Development of large-area 3D fabrication process using continuous scanning method and its micro-applications

Abstract

Recently, the demands for the ultra-precision technology related with the nanotechnology (NT), the biotechnology (BT), and the information technology (IT) have been enormously increased to develop a new conceptual and high value added product. And, many researchers have made the special studies of a miniature technology based on the semiconductor processes, and also, a lot of applications of the micro-fabrication technologies have been introduced. In the last ten years, concentrated researches have been conducted into two-photon stereolithography (TPS) process using a femtosecond laser. The TPS has many advantages as a technique for the direct fabrication of true three-dimensional shapes in the range of several microns, which might be difficult to obtain by general miniature technologies. Previous works using the TPS have been focused on a process development. Until now the conventional process employing beam-scanning system is limited to fabricate micro-prototypes in small area of several tens micrometers. However, large structures of several tens/hundred micrometers are sometimes required for devices in the applications. In this research, large-area two-photon stereolithography process (La-TPS) is investigated for IT/BT applications. In large-scale TPS based on a stage-scanning system, the long processing time due to the intrinsic slow response in the stage scanning system is a major obstacle to its use as a practical nanofabrication process. To overcome this drawback, a continuous scanning method (CSM) for a stage scanning system is proposed here. In CSM, a pattern is generated with continuous movement of the stage during laser beam exposure. A stable fabrication window (SFW), which enables uniform motion of the stage without errors considering the stage characteristics, was obtained from fundamental experiments. Within the condition of a SFW, 2D and 3D microstructures having nanoscale details were fabricated with a whole scale range of several hundred m...