Filling high aspect-ratio nano-structures by atomic layer deposition and its applications in nano-optic devices and integrations

摘要

Atomic layer deposition, a highly uniform and conformal deposition process, was utilized to fill trenches of various high aspect-ratio nano-grating structures. Dielectric (e.g., SiO_2), metal (e.g., aluminum), and dielectric/metal (e.g., Au/SiO_2) hybrid nano-gratings with a linewidth down to < 50 nm and an aspect ratio up to 14:1 (700 nm:50 nm) were trench-filled with various materials particularly nano-laminate materials such as TiO_2/SiO_2 and SiO_2/Al_2O_3. Various high-performance optical devices such as true-zero-order optical retarders (i.e., wave plates) and nanowire-grid polarizers were realized based on an UV-nanoimprint lithography process and the atomic layer deposition for trench fillings. Thanks to both unique material properties and nano-structure trench filling capability, the atomic layer deposition opens a path for innovative nano-structure based optical devices and integrated optical devices.