Stephen Phillips, Frank Merat, Bin Mi
Department of EECS, Case School of Engineering
CWRU researchers have developed a MultiPoly process which precisely controls
the residual stress and stress gradient of large silicon structures. This,
in turn, leads to the potential of new optical and quasi-optical devices suitable
for many applications.
In particular, the process allows the fabrication of large (~several millimeter) optical surfaces whose shape can be precisely controlled during the fabrication process allowing for the production of flat and concave optical elements suitable for optical communications systems. If the fabricated surface is suspended, metal electrodes can additionally be placed beneath the optical element to allow electrostatic modification ("tuning") of the geometry of the surface. Such devices are inherently low power and can be integrated with silicon microelectronic devices. Concave mirrors with diameters of 300 µm-and radii of curvature from 7.5-12.5mm have been fabricated. The interferometrically measured radii of these mirrors agree very well with predicted values using a computer model based upon laminate theory. Mirrors with underlying steering/shaping electrodes have been designed and are currently being fabricated.