Laminated high-aspect-ratio microstructures in a conventional CMOS process

摘要: Abstract Electrostatically actuated microstructures with high-aspect-ratio laminated-beam suspensions have been fabricated using a 0.8 μm three-metal CMOS process followed by sequence of three maskless dry-etching steps. Laminated structures are etched the silicon oxide, nitride, and aluminum layers. The key to is use metallization as an etch-resistant mask define microstructures. A minimum beam width 1.2 μm, gap maximum thickness 4.8 obtained. These structural features will scale in size technology improves. laminated material has effective Young's modulus 61 GPa, residual stress 69 MPa, strain gradient 2 × 10 −4 −1 . Multi-conductor electrostatic micromechanisms, such self-actuating springs, x−y microstages, nested comb-drive lateral resonators, successfully produced. spring microactuator without stator that insensitive out-of-plane curl. 107 wide 109 long excited 11 V a.c. signal measured resonance amplitude 1 at 14.9 kHz. Finite-element simulation extracted value predicts frequencies springs within 7% values.