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Wafer Chamber     

Please note:  wafer level TXRF measurements are no longer available, details on TXRF Home Page.

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Shown below is the wafer loading sequence into the TXRF chamber.  This chamber has been placed in a cleanroom to prevent contamination while measuring the wafer.  Seen in the pictures below are the chamber (center bottom), the SiLi detector (left), and the wafer loading robot (top, middle).  

Initially, the wafer is placed on top of the chamber on Teflon plugs by a human, with the wafer backside up. 
The motorized robot then descends towards the wafer, and establishes contact with the wafer.
By using a vacuum wand, the robot maintains its "grip" on the wafer as it slowly raises it.
After reaching a predetermined height, the robot then rotates the wafer 90 degrees for entry into the TXRF chamber.
Upon completion of the rotation, the robot then lowers the wafer slowly into the chamber.
Inside the chamber, an electrostatic chuck exists, however, this chuck can only be used in near vacuum conditions.
After leaving the wafer inside the chamber, the robot arm moves up and out of the way.
Finally, the chamber door is closed and the can now be pumped down.  After pumping, the electrostatic chuck is turned on and provide the force to hold the wafer upright.
vacuum chamber GIF Lower part of TXRF vacuum chamber. Seen on side of chamber are electrical inputs to hold the wafer on the chuck and move the wafer to various positions in the X-Ray beam, connections to vacuum pumps, and a viewing port to allow visual check of the wafer position.


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Last modified: January 26, 2007