Molecular resists for EUV and EB lithography

Abstract

Extreme ultraviolet lithography at a wavelength of 13.5 nm has been prepared for next generation lithography for several years. Of primary concern in EUV lithography is line edge roughness as well as high sensitivity. In recent years, various types of resist, such as protected PHS resin resist and molecular resist, have been investigated. In order to reduce LER, we have studied novel molecular resists which are promising alternative to polymeric photoresists for use as imaging materials with improved resolution and line edge roughness. The work reported in this paper has focused on the development of a new class of chemically amplified molecular resists that are composed of a single molecule which contains all of the different functionalities desired in a chemically amplified resists. For the purpose of improvement of the resist performance, we have designed the resist material of a protected polyphenol derivative (protected Compound A). PAG moiety is bonded to Compound A to achieve uniform PAG density and to control the acid diffusion length in a resist film. We analyzed uniformity of PAG density in a resist film by using gradient shaving preparation and TOF-SIMS analysis. From the TOF-SIMS spectra, the ions intensities of the PAG moiety are almost constant from the surface to the bottom of the film. Therefore, we can conclude that PAG is distributed homogeneously. Under e-beam exposure, a 100nm thick film of the PAG bonded molecular resist resolved lines down to 100nm. We also discussed the new design for molecular resists, their synthesis and lithographic performance.

Novel extreme ultraviolet (EUV)-resist material based on noria (water wheel-like cyclic oligomer)

“…6 Furthermore, the chemical amplification resist system using a photo-acid generator has become an important photolithographic technology, offering enhanced photosensitivity. [7][8][9] Recently, many molecular glass resists using dendritic oligomers, [10][11][12][13][14][15][16][17][18][19][20] calixarenes, [21][22][23][24][25][26][27][28][29][30][31][32] low-molecular-weight polyphenols, 33,34 and fullerenes 35,36 have been reported for EB and EUV resist systems. These molecular glass resists show high photo-sensitivity, and can provide clear line and space patterns in the 50 nm region.…”

Full‐Thickness Characterization of Plasma Polymerized Hexane Films Irradiated by an Electron Beam

“…The technique of ToF‐SIMS has been extensively used to analyze the surface of resists, with and without electron beam exposure 13–17. In the field of plasma polymerized films, the ToF‐SIMS method has also been adopted to provide a chemical characterization of thin films,18–21 but the depth profiling method has not previously been employed.…”