Etch-selective bonding layer for hybrid photonic devices

Abstract

'Hybrid photonic devices' describe devices wherein the optical portion—i.e., the optical mode, comprises both the silicon and III-V semiconductor regions, and thus the refractive index of the semiconductor materials and the refractive index of the bonding layer region directly effects the optical function of the device. Prior art devices utilize an optically compliant layer that is the same material as the III-V substrate; however, during the final sub-process of the bonding process, the substrates must be removed by acids. These acids can etch into the bonding layer, causing imperfections to propagate at the interface of the bonded material, adversely affecting the optical mode shape and propagation loss of the device. Embodiments of the invention utilize a semiconductor etch-selective bonding layer that is not affected by the final stages of the bonding process (e.g., substrate removal), and thus protects the bonding interface layer from being affected.