US Patent 11528546 Sealed vacuum MEMS die

A MEMS die includes a substrate having an opening formed therein, and a diaphragm attached around a periphery thereof to the substrate and over the opening, wherein the diaphragm comprises first and second spaced apart layers. A backplate is disposed between the first and second spaced apart layers. One or more columnar supports are disposed through holes disposed through the backplate and connecting the first and second spaced apart layers. At least a partial vacuum exists between at least a portion of the first and second spaced apart layers. The first layer further comprises interior and exterior sub-layers at least proximate to each of the one or more columnar supports, wherein the interior sub-layers include one or more apertures disposed therethrough.