|
International Conference on Nanoscience and Technology 2006Basel, CH
30.07.2006 - 04.08.2006 |
| Please enter your email address here in order to bring up your personal programme |
|
|
|
NanostructuringWednesday, August 02, 2006, 18:30 - 20:30Nanofabrication via direct Transfer of BOE Treated PDMS Stamp Patterns onto SiO_2 Surfaces Y.-K. Kim, J.-H. Park, G.-C. Shin, J.S. Ha*, S.J. Park, S.M. Park, G.T. Kim
Korea University (Seoul, KR)
Soft lithography using a poly dimethylsiloxane (PDMS) stamp has been extensively studied in the field of micro and nano fabrication owing to its simplicity and applicability for the large-area patterning. Various kinds of molecules and nanomaterials were successfully transferred on the desired site of substrates, according to the shape of the PDMS stamp. Recently, ultraviolet/ozone (UVO) treated PDMS itself, without using inks, was patterned on substrates [1, 2]. Such transferred PDMS worked as successful passivation layers over reactive ion etching and atomic layer deposition processes.
In this paper, we will introduce much simpler and selective pattern transfer technique using Buffered Oxide Etch (BOE) treated PDMS stamp. BOE has been widely used in the semiconductor processing for the removal of silicon oxide (SiO_2). After dipping the patterned PDMS stamp into BOE (30:1) solution for few minutes, it was stamped onto thermally grown SiO_2 substrate. Fig. 1(a) is a non-contact mode atomic force microscope (AFM) topography image of the transferred PDMS pattern onto SiO_2 surface. The width and the height of the transferred PDMS lines are 700 nm and 30 nm, respectively. Of particular interest, a subsequent stamping onto the SiO_2 surface pre-patterned by BOE-treated PDMS stamp resulted in the direct transfer of the second PDMS patterns in the remaining SiO_2 area as shown in Fig. 1(b). It was possible to use the patterned PDMS stamp multiple times in this process. However, direct transfer of BOE-treated PDMS pattern showed a strong selectivity onto SiO_2 substrate, which was not transferred onto other substrates such as metal and polymer. We attribute the transfer mechanism to the interaction of BOE with SiO_2 as well as the weakening of PDMS bonding by BOE.
On the PDMS patterned substrates, Au was deposited via e-beam evaporation and the PDMS was selectively removed by tetra-n-butylammonium fluoride. Fig. 1(c) is the non-contact AFM topography image of Au line patterns clearly showing that the PDMS pattern worked as successful passivation layers. It was also observed that semi-conducting V_2O_5 nanowires were selectively adsorbed onto SiO_2 area using PDMS as passivation layers. This simple patterning method can be widely used for the fabrication of nano-devices such as nanowire field effect transistors.
Reference
[1] H. Ahn et al., Nano Lett. 5, 2533 (2004)
[2] K.S. Park et al., J. Am. Chem. Soc. 124, 13583 (2006)
|
|
|
