Cryopump and method of monitoring cryopump

A cryopump for pumping gas from a vacuum chamber in a vacuum apparatus performing vacuum processing, the vacuum apparatus provided with a vacuum apparatus controller for executing the vacuum processing, the cryopump comprising:

• a first stage cryopanel;
• a first temperature sensor that measures a temperature of the first stage cryopanel;
• a second stage cryopanel cooled to a lower temperature than the first stage cryopanel in conjunction with the temperature of the first stage cryopanel;
• a second temperature sensor that measures the temperature of the second stage cryopanel;
• and
• a cryopump controller configured to perform a cool-down step in which the second stage cryopanel is cooled to a temperature less than 20K and a subsequent normal pumping operation of the cryopump after completion of the cool-down step, the normal pumping operation including controlling the first stage cryopanel to have a target temperature,
• wherein the cryopump controller is provided apart from the vacuum apparatus controller and communicatably connected with the vacuum apparatus controller,
• wherein the vacuum apparatus controller sets a maximum cryogenic temperature of the second stage cryopanel for the vacuum processing, and the cryopump controller sets an alert temperature that is irrespective of the measured temperature of the second stage cryopanel based on the maximum cryogenic temperature,
• wherein the cryopump controller performs, while controlling the first stage cryopanel to have the target temperature during the subsequent normal pumping operation:
• a first determination in which the cryopump controller compares the measured temperature of the second stage cryopanel with the alert temperature and determines whether the measured temperature of the second stage cryopanel is higher than or equal to the alert temperature set to be lower than the maximum cryogenic temperature of the second stage cryopanel set in the vacuum apparatus, wherein the alert temperature is less than 20K;
• and
• a second determination in which it is determined whether the second stage cryopanel is continuously being heated, for a preset period of time or longer, to a temperature within a temperature range set on condition that the alert temperature is a maximum,
• wherein, when it is determined that the measured temperature of the second stage cryopanel is higher or equal to the alert temperature in the first determination, the cryopump controller allows the normal pumping operation to continue.