Laser direct write for release of SiO₂ MEMS and nano-scale devices with an eye to intergration with standard Si based electronics fabrication Available to Purchase

We have developed a novel process for releasing MEMS and nano-scale devices formed in SiO₂ on a Si substrate. Current approaches for releasing MEMS made of SiO₂ use wet chemical etches (e.g. EDTA or KOH) or gas phase chemical etches such as xenon difluoride. These approaches are inherently messy and difficult to control. We have shown that it is possible to release patterned SiO₂ structures using a direct write laser assisted chemical etching technique. The developed process removes Si only from the immediate area leaving behind the SiO₂ device. The technique allows the surrounding larger area of the Si wafer to be conserved for use in packaging or integration with electronics. Further, as the release is accomplished in the gas phase, we see none of the problems of “stiction” associated with a liquid etch release process. In fact, we have found this method to be so gentle that we have been able to release devices made from SiO₂ films on the order of hundreds of nanometers. Finally, this technique can be used to sculpt the silicon such that it can also be incorporated into the device design without additional lithography steps.