Patent ID: 6136390
Filing Date: 2000-10-24
Classification: G02B,G21K

Abstract:
A method for manufacturing an array of M.times.N thin film actuatable mirrors, wherein M and N are integers, for use in an optical projection system, the method comprising the steps of:preparing an active matrix including a substrate and an array of M.times.N connecting terminals;depositing successively a passivation layer, an etchant stopping layer and a thin film sacrificial layer on top of the active matrix, respectively;depositing a first mask layer on top of the thin film sacrificial layer;forming a second mask layer on top of the first mask layer;etching the first mask layer and the thin film sacrificial layer, selectively, thereby creating an array of M.times.N pairs of trapezoid-shaped cavities in the thin film sacrificial layer, one of the cavities in each pair exposing a portion of one of the connecting terminals;removing the second mask layer;removing the first mask layer, thereby causing the cavities to have rounded top edges;forming an array of M.times.N actuating structures on top of the thin film sacrificial layer, each of the actuating structures including a supporting member, a second thin film electrode, a thin film electrodisplacive layer, and a first thin film electrode and a via, the first thin film electrode being of made of a light reflecting and electrically conducting material, thereby allowing it to function as an electrode and a mirror, wherein each of the actuating structures deforms in response to an electrical signal applied from the corresponding terminal through the via between the second thin film electrode and the first thin film electrode with the first thin film electrodisplacive layer disposed therebetween; andremoving the thin film sacrificial layer to thereby form the array of M.times.N thin film actuatable mirrors.