Optical System with 4 ㎛ Resolution for Maskless Lithography Using Digital Micromirror Device

Abstract

In the present study, an optical system is proposed for maskless lithography using a digital micromirror device (DMD). The system consists of an illumination optical system, a DMD, and a projection lens system. The illumination optical system, developed for 95% uniformity, is composed of fly's eye lens plates, a 405 nm narrow band pass filter (NBPF), condensing lenses, a field lens and a 250W halogen lamp. The projection lens system, composed of 8 optical elements, is developed for 4 µm resolution. The proposed system plays a role of an optical engine for PCB and/or FPD maskless lithography. Furthermore, many problems arising from the presence of masks in a conventional lithography system, such as expense and time in fabricating the masks, contamination by masks, disposal of masks, and the alignment of masks, may be solved by the proposed system. The proposed system is verified by lithography experiments which produce a line pattern with the resolution of 4 µm line width.

Diffraction analysis of digital micromirror device in maskless photolithography system

“…[4][5][6][7][8][9] In MPLS, DMD replaces the traditional photomask to contribute to the cost-effective production of printed circuit boards and flat liquid crystal panels, by circumventing the expense of fabrication, maintenance, and the process period of the mask. 8 Because of the periodical configuration and the coherence of the light source, the irradiance of the DMD is influenced by diffraction effects. 8 Because of the periodical configuration and the coherence of the light source, the irradiance of the DMD is influenced by diffraction effects.…”

In Situ Fluorescence Optical Detection Using a Digital Micromirror Device (DMD) for 3D Cell-based Assays

“…For example, a DMD can be used to form multiple pinholes, multiple line slits, or an S-matrix based pseudorandom sequence to reduce photobleaching and photodamage while improving resolution via structured illumination [14][15][16][17]. A DMD consists of multiple micromirror arrays which can be controlled electronically [18,19]. Thus, lateral scanning can be implemented in a short time compared to using a motorized stage and structured wavefront modulation can be performed for flexible fluorescence microscopy.…”

Multi-scale structure patterning by digital-mask projective lithography with an alterable projective scaling system

“…The projection law of DMD-based DMPL system is an important feature to show the flexibility and multi-scale capabilities. 29 Fig. 1(b) shows the simplified ray track diagram for laser beam through the inverted-telescope system according to geometric optics theory.…”