Method for reducing harmonic distortion in comb drive devices

Abstract

Methods of fabricating comb drive devices utilizing one or more sacrificial etch-buffers are disclosed. An illustrative fabrication method may include the steps of etching a pattern onto a wafer substrate defining one or more comb drive elements and sacrificial etch-buffers, liberating and removing one or more sacrificial etch-buffers prior to wafer bonding, bonding the etched wafer substrate to an underlying support substrate, and etching away the wafer substrate. In some embodiments, the sacrificial etch-buffers are removed after bonding the wafer to the support substrate. The sacrificial etch-buffers can be provided at one or more selective regions to provide greater uniformity in etch rate during etching. A comb drive device in accordance with an illustrative embodiment can include a number of interdigitated comb fingers each having a more uniform profile along their length and/or at their ends, producing less harmonic distortion during operation.