As electronic systems become more complex, troubleshooting manufacturing and field failures becomes more difficult. Hard failures (i.e. permanent changes in a device that lead to reproducible failures) are straightforward to isolate and determine a root cause. The more problematic area is “no trouble found” or NTF – meaning the original failure is difficult (if not impossible) to reproduce. There are several sources of NTF: Noise – Signal reflections, cross-talk, ground bounce Timing marginality – Variations in rise times and delay times over temperature and voltage Weak cells (memory) – leakage in DRAM, read-write instability in SRAM Soft errors - upsets in memory and logic due to radiation from alpha particles within the IC package or neutrons generated from cosmic rays Each of …
Semiconductor Reliability
The Value of Defective Devices in the Semiconductor Industry
Semiconductor manufacturing employs high volume automated production lines using very complex wafer processing technologies requiring tight controls throughout the flow. Specific physical, optical, chemical and electrical tests are being performed at several stages in the manufacturing flow, to screen out wafer batches, wafers or single devices outside of the tight distribution limits of a given processing step. At the end of the wafer processing line, the wafers are tested using special test chips or test structures on the wafers and all product die are thoroughly tested for functionality. Finished encapsulated devices are tested again for full functionality and performance against the data sheet specification limits. New technologies, new products, new packages, are qualified for …
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