Deposition Substrate Temperature and Monitoring

Abstract

The disclosure provides an apparatus for depositing a coating on one or more parts ( 21 ). The apparatus has: a chamber ( 22 ); a part holder ( 64 ) for carrying the part(s); a bias voltage source ( 94 ) coupled to the part(s) to apply a bias voltage to the part(s); a source ( 34 ) of the coating material; a plurality of temperature sensors ( 76 ); and a plurality of leads ( 90 ) passing outputs of the temperature sensors out from the chamber. A temperature monitoring system ( 150 ) has a temperature data processor ( 300 ). At least one fiber optic link ( 223 ) couples the temperature data processor to the temperature sensors so as to electrically isolate the temperature data processor from the bias voltage.

1 . An apparatus for depositing a coating on one or more part(s) ( 21 ), the apparatus comprising:
 a chamber ( 22 );   a part holder ( 64 ) for carrying the part(s) ( 21 );   a bias voltage source ( 94 ) coupled to the part(s) to apply a bias voltage to the part(s);   a source ( 34 ) of the coating material;   a plurality of temperature sensors ( 76 );   a plurality of leads ( 90 ) passing outputs of the temperature sensors out from the chamber;   a temperature monitoring system ( 150 ) comprising a temperature data processor ( 300 ); and   at least one fiber optic link ( 223 ) coupling the temperature data processor to the temperature sensors so as to electrically isolate the temperature data processor from the bias voltage.   
     
     
         2 . The apparatus of  claim 1  wherein:
 the temperature monitoring system comprises a temperature registration/recording unit ( 308 ) with one or more temperature monitors ( 310 ). 
 
     
     
         3 . The apparatus of  claim 1  further comprising:
 an automatic temperature control system ( 160 ) connected with the temperature data processor ( 300 ) at the input and with the bias power source ( 94 ) at the output to provide feedback temperature control by regulating parameters of substrate bias voltage. 
 
     
     
         4 . The apparatus of  claim 1  wherein:
 the source of coating material comprises an ingot ( 35 ) and an electron beam source ( 50 ) positioned to direct a beam ( 52 ) to the ingot. 
 
     
     
         5 . The apparatus of  claim 1  wherein:
 the part holder is on a sting assembly shiftable between: 
 an inserted condition where the sting assembly holds the part(s) within the chamber for coating; and 
 a retracted condition where the sting assembly holds the part(s) outside of the chamber; and 
 the source of the coating material is positioned to direct a flow of the coating material to the part(s) in the inserted condition. 
 
     
     
         6 . The apparatus of  claim 1  wherein:
 the temperature sensors are a plurality of thermocouples. 
 
     
     
         7 . The apparatus of  claim 1  wherein for each temperature sensor, the apparatus comprises:
 an associated said fiber optic link ( 223 ); and 
 a non-fiber optic optical isolator ( 242 ) between the temperature sensor and the fiber optic link. 
 
     
     
         8 . The apparatus of  claim 7  wherein for each temperature sensor, the apparatus comprises:
 a preamplifier ( 228 ) receiving output of the temperature sensor; 
 a low-pass filter ( 240 ); 
 the associated said optical isolator ( 242 ) between the preamplifier and the low-pass filter; and 
 a voltage-to-frequency converter ( 262 ) between the low-pass filter and the fiber optic link ( 223 ); and 
 a frequency-to-voltage converter ( 280 ) between the fiber optic link and the temperature data processor ( 300 ). 
 
     
     
         9 . The apparatus of  claim 1  wherein each fiber optic link comprises:
 a LED ( 284 ); a photodiode ( 286 ); and a flexible optical fiber ( 224 ) positioned to carry light from the LED to the photodiode. 
 
     
     
         10 . The apparatus of  claim 9  wherein:
 the optical fiber has a length of at least 1 m. 
 
     
     
         11 . The apparatus of  claim 1  wherein:
 a rotating brush collector ( 152 ) conveys outputs of the temperature sensors. 
 
     
     
         12 . The apparatus of  claim 11  wherein:
 the rotating brush collector also conveys the bias voltage from the bias voltage source to the part(s). 
 
     
     
         13 . A method for using the apparatus of  claim 1 , the method comprising:
 coating a first said part;   after the coating, retracting a sting assembly carrying the part holder from an inserted condition to a retracted condition to retract the first part from the chamber;   replacing the first part with a second said part;   inserting the second part into the chamber; and   coating the second part.   
     
     
         14 . The method of  claim 13  wherein:
 the retracting brings the part holder into a load lock chamber. 
 
     
     
         15 . The method of  claim 13  wherein:
 during the coating of the first part and the second part, the bias voltage has a peak magnitude of at least 100 volts. 
 
     
     
         16 . The method of  claim 15  wherein:
 during the coating of the first part and the second part, the bias voltage is pulse width modulated. 
 
     
     
         17 . The method of  claim 13  wherein:
 during coating, the part being coated is rotated. 
 
     
     
         18 . The method of  claim 13  wherein:
 the coating passes to the part being coated as a vapor.