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We present the integration of an optical fiber interferometer with a MEMS probe station for measuring the out-of-plane displacement of MEMS structures. The interferometric system presented uses a phase generated carrier demodulation scheme. Digital signal processing techniques provide a theoretical measurement dynamic range greater than 10 . Experimental results characterizing a novel vertical-lift electro-thermal actuator are presented. These results are in good agreement with modeling data based on finite element analysis.

Several microactuator technologies have been investigated for positioning individual elements in large-scale microelectromechanical systems (MEMS). Electrostatic, magnetostatic, piezoelectric and thermal expansion represent the most common modes of microactuator operation. This investigation optimized the geometry of the asymmetrical electrothermal actuator to maximize its in-plane deflection characteristics. The MEMS polysilicon surface micromachined electrothermal actuator uses resistive (Joule) heating to generate differential thermal expansion and movement. In this investigation, a 3-D model of the electrothermal actuator was designed, and its geometry was optimized using the finite-element analysis (FEA) capabilities of the ANSYS computer program. The electrothermal actuator's geometry was systematically varied to establish optimum values of several critical geometrical ratios that maximize tip deflection. The value of the ratio of the length of the flexure component relative to the length of the hot arm was discovered to be the most sensitive geometrical parameter ratio that maximizes tip deflection.

This paper presents a systematic approach of failure analysis to determine the source of electrical overstress condition to a digital variable gain amplifier (DVGA) module where the failure was due to attenuation accuracy. Having consideration of the physical evidence on the failed devices and the root cause of the failure gives an insight of how the mechanical damage caused an electrical overstress exposure to the devices. The paper provides information on destructive analysis and non-destructive analysis conducted for determining the root cause of the failure of the DVGA module. Analysis revealed that devices failed due to an electrical overstress exposure through mechanical damage to the passivation of the metal-2 lines. The mechanical damage occurred during die-sort testing due to misalignment of the probes which delivered unintended electrical stress to the devices.