SPIE - International Society for Optical Engineering
Journal of Micro/Nanolithography, MEMS, and MOEMS vol:11 issue:2
This paper presents an integrated reliability test methodology for electrostatic discharge (ESD) testing of microelectromechanical systems (MEMS). It is shown that conventional ESD test methods like dc leakage and current, voltage waveforms during ESD stress are insufficient for MEMS and a functionality-based approach using the mechanical response of the MEMS during ESD is needed to accurately and conclusively detect ESD failure in MEMS. A novel test setup with a probe-mountable human body model (HBM) tester is presented for this purpose. This setup can perform simultaneous measurements of MEMS out-of-plane displacement, HBM current and HBM voltage in the MEMS in situ during ESD stress. Using this setup, a few examples are demonstrated which show that that traditional electrical characterization is overestimating the ESD robustness of MEMS devices. ESD testing of MEMS is performed at different pressures on RF MEMS actuators which show that more than one type of pressure-dependent failure mechanism, such as charging, can occur due to ESD stress.