Method for regenerating cryopump

Abstract

A method for regenerating a cryopump that includes a cooler equipped with a first stage part and a second stage part which is cooled to a lower temperature than the first stage part; a cryopanel equipped with a first panel including a heat-shield body and a baffle which is cooled by the first stage part and a second panel which is cooled by the second stage part; a cryopump vessel configured to surround the cryopanel; a first heater provided in the first stage part; and a second heater provided in the second stage part, includes a temperature increasing process of increasing temperatures of the first stage part and the second stage part by supplying a purge gas into the cryopump vessel during an operation of the cooler, a roughing process of evacuating gases captured in the cryopump vessel until the cryopump vessel has a predetermined pressure and a cool-down process of lowering the temperatures of the first stage part and the second stage part to their operating temperatures, respectively.

We claim: 
     
         1 . A method for regenerating a cryopump that includes: a cooler equipped with a first stage part and a second stage part which is cooled to a lower temperature than the first stage part; a cryopanel equipped with a first panel including a heat-shield body and a baffle which is cooled by the first stage part and a second panel which is cooled by the second stage part; a cryopump vessel configured to surround the cryopanel; a first heater provided in the first stage part; and a second heater provided in the second stage part, the method comprising:
 a temperature increasing process of increasing temperatures of the first stage part and the second stage part by supplying a purge gas into the cryopump vessel during an operation of the cooler;   a roughing process of evacuating gases captured in the cryopump vessel until the cryopump vessel has a predetermined pressure; and   a cool-down process of lowering the temperatures of the first stage part and the second stage part to their operating temperatures, respectively.   
     
     
         2 . The method for regenerating a cryopump of  claim 1 ,
 wherein the temperature increasing process includes:   increasing the temperature of the second stage part to be higher than that of the first stage part.   
     
     
         3 . The method for regenerating a cryopump of  claim 2 ,
 wherein the temperature increasing process includes:   increasing the temperature of the first stage part to between 120K and 160K by using the first heater; and   increasing the temperature of the second stage part to between 130K and 170K by using the second heater.   
     
     
         4 . The method for regenerating a cryopump of  claim 1 ,
 wherein the roughing process includes:   turning off the first heater when the temperature of the first stage part reaches a predetermined first temperature; and   evacuating the gases captured in the cryopump vessel when the first heater is turned off.   
     
     
         5 . The method for regenerating a cryopump of  claim 1 ,
 wherein the roughing process includes:   evacuating water captured by the first stage part; and   evacuating at least one of hydrogen, helium, neon, argon, nitrogen, and oxygen captured by the second stage part.   
     
     
         6 . The method for regenerating a cryopump of  claim 1 ,
 wherein the roughing process includes:   turning off the second heater when the cryopump vessel has the predetermined pressure.   
     
     
         7 . The method for regenerating a cryopump of  claim 1 ,
 wherein the predetermined pressure is in the range of from 5 Torr to 15.2 Torr.