Nano Archive

Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

Kim, Yong Chul and Lee, Seung S. (2007) Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask. JOURNAL OF MICROMECHANICS AND MICROENGINEERING, 18 (1).

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Official URL: http://www.iop.org/EJ/abstract/0960-1317/18/1/0150...

Abstract

This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (SixNy) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined SixNy membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method.

Item Type:Article
Subjects:Material Science > Nanofabrication processes and tools
Physical Science > Nano objects
ID Code:6163
Deposited By:IoN
Deposited On:05 Aug 2009 14:33
Last Modified:05 Aug 2009 14:33

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