STRUCTURED GAP FOR A MEMS PRESSURE SENSOR

A method of fabricating a pressure sensor includes performing a chemical vapor deposition (CVD) process to deposit a first sacrificial layer having a first thickness onto a substrate. A portion of the first sacrificial layer is then removed down to the substrate to form a central region of bare silicon. One of a thermal oxidation process and an atomic layer deposition process is then performed to form a second sacrificial layer on the substrate having a second thickness in the central region that is less than the first thickness. A cap layer is then deposited over the first and second sacrificial layers. The second sacrificial layer is removed from the central region, and the first and second sacrificial layers are removed from a perimeter region that at least partially surrounds the central region on the substrate to form a contiguous, structured gap between the cap layer and the substrate, the structured gap having a first width in the central region and a second width in the perimeter region with the second width being greater than the first width.