A simple and residual-layer-free solute–solvent separation soft lithography method. (19th August 2015)

• Record Type: Journal Article
• Authors: Dai, Xianglu; Xie, Huimin
• Is Part Of: Journal of micromechanics and microengineering. Volume 25:Number 9(2015:Sep.)
• Publication Date: 2015-08-19
• Subjects: 3S soft lithography -- residual layer free -- residual resist -- PDMS; Microelectromechanical systems -- Periodicals; Micromechanics -- Periodicals; 621.38105
• DOI: 10.1088/0960-1317/25/9/095013
• Languages: English
• ISSNs: 0960-1317

Abstract

Abstract: A solute–solvent separation soft lithography (3S soft lithography) is reported in this paper, which aims at offering a residual-layer-free micromachining technique that can be realized in an ordinary laboratory conveniently. In 3S soft lithography, a polydimethylsiloxane (PDMS) block containing micro-structure relief serves as the stamp, and the resist (as the solute) is dissolved in a solvent to form a solution before being molded by the stamp. During the molding process, the stamp absorbs the solvent and filters the resist; as a result, the resist can solidify on the substrate and replicate the pattern on the stamp. To improve the global geometric uniformity of the duplicated pattern, a hybrid PDMS stamp whose effectiveness is verified by the finite element analysis is used. Moreover, the liquid bridge phenomenon is creatively applied to remove the bubble defects caused during the molding process. The pattern transfer fidelity of 3S soft lithography is analyzed, and some suggestions are summarized for performing a high quality 3S soft lithography based on the experimental results. Verified by our experiment, the micro-structure fabricated by 3S soft lithography can serve as a mask for the following etching, and a lattice with minimum line width of 200 nm has been successfully fabricated on the silicon wafer in our study.