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 de-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 method, comprising:
- placing a wafer onto a chuck equipped with lift pins, wherein one or more of the lift pins incorporates thereon an integrated pressure sensor configured to measure a pressure exerted by the wafer;
- 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;
- applying a first voltage to the wafer through the chuck;
- processing the wafer;
- and
- removing the wafer from the chuck, wherein removing the wafer comprises:
- applying a second voltage to the wafer;
- flowing a gas over the wafer to remove a residual electrostatic charge;
- pressing the one or more lift pins against the wafer to measure a second pressure exerted by the wafer;
- and
- in response to the measured second pressure being substantially equal to the first pressure, raising the wafer, with the lift pins, above the chuck.
A method, comprising:
- placing a wafer onto a chuck equipped with lift pins, wherein one or more of the lift pins incorporates thereon an integrated pressure sensor configured to measure a pressure exerted by the wafer;
- resting the wafer on the lift pins above the chuck to measure 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;
- processing the wafer;
- and
- removing the wafer from the chuck, wherein removing the wafer comprises:
- flowing a gas over the wafer;
- pressing the lift pins against the wafer to measure a second pressure exerted on the one or more lift pins by the wafer;
- and
- in response to the measured second pressure being substantially equal to the first pressure, raising the wafer, with the lift pins, above the chuck.
A method, comprising:
- lowering, with lift pins, a wafer onto a chuck;
- applying a first voltage to the wafer through the chuck;
- applying, after processing the wafer, a second voltage to the wafer;
- flowing a gas over the wafer to remove a residual electrostatic charge;
- measuring, prior to processing the wafer, a first pressure applied to the lift pins by the wafer;
- measuring, after processing the wafer, a second pressure exerted by the wafer, wherein measuring the first and second pressures comprises sensing pressures using one or more pressure sensors attached to corresponding lift pins;
- and
- in response to the second pressure being substantially equal to the first pressure, raising, with the lift pins, the wafer above the chuck.
Dependencies are inferred from the claim text.