Temperature measuring method, substrate processing system and component to be provided in substrate processing apparatus of the substrate processing system

Abstract

A temperature measuring method of a component of a substrate processing chamber including a surface being worn or being deposited with a foreign material by using. The method includes: providing data representing a relationship between a temperature of the component and an optical path length of a predetermined path within the component; measuring an optical path length of the predetermined path within the component by using optical interference of reflection lights of a low-coherence light from the component when the low-coherence light is irradiated onto the component to travel through the predetermined path; and obtaining a temperature of the component by comparing the measured optical path length with the data.

What is claimed is: 
     
         1 . A substrate processing system comprising:
 a substrate processing chamber configured to perform a predetermined process on a substrate accommodated therein;   a component provided in the substrate processing chamber and including at least one surface being worn or being deposited with a foreign material with a lapse of time during the predetermined process; and   a temperature measuring device configured to measure a temperature of the component,   wherein the temperature measuring device includes:   an optical system configured to irradiate a low-coherence light to the component and receive reflection lights of the low-coherence light; and   an analyzer configured to measure an optical path length of a predetermined path within the component through which the low-coherence light travels by using optical interference of the reflection lights from the component and obtain a current temperature of the component by comparing the optical path length with previously generated data representing a relationship between a temperature of the component and an optical path length of the predetermined path,   wherein the component further includes:   a first surface to which the low-coherence light from the optical system is irradiated and which is not worn and is not deposited with a foreign material with a lapse of time;   a second surface which is not worn and is not deposited with a foreign material with a lapse of time; and   a reflection surface at which a portion of the low-coherence light entering into the component at the first surface is reflected to proceed to the second surface, and   wherein the predetermined path is set such that the portion of the low-coherence light entering into the component through the first surface is reflected at the reflection surface to proceed to the second surface and travels back along a route through which the portion of the low-coherence light has traveled, after being reflected at the second surface.   
     
     
         2 . The substrate processing system of  claim 1 , wherein the second surface and the reflection surface of the component are mirror surfaces. 
     
     
         3 . The substrate processing system of  claim 1 , wherein the component has a plate-like shape, the reflection surface is inclined with respect to the first surface at an angle of about 45° and the second surface is substantially perpendicular to the first surface. 
     
     
         4 . The substrate processing system of  claim 1 , wherein the component has a plate-like shape and contains a first slit which is formed to be inclined with respect to the first surface at an angle of about 45° and a second slit which is formed to be substantially perpendicular to the first surface, and
 wherein the refection surface is a surface of the first slit and the second surface is a surface of the second slit. 
 
     
     
         5 . A substrate processing system comprising:
 a substrate processing chamber configured to perform a predetermined process on a substrate accommodated therein;   a component provided in the substrate processing chamber and including at least one surface being worn or being deposited with a foreign material with a lapse of time during the predetermined process; and   a temperature measuring device configured to measure a temperature of the component,   wherein the temperature measuring device includes:   an optical system configured to irradiate a low-coherence light to the component and receive reflection lights of the low-coherence light; and   an analyzer configured to measure an optical path length of a predetermined path within the component through which the low-coherence light travels by using optical interference of the reflection lights from the component and obtain a current temperature of the component by comparing the optical path length with previously generated data representing a relationship between a temperature of the component and an optical path length of the predetermined path,   wherein the component further includes:   an entrance surface to which a portion of the low-coherence light from the optical system is irradiated and which is not worn and is not deposited with a foreign material with a lapse of time; and   a slit is formed to be parallel to the entrance surface, and   wherein the predetermined path is set such that the portion of the low-coherence light entering into the component through the entrance surface of the component is reflected at the slit and travels back along a route through which the portion of the low-coherence light has traveled.   
     
     
         6 . The substrate processing system of  claim 5 , wherein the slit contains a reflection surface which is a mirror surface for reflecting the low-coherence light thereat. 
     
     
         7 . The substrate processing system of  claim 5 , further comprising another component provided in the substrate processing chamber to be adjacent to the component,
 wherein the low-coherence light is irradiated onto a surface of the another component and is reflected at the surface of the another component to be irradiated onto the entrance surface, the surface of the another component being not worn and being not deposited with a foreign material.   
     
     
         8 . The substrate processing system of  claim 1 , wherein the component is an electrode plate constituting a shower head disposed in the substrate processing chamber or a focus ring disposed in the substrate processing chamber. 
     
     
         9 . The substrate processing system of  claim 5 , wherein the component is an electrode plate constituting a shower head disposed in the substrate processing chamber or a focus ring disposed in the substrate processing chamber. 
     
     
         10 . The substrate processing system of  claim 1 , wherein the reflection lights includes a first refection light reflected at the first surface and a second reflection light reflected at the second surface, and
 wherein the optical path length is measured by performing Fourier transform on an interference light of the first reflection light and the second reflection light.   
     
     
         11 . The substrate processing system of  claim 5 , wherein the reflection lights includes a first refection light reflected at the entrance surface and a second reflection light reflected at the silt, and
 wherein the optical path length is measured by performing Fourier transform on an interference light of the first reflection light and the second reflection light.   
     
     
         12 . The substrate processing system of  claim 1 , wherein the optical system includes a light source for irradiating a basic low-coherence light,
 wherein the optical system divides the basic low-coherence light from the light source into a first low-coherence light which is the low-coherence light and a second low-coherence light, obtains the reflection lights including a first reflection light reflected at the first refection surface and a second reflection light reflected at the second reflection surface, irradiates the second low-coherence light onto a reference mirror to obtain a third reflection light reflected at the reference mirror while moving the reference mirror in a direction parallel to an incident direction of the second low-coherence light and receives an interference light of the first reflection light, the second reflection light and the third reflection light, and   wherein the analyzer obtains the optical path length by using the interference light and a moving distance of the reference mirror.   
     
     
         13 . The substrate processing system of  claim 5 , wherein the optical system includes a light source for irradiating a basic low-coherence light,
 wherein the optical system divides the basic low-coherence light from the light source into a first low-coherence light which is the low-coherence light and a second low-coherence light, obtains the reflection lights including a first reflection light reflected at the entrance surface and a second reflection light reflected at the slit, irradiates the second low-coherence light onto a reference mirror to obtain a third reflection light from the reference mirror while moving the reference mirror in a direction parallel to an incident direction of the second low-coherence light and receives an interference light of the first reflection light, the second reflection light and the third reflection light, and   wherein the analyzer obtains the optical path length by using the interference light and a moving distance of the reference mirror.