This disclosure provides mechanical layers and methods of forming the same. In one aspect, a method of forming a pixel includes depositing a black mask on a substrate, depositing an optical stack over the black mask, and forming a mechanical layer over the optical stack. The black mask is disposed along at least a portion of a side of the pixel, and the mechanical layer defines a cavity between the mechanical layer and the optical stack. The mechanical layer includes a reflective layer, a dielectric layer, and a cap layer, and the dielectric layer is disposed between the reflective layer and the cap layer. The method further includes forming a notch in the dielectric layer of the mechanical layer along the side of the pixel so as to reduce the overlap of the dielectric layer with the black mask along the side of the pixel.