Endpoint detection method for chamber component refurbishment
An endpoint detection system for use in detecting an endpoint of a refurbishment process for process chamber components. The refurbishment process involves use of an etchant bath to etch or clean chamber components after their use a reaction chamber in semiconductor processing to remove deposited materials including oxide films or the like. The endpoint detection system is configured to use measurements of reflected electromagnetic radiation from surfaces of the component in an etchant bath, transmitted electromagnetic radiation passing through holes in the chamber component while the component is in the etchant bath, or both to detect process endpoints. The process endpoints can coincide with a desired amount of removal of the deposited materials from surfaces and/or through holes in the chamber component. Upon detection of the endpoints, the chamber component can be removed from the etchant to limit over etching of materials from the chamber component to increase useful life.
1 . A method of detecting an endpoint of a refurbishment process for process chamber components, comprising:
submerging a process chamber component in a volume of etchant;
transmitting electromagnetic radiation from an electromagnetic radiation source through the etchant onto the process chamber component;
receiving electromagnetic radiation from the process chamber component, wherein the received electromagnetic radiation comprises electromagnetic radiation transmitted through the process chamber component via one or more through holes having inlets on a surface of the process chamber component; and
determining an endpoint of the refurbishment process for the process chamber component based on the received electromagnetic radiation, wherein the determining the endpoint comprises determining an intensity of the electromagnetic radiation transmitted from the one or more through holes and comparing the intensity with a transmission intensity threshold associated with a size of the one or more through holes.
2 . The method of claim 1 , wherein the received electromagnetic radiation comprises electromagnetic radiation reflected from a surface of the process chamber component.
3 . The method of claim 2 , wherein the determining of the endpoint comprises determining an intensity of the electromagnetic radiation reflected from the surface and comparing the intensity with a reflectance intensity threshold associated with the surface free of deposition materials.
4 . The method of claim 1 , wherein the electromagnetic radiation from the electromagnetic radiation source is non-collimated electromagnetic radiation focused on the inlets of the one or more through holes or is collimated electromagnetic radiation provided to the inlets of the one or more through holes.
5 . The method of claim 1 , further comprising mounting the process chamber component in a jig between the electromagnetic radiation source and an electromagnetic radiation receiving assembly adapted to perform the receiving step, wherein the submerging of the process chamber component comprises at least partially submerging the jig in the etchant.
6 . The method of claim 5 , wherein the jig orients and aligns the process chamber component with the one or more through holes between the electromagnetic radiation source and an inlet of the electromagnetic radiation receiving assembly.
7 . The method of claim 1 , wherein the determining of the endpoint includes determining when both the reflectance intensity threshold and the transmission intensity threshold are met or exceeded.
8 . The method of claim 1 , wherein the electromagnetic radiation comprises visible waveband electromagnetic radiation.
9 . The method of claim 1 , wherein the electromagnetic radiation comprises electromagnetic radiation outside of a visible waveband.
10 . The method of claim 1 , wherein the electromagnetic radiation traverses entrapped air within the etchant.