US Patent 11365119 Device having a membrane and method of manufacture

In an embodiment a device includes a substrate including an upper substrate surface and a lower substrate surface and a membrane-layer suspended above the upper substrate surface, wherein the substrate includes a recess penetrating the substrate between the lower substrate surface and the upper substrate surface, wherein the membrane-layer spans the recess, wherein the recess includes an upper recess region, an intermediate recess region, and a lower recess region, wherein the upper recess region is a part of the recess in direct vicinity to the upper substrate surface, the intermediate recess region is a part of the recess directly below the upper recess region, and the lower recess region is a part of the recess other than the upper recess region and the intermediate recess region, and wherein a cross-sectional area of the upper recess region determined parallel to the upper substrate surface is larger than a respective cross-sectional area of the intermediate recess region.