2012•Japanese Journal of Applied PhysicsRequires access
Electron Beam Lithography of 15×15 nm2 Pitched Nanodot Arrays with a Size of Less than 10 nm Using High Development Contrast Salty Developer
Takuya Komori, Hui Zhang, Takashi Akahane, Zulfakri bin Mohamad, You Yin, Sumio Hosaka
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Abstract
We investigated the effects of developer and hydrogen silsesquioxane (HSQ) resist thickness in the formation of dot arrays with a pitch of <18×18 nm2 by using 30-keV electron beam (EB) lithography for bit patterned media (BPM). Optimum resist thickness and developer were investigated for the formation of fine dot arrays. We found that a 12-nm-thick HSQ resist was suitable to form fine dot patterns and the addition of NaCl into tetramethylammonium hydroxide (TMAH) could improve the development contrast (γ-value) of HSQ (the highest is 9.7). By using the 12-nm-thick HSQ resist film and 2.3 wt % TMAH/4 wt % NaCl developer, we successfully fabricated very fine resist dot arrays with a dot size of <10 nm and a pitch of 15×15 nm2, which corresponds to a storage density of about 3 Tbit/in.2 in BPM.