Meaning
Formal procedures evaluate the electrical performance of test structures on a semiconductor wafer to determine if the lot meets production requirements. A successful wafer acceptance testing process confirms that the manufacturing parameters remain within the tolerances defined by the design house and the foundry. This data provides the primary basis for financial settlement.
Lot Disposition
Pass or fail criteria are applied to each wafer based on the measurement of sheet resistance, transistor threshold voltage and contact resistance. If the results of the wafer acceptance testing fall outside the specification limits, the entire lot may be scrapped or downgraded. This decision prevents defective components from moving to the assembly and packaging stage.
Traceability Log
Requirements for data storage necessitate the retention of all results for a minimum of five years. This documentation allows manufacturers to perform root cause analysis if a component fails in the field. The State Administration for Market Regulation may audit these logs during an investigation into product quality or safety.
Digital records must be secured against tampering to maintain their validity in a legal dispute. Furthermore, the log must identify the specific equipment used for each test and the calibration status of those instruments at the time of the measurement.
Regulatory Inspection
Teams from the Ministry of Industry and Information Technology frequently review these testing protocols at fabrication plants. A wafer acceptance testing report is often a mandatory attachment for the registration of new semiconductor designs. Failure to comply with these inspection rules can lead to the suspension of production licenses.
The record of these tests remains a mandatory component of the compliance dossier for any semiconductor product seeking entry into the domestic civil aviation or medical equipment market.
