MEMS components and method of wafer-level manufacturing thereof
A MEMS and a method of manufacturing MEMS components are provided. The method includes providing a MEMS wafer stack including a top cap wafer, a MEMS wafer and optionally a bottom cap wafer. The MEMS wafer has MEMS structures patterned therein. The MEMS wafer and the cap wafers include insulated conducting channels forming insulated conducting pathways extending within the wafer stack. The wafer stack is bonded to an integrated circuit wafer having electrical contacts on its top side, such that the insulated conducting pathways extend from the integrated circuit wafer to the outer side of the top cap wafer. Electrical contacts on the outer side of the top cap wafer are formed and are electrically connected to the respective insulated conducting channels of the top cap wafer. The MEMS wafer stack and the integrated circuit wafer are then diced into components having respective sealed chambers and MEMS structures housed therein.
1. A microelectromechanical system (MEMS) component, comprising:
a top cap wafer having an inner side and an outer side and insulated conducting channels extending between the inner side and the outer side through a thickness of the top cap wafer, the outer side being provided with electrical contacts connected to the insulated conducting channels;
a MEMS wafer having a first side and a second side and insulated conducting channels extending between the first side and the second side through a thickness of the MEMS wafer, the MEMS wafer including a MEMS structure patterned therein, the inner side of the top cap wafer and the first side of the MEMS wafer being bonded such that the insulated conducting channels of the top cap wafer and the insulated conducting channels of the MEMS wafer are aligned to form insulated conducting pathways; and
an integrated circuit wafer having an inner side and an outer side, the inner side of the integrated circuit wafer including electrical contacts, the inner side of the integrated circuit wafer facing the second side of the MEMS wafer such that electrical contacts of the integrated circuit wafer are electrically connected to the electrical contacts of the top cap wafer with the insulated conducting pathways, the top cap wafer and the MEMS wafer providing a top cap wafer side wall and a MEMS wafer side wall defining at least a part of a hermetically sealed chamber that houses the MEMS structure.
2. The MEMS component according to claim 1 , wherein the top cap wafer and the MEMS wafer comprise a silicon material and the integrated circuit wafer is a CMOS wafer.
3. The MEMS component according to claim 1 , wherein a conducting portion of each insulated conducting channel of the top cap wafer includes a filled trench.
4. The MEMS component according to claim 1 , wherein each insulated conducting channel of the top cap wafer comprises a conductive plug of a silicon material surrounded by an insulating material and each insulating conducting channel of the MEMS wafer comprises a conductive plug of a silicon material surrounded by an air gap.
5. The MEMS component according to claim 1 , wherein each insulated conducting channel of the top cap wafer and/or of the MEMS wafer comprises an etched channel lined with an insulating material and filled with a conductive material.
6. The MEMS component according to claim 1 , comprising a bottom cap wafer having an inner side and an outer side and insulated conducting channels extending through the bottom cap wafer between the inner side and the outer side, the inner side of the bottom cap wafer being bonded to the second side of the MEMS wafer, the insulated conducting channels of the bottom cap wafer being respectively aligned with the insulated conducting channels of the MEMS wafer and forming a part of the insulated conducting pathways, the outer side of the bottom cap wafer being bonded to the integrated circuit wafer, the insulated conducting pathways extending from the electrical contacts of the integrated circuit wafer and successively through the bottom cap wafer, the MEMS wafer and the top cap wafer to the electrical contacts of the top cap wafer.
7. The MEMS component according to claim 6 , wherein at least one of the top cap wafer and the bottom cap wafer comprises:
additional electrical contacts on the outer side of said at least one of the top cap wafer and the bottom cap wafer, said additional electrical contacts being electrically connected to integrated circuits of the integrated circuit wafer; and
electrodes operatively coupled to the MEMS structure and to the additional electrical contacts, respectively.
8. The MEMS component according to claim 1 , comprising at least one of an inertial sensor, an accelerometer, a gyroscope and a pressure sensor.