Effect of Profile Shape on Mechanical Performance of Silicon Lateral Suspension

 High-aspect-ratio mechanical structures fabricated using deep reactive ion etching generally have a non-rectangular profile. The profile can severely influence the mechanical performance of the device. We have quantified the profile shape for through-wafer etched beams and presented an analytical model to evaluate the effect of profile shape on silicon lateral suspensions. A design methodology is developed to compensate for the nonrectangular spring cross-section and to achieve the requisite mechanical performance targets.