117925182-A
Country	US
Kind code	B2
Filing date	Aug 10, 2021
Priority date	Aug 25, 2020
Publication date	Sep 24, 2024
Grant date	Sep 24, 2024

Abstract

A method for in-situ measurement of a thickness of a coating deposited by a deposition process, includes the steps of initiating deposition within a deposition chamber such that a first coating forms on an outer surface of a probe disposed in the deposition chamber, wherein the probe comprises a coil assembly including at least one coil, wherein the probe is separated by a distance from a substrate disposed within the deposition chamber; exciting the coil assembly with a first alternating current to produce a first time-varying magnetic field, the first time-varying magnetic field generating an eddy current in the first coating; determining a metric related to an inductance or resistance of the coil assembly, wherein a value of the metric is related to a first thickness of the first coating and results at least partially from an eddy current magnetic field produced by an eddy current in the coating; and correlating the first thickness of the first coating to a second thickness of a second coating deposited on a surface of the substrate.

First claim

What is claimed is:

1. A method for in-situ measurement of a thickness of a coating deposited by a deposition process, comprising the steps of:
initiating deposition within a deposition chamber such that a first coating forms on an outer surface of a probe disposed in the deposition chamber, wherein the probe comprises a coil assembly including at least one coil, wherein the probe is separated by a distance from a substrate disposed within the deposition chamber;
exciting the coil assembly with a first alternating current to produce a first time-varying magnetic field, the first time-varying magnetic field generating an eddy current in the first coating;
determining a metric related to an inductance or resistance of the coil assembly, wherein a value of the metric is related to a first thickness of the first coating and results at least partially from an eddy current magnetic field produced by the eddy current in the first coating; and
correlating the first thickness of the first coating to a second thickness of a second coating deposited on a surface of the substrate.

2. The method of claim 1 , wherein the the coil assembly comprises a first coil and a second coil, wherein first coil and the second coil are wound about an axis, wherein the first coil is spaced apart from the second coil to define a gap therebetween, and wherein a third coil is disposed in the gap between the first coil and the second coil.

3. The method of claim 2 , further comprising the step of exciting the second coil with a second alternating current, the second alternating current flowing in a direction opposite to the first alternating current to produce a second time-varying magnetic field that at least reduces the first time-varying magnetic field in the gap between first coil and the second coil, wherein the first alternating current excites the first coil.

4. The method of claim 3 , wherein the first coil is wound about the axis in a first direction and the second coil is wound about the axis in a second direction.

5. The method of claim 4 , wherein the first coil and the second coil are formed from the same conducting wire such that the first alternating current and the second alternating current are the same.

6. An electrical probe for measuring the thickness of a coating, comprising:
a first coil being wound about an axis in a first direction and having a first number of turns;
a second coil being wound about the axis in a second direction and having a second number of turns, wherein the first coil is spaced apart from the second coil to define a gap therebetween, wherein the first direction is opposite the second direction such that a first time-varying magnetic field generated by a first alternating current flowing through the first coil reduces, in the gap, a second time-varying magnetic field generated by a second alternating current flowing through the second coil; and
a third coil disposed in the gap between the first coil and the second coil, wherein a coating deposited on an outer surface of the electrical probe measurably changes a metric related to a mutual inductance between the third coil and the first coil and the second coil during operation.

7. The electrical probe of claim 6 , wherein the first coil and the second coil are formed by the same wire such that the first alternating current and the second alternating current are the same.

8. The electrical probe of claim 6 , wherein the first number of turns are the same as the second number of turns.

9. The electrical probe of claim 6 , wherein at least one of the first coil, the second coil, or the third coil is operatively connected to at least one capacitor to form a resonant circuit.

10. The electrical probe of claim 6 , wherein the first coil, the second coil, and the third coil are housed in a housing comprising a body and a cap.

11. The electrical probe of claim 10 , wherein the cap is removable from the body.

12. The electrical probe of claim 6 , wherein the first coil, the second coil, and the third coil are wound about a threaded mandrel such that the first coil, the second coil, and the third coil are restrained in an axial direction.

13. A deposition system providing in-situ measurement of deposition thickness, comprising:
a deposition chamber dimensioned to receive a substrate and having an inlet that receives a chemical vapor to apply a coating to a surface of the substrate;
an electrical probe positioned in the chemical vapor deposition chamber such that an outer surface of the electrical probe is coated by the chemical vapor, wherein the electrical probe comprises a coil assembly including at least one coil, wherein the probe is separated by a distance from the substrate; and
a signal generator supplying an alternating current signal to the coil assembly to generate a first time-varying magnetic field such that eddy currents are generated in the coating on the outer surface of the electrical probe.

14. The deposition system of claim 13 , wherein the probe comprises a first coil and a second coil.

15. The deposition system of claim 14 , wherein the first coil and the second coil are wound about an axis, wherein the first coil is spaced apart from the second coil to define a gap therebetween, wherein a third coil is disposed in the gap between the first coil and the second coil, wherein the coating deposited on the outer surface of the electrical probe measurably changes a metric related to mutual inductance between the third coil and the first coil and the second coil.

16. The deposition system of claim 15 , wherein the first coil is wound about the axis in a first direction and the second coil is wound about the axis in a second direction.

Assignees

• Corning Inc

Inventors

• Paulson Charles Andrew
• Thelen Dean Michael

Classifications

• C23C16/52

  Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} · CPC title

• C23C16/36

  Carbonitrides · CPC title

• C23C16/34

  Nitrides {(C23C16/303 takes precedence)} · CPC title

• G01B7/105 Primary

  for measuring thickness of coating · CPC title

• G01B7/107 Primary

  for measuring objects while moving (G01B7/105 takes precedence) · CPC title