Control Etch Rates on PZT for MEMS Fabrication

Precise erosion of thin layers from delicate substrates—this is what MicroBlasting is designed to do, and the capability extends to ceramics.

The following paper, published in the Journal of Micromechanics and Microengineering, dives into how researchers at the University of Maryland used Comco micro-precision sandblasting technology (referred to as micro powder blasting) to etch features into the surface of piezoelectric ceramic material (PZT). Their research determined that this etching method is mass-producible, commercially viable, fast, and inexpensive.

The researchers detail why MicroBlasting is an excellent tool for creating micro-mechanical systems (MEMS) from bulk PZT that has been patterned using a dry-film photoresist mask. They show how abrasive type, blast pressure, and nozzle-to-part distance can be manipulated to control etching rates and create features as small as 25 microns—all without undercutting the mask.

The team used micro-precision sandblasting to create two different cantilever micro-actuators. They concluded that using this technology on dry-film patterned PZT greatly simplified fabricating devices out of bulk PZT compared to other existing techniques. The entire fabrication process for each device took less than an hour, allowing for the rapid development of a range of micromechanical devices to be built out of bulk PZT. 

The paper is available at the link above through June 1, 2020, courtesy of IOP Publishing and the Journal of Micromechanics and Microengineering.