Direct Patterning of TiO2 Using Step-and-Flash Imprint Lithography
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- 作者：Ramakrishnan Ganesan ; Jarrett Dumond ; Mohammad S. M. Saifullah ; Su Hui Lim ; Hazrat Hussain ; Hong Yee Low
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：February 28, 2012
- 年：2012
- 卷：6
- 期：2
- 页码：1494-1502
- 全文大小：558K
- 年卷期：v.6,no.2(February 28, 2012)
- ISSN：1936-086X
文摘
Although step-and-flash imprint lithography, or S-FIL, has brought about tremendous advancement in wafer-scale fabrication of sub-100 nm features of photopolymerizable organic and organo-silicon-based resists, it has not been successful in direct patterning of inorganic materials such as oxides because of the difficulties associated with resist formulation and its dispensing. In this paper, we demonstrate the proof-of-concept S-FIL of titanium dioxide (TiO2) carried by an acrylate-based formulation containing an allyl-functionalized titanium complex. The prepolymer formulation contains 48 wt % metal precursor, but it exhibits low enough viscosity (5 mPa路s) to be dispensed by an automatic dispensing system, adheres and spreads well on the substrate, is insensitive to pattern density variations, and rapidly polymerizes when exposed to broadband UV radiation to give a yield close to 95%. Five fields, each measuring 1 cm 脳 1 cm, consisting of 100 nm gratings were successively imprinted. Heat-treatment of the patterned structures at 450 掳C resulted in the loss of organics and their subsequent shrinkage without the loss of integrity or aspect ratio and converted them to TiO2 anatase nanostructures as small as 30 nm wide. With this approach, wafer-scale direct patterning of functional oxides on a sub-100 nm scale using S-FIL can become a distinct possibility.