METROLOGY SAMPLING METHOD AND COMPUTER PROGRAM PRODUCT THEREOF

摘要

In a metrology sampling method, various index values that can detect various status changes of a process tool (such as maintenance operation, parts changing, parameter adjustment, etc.), and/or information abnormalities of the process tool (such as abnormal process data, parameter drift/shift, abnormal metrology data, etc.) appear in a manufacturing process are applied to develop an intelligent sampling decision (ISD) scheme for reducing sampling rate while VM accuracy is still sustained. The indices includes a reliance Index (RI), a global similarity index (GSI), a process data quality index (DQIX) and a metrology data quality index (DQIy).

主权项

1. A metrology sampling method, comprising:
collecting a plurality of sets of historical process data used by a process tool for processing a plurality of historical workpieces; performing a model-creation step, comprising:
building a DQIX (Process Data Quality Index) model and a GSI (Global Similarity index) model and computing a DQIX threshold and a GSI threshold by using the sets of historical process data; and performing a metrology workpiece sampling step, comprising:
providing a workpiece to the process tool, the process tool having a set of process data for processing the workpiece;inputting the set of process data into the DQIX model and the GSI model, thereby obtaining a DQIX value and a GSI value of the set of process data of the workpiece;skipping an measurement of the workpiece when the DQIX value is greater than the DQIX threshold;checking if the workpiece is a workpiece expected to be measured when the DQIX value is smaller than or equal to the DQIX threshold, thereby obtaining a first checking result;performing metrology on the workpiece when the first checking result is true;checking if the GSI value is smaller than or equal to the GSI threshold when the first checking result is false, thereby obtaining a second checking result; andskipping the measurement of the workpiece when the second checking result is true.