Long lifetime thermal spray coating for etching or deposition chamber application

1. A substrate processing apparatus comprising a chamber configured to contain a plasma, wherein the apparatus comprises one or more multi-layer surfaces oriented to face the plasma, the one or more multi-layer surfaces each comprising:

a base material;

a first layer over the base material consisting essentially of zirconia stabilized with a dopant oxide; and

a second layer over the first layer, comprising a yttrium-aluminum composite.

2. The apparatus of claim 1 , wherein the yttrium-aluminum composite is yttrium aluminum garnet (YAG).

3. The apparatus of claim 1 , wherein the yttrium-aluminum composite is yttrium aluminum monoclinic (YAM) and yttrium aluminum perovskite (YAP).

4. The apparatus of claim 1 , wherein the first layer is yttria stabilized zirconia (YSZ).

5. The apparatus of claim 1 , wherein the base material is metallic aluminum or aluminum alloy.

6. The apparatus of claim 5 , further comprising a third layer above the base material and below the first layer comprising aluminum oxide.

7. The apparatus of claim 1 , wherein the base material is quartz.

8. The apparatus of claim 1 , wherein the first layer has a thickness of at least about 0.05 mm and no greater than about 0.1 mm, and wherein the second layer has a thickness of at least about 0.05 mm and no greater than about 0.15 mm.

9. The apparatus of claim 1 , wherein the total thickness of the first layer and the second layer is less than about 0.2 mm.

10. The apparatus of claim 1 , wherein at least one of the one or more multi-layer surfaces is a replaceable chamber liner configured to fit within the chamber to face the plasma, such that it may be removed from the chamber and replaced with an identical chamber liner to refurbish the apparatus.

11. The apparatus of claim 1 , wherein at least one of the one or more multi-layer surfaces is a transparent quartz window.

12. The apparatus of claim 11 , further comprising:

a spectrometric sensor positioned to take spectrometric measurements inside the chamber, through the quartz window;

an analog to digital converter configured to convert signals corresponding to the spectrometric measurements into one or more digital signals; and

a general purpose computer comprising:

one or more processors;

a digital memory system; and

an I/O bus in communication with the analog to digital converter and configured to receive the one or more digital signals; and

one or more interconnection busses configured to transmit data between the one or more processors, the data receiver, the digital memory system, and the I/O bus.

13. The apparatus of claim 12 , wherein the digital memory system is loaded with executable program instructions comprising instructions to repeatedly cycle through a set of steps, the steps in the cycle comprising:

(1) receiving a digital signal from among the one or more digital signals from the analog to digital converter, wherein the signal is a number reflecting a spectrometric measurement of the level of zirconium within the chamber;

(2) comparing the number to a threshold number representing the maximum the level of zirconium reflecting a failure of one or more surfaces in the chamber;

(3) if the number equals and/or exceeds the threshold number, ending the cycle and transmitting a signal indicating the failure of a coating on a surface within the apparatus; otherwise, repeating the cycle.

14. A method of operating the apparatus of claim 12 , comprising:

using the spectrometric sensor to repeatedly take spectrometric measurements of the level of zirconium within the chamber, through the quartz window, wherein the spectrometric measurements are converted into the one or more digital signals by the analog to digital converter and transmitted to the I/O bus of the general purpose computer;

causing the general purpose computer to run computer executable program instructions comprising instructions to monitor the digital signals until the signals reflect a spike in the level of zirconium in the chamber, and then to transmit a signal indicating the failure of a coating on a surface within the apparatus.

15. A method of making an apparatus as recited in claim 1 , comprising, for each surface of the one or more surfaces:

providing the base material;

forming the first layer over the base material by exposing the surface to a plasma thermal spray; and

after the first layer is formed, forming the second layer over the first layer by exposing the surface to a plasma thermal spray.

16. The apparatus of claim 1 , wherein the second layer consists essentially of the yttrium-aluminum composite.