Semiconductor wafer cooling
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYung-Yao Lee, Cheng-Kang Hu, Jui-Chun Peng, Hsu-Shui Liu
Life of this patent
Estimating the term…
Abstract
A cooling controller receives, from one or more sensors, wafer information associated with a wafer. The cooling controller determines a pattern mask area for the wafer based on the wafer information. The cooling controller determines a cooling time for the wafer based on the pattern mask area. The cooling controller causes a cooling plate to cool the wafer for a time duration equal to the cooling time. Determining the cooling time for a wafer based on a pattern mask area provides stable and consistent wafer temperatures for wafers having different mask and layout properties, which reduces mask overlay variation and increases wafer yield.
Claims20
A method, comprising:
- receiving, by a cooling controller, wafer information associated with a wafer from one or more sensors;
- determining, by the cooling controller and based on the wafer information, a center point of the wafer;
- determining, by the cooling controller and based on the center point, a plurality of field edge points for the wafer,
- wherein a first vector between a first field edge point of the plurality of field edge points and the center point is orthogonal to a second vector between a second field edge point of the plurality of field edge points and the center point;
- determining, by the cooling controller, a pattern mask area based on the plurality of field edge points;
- determining, by the cooling controller, a cooling time for the wafer based on the pattern mask area and exposure process information;
- and
- causing, by the cooling controller, a cooling plate to cool the wafer for a time duration equal to the cooling time.
A method, comprising:
- coating each wafer in a wafer lot with a photoresist;
- determining a cooling time for the wafer lot,
- wherein determining the cooling time for the wafer lot comprises:
- determining a pattern mask area for a wafer based on wafer information, associated with the wafer, received from one or more sensors,
- identifying a first cooling time for the wafer,
- determining a time adjustment based on the pattern mask area, and
- determining a second cooling time for the wafer based on the time adjustment;
- cooling each wafer in the wafer lot based on the cooling time for the wafer lot, wherein the wafer is cooled for a time duration equal to the second cooling time;
- exposing each wafer in the wafer lot to a radiation source to transfer a pattern from a photomask to the photoresist;
- and
- developing the pattern transferred to the photoresist on each wafer in the wafer lot.
A system, comprising:
- one or more sensors configured to:
- generate an image scan of a wafer, and
- provide the image scan to a cooling controller;
- the cooling controller configured to:
- determine a center point of the wafer based on the image scan,
- determine a plurality of field edge points for the wafer based on the center point,
- determine a pattern mask area for the wafer based on the plurality of field edge points,
- determine a time adjustment based on the pattern mask area,
- adjust a default cooling time for the wafer based on the time adjustment,
- determine a cooling time for the wafer based on the adjustment to the default cooling time, and
- provide a signal to a cooling plate based on the cooling time;
- and
- the cooling plate configured to cool the wafer for a time duration equal to the cooling time based on the signal.
Dependencies are inferred from the claim text.