Three dimensional HSQ structures formed using multiple low energy electron beam lithography

Abstract

A method is presented for the fabrication of three-dimensional (3D) structures formed in Hydrogen Silsequioxane (HSQ) by a process of multiple low energy electron beam exposures with a single development step. Structures have been produced consisting of multiple layers of dielectric rods with widths and heights of 150nm and a separation of 1µm in the horizontal plane and 360nm in the vertical direction.

Fabrication of 3D SiOxstructures using patterned PMMA sacrificial layer

“…Differing from the typical planar lithographic process, which is finished using a single-layer resist with a fixed exposure dose and exposure voltage, 3D EBL nanofabrication is commonly achieved by the fact that the formation of resist structures is relevant to the exposure doses, voltages and resist sensitivity. According to the varied process parameters, three methods can be cataloged: grayscale process [7,8], high-/low-voltage hybrid process [9,10] and multilayer resist process [11,12]. In these processes, the grayscale process is used mostly to obtain grayscale patterns, and it does not allow the fabrication of freestanding structures.…”

Three-dimensional nanofabrication using hydrogen silsesquioxane/poly(methylmethacrylate) bilayer resists

“…Methods for fabricating such 3D nanostructures using electron-beam lithography (EBL) include consecutive overlay exposures 4,5 or low-and high-electron energy exposures. 6,7,8 However, these approaches require alignment markers and accurate alignment routines for each additional layer. 3D nanostructures have also been fabricated using grayscale lithography, 9 but in this approach, the feature size was limited to several hundred nanometers.…”

Rapid and Low‐Cost Prototyping of 3D Nanostructures with Multi‐Layer Hydrogen Silsesquioxane Scaffolds

“…Various approaches that aimed to circumvent the LBL method have been developed and can be categorized in two groups. One is to custom design the fabrication method based on the structures of interest, and includes holography,4 self assembly,5 directional etching,6 using different accelerating voltages in electron‐beam lithography (EBL),7–9 or multiple exposure 10. These approaches have heavy restrictions on the patterns, such as periodicity and limited number of layers, and are not viewed as a versatile solution to 3D nanofabrication.…”