Wafer release mechanism
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYan-Hong Liu, Che-fu Chen
Life of this patent
Estimating the term…
Abstract
The present disclosure describes a method that prevents pre-mature dc-chucking in processing modules. The method includes placing a wafer onto a chuck equipped with lift pins. One or more of the lift pins include a pressure sensor configured to measure a pressure exerted by the wafer. The method further includes measuring a first pressure applied to the one or more lift pins by the wafer, lowering the lift pins to place the wafer on the chuck, and processing the wafer. The method also includes removing the wafer from the chuck by pressing the one or more lift pins against the wafer to measure a second pressure exerted by the wafer. If the measured second pressure is equal to the first pressure, the method raises the wafer using the lift pins above the chuck.
Claims20
A processing module, comprising:
- a chuck;
- a wafer lift mechanism comprising one or more lift pins configured to raise a wafer from the chuck or lower the wafer onto the chuck, wherein the one or more of the lift pins comprises a pressure sensor configured to measure a pressure exerted on the one or more lift pins by the wafer, and wherein the pressure comprises a weight of the wafer and a differential pressure due to a vacuum created on a backside of the wafer by the chuck;
- and
- a gas source configured to flow a gas over the wafer in response to the measured pressure being greater than a pressure corresponding to a weight of the wafer.
A processing module, comprising:
- a chuck with lift pins configured to raise and lower a wafer;
- a pressure sensor integrated into one or more of the lift pins, the pressure sensor configured to:
- measure a pressure exerted by the wafer on the lift pins;
- and
- measure a differential pressure at a backside of the wafer relative to that at a front side of the wafer, wherein the differential pressure is due to a vacuum provided by the chuck;
- and
- a gas line configured to flow an inert gas over the wafer.
A chuck, comprising:
- a plurality of lift pins configured to:
- lower a wafer;
- and
- raise the wafer after a wafer process is completed;
- and
- a pressure sensor incorporated as a cylindrical cap on a top surface of each one of the plurality of lift pins, wherein the pressure sensor is configured to measure a pressure exerted on the one or more lift pins by the wafer, and wherein the pressure comprises a weight of the wafer and a differential pressure due to a vacuum created on a backside of the wafer by the chuck.
Dependencies are inferred from the claim text.