edfas.org 31 ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 26 NO. 1 CONCLUSIONS Thinning a die isn’t, and cannot be, easy or simple. There are too many uncontrolled variables to have a turnkey process. With reasonable attention to detail and a moderate level of skill, every live sample can be thinned to the desired thickness and tolerance. It may take a few practice samples to finetune a recipe but, once this is done, reproducing the results should not be a problem. Some of the details that require reasonable attention are: solid and level mounting of the sample, the use of fresh films, pads, and slurries, not requiring a process step to remove more than a recommended amount of silicon, changing films and refreshing slurries when required, and reviewing the results of each process step. The last item is critical. If the results are significantly different from what is desired, it must be determined why. Some frequent problems include faulty pad or film attachment on the lapping and polishing tools, cross contamination of slurries, and particulate contamination from the environment or inadequate cleaning of the sample between process steps. REFERENCES 1. K. Martin: “Processes for Thinning and Polishing Highly Warped Die to a Nearly Consistent Thickness: Part I,” Electronic Device Failure Analysis, 2022, 24(4), p. 34-38. 2. K. Martin: “Processes for Thinning and Polishing Highly Warped Die to a Nearly Consistent Thickness: Part II,” Electronic Device Failure Analysis, 2023, 25(1), p. 18-21. ABOUT THE AUTHOR Kirk Martin has almost 50 years of experience in designing and building specialized equipment for all aspects of the semiconductor industry, from crystal growth through final test and failure analysis. In 2017, he became a founder of RKD Systems, which designs and builds equipment for semiconductor failure analysis sample preparation. Martin has patents in the fields of sample preparation, chemical vapor generation, fluid handling, and electrostatic discharge detection and mitigation. His previous positions include vice president at Nisene Technology Group, director of Advanced Products at Texas Materials Labs, a manufacturer of specialty semiconductor materials, and vice president at Automated Technology Inc., a manufacturer of front-end test and measurement systems.
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