Cryopump with selective condensation and defrost
AssigneeHelix Technology Corporation
InventorsMichael J. Eacobacci, Jr., Stephen R. Matte
Life of this patent
Estimating the term…
Abstract
The cryopanel of a cryopump can be preferentially defrosted to remove an acid-forming or toxic gas while leaving a second gas substantially condensed upon the cryopanel thereby limiting interaction between the vapor phases of the two gases. The cryopanel is warmed to a temperature within a selective defrost range at which the first gas selectively sublimates from the cryopanel. The temperature of the cryopanel is then maintained at a temperature within this range until the cryopanel is substantially cleared of the first gas leaving the second gas substantially undisturbed as a condensate upon the cryopanel. In a preferred embodiment, the cryopanel is maintained at about 50 to 85K during standard operation before being defrosted.
Claims24
A method for preferentially defrosting a cryopanel having at least two gases condensed upon it comprising the steps of:
- warming the cryopanel to a temperature within a selective defrost range at which a first condensed gas selectively sublimates from the cryopanel into a chamber surrounding the cryopanel while water remains substantially condensed upon the cryopanel, the first condensed gas being reactive with water to produce an acid;
- and
- maintaining the temperature of the cryopanel within the selective defrost range until the first condensed gas is substantially released from the cryopanel and removed from the chamber.
A method for selectively defrosting a cryopanel within a chamber, the cryopanel having water and chlorine condensed upon it, the method comprising the steps of:
- warming the cryopanel to a temperature between about 115K and 180K to vaporize the chlorine;
- removing the chlorine vapor from the chamber;
- and
- maintaining the temperature of the cryopanel between about 115K and 180K until the chlorine vapor pressure within the chamber drops below about 0.01 torr.
A method for preferentially defrosting a cryopanel having at least two gases condensed upon it comprising the steps of:
- warming the cryopanel to a temperature within a selective defrost range at which a first condensed gas selectively sublimates from the cryopanel while a second condensed gas remains substantially condensed upon the cryopanel, the first condensed gas being toxic to humans upon inhalation;
- and
- maintaining the temperature of the cryopanel within the selective defrost range until the first condensed gas is substantially released from the cryopanel.
A cryopump comprising:
- a refrigerator;
- a cryopanel in thermal contact with the refrigerator;
- and
- an electronic module programmed to:
- warm the cryopanel to a temperature within a selective defrost range at which a first condensed gas selectively sublimates from the cryopanel while water remains substantially condensed upon the cryopanel, the first condensed gas being reactive with water to produce an acid, and
- maintain the temperature of the cryopanel within the selective defrost range until the first condensed gas is substantially released from the cryopanel.
An electronic module for controlling a cryopump having a cryopanel, the electronic module comprising electronics programmed to:
- warm the cryopanel to a temperature within a selective defrost range at which a first condensed gas selectively sublimates from the cryopanel while water remains substantially condensed upon the cryopanel, the first condensed gas being reactive with water to produce an acid;
- and
- maintain the temperature of the cryopanel within the selective defrost range until the first condensed gas is substantially released from the cryopanel.
A method for vacuum pumping a cluster process tool comprising the steps of:
- installing a single-stage cryopump within a transfer chamber of a cluster process tool;
- and
- maintaining the temperature of the cryopump within an operating temperature range of about 50K to about 85K between successive regenerations of the cryopump.
Dependencies are inferred from the claim text.