Determining appropriateness of sampling integrated circuit test data in the presence of manufacturing variations

A method comprising:

• manufacturing a wafer comprising integrated circuit chips using a wafer design and a manufacturing process that uses wafer manufacturing machines;
• testing the wafer to produce test data;
• determining an original statistical variance of an original failure distribution of a component common to all of the integrated circuit chips using the test data;
• performing a process of creating a reconstructed failure distribution of the component using sampling sizes of the test data that are less than all of the test data;
• determining a first statistical variance of the reconstructed failure distribution relative to sample size;
• determining a second statistical variance of a mean time to failure of the component relative to sample size using all of the test data of the test data;
• combining the first statistical variance and the second statistical variance into a total reconstruction variance;
• determining whether the original statistical variance is less than the total reconstruction variance to identify whether additional wafers manufactured according to the wafer design and the manufacturing process can be subjected to sample-based testing using the process of creating the reconstructed failure distribution with the sampling sizes;
• prohibiting the sample-based testing of the additional wafers based on the original statistical variance being less than the total reconstruction variance;
• and
• permitting the sample-based testing of the additional wafers based on the original statistical variance not being less than the total reconstruction variance.

A computer program product for testing wafers, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a computer to cause the computer to perform a method comprising:

• testing a wafer comprising integrated circuit chips to produce test data;
• determining an original statistical variance of an original failure distribution using the test data;
• performing a process of creating a reconstructed failure distribution using sampling sizes of the test data that are less than all of the test data;
• determining a first statistical variance of the reconstructed failure distribution relative to sample size;
• determining a second statistical variance of a mean time to failure relative to sample size using the test data;
• combining the first statistical variance and the second statistical variance into a total reconstruction variance;
• determining whether the original statistical variance is less than the total reconstruction variance to identify whether additional wafers can be subjected to sample-based testing using the process of creating the reconstructed failure distribution with the sampling sizes;
• prohibiting the sample-based testing of the additional wafers based on the original statistical variance being less than the total reconstruction variance;
• and
• permitting the sample-based testing of the additional wafers based on the original statistical variance not being less than the total reconstruction variance.