Electrothermal actuators for SiO₂ photonic MEMS

Electrothermal actuators for SiO₂ photonic MEMS

Peters, T.J. (TU Delft Micro and Nano Engineering)
Tichem, M. (TU Delft Micro and Nano Engineering)

2016

This paper describes the design, fabrication and characterization of electrothermal bimorph actuators consisting of polysilicon on top of thick (>10 μm ) silicon dioxide beams. This material platform enables the integration of actuators with photonic waveguides, producing mechanically-flexible photonic waveguide structures that are positionable. These structures are explored as part of a novel concept for highly automated, sub-micrometer precision chip-to-chip alignment. In order to prevent residual stress-induced fracturing that is associated with the release of thick oxide structures from a silicon substrate, a special reinforcement method is applied to create suspended silicon dioxide beam structures. The characterization includes measurements of the post-release deformation (i.e., without actuation), as well as the deflection resulting from quasi-static and dynamic actuation. The post-release deformation reveals a curvature, resulting in the free ends of 800 μm long silicon dioxide beams with 5 μm-thick polysilicon to be situated approximately 80 μm above the chip surface. Bimorph actuators that are 800 μm in length produce an out-of-plane deflection of approximately 11 μm at 60 mW dissipated power, corresponding to an estimated 240 ^oC actuator temperature. The delivered actuation force of the 800 μm-long bimorph actuators having 5 μm-thick polysilicon is calculated to be approximately 750 μN at 120 mW.

bimorph actuator
photonic waveguide
silicon reinforcement
curvature
deflection
bending stiffness
transient response
OA-Fund TU Delft

http://resolver.tudelft.nl/uuid:89e0ed2b-5016-493d-a6b5-0600d97beed4

https://doi.org/10.3390/mi7110200

2072-666X

Micromachines, 7 (11), 1-20

Institutional Repository

journal article

© 2016 T.J. Peters, M. Tichem