Monitoring processing of a substrate in a processing chamber

Abstract

A substrate processing apparatus comprises a process chamber comprising walls defining an enclosure for processing a substrate, and having at least one window in a wall to allow a radiation to be transmitted therethrough. A process monitoring assembly is provided to monitor a process being conducted in the chamber. The process monitoring assembly comprises a plurality of signal sensors that each receive a radiation reflected from the substrate and that passes through the window, each signal sensor being capable of generating a signal in relation to a received radiation.

1 . A substrate processing apparatus comprising: 
 (a) a process chamber comprising walls defining an enclosure for processing a substrate, and having at least one window to allow a radiation to be transmitted therethrough; and    (b) a process monitoring assembly to monitor a process being conducted in the chamber, the process monitoring assembly comprising a plurality of signal sensors that each receive a radiation that is reflected from the substrate and that passes through the window, each signal sensor being capable of generating a signal in relation to a received radiation.    
   
   
       2 . An apparatus according to  claim 1  wherein the signal sensors monitor radiation reflected from two spaced apart surfaces on the substrate.  
   
   
       3 . An apparatus according to  claim 1  wherein the signal sensors monitor radiation reflected from two spaced apart surfaces on the substrate which include a surface of a mask pattern and an etched portion of the substrate.  
   
   
       4 . An apparatus according to  claim 1  wherein the signal sensors monitor radiation reflected from a surface of a mask pattern on the substrate and a spaced apart surface.  
   
   
       5 . An apparatus according to  claim 4  wherein the signal sensors monitor the radiation to determine a thickness.  
   
   
       6 . An apparatus according to  claim 1  wherein the source of the radiation comprises a plasma in the chamber, and wherein the process monitoring assembly monitors an optical emission intensity of the plasma in a wide band to generate a plurality of signals indicative of the spectral intensity of the plasma.  
   
   
       7 . An apparatus according to  claim 1  wherein the process monitoring assembly generates a termination signal to terminate an etch process being conducted in the chamber when the signals diverge.  
   
   
       8 . An apparatus according to  claim 1  wherein the source of radiation comprises a signal source.  
   
   
       9 . An apparatus according to  claim 8  wherein the signal source comprises an optical source capable of emitting an optical beam.  
   
   
       10 . An apparatus according to  claim 8  wherein the signal source comprises a plasma lamp operating in the nm range.  
   
   
       11 . An apparatus according to  claim 10  wherein the plasma lamp operates in the 185-700 nm range.  
   
   
       12 . An apparatus according to  claim 8  wherein the signal sensor is a narrow band monochromator.  
   
   
       13 . An apparatus according to  claim 8  wherein the signal source is a CCD system.  
   
   
       14 . An apparatus according to  claim 8  wherein the signal source is a spectroscopy system.  
   
   
       15 . An apparatus according to  claim 8  wherein the signal source is a laser interferometer.  
   
   
       16 . An apparatus according to  claim 8  wherein the signal source is connected to the signal sensor via one end of a fiber-optic cable that is bifurcated into first and second branches, the first branch comprising an end that is attached to the signal source, and the second branch comprising an end that is attached to the signal sensor.  
   
   
       17 . An apparatus according to  claim 1  wherein the window comprises quartz or fused silica.  
   
   
       18 . An apparatus according to  claim 1  comprising a plurality of separate windows in the walls of the process chamber, each window provided to receive a radiation reflected from the substrate.  
   
   
       19 . An apparatus according to  claim 18  comprising a plurality of radiation sources to provide the radiation to each window individually.  
   
   
       20 . An apparatus according to  claim 1  wherein the window is transparent to radiation having infrared wavelengths.  
   
   
       21 . A substrate processing apparatus for processing substrate in a plasma, the apparatus comprising: 
 (a) a process chamber comprising walls defining an enclosure for processing a substrate in a plasma, and having at least one window in a wall to allow a process monitoring radiation to be transmitted therethrough; and    (b) a process monitoring assembly to monitor a process being conducted in the chamber, the process monitoring assembly comprising at least one signal sensor capable of monitoring, through the window, an optical emission intensity of the plasma in a wide band and generating a plurality of signals indicative of the spectral intensity of the plasma.    
   
   
       22 . An apparatus according to  claim 21  comprising a plurality of sensors.  
   
   
       23 . An apparatus according to  claim 22  wherein the sensors monitor radiation arising from two spaced apart surfaces on the substrate.  
   
   
       24 . An apparatus according to  claim 22  wherein the sensors monitor radiation reflected from two spaced apart surfaces on the substrate which include a surface of a mask pattern and an etched portion of the substrate.  
   
   
       25 . An apparatus according to  claim 22  wherein the sensors monitor radiation reflected from a surface of a mask pattern on the substrate.