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US 9,958,494 B2Granted
Hierarchical wafer lifetime prediction method
AssigneeUnited Microelectronics Corp.
InventorsHsin-Ming Hou, Ji-Fu Kung
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Abstract
For improving wafer fabrication, yield and lifetime of wafers are predicted by determining coefficients of a yield domain for wafer yield prediction and a lifetime domain for a wafer lifetime prediction, an integral domain, an electric/layout domain, a metrology/defect domain, and a machine sensor domain in a hierarchical manner. With the aid of the hierarchically-determined coefficients, noises in prediction can be reduced so that precision of prediction results of the yields or the lifetimes of wafers can be raised.
Claims12
A method of wafer fabrication comprising:
- performing a wafer fabrication process;
- measuring an overall die lifetime of at least one wafer from the wafer fabrication process;
- updating a profile of a lifetime prediction according to the overall die lifetime, updating the profile of the lifetime prediction comprises:
- a processor determining an extrinsic lifetime and an intrinsic lifetime according to the overall die lifetime;
- the processor determining at least one extrinsic integral value according to the extrinsic lifetime;
- the processor determining at least one extrinsic fault detection and classification value according to the at least one extrinsic integral value;
- the processor determining an intrinsic integral value according to the intrinsic lifetime;
- the processor determining an intrinsic fault detection and classification value according to the intrinsic integral value;
- and
- the processor generating an updated profile of the lifetime prediction according to the at least one extrinsic fault detection and classification value and the intrinsic fault detection and classification value;
- and
- determining a lifetime of a subsequent wafer fabrication process using the updated profile of the lifetime prediction.
9 more elements
Dependencies are inferred from the claim text.