3D MEMS device and method of manufacturing

A method for manufacturing a three dimensional MEMS device, the method comprising the steps of:

• forming insulated conducting cap wafer channels on an inner side of a first cap wafer and on an inner side of a second cap wafer;
• patterning first portions of a MEMS structure and portions of insulated conducting MEMS wafer channels in a first side of a MEMS wafer;
• bonding said first side of the patterned MEMS wafer to the inner side of the first cap wafer by aligning the insulated conducting cap wafer channels of said first cap wafer with the portions of the insulated conducting MEMS wafer channels;
• patterning second portions of the MEMS structure and further portions of the insulated conducting MEMS wafer channels on a second side of the MEMS wafer;
• further bonding the second side of the patterned MEMS wafer to the inner side of the second cap wafer, by aligning such that the insulated conducting cap wafer channels of said second cap wafer are aligned with the further portions of the insulated conducting MEMS wafer channels, thereby forming insulated conducting pathways extending from within the second cap wafer, through the MEMS wafer and through the first cap wafer;
• and
• removing a portion of the an outer sides side of the first cap wafer and a portion of an outer side of the second cap wafer to expose the insulated conducting pathways.

A three dimensional (3D) MEMS device comprising:

• an electrically conductive MEMS wafer including a MEMS structure, the MEMS wafer having a first side and a second side;
• an electrically conductive top cap wafer having an inner top cap side and an outer top cap side, the inner top cap side being bonded to the first side of the MEMS wafer, the outer top cap side having electrical contacts;
• an electrically conductive bottom cap wafer having an inner bottom cap side and an outer bottom cap side, the inner bottom cap side being bonded to the second side of the MEMS wafer such that the MEMS wafer, the top cap wafer and the bottom cap wafer define a cavity for housing the MEMS structure;
• and
• insulated conducting pathways extending from the bottom cap wafer, through the MEMS wafer and through the top cap wafer, to respective electrical contacts such that the insulated conducting pathways are operative to conduct electrical signals from portions of the insulated conducting pathways extending from within the bottom cap wafer to the electrical contacts on the top cap wafer, wherein at least one of said insulated conducting pathways comprises a top cap wafer channel, a MEMS wafer channel and a bottom cap wafer channel, said channels being aligned at a first wafer interface between the top cap wafer and the MEMS wafer and a second wafer interface between the MEMS wafer and the bottom cap wafer.