Reflectometer to monitor substrate movement

Abstract

Various embodiments include a reflectometer and a reflectometry system for monitoring movements of a substrate, such as a silicon wafer. In one embodiment, a reflectometry system monitors and controls conditions associated with a substrate disposed within a process chamber. The process chamber includes a substrate-holding device having an actuator mechanism to control movement of the substrate with respect to the substrate-holding device. The reflectometry system includes a light source configured to emit a beam of light directed at the substrate, collection optics configured to receive light reflected from the substrate by the beam of light directed at the substrate and output a signal related to one or more conditions associated with the substrate, and a processor configured to process the signal and direct the actuator mechanism to control the movement of the substrate with respect to the substrate-holding device based on the signal. Other devices and methods are disclosed.

What is claimed is: 
     
         1 . A reflectometry system to monitor one or more conditions associated with an electrostatic chuck (ESC) in a process chamber, the reflectometry system comprising:
 a light source configured to emit a beam of light directed at the ESC;   collection optics configured to receive light reflected from the ESC by the beam of light directed at the ESC and output a signal related to the one or more conditions associated with the ESC; and   a processor configured to
 process the output signal and compare the output signal with an expected signal; and 
 based on the determination that the output signal does not match the expected signal, the processor further to provide an indication of the one or more conditions of the ESC. 
   
     
     
         2 . The reflectometry system of  claim 1 , wherein the indication is at least one of an alarm and an annunciator. 
     
     
         3 . The reflectometry system of  claim 2 , wherein the annunciator is a display on a graphical user-interface (GUI) of the reflectometry system. 
     
     
         4 . The reflectometry system of  claim 1 , wherein the one or more conditions includes bolts holding the ESC to a remainder of the process chamber have loosened. 
     
     
         5 . The reflectometry system of  claim 1 , wherein the indication of the one or more conditions includes a microroughness level of an uppermost surface of the ESC has changed from an expected value of microroughness. 
     
     
         6 . The reflectometry system of  claim 1 , wherein the one or more conditions includes an indication that maintenance of the ESC is needed.