Cryopump and method of operating cryopump

Abstract

A cryopump capable of being mounted on a vacuum chamber via a gate valve, the cryopump includes a cryocooler, and a controller configured to detect whether or not the gate valve is closed, and to control the cryocooler such that a cooling capacity of the cryocooler when the gate valve is closed is increased compared to a cooling capacity of the cryocooler when the gate valve is opened.

What is claimed is: 
     
         1 . A cryopump capable of being mounted on a vacuum chamber via a gate valve, the cryopump comprising:
 a cryocooler; and   a controller configured to detect whether or not the gate valve is closed, and to control the cryocooler such that a cooling capacity of the cryocooler when the gate valve is closed is increased compared to a cooling capacity of the cryocooler when the gate valve is opened.   
     
     
         2 . The cryopump according to  claim 1 , wherein the controller is configured to receive a gate valve signal indicating an opening/closing state of the gate valve, and to detect whether or not the gate valve is closed, based on the gate valve signal. 
     
     
         3 . The cryopump according to  claim 1 , wherein the controller is configured to acquire a heat load on the cryocooler and to detect whether or not the gate valve is closed, based on the acquired heat load. 
     
     
         4 . The cryopump according to  claim 1 , wherein the cryocooler is configured to have a variable operation frequency, and
 the controller is configured to operate the cryocooler at an operation frequency equal to or higher than a first lower limit value when the gate valve is opened, and to operate the cryocooler at an operation frequency equal to or higher than a second lower limit value larger than the first lower limit value when the gate valve is closed.   
     
     
         5 . The cryopump according to  claim 1 , wherein the cryocooler is configured to have a variable operation frequency,
 the cryopump further comprises a temperature sensor that measures a cooling temperature of the cryocooler, and   the controller is configured to determine the operation frequency of the cryocooler such that a cooling temperature measured by the temperature sensor when the gate valve is opened coincides with a first target temperature, to determine the operation frequency of the cryocooler such that a cooling temperature measured by the temperature sensor when the gate valve is closed coincides with a second target temperature lower than the first target temperature, and to operate the cryocooler at the determined operation frequency.   
     
     
         6 . The cryopump according to  claim 1 , wherein the cryocooler includes a heating device, and
 the controller is configured to operate the heating device at a first output when the gate valve is opened, and to operate the heating device at a second output lower than the first output or not to operate the heating device when the gate valve is closed.   
     
     
         7 . A method of operating a cryopump, in which the cryopump is capable of being mounted on a vacuum chamber via a gate valve and includes a cryocooler, the method comprising:
 detecting whether or not the gate valve is closed; and   increasing a cooling capacity of the cryocooler when the gate valve is closed, compared to a cooling capacity of the cryocooler when the gate valve is opened.   
     
     
         8 . A cryopump comprising:
 a cryocooler; and   a controller that detects whether or not regeneration of the cryopump is completed and that controls the cryocooler to temporarily increase a cooling capacity of the cryocooler following the completion of the regeneration.