Production metrology for MEMS characterization

Abstract

Accurate measurements of MEMS geometries and motions are crucial to achieving the desired performance of the devices. The wide variety of MEMS devices in development and production requires very flexible metrology for single-platform characterization.In addition to having greatly varying geometries, devices must also be characterized statically and under actuation.White-light interferometry, fortunately, is a technique flexible enough to meet most MEMS measurement needs. This high-speed, noncontact measurement method allows both large lateral and vertical ranges with nanometerlevel vertical resolution and position accuracy. When standard illumination is replaced with strobed light, dynamic measurements of MEMS can also be carried out.This paper presents some of the hardware and software design considerations for producing a single metrology platform with the required flexibility for production MEMS metrology. Several static and dynamic MEMS measurements are presented to illustrate the design requirements.

White light optical profiling to unworn contact lenses surface topography analysis

“…It is a powerful and well-established technique for non-contact measurement of surface topography for quickly determining three-dimensional surface shape over larger areas at high vertical and moderate lateral resolution. 4,20,21 Two modes of operation are generally available for the optical profilers. For smooth surfaces the phase-shifting integrating bucket technique (PSI) is generally used since it gives sub-nanometer height resolution capability.…”

White light interferometry to characterize the hydrogel contact lens surface

“…, 2008). It is a powerful and well‐established technique for non‐contact measurement of surface topography, which can quickly determine three‐dimensional surface shape over larger areas at high vertical and moderate lateral resolution (Bennett, 1992; Novak et al. , 2003; O’Mahony et al.…”