Deep silicon etching: current capabilities and future directions

Deep Reactive Ion Etching (DRIE) has revolutionized a wide variety of MEMS applications since its inception nearly two decades ago. The DRIE technology has been largely responsible for allowing lab scale technology demonstrations to become manufacturable and profitable consumer products. As applications which utilize DRIE technologies continue to expand and evolve, they continue to spawn a range of new requirements and open up exciting opportunities for advancement of DRIE. This paper will examine a number of current and emerging DRIE applications including nanotechnology, and DRIE related packaging technologies such as Through Silicon Via (TSV) and plasma dicing. The paper will discuss a number of technical challenges and solutions associated with these applications including: feature profile control at high aspect ratios, causes and elimination of feature tilt/skew, process options for fragile device structures, and problems associated with through substrate etching. The paper will close with a short discussion around the challenges of implementing DRIE in production environments as well as looking at potentially disruptive enhancements / substitutions for DRIE.