Method and apparatus for measuring temperature of substrate

Abstract

The temperature of the surface and/or inside of a substrate is measured by irradiating the front surface or rear surface of the substrate, whose temperature is to be measured, with light and measuring the interference of a reflected light from the substrate and a reference light. A method and apparatus for measuring temperature or thickness which is suitable for directly measuring the temperature of the outermost surface layer of a substrate, and an apparatus for treating a substrate for an electronic device, which uses such method, are provided.

1 . A method for measuring temperature, comprising: 
 irradiating with light the front surface or rear surface of a substrate, whose temperature is to be measured, and    measuring the interference of a reflected light from the substrate and a reference light, to thereby measure the temperature of the front surface, rear surface, and/or inside of the substrate.    
   
   
       2 . A method for measuring temperature according to  claim 1 , wherein the light is a low-coherence light.  
   
   
       3 . A method for measuring temperature according to  claim 1 , wherein the reflected light and reference light are the split lights from a same light source and the reference light is a light corresponding to a predetermined optical path length.  
   
   
       4 . A method for measuring temperature according to  claim 1 , wherein the light is applied to the rear surface on the opposite side from the front surface of the substrate, whose temperature is to be measured.  
   
   
       5 . A method for measuring temperature according to  claim 1 , wherein the light is applied to the same side as the front surface of the substrate, whose temperature is to be measured.  
   
   
       6 . A control method comprising the steps of: 
 irradiating with light the front surface or rear surface of a substrate to be treated, whose temperature is to be measured, in an apparatus for treating the substrate to be treated,    measuring the interference of a reflected light from the substrate and a reference light, to thereby measure the temperature of the front surface, rear surface, and/or inside of the substrate, and    adjusting and/or controlling an operation variable of the apparatus based on the result of the measurement.    
   
   
       7 . A control method according to  claim 6 , wherein the light is a low-coherence light.  
   
   
       8 . A control method according to  claim 6 , wherein the temperature to be measured is the temperature of the front surface or the inside of the substrate to be treated, and the variable is the temperature of a susceptor for holding the substrate to be treated.  
   
   
       9 . A control method according to  claim 6 , wherein the temperature to be measured is the temperature of the front surface or the inside of the substrate to be treated, and the variable is at least one process parameter selected from the group consisting of; the total flow rate of a gas to be supplied into a container containing the substrate to be treated, gas flow rate ratio, gas pressure, plasma-generating power, and bias power.  
   
   
       10 . A control method according to  claim 6 , wherein the temperature to be measured is the temperature distribution on the front surface or inside of the substrate to be treated, and the variable is at least one selected from the group consisting of: zone control of the susceptor temperature, attraction force zone control of the susceptor electrostatic chuck, and zone control of plasma-generating power.  
   
   
       11 . A control method according to  claim 6 , wherein the temperature to be measured is the temperature distribution on the front surface or inside of the substrate to be treated, and the variable is at least one selected from the group consisting of: the total flow rate or distribution thereof of a gas to be supplied into a container containing the substrate to be treated, gas flow rate ratio or distribution thereof, gas pressure, plasma-generating power, and bias power.  
   
   
       12 . A control method according to  claim 6 , wherein the temperature to be measured is the temperature history of the front surface or inside of the substrate to be treated while the substrate is being processed, and the adjustment and/or control of the variable is conducted as part of statistic processing of data with the object of controlling subsequent device substrate treatment based on the decision relating to the treatment results.  
   
   
       13 . A treatment method comprising the steps of: 
 irradiating with light the front surface or rear surface of a substrate to be treated, whose temperature is to be measured, in an apparatus for treating the substrate to be treated,    measuring the interference of a reflected light from the substrate and a reference light, to thereby measure the temperature of the front surface, rear surface, and/or inside of the substrate, and    adjusting and/or controlling an operation variable relating to the treatment of the substrate to be treated, based on the result of the measurement.    
   
   
       14 . A treatment method according to  claim 13 , wherein the light is a low-coherence light.  
   
   
       15 . A treatment method according to  claim 12 , wherein the treatment of the substrate to be treated is the formation of a film on the substrate to be treated.  
   
   
       16 . A treatment method according to  claim 15 , wherein surface temperature of the substrate to be treated is measured prior to the treatment for determining the starting point of the treatment.  
   
   
       17 . A treatment method according to  claim 15 , wherein the temperature and/or film thickness of the outermost surface layer is measured during the treatment for determining the end point of the treatment.  
   
   
       18 . A treatment method according to  claim 15 , wherein the treatment is started by turning on the plasma-generating power and/or bias power.  
   
   
       19 . A treatment method according to  claim 15 , wherein the temperature of the intermediate layer of substrate to be treated is measured during the treatment and employed as a temperature of the outermost surface (on which the film is being formed).  
   
   
       20 . A treatment method according to  claim 16 , wherein the intermediate layer is the second layer from the outermost surface.  
   
   
       21 . A treatment method according to  claim 13 , wherein the treatment of the substrate to be treated is etching of the substrate to be treated.  
   
   
       22 . A treatment method according to  claim 21 , wherein the surface temperature of the substrate to be treated is measured prior to the treatment for determining the starting point of the treatment,  
   
   
       23 . A treatment method according to  claim 21 , wherein the treatment is started by turning on the plasma-generating power and/or bias power.  
   
   
       24 . A treatment method according to  claim 21 , wherein the temperature of the second layer from the front surface of the substrate to be treated is measured during the treatment and the measured temperature is employed as the temperature of the outermost surface (which is being etched).  
   
   
       25 . An apparatus for measuring temperature, comprising: 
 light irradiation means for irradiating with light the front surface or rear surface of a substrate whose temperature is to be measured;    a splitter for splitting the light into a reference light and a measurement light;    reference light reflecting means for reflecting the reference light;    optical path changing means for changing the optical path length of light reflected from the reference light reflecting means; and    light receiving means for measuring the interference of the reflected light from the substrate and the reference light from the reference light reflecting means,    wherein the temperature of the front surface, rear surface and/or inside of the substrate is measured based on the measurement of the interference.    
   
   
       26 . An apparatus for measuring temperature according to  claim 25 , wherein the light is a low-coherence light.  
   
   
       27 . An apparatus for measuring temperature according to  claim 25 , wherein the interference corresponds to changes in the optical path length in the reference light.  
   
   
       28 . An apparatus for measuring temperature according to  claim 25 , wherein the interference corresponds to a phase shift in the reference light.  
   
   
       29 . An apparatus for measuring temperature according to  claim 25 , further comprising displacement measurement means for measuring the displacement of the reference light reflection means.  
   
   
       30 . An apparatus for treating a substrate for a device, comprising: 
 a treatment chamber for conducting a treatment of the substrate for a device; and    temperature measurement means for measuring the temperature of the front surface, rear surface, and/or the inside of the substrate to be disposed and treated in the treatment chamber,    wherein the temperature measurement means comprises:    light irradiation means for irradiating with light the front surface or rear surface of the substrate to be treated and whose temperature has to be measured;    a splitter for splitting the light into a reference light and a measurement light, reference light reflecting means for reflecting the reference light;    optical path changing means for changing the optical path length of the light reflected from the reference light reflecting means; and    light receiving means for measuring the interference of the reflected light from the substrate and the reference light from the reference light reflecting means.    
   
   
       31 . An apparatus for treating a substrate for a device according to  claim 30 , wherein the light is a low-coherence light.  
   
   
       32 . An apparatus for treating a substrate for a device according to  claim 30 , further comprising control means for adjusting and/or controlling an operation variable for the treatment.  
   
   
       33 . An apparatus for treating a substrate for a device according to  claim 30 , wherein the treatment of the substrate to be treated is the formation of a film on the substrate to be treated.  
   
   
       34 . An apparatus for treating a substrate for a device according to  claim 30 , wherein the treatment of the substrate to be treated is etching of the substrate.  
   
   
       35 . An apparatus for treating a substrate for a device according to  claim 30 , wherein the treatment of the substrate to be treated is annealing of the substrate.  
   
   
       36 . An apparatus for measuring temperature or thickness, comprising: light source means for irradiating with light the front surface or rear surface of a substrate whose temperature or thickness is to be measured, a splitter for splitting the light into a reference light and a measurement light; reference light reflecting means for reflecting the reference light; optical path changing means for changing the optical path length of light reflected from the reference light reflecting means; and light receiving means for measuring the interference of the reflected light from the substrate and the reference light from the reference light reflecting means, wherein the temperature or thickness of the front surface, rear surface and/or inside of the substrate is measured based on the measurement of the interference; 
 wherein the light source means comprises: one light source or two light sources having different wavelengths, for measuring the temperature or thickness of the substrate; and a displacement-measuring light source for measuring the displacement in the optical path changing means; and    the light receiving means comprises: one or two light-receiving devices corresponding to the one or two light sources, for receiving the interference light based on the light from the one or two light sources, which has been reflected from the substrate and the reference light reflecting means; and a displacement-measuring light-receiving device for receiving the interference light based on the light from the displacement-measuring light source, which has been reflected from the substrate and the reference light reflecting means.    
   
   
       37 . An apparatus for measuring temperature or thickness according to  claim 36 , wherein the light source for measuring the temperature or thickness of the substrate has a wavelength of 0.3-20 μm, and a coherence length of 0.1-100 μm.  
   
   
       38 . An apparatus for measuring temperature or thickness according to  claim 36 , wherein the light source means comprises two light sources, one of which has a wavelength providing a relatively large temperature coefficient of change in refractive index of the substrate, and the other of which has a wavelength providing a relatively small coefficient of temperature change in the refractive index of the substrate.