Patent ID: 9073749
Filing Date: 2015-07-07
Classification: B81B,B81C,G01L

Abstract:
1. A method of fabricating a pressure sensor comprising: performing chemical vapor deposition (CVD) process to deposit a first sacrificial layer having a first thickness onto a substrate; removing a portion of the first sacrificial layer down to the substrate to form a central region of bare silicon; performing one of a thermal oxidation process and an atomic layer deposition process after removing the portion of the first sacrificial layer to form a second sacrificial layer on the region of bare silicon of the substrate and on top of or below the remaining first sacrificial layer, the second sacrificial layer having a second thickness in the central region, the second thickness being less than the first thickness and greater than a thickness of the second sacrificial layer on top of or below the first sacrificial layer; depositing a cap layer over the first and second sacrificial layers; and after depositing the cap layer, removing the second sacrificial layer from the central region and removing the first and second sacrificial layers 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, the second width being greater than the first width.