Preparation of nanostructured NiCr film as a terahertz absorption layer by magnetron sputtering and RIE

Nanostructured NiCr thin film was prepared by a combination of magnetron sputtering and reactive ion etching (RIE) in 80 × 60 uncooled infrared focal plane arrays (IRFPA). The surface morphologies and THz absorption characteristics of the IRFPAs were tested with NiCr absorption layers prepared by magnetron sputtering and the combined process respectively. The tests suggested that THz absorption could be effectively enhanced by RIE processes applied to the dielectric substrate and NiCr film, which increased the specific surface area of NiCr absorption film by generating nanoscale structures on upper and lower surfaces.