13 February 2012 Application of DMD: laser speckle control for rough surface photofabrication
Author Affiliations +
Proceedings Volume 8254, Emerging Digital Micromirror Device Based Systems and Applications IV; 82540N (2012); doi: 10.1117/12.905856
Event: SPIE MOEMS-MEMS, 2012, San Francisco, California, United States
Abstract
Digital Micromirror Devices are mainly known for display in video projectors. More and more, they are used in industrial or research applications. DMD is a versatile tool for lithography allowing photoresist exposure with easy-changing masking step in direct-patterning. Any application where light shaping is necessary can be considered by using DMD. We here show photofabrication of random rough surfaces using an indirect modified beam exposure. A laser beam is enlarged and scattered by a diffusing element. The scattering from this diffusing surface allows the creation of a speckle pattern with a random light distribution. The intensity is then recorded on a photoresist coated substrate. The patterned photoresist is next developed and an etching step enables the transfer on the silicon. It can be shown that the statistical properties of the speckle pattern can be controlled. The intensity distribution is modified by the number of exposures and the correlation function is linked to the spatial distribution of the laser beam. Some examples of such photofabrication can be found using a Gaussian unmodified beam leading to Gaussian correlation photofabricated surfaces. In order to design random rough surfaces having a non Gaussian correlation we need to modify the laser beam shape. This modification is achieved using a DMD. The experimental processes from photoresist deposition to modified exposure are discussed in this paper.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vincent Brissonneau, Ludovic Escoubas, François Flory, Gérard Berginc, "Application of DMD: laser speckle control for rough surface photofabrication", Proc. SPIE 8254, Emerging Digital Micromirror Device Based Systems and Applications IV, 82540N (13 February 2012); doi: 10.1117/12.905856; http://dx.doi.org/10.1117/12.905856
PROCEEDINGS
7 PAGES


SHARE
KEYWORDS
Speckle pattern

Correlation function

Digital micromirror devices

Photoresist materials

Beam shaping

Speckle

Silicon

Back to Top