Abstract
When considering CDM-like discharge, as it happens frequently in modern high-speed process and test equipment, it is important to avoid a so-called hard discharge in various electrostatic discharge (ESD)-sensitive devices. This study presents the results of experiments that were conducted to characterize the nature of hard discharge in various ESD sample materials: electrical pre-characterization, hard- vs. soft discharge test, oscilloscope measurements of the discharge characteristics, thickness measurements of metal table coatings and mates, and chargeability experiment. The results show that, following the existing standards in semiconductor manufacturing, hard CDM discharge cannot be prevented within the standardized lower resistance bandwidth. Insofar, the related standards ANSI 20.20 and IEC EN 61340-5-1 need to undergo a significant revision in the near future. For failure analysts, the results should be taken into consideration in order to advice useful corrective actions when accompanying client audits or doing ESD risk evaluations, especially within automated process equipment.
