Semiconductor device and method

Abstract

A method includes depositing a photonic structure over a substrate, the photonic structure including photonic semiconductor layer, forming conductive pads over the photonic structure, forming a hard mask over the conductive pads, wherein the hard mask is patterned to cover each conductive pad with a hard mask region, etching the photonic structure using the hard mask as an etching mask to form multiple mesa structures protruding from the substrate, each mesa structure including a portion of the photonic structure, a contact pad, and a hard mask region, depositing a first photoresist over the multiple mesa structures, depositing a second photoresist over the first photoresist, patterning the second photoresist to expose the hard mask regions of the multiple mesa structures, and etching the hard mask regions to expose portions of the contact pads of the multiple mesa structures.