High vacuum dual stage load lock and method for loading and unloading wafers using a high vacuum dual stage load lock

A method for transferring an article between an ambient atmospheric pressure environment and a processing vacuum environment, through a load lock chamber having loading and transfer chambers that are separated by a ledge having an opening for passing the article there between, the ledge having a first side that faces the loading chamber and a second side that faces the transfer chamber, comprising:

• moving an article-bearing stage contained within the transfer chamber toward the second side to operably abut the ledge to create fluid isolation between the loading and transfer chambers to allow ambient atmospheric and vacuum pressures to coexist in the loading and transfer chambers respectively;
• loading the article from the first ambient atmospheric pressure environment into the loading chamber onto the article-bearing stage while the loading chamber is at ambient atmospheric pressure and in fluid isolation from the transfer chamber with the transfer chamber being at a vacuum pressure;
• moving a moveable subchamber contained within the loading chamber toward the article-bearing stage to cooperate with the ledge and article bearing stage to create a sealing surroundment of the article;
• evacuating the moveable subchamber to a pressure substantially equal to the vacuum of the transfer chamber;
• lowering the article-bearing stage away from the second side of the ledge, whereby the article is moved from the loading chamber into the transfer chamber;
• transferring the article from the transfer chamber to the processing vacuum environment.

A method for transferring an article between a first ambient atmospheric pressure environment and a processing vacuum environment, through a load lock chamber having selectively separable first and second chambers, comprising:

• maintaining the second chamber at a vacuum;
• transferring the article from the processing environment onto a controllably moveable pedestal in the second chamber while an interior region of the first chamber exterior to a moveable subchamber within the first chamber is in fluid isolation from the second chamber;
• moving the pedestal upward to position the article into the moveable subchamber and to cause the pedestal to cooperate with a ledge projecting inward from the load lock chamber to create fluid isolation between the subchamber and second chamber to allow ambient atmospheric pressure and high vacuum to coexist in the subchamber and second chamber respectively;
• adjusting the moveable subchamber to ambient atmospheric pressure;
• raising the moveable subchamber;
• and
• transferring the article from the first chamber to the first ambient atmospheric pressure environment.