Session RI2 - Applications of Low Temperature Plasmas.
INVITED session, Thursday afternoon, October 30
Brazos, ACC
Deep reactive ion etching (DRIE) of Si, also referred to as the Bosch process, has opened new areas of application in microelectromechanical systems (MEMS) and mixed technology integration. A fully integrated microsystem could include biological or chemical sensors, mechanical gears and actuators, control electronics, micro-fluidics, and optics in a variety of material systems on a single chip or in a single package. As the device designs become more complicated or monolithic integration becomes necessary, the requirements for DRIE of Si become more difficult. For example, anisotropic etch profiles, smooth etch morphology, high etch selectivity to form freestanding membrane structures, and the fabrication of multi-level etched features becomes critical to device performance. The DRIE process relies on the formation of a sidewall etch inhibitor to prevent lateral etching of the Si thus resulting in highly anisotropic etch profiles at reasonably high etch rates. In this presentation we will report on the use of the DRIE platform to fabricate deep, high-aspect ratio Si features 100 microns wide, 400 microns deep with 25 microns walls. Optimization of the DRIE process by varying process parameters including reactive gas flow, pressure, and ion energy will be discussed. The use of parameter ramping as well as multi-level masking processes to meet the challenges of advanced micro-sensor designs will also be discussed.
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.