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Molecular Lithography Using DNA Nanostructures
Published in James E. Morris, Kris Iniewski, Graphene, Carbon Nanotubes, and Nanostructures, 2017
Nanolithography is a lithography process that can produce nanometer-scale features on the surface. The technique of nanolithography can be divided into two types depending upon whether the pattern is transferred using a mask, referred to as masked lithography, or without a mask, referred to as maskless lithography. The forms of masked nanolithography include photolithography [2–8], nanoimprint lithography [9–16], and soft lithography [17–20]. Maskless nanolithography includes methods such as electron beam lithography [21–27], x-ray lithography [28,29], focused ion beam lithography [30–33], and scanning probe lithography [34–40] that fabricate patterns by serial writing without the use of a mask. Since this chapter focuses on the use of DNA nanostructures as the mask for lithography, the maskless lithography methods will not be discussed.
Fabrication of BioMEMS Devices
Published in Simona Badilescu, Muthukumaran Packirisamy, BioMEMS, 2016
Simona Badilescu, Muthukumaran Packirisamy
Electron beam lithography (often abbreviated as e-beam lithography), explained in Figure 7.42, is the technique of scanning an electron beam in a patterned fashion across a surface covered with a resist film, and of selectively removing either the exposed or the nonexposed regions of the resist. The purpose, as in photolithography, is to create very small structures in the resist that can subsequently be transferred to the substrate material, often by etching. It was developed for manufacturing integrated circuits, and is also used for creating nanostructures. The primary advantage of electron beam lithography is that it is one of the ways to exceed the diffraction limit of light and make features in the nanometer regime. This form of maskless lithography has found wide usage in photomask making used in photolithography and low-volume production of semiconductor components.
Effect of gradual widening of d/w-ratio on optical performance of photon sieves produced by two maskless lithography techniques: lift-off and chemical etching
Published in Journal of Modern Optics, 2020
The lithography technique, mostly used for photon sieve production in the literature, has several parameters to be concerned. They depend on the particular lithography technique preferred (optical, x-ray and e-beam, etc.), as well. The technique presented in this study is a special form of optical lithography, maskless lithography. No mask is used in this method and all patterns are written directly with a focused laser beam, which makes the application be much easier. The optical lithography method has two main steps: pattern writing and generation. In the pattern-writing step, optical maskless or mask aligner method is used for writing the pattern on photoresist material. In the generation step, there are two main sub-steps: lift off [23] and chemical etching [24]. During this study, we tried both to reveal the dependence of the quality of the pattern written on the different production methods. For a better diameter modulation, not only proper resolutions, but also changing parameters give satisfactory results for the diameter modulation. The production, though, might give different results than the design. In this work, we investigate and generalize the differences between production and design of the pinholes.