Helium ion beam lithography on fullerene molecular resists for sub-10 nm patterning

Helium ion beam lithography (HIBL) is an emerging technique that uses a sub-nanometre focused beam of helium ions generated in the helium ion microscope to expose resist. It benefits from high resolution, high sensitivity and a low proximity effect. Here we present an investigation into HIBL on a novel, negative tone fullerene-derivative molecular resist. Analysis of large area exposures reveals a sensitivity of ~40 µC/cm2 with a 30 keV helium beam which is almost three orders of magnitude higher than the sensitivity of this resist to a 30 keV electron beam. Sparse line features with line widths of 7.3 nm are achieved on the ~10 nm thick resist. The fabrication of 8.5 half-pitched lines with good feature separation and 6 nm half-pitched lines with inferior but still resolvable separation is also shown in this study. Thus, sub-10 nm patterning with small proximity effect is demonstrated using HIBL using standard processing conditions, establishing its potential as an alternative to EBL for rapid prototyping of beyond CMOS devices

Dataset for Helium Ion Beam Lithography on Fullerene Molecular Resists for Sub-10 nm Patterning

Dataset supporting: Shi, Xiaoqing et al (2016) Helium ion beam lithography on fullerene molecular resists for sub-10 nm patterning. Microelectronic Engineering. Helium ion beam lithography (HIBL) is an emerging technique that uses a sub-nanometre focused beam of helium ions generated in the helium ion microscope to expose resist. It benefits from high resolution, high sensitivity and a low proximity effect. Here we present an investigation into HIBL on a novel, negative tone fullerene-derivative molecular resist. Analysis of large area exposures reveals a sensitivity of ~40 ?C/cm2 with a 30 keV helium beam which is almost three orders of magnitude higher than the sensitivity of this resist to a 30 keV electron beam. Sparse line features with line widths of 7.3 nm are achieved on the ~10 nm thick resist. The fabrication of 8.5 half-pitched lines with good feature separation and 6 nm half-pitched lines with inferior but still resolvable separation are also shown in this study. Thus, sub-10 nm patterning with small proximity effect is demonstrated using HIBL using standard processing conditions, establishing its potential as an alternative to EBL for rapid prototyping of beyond CMOS devices. Funded by Single Nanometer Manufacturing for beyond CMOS devices (SNM, 318804), 2013 to 2016.</span

Electron beam lithography for high density meta fish scale operational at optical frequency

This paper reports our recent progress in electron beam lithography for high resolution and highly dense metallic structures such as fish scale on both silicon and quartz. To observe photonic property in optical frequency, the pitch of 500 nm with both linewidth and gap of 50 nm gap in Al is demanded. For reliable lift-off process, adequate undercut in bilayer layer of resists is essential. Three different bilayers, PMMA/LOR, PMMA/copolymer and PMMA/PMMA (with different molecular weights) were compared and the most suitable bilayer was found to be the PMMA/PMMA with a difference in molecular weight between the top and bottom layer. With such a bilayer stack, dense fish scale pattern with minimum linewidth of 50 nm in Al were fabricated for both transparent and reflective configurations. Astonishing optical properties such as magnetic wall and asymmetric propagating waves through the chiral fish scale were observed

Nanofabrication of SiC templates for direct hot embossing for metallic photonic structures and meta materials

A reliable nanofabrication process for hard templates in SiC amorphous film was developed. The process involves high resolution electron beam lithography and reactive ion etch for nanosize structures in SiC. Study of the RIE property in SiC narrow trenches and dot array indicates that various profiles of sidewall can be achieved by controlling the etch power and ratio of fluorine-based gas mixture. It was also discovered that SiC material is RIE lag free in dry etch, which opens up a broader applications for deep and narrow structures. Applications of SiC templates for hot embossing into metals and plastics prove that the SiC templates formed in amorphous film are hard enough for the fabrications of metallic photonic structures and meta materials