Patent ID: 6059416
Filing Date: 2000-05-09
Classification: G02B

Abstract:
A method for fabricating and mounting a mirror array on an actuator array to thereby form an actuated mirror array for use in an optical projection system, wherein the actuator array is composed of M.times.N equal-sized actuators with M, N being integers, each actuators being made of an electrodisplacive material which deforms in response to an electrical signal applied thereto, the mirror array is composed M.times.N mirrors of an identical size, each of the mirrors reflecting a ray of light incident thereon in accordance with a deformation of each of the M.times.N actuators coupled thereto to thereby modulate an optical path of the reflected light, and including a reflector having a flat surface for causing the reflection of said ray of incident light and the top surface of each of the M.times.N mirrors being substantially larger than that of each of the M.times.N actuators, said method comprising the steps of:(a) patterning a substrate into an array of M.times.N identically sized, regularly spaced and disjointed protrusions, each of the M.times.N protrusions having a flat top surface, by forming regularly spaced and identical (M-1) trenches in the vertical direction and (N-1) trenches in the horizontal direction and each of the (M-1).times.(N-1) trenches having a flat bottom surface;(b) forming a separation layer on the flat top surface of each of the M.times.N protrusions and the flat bottom surface of each of the (M-1).times.(N-1) trenches;(c) defining each of the M.times.N mirrors by forming subsequently a first metallic layer on a top surface of the separation layer, a second metallic layer on a top surface of said first metallic layer, and a third metallic layer on a top surface of said second metallic layer;(d) bonding the array of M.times.N actuators onto the array of M.times.N protrusions such that each of the M.times.N actuators is aligned with each of the M.times.N mirrors;(e) disengaging the substrate from the array of M.times.N mirrors by removing the separation layer; and(f) forming a fourth metallic layer on a bottom surface of the first metallic layer so as to construct the reflector to thereby provide an array of M.times.N actuated mirrors.