Advances in MEMS using SFB and DRIE technology

The combination of aligned silicon fusion bonding (SFB) with deep reactive ion etching (DRIE) is a flexible technology platform that can be used to fabricate complex multi-layer MEMS devices. Silicon wafers can be processed separately and subsequently aligned and bonded and further processed. DRIE technology enables very deep (through-wafer) silicon etching with high-aspect-ratio beams and trenches (1:20), using standard resist masks. DRIE technology can be used in combination with a buried cavity, etched into the bottom substrate before bonding, to fabricate a suspended microstructure. Based on this technology platform, a multi-level microfluidics board, thermal actuators, a microvalve, and a high sensitivity accelerometer have been designed, fabricated, and tested.