ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 49, Number 3
JKCSEZ 49(3)
June 20, 2005 

A scheme to control the laser power and the exposure time was studied to fabricate precise microstructures using the nano-stereolithography (nSL) process. Some recent works have shown that a three-dimensional (3D) microstructure can be fabricated by the photopolymerization process which is induced by two-photon absorption (TPA) with a femtosecond-pulse laser. TPA provides the ability to confine photochemical and physical reactions within the order of laser wavelength, so near-diffraction limit features can be produced. In the nSL process, voxels are continuously generated to form a layer and then another layer is stacked in the normal direction of a plane to construct a 3D structure. Thus, fabrication of a voxel with low aspect ratio and small diameter is one of the most important parameters for fabricating precise 3D microstructures. In this work, the mechanism of a voxel formation is studied and the scheme of minimum power & minimum exposure time (MPMT) is proposed to minimizing the aspect ratio of a voxel.