Fabrication of Broadband Antireflective Sub-Micro Structures on 4H-SiC by Mesh Patterning Etching

Abstract

An approach to fabricating pseudoperiodic antireflective subwavelength structures on silicon carbide by using modified resist as etching mask is demonstrated. The etched submicron structure is a mesh-trenched pattern thus as the so called “mesh patterning etching”. The mesh patterning process is more time-efficient than the e-beam lithography or nanoimprint lithography process. The influences of the reactive-ion etching conditions and post bake temperature of the resist film to the sub-micron structure profile and its corresponding surface reflectance have been systematically investigated. Under optimal experimental conditions, the average reflectance of the silicon carbide in the range of 390-800 nm is dramatically suppressed from 40% to around 8% after introducing the mesh patterning sub-micro structures.