Patent ID: 8907434
Filing Date: 2014-12-09
Classification: B81B,B81C,G01C,G01P

Abstract:
1. A method for manufacturing a MEMS inertial sensor, comprising: providing a semiconductor substrate comprising a first dielectric layer, a bottom induction interconnect pad and a bottom reference interconnect pad embedded at a top of the first dielectric layer; depositing a first carbon layer on the first dielectric layer as a sacrificial layer; patterning the first carbon layer to form a plurality of openings therein; depositing a second dielectric layer on the first carbon layer and removing a portion of the second dielectric layer on the first carbon layer by chemical mechanical polishing (CMP), wherein the remaining second dielectric layer in the openings forms a fixed anchor bolt, an inertial anchor bolt and a bottom sealing ring; selectively etching the fixed anchor bolt and the inertial anchor bolt, so as to form an opening in the fixed anchor bolt which exposes the bottom induction interconnect pad and an opening in the inertial anchor bolt which exposes the bottom reference interconnect pad; filling the openings with a conductive material to form contact plugs and depositing a conductive layer on the first carbon layer, the fixed anchor bolt, the inertial anchor bolt and the contact plugs; selectively etching the conductive layer to form a first fixed electrode, an inertial electrode and a connection electrode which is connected to the inertial electrode, wherein the first fixed electrode and the inertial electrode constitute a capacitor, and the connection electrode works as a support body for the inertial electrode; the first fixed electrode is arranged on and connected to the fixed anchor bolt, and is electrically connected to the bottom induction interconnect pad through the contact plug in the fixed anchor bolt; the connection electrode is connected to the inertial anchor bolt and is electrically connected to the bottom reference interconnect pad through the contact plug in the inertial anchor bolt; forming a MEMS peripheral support body on the bottom sealing ring; forming a second carbon layer on the first fixed electrode, the inertial electrode, the connection electrode and a portion of the MEMS peripheral support body, and forming a top sealing ring surrounding the second carbon layer and on a portion of the MEMS peripheral support body; forming a sealing cap layer on the second carbon layer and the top sealing ring, and etching the sealing cap layer to form an opening therein; removing the first carbon layer and the second carbon layer through the opening in the sealing cap layer; and filling the opening in the sealing cap layer.