Fabrication of silicon nanostructures is a key technique for the development of monolithically integrated optoelectronic circuits. We demonstrate that the process of scanning probe lithography (SPL) and anisotropic TMAH etching is a low-cost and reliable method to produce smooth and uniform silicon nanostructures on a variety of silicon substrates. Etched structures with a pitch of 100 nm, positive- and negative-contrast structures, and features height greater than 100 nm have been produced on bare silicon, Si3N4-coated and silicon-on-insulator wafers. Evolution of hexagonal pits on two-dimensional grid structures are shown to depend on the pattern spacing and orientation with respect to (110)-silicon crystal directions. We successfully combined SPL with traditional optical lithography in a mixed, multilevel patterning method for realizing micrometer- and nanometer-scale feature sizes, as required for photonic device designs. The process of SPL + TMAH etching is a promising approach to rapid prototyping of functional nano-pholonic devices.
Citation: Journal of Applied Physics
Pub Type: Journals
anisotropic etching, nanostructures, optoelectronics, scanning probe microscopy