Patent ID: 6767757
Filing Date: 2004-07-27
Classification: B81B,B81C,G01C,G01P

Abstract:
A method for manufacturing a high-vacuum packaged microgyroscope, comprising the steps of:(a) etching a first substrate to form a groove cavity at the center of the first substrate, where a suspension structure is to be formed, and forming a first passivation layer for protecting the first substrate; (b) depositing a polysilicon layer on the etched surface of the first substrate and patterning the polysilicon layer into inner and outer electrode pads; (c) forming a suspension structure by depositing a sacrificial layer over the inner and outer electrode pads, patterning the sacrificial layer to form openings to be anchors for sustaining the suspension structure, depositing polysilicon over the opening and the sacrificial layer and patterning the deposited polysilicon layer; (d) removing the sacrificial layer by etching to float the suspension structure; (e) forming an oxide pattern on a second substrate having a signal processing circuit for sensing the motion of the suspension structure; (f) patterning the second substrate using the oxide pattern as an etching mask to form through holes for interconnection to the outside, removing the oxide pattern, and forming a first passivation layer for protecting the entire surface of the second substrate; (g) forming an interconnect by depositing a polysilicon layer to cover both sides and the top and bottom edges of the second substrate surrounded by the first passivation layer, and patterning the polysilicon layer; (h) depositing a second passivation layer to cover the interconnect and the second substrate and patterning the second passivation layer to form openings for interconnection to the outside; (i) forming inner metal/semiconductor composite layers for connection through the openings to the interconnect, and outer metal/semiconductor composite layer for vacuum packaging on the second passivation layer; and (j) vacuum sealing the first and second substrates by co-melting bond between the inner electrode pads of the first substrate and the inner metal/semiconductor composite layers, and between the outer electrode pads of the first substrate and the outer metal/semiconductor composite layers of the second substrate, to maintain the cavity of the suspension structure in a vacuum condition.