Sudipta Roy 2007 J. Phys. D: Appl. Phys. 40 R413 doi:10.1088/0022-3727/40/22/R02
Sudipta Roy
Show affiliationsMicro- and nano-scale devices are used in electronics, micro-electro- mechanical, bio-analytical and medical components. An essential step for the fabrication of such small scale devices is photolithography. Photolithography requires a master mask to transfer micrometre or sub-micrometre scale patterns onto a substrate. The requirement of a physical, rigid mask can impede progress in applications which require rapid prototyping, flexible substrates, multiple alignment and 3D fabrication. Alternative technologies, which do not require the use of a physical mask, are suitable for these applications. In this paper mask-less methods of micro- and nano-scale fabrication have been discussed. The most common technique, which is the laser direct imaging (LDI), technique has been applied to fabricate micrometre scale structures on printed circuit boards, glass and epoxy. LDI can be combined with chemical methods to deposit metals, inorganic materials as well as some organic entities at the micrometre scale. Inkjet technology can be used to fabricate micrometre patterns of etch resists, organic transistors as well as arrays for bioanalysis. Electrohydrodynamic atomisation is used to fabricate micrometre scale ceramic features. Electrochemical methodologies offer a variety of technical solutions for micro- and nano-fabrication owing to the fact that electron charge transfer can be constrained to a solid–liquid interface. Electrochemical printing is an adaptation of inkjet printing which can be used for rapid prototyping of metallic circuits. Micro-machining using nano-second voltage pulses have been used to fabricate high precision features on metals and semiconductors. Optimisation of reactor, electrochemistry and fluid flow (EnFACE) has also been employed to transfer micrometre scale patterns on a copper substrate. Nano-scale features have been fabricated by using specialised tools such as scanning tunnelling microscopy, atomic force microscopy and focused ion beam. The methodologies adopted for nano-fabrication have analogies with the micrometre scale patterning methods. Currently, the resolution of mask-less techniques is lower than that of lithographic methods using a physical mask. However, in future, hybridisation or combination of the mask-less methods could lead to high resolution and higher precision micro- and nano-scale patterning methods.
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
Issue 22 (21 November 2007)
Received 20 October 2006, in final form 11 September 2007
Published 2 November 2007
Sudipta Roy 2007 J. Phys. D: Appl. Phys. 40 R413
J Tempere and J T Devreese 2006 J. Phys. B: At. Mol. Opt. Phys. 39 S57
Sang-Yoon Kim and Woochang Lim 2003 J. Phys. A: Math. Gen. 36 6951
M. Tsujimoto et al. 2005 ApJS 160 503
Klaus Baberschke 2009 J. Phys.: Conf. Ser. 190 012012
A. Mastichiadis and D. Kazanas 2006 ApJ 645 416
Hiroyuki Hirashita 1999 ApJ 522 220
Kazuya Tada and Mitsuyoshi Onoda 2009 J. Phys. D: Appl. Phys. 42 132001
Z Cao et al 2009 J. Phys. D: Appl. Phys. 42 222003
X. Calmet and H. Fritzsch 2006 Europhys. Lett. 76 1064