Stretched-film micromirrors for improved optical flatness

Nee, Julia; Conant, Robert A.; Hart, Matthew; Muller, R.S.; Lau, Kam Y.

doi:10.1109/memsys.2000.838604

Cited by 36 publications

(14 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even for flat mirrors with balanced stress, the difference in thermal expansion coefficients between the thin mirror and the metal coating causes the mirror curvature to change with temperature. Techniques to improve the FREE-SPACE OPTICAL MEMS, WU, PATTERSON 353 curvature of polysilicon micromirrors have been reported: by incorporating an outer-edge folded frame in the mirror film formed by depositing the polysilicon in an etched trench; [19] by exploiting the tensile stress of the polysilicon to create a drum-like mirror structure on a rigid solid frame; [20] and by a combination of high-temperature annealing and thick polysilicon cross-bar support structures. [21] Hybrid structures that use single-crystal silicon for the mirror structure and polysilicon for the actuators offer an alternative to polysilicon mirrors.…”

Section: Scanners With Electrostatic Parallel-plate Actuatorsmentioning

confidence: 99%

Free-Space Optical MEMS

Wu¹,

Patterson²

2006

Mems

View full text Add to dashboard Cite

Section: Scanners With Electrostatic Parallel-plate Actuatorsmentioning

confidence: 99%

Free-Space Optical MEMS

Wu¹,

Patterson²

2006

Mems

View full text Add to dashboard Cite

“…Even for flat mirrors with balanced stress, the difference of thermal expansion coefficients between the thin mirror and the metal coating causes the mirror curvature to change with temperature. Techniques to improve the curvature of polysilicon micromirrors have been reported: by incorporating an outer edge folded frame in the mirror film formed by depositing the polysilicon in an etched trench 21 ; by exploiting the tensile stress of the polysilicon to create a drum like mirror structure on a rigid solid frame 22 ; and by a combination of high temperature annealing and thick polysilicon cross bar support structures. 23 Hybrid structures that utilize single crystal silicon for the mirror structure and polysilicon for the actuators offer an alternative to polysilicon mirrors.…”

Section: Electrostatic Parallel-plate Scannersmentioning

confidence: 99%

Scanning micromirrors: an overview

Patterson

Hah

Fujino

et al. 2004

Optomechatronic Micro/Nano Components, Devices, and Systems

View full text Add to dashboard Cite

An overview of the current state of the art in scanning micromirror technology for switching, imaging, and beam steering applications is presented. The requirements that drive the design and fabrication technology are covered. Electrostatic, electromagnetic, and magnetic actuation techniques are discussed as well as the motivation toward combdrive configurations from parallel plate configurations for large diameter (mm range) scanners. Suitability of surface micromachining, bulk micromachining, and silicon on insulator (SOI) micromachining technology is presented in the context of the length scale and performance for given scanner applications.

show abstract

“…3,4 These designs tended to be very low mass/low moment of inertia, but exhibited unwanted curvature and nonuniformity in the mirror surface due to stresses inherent to the films and coatings used. Several clever approaches have been devised to minimize the unwanted deformation of these types of mirrors, including using vertical stiffening members, 5 creating tensile membranes similar to a drum, 6 and sandwiching lattice structures. 7,8 The utilization of single-crystalline silicon to provide an inherently stiff flat mirror surface was proposed by some early bulk micromachined designs, 9 but was not widespread until the emergence of silicon-on-insulator (SOI) fabrication technology in the late 1990, which offered readily available wafers with a thick releasable silicon device layer.…”

Section: Introductionmentioning

confidence: 99%

Mass reduction patterning of silicon-on-oxide–based micromirrors

Hall

Green

Dooley

et al. 2016

J. Micro/Nanolith. MEMS MOEMS

View full text Add to dashboard Cite

Abstract. It has long been recognized in the design of micromirror-based optical systems that balancing static flatness of the mirror surface through structural design with the system's mechanical dynamic response is challenging. Although a variety of mass reduction approaches have been presented in the literature to address this performance trade, there has been little quantifiable comparison reported. In this work, different mass reduction approaches, some unique to the work, are quantifiably compared with solid plate thinning in both curvature and mass using commercial finite element simulation of a specific square silicon-on-insulator-based micromirror geometry. Other important considerations for micromirror surfaces, including surface profile and smoothness, are also discussed. Fabrication of one of these geometries, a two-dimensional tessellated square pattern, was performed in the presence of a 400-μm-tall central post structure using a simple single mask process. Limited experimental curvature measurements of fabricated samples are shown to correspond well with properly characterized simulation results and indicate ∼67% improvement in radius of curvature in comparison to a solid plate design of equivalent mass. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Stretched-film micromirrors for improved optical flatness

Cited by 36 publications

References 4 publications

Free-Space Optical MEMS

Free-Space Optical MEMS

Scanning micromirrors: an overview

Mass reduction patterning of silicon-on-oxide–based micromirrors

Contact Info

Product

Resources

About