Investigation of problems in JEDEC HBM ESD test standard

Sufficient emphasis need be applied to current EIA/JEDEC Human-Body Model (HBM) Electrostatic Discharge (ESD) test standard, which does not define the start and step test voltages. Some measurement begins from several kilo-volts, which makes it ignored that ESD protection devices might fail under low voltage stresses. A Gate-Grounded NMOS (GGNMOS) structure with an NWell-ballast resistor connecting its drain and PAD is investigated for HBM ESD sustaining levels in this paper. When tested with a Zapmaster of HBM model starting from 1 kilo-volt, the withstand voltage exceeds 8 kilo-volts, whereas the structure failed at 350 volts when the test initiates from 50 volts. The test results from a Transmission-Line Pulsing (TLP) system validate the phenomenon. The reason of the failure is also analyzed and proved with OBIRCH Failure Analysis (FA) results. To overcome this general issue, a suggestion for improving present HBM ESD testing standards for industry application is proposed.