Interferometer endpoint monitoring device

Abstract

A photomask etch chamber, which includes a substrate support member disposed inside the chamber. The substrate support member is configured to support a photomask substrate. The chamber further includes a ceiling disposed on the chamber and an endpoint detection system configured to detect a peripheral region of the photomask substrate.

1 . A photomask etch chamber, comprising: 
 a substrate support member disposed inside the chamber, wherein the substrate support member is configured to support a photomask substrate;    a ceiling disposed on the chamber; and    an endpoint detection system configured to detect a peripheral region of the photomask substrate.    
   
   
       2 . The chamber of  claim 1 , wherein the endpoint detection system is disposed through a peripheral region of the ceiling and positioned directly above the peripheral region of the photomask substrate.  
   
   
       3 . The chamber of  claim 1 , wherein the endpoint detection system is disposed through a peripheral region of the substrate support member and positioned directly below the peripheral region of the photomask substrate.  
   
   
       4 . The chamber of  claim 1 , wherein the endpoint detection system is an interferometer endpoint detection system.  
   
   
       5 . A photomask etch chamber, comprising: 
 a substrate support member disposed inside the chamber, wherein the substrate support member is configured to support a photomask substrate;    a ceiling disposed on the chamber; and    an interferometer endpoint detection system disposed through a peripheral region of the ceiling.    
   
   
       6 . The chamber of  claim 5 , wherein the interferometer endpoint detection system is disposed directly above a corner region of the photomask substrate.  
   
   
       7 . The chamber of  claim 5 , wherein the photomask substrate is about 6 inches wide and about 6 inches long and the interferometer endpoint detection system is disposed about 2.8 inches from a horizontal center line and about 2.8 inches from a vertical center line of the photomask substrate.  
   
   
       8 . The chamber of  claim 5 , wherein the interferometer endpoint detection system is disposed directly above a peripheral region of the photomask substrate.  
   
   
       9 . The chamber of  claim 5 , wherein the interferometer endpoint detection system is configured to detect a peripheral region of the photomask substrate.  
   
   
       10 . The chamber of  claim 5 , wherein the interferometer endpoint detection system is configured to detect one or more test patterns disposed on a peripheral region of the photomask substrate.  
   
   
       11 . The chamber of  claim 5 , wherein the interferometer endpoint detection system is configured to detect one or more test patterns disposed on a corner region of the photomask substrate.  
   
   
       12 . The chamber of  claim 5 , wherein the interferometer endpoint detection system comprises: 
 a light source for sending a light beam to a surface of the substrate; and    a light detector for measuring the intensity of the light beam reflected from the substrate surface.    
   
   
       13 . The chamber of  claim 5 , wherein the interferometer endpoint detection system further comprises a focusing assembly for focusing the light beam to a spot on the substrate surface.  
   
   
       14 . The chamber of  claim 5 , wherein the interferometer endpoint detection system further comprises a computer for calculating at least a portion of the waveform spectra of the reflected light beam.  
   
   
       15 . The chamber of  claim 14 , wherein the computer is configured to compare the waveform spectra of the reflected light beam with a stored characteristic waveform spectra pattern.  
   
   
       16 . A photomask etch chamber, comprising: 
 a substrate support member disposed inside the chamber, wherein the substrate support member is configured to support a photomask substrate; and    an interferometer endpoint detection system disposed through a peripheral region of the substrate support member.    
   
   
       17 . The chamber of  claim 16 , wherein the interferometer endpoint detection system is disposed directly below a corner region of the photomask substrate.  
   
   
       18 . The chamber of  claim 16 , wherein the photomask substrate is about 6 inches wide and about 6 inches long and the interferometer endpoint detection system is disposed about 2.8 inches from a horizontal center line and about 2.8 inches from a vertical center line of the photomask substrate.  
   
   
       19 . The chamber of  claim 16 , wherein the interferometer endpoint detection system is disposed directly below a peripheral region of the photomask substrate.  
   
   
       20 . The chamber of  claim 16 , wherein the interferometer endpoint detection system is configured to detect a peripheral bottom region of the photomask substrate.  
   
   
       21 . The chamber of  claim 16 , wherein the interferometer endpoint detection system is configured to detect one or more test patterns disposed on a peripheral region of the photomask substrate.  
   
   
       22 . The chamber of  claim 16 , wherein the interferometer endpoint detection system is configured to detect one or more test patterns disposed on a corner region of the photomask substrate.