Fullerene Resist Materials for the 32 nm Node and Beyond

Abstract

Current resist materials cannot simultaneously meet the sensitivity, resolution and line width roughness (LWR) requirements set out by the International Technology Roadmap for Semiconductors (ITRS) for the 32nm node and beyond. Here we present a fullerene‐based, chemically amplified resist system, which demonstrates the potential to fulfill these requirements for next generation lithography. A chemically amplified fullerene resist was prepared, consisting of the derivative MF07‐01, an epoxide crosslinker, and a photoacid generator, such as triarylsulfonium hexafluoroantimonate. The sensitivity of this resist was shown to be between 5 and 10 µC cm−2 at 20 keV for various combinations of post‐application bake and post‐exposure bake conditions. Using 30 keV electron beam exposure, sparse patterns with 15 nm resolution were demonstrated, whilst for dense patterns a half‐pitch of 25 nm could be achieved. The LWR for the densely patterned features is ∼4 nm. The etch durability of the fullerene CA system was shown to be comparable to that of SAL601, a common novolac‐based commercial resist, at almost four times that of silicon.

Chemically amplified phenolic fullerene electron beam resist

“…The crosslinking reaction mechanism of the tBOC protected material IM-MFPT12-2 is still under investigation, but we speculate a two-step reaction in which the tBOC protection group is rst removed catalytically by the PAG generated acid, leaving a phenol, which then crosslinks cationically with the epoxy. 38,41 The additional deprotection step might result in the lower sensitivity and higher contrast of IM-MFPT12-2 compared with IM-MFP12-3.…”

Spin-on carbon based on fullerene derivatives as hardmask materials for high-aspect-ratio etching

“…A number of different resists have been successfully tested in this application including SAL601 (Shipley), our in-house fullerene-based chemically amplified molecular resist, 2,3 and, as used for the work presented here, a nonchemically amplified triphenylene derivative molecular resist. 13 Resist patterning was done with a FEI XL30 SFEG scanning electron microscope equipped with an ELPHY Plus pattern generator (Raith GmbH, Dortmund, Germany).…”

Synthesis and characteristics of multi-aryl substituted molecular glasses bearing biphenyl core

“…Molecular glasses have been explored to improve line edge roughness (LER) comparing to the conventional polymeric resists, whose performance issues was originating from chain entanglement, molecular size and composition distribution as well as acid diffusion control that hinders optimal lithographic performance [6,7]. Molecular glass resists such as polyphenol [8][9][10][11], calyx[n] arene [12][13][14][15], fullerene [16][17][18][19] and ladder cyclic molecule (noria) [20,21] are of great interest for its potential application for EUV resists. A series of tert-butyloxycarbonyl (t-Boc) protected C-4-hydroxyphenyl-calix [4]resorcinarene derivatives that produces 30 nm line space patterns under EUV conditions was developed by Chang and co-workers [22], and the first report on sub-50 nm features was obtained by a molecular glass resist using standard processing conditions.…”