Fabrication of nanopillar forests with high infrared absorptance based on rough poly-Si and spacer technology

摘要

Nanopillar forests with high infrared (IR) absorptance are fabricated based on a highly flexible, controllable and micro-fabrication compatible parallel approach. The key technique of the approach is using rough surfaces of poly-Si films as support structures in spacer technology. In a wavelength region of 1.5-5 μm, IR absorptance of the large-area nanopillar forests reaches a minimum of 95%, which is much higher than that of poly-Si films and Si_3N_4-based IR absorbers. As the approach is compatible with conventional micro-fabrication process, the nanopillar forests can be photo-patterned and generated on microstructures or devices. It is expected that the nanopillar forests can be employed as absorbers in micro-electro-mechanical system IR sensors to improve performance.