Control system and method for semiconductor integrated circuit test process
First Claim
1. A method of specifying quality assurance testing of integrated circuit devices, said method comprising the steps of:
- loading a tester with a test program, and identifying IC devices to be tested by the tester by lot;
testing each of the IC devices of a said lot under a plurality of test sequences, and sorting the IC devices of the lot into bin categories according to results of the test sequences, the test sequences each defining a pass or fail standard for the IC devices;
monitoring progress of the testing of the lot of IC devices, while storing test result data indicative of the results of the test sequences;
establishing limits for each of the bin categories;
when the testing and sorting is completed, making a lot decision governing a subsequent test flow path of a tested lot by using the stored test result data and the bin category limits, said making of the lot decision including determining whether the lot meets a yield requirement of the test sequences;
storing the test result data in different memory locations in a computer in accordance with the lot decision, and displaying the lot decision; and
executing quality assurance test decisions when the lot meets the yield requirement, said quality assurance test decisions including;
if the tested lot has a quantity of IC devices exceeding the bin category limits, which quantity is equal to or greater than a predetermined number, then performing both a sampling test and a production reliability test on IC devices in the lot which have passed the test sequences,if the tested lot has a quantity of IC devices exceeding the bin category limits, which quantity is less than the predetermined number, then performing only the sampling test only on the IC devices in the lot which have passed the test sequences, andif the tested lot has no IC devices exceeding the bin category limits, then omitting the sampling test and the production reliability test.
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Abstract
A test control system for controlling overall test procedures which processes test data generated from the final test process and analyzes bin category results. The control system uses testers for testing electrical characteristics of IC devices, a host computer for processing data transmitted from the testers and for creating a number of database structures, and distributed computers for monitoring the test progress and analyzing the test results using the database structures stored in the host computer. A control method using the control system includes the steps of: performing a final test as a lot; monitoring the status of the final test progress while storing test data during the final test; determining if the final test is completed; performing a lot decision after the final test is completed based on bin category limits; and displaying the lot decision result and storing the test data. The lot decision is based upon any bin category having a bin capacity exceeding its bin category limit by greater than a certain predetermined value even though the lot meets the yield requirement. As a result, the control system can detect an abnormal lot more easily than a system in which the lot decision is based only on yield.
118 Citations
9 Claims
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1. A method of specifying quality assurance testing of integrated circuit devices, said method comprising the steps of:
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loading a tester with a test program, and identifying IC devices to be tested by the tester by lot; testing each of the IC devices of a said lot under a plurality of test sequences, and sorting the IC devices of the lot into bin categories according to results of the test sequences, the test sequences each defining a pass or fail standard for the IC devices; monitoring progress of the testing of the lot of IC devices, while storing test result data indicative of the results of the test sequences; establishing limits for each of the bin categories; when the testing and sorting is completed, making a lot decision governing a subsequent test flow path of a tested lot by using the stored test result data and the bin category limits, said making of the lot decision including determining whether the lot meets a yield requirement of the test sequences; storing the test result data in different memory locations in a computer in accordance with the lot decision, and displaying the lot decision; and executing quality assurance test decisions when the lot meets the yield requirement, said quality assurance test decisions including; if the tested lot has a quantity of IC devices exceeding the bin category limits, which quantity is equal to or greater than a predetermined number, then performing both a sampling test and a production reliability test on IC devices in the lot which have passed the test sequences, if the tested lot has a quantity of IC devices exceeding the bin category limits, which quantity is less than the predetermined number, then performing only the sampling test only on the IC devices in the lot which have passed the test sequences, and if the tested lot has no IC devices exceeding the bin category limits, then omitting the sampling test and the production reliability test. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification