Flexible fabrication of large pixel count piston-tip-tilt mirror arrays for fast spatial light modulators

• Published in: Microelectronic engineering Vol. 84; no. 5; pp. 1157 - 1161
• Main Authors: Pardo, Flavio, Cirelli, R.A., Ferry, E.J., Lai, W.Y.-C., Klemens, F.P., Miner, J.F., Pai, C.S., Bower, J.E., Mansfield, W.M., Kornblit, A., Sorsch, T.W., Taylor, J.A., Baker, M.R., Fullowan, R., Simon, M.E., Aksyuk, V.A., Ryf, R., Dyson, H., Arney, S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2007; Elsevier Science
• Subjects: Adaptive optics; Applied sciences; Circuit properties; Comb-drives; Computer science; control theory; systems; Control theory. Systems; DUV; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Integrated optics. Optical fibers and wave guides; MEMS; Micro- and nanoelectromechanical devices (mems/nems); Microelectronic fabrication (materials and surfaces technology); Modular fabrication; Optical and optoelectronic circuits; Phase mirrors; Piston-tip-tilt mirrors; Robotics; Scanning mirrors; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Spatial light modulators; Wavefront control; Piston-tip-tilt mirrors; DUV; Phase mirrors; Wavefront control; Spatial light modulators; MEMS; Adaptive optics; Comb-drives; Modular fabrication; Scanning mirrors; Critical size; Micromachining; Polycrystal; Mask; Aspect ratio; Microoptics; Wavefront; Image analysis; Microelectronic fabrication; UV lithography; Vacuum ultraviolet radiation; Photolithography; Electrostatic actuators; Microelectromechanical device
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2007.01.099

We present arrays of electrostatically actuated piston-tip-tilt micromirrors realized using a surface micromachining 3-structural-layer polysilicon process. High fill factor, flat mirrors 120
μm in size have mechanical response in the order of 10
μs, with ±4° mechanical tip and tilt and 5
μm piston continuous, controllable range under 110
V. The actuator design is based on four dual in-plane comb drives with 0.5
μm critical feature size and high aspect ratio. We show a modular approach to fabricate these arrays, allowing multiple array sizes (64
2 and 256
2 mirrors) and four different designs to be implemented in three DUV masks per lithography level.