Ultrasensitive non-chemically amplified low-contrast negative electron beam lithography resist with dual-tone behaviour

Abstract

A non-chemically amplified negative-tone electron-beam resist with an extremely high sensitivity is presented in this work. The resist, poly(2-hydroxyethyl methacrylate-co-2-methacrylamidoethyl methacrylate) (P(HEMA-co-MAAEMA)), has been synthesized using free radical polymerization of 2-hydroxyethyl methacrylate and 2-aminoethyl methacrylate, and exhibits a crosslinking threshold dose as low as 0.5 mC cm À2 . Exposed resist patterns show good adherence to silicon substrates without the assistance of adhesion promoters or thermal treatments and are shown to be adequate for use as a mask for both wet and dry etching of Si. A low contrast value of 1.2 has been measured, indicating that the synthesized polymeric mixture is particularly suitable for achieving grey (3D) lithography. Other relevant properties of the new e-beam resist are optical transparency, visible photoluminescence when crosslinked at low electronic doses, and dose-dependent dual-tone behaviour.

Performance evaluation of nonchemically amplified negative tone photoresists for e-beam and EUV lithography

“…4. These are highly improved when compared with the e-beam dose values reported in the literature for other nCARs, such as AR-N7500, 17,19 maN2400, 17,20 HSQ, 21 and Fullerol. 22 …”

“…The synthesized resist materials were characterized using Fourier transform infrared spectroscopy, 1 H NMR, and differential scanning calorimetry and thermal gravimetric analysis. 17 …”

EUV photofragmentation study of hybrid nonchemically amplified resists containing antimony as an absorption enhancer

“…[2][3][4] The concepts to be considered, among others, include essentially non-chemically amplied resists (n-CARs) and hybrids. [4][5][6][7][8][9][10][11][12][13][14][15] The design paradigm has to incorporate the basic principles of conventional resists superimposed with the specic requirements of EUVL for attaining the lower nodes. 12,15,16 The interaction of the resist thin lms with high energy EUV photons (13.5 nm) is a very complex process triggered by EUV radiation that breaks the chemical bonds and simultaneously produces ablation and a high yield of secondary electrons.…”

A simple PAN-based fabrication method for microstructured carbon electrodes for organic field-effect transistors

“…The normalized thickness of the PAN microstructures after development was increased with an increasing fluence up to 3 · 10 15 ions cm À2 , after which it levelled off. The contrast (c) is determined by c = [log 10 (D 100 /D 0 )] À1 , where D 100 and D 0 are the fluences at the normalized thickness of 100% and the onset of the complete development, respectively [29,30]. The calculated contrast and sensitivity of the PAN thin films were 3.3 and 1.9 · 10 15 ions cm À2 , respectively.…”