Mechanism Of Phase-change Lithography Based On PrAlNiCu Metallic Glass Film

Lithography, as one of the most important processes in semiconductor manufacturing,is facing unprecedented challenges due to the proximity of physical limits and the increasingly high requirements. Therefore, as one of the most promising lithography, phase change lithography(PCL) is receiving more and more attention. PCL is a mask-less lithography technology by using laser-direct-writing, transforming the phase change photoresist from amorphous to crystalline under the heat caused by laser, to create the nano-patterns by different etching rate between the two states in the etching solution. In this paper, the PrAlNiCu metallic glass film is used to research the PCL characteristics as phase change photoresist, to research the preparation of thin films, temperature distribution of exposure, continuous and pulse laser exposure characteristics, wet etching characteristics and so on.The amorphous and crystalline Pr AlNiCu metallic glass thin films were prepared by magnetron sputtering and annealing respectively, and the physical characteristics were tested and analyzed to prove the degree of amorphous and crystallization.The temperature distribution on the surface and internal of Pr AlNiCu films under exposure was simulated by ANSYS to prove the effect of laser thermal inducing crystallization in theory. The advantage of Pr AlNiCu metallic glass films being phase change photoresist was highlighted by comparing with the temperature distribution on MgCuY films.The PCL platform built by research group was used to accomplish the continuous and pulse laser exposure test to prove the feasibility of laser thermal inducing crystallization.The relationship between the crystallization size and laser power or pulse width was discussed based on the exposure results.The 0.5% of mass fraction nitric acid solution was selected as the etching solution by comparison, an etching selection ratio of 5:1 was obtained by wet etching experiment of amorphous and crystalline PrAlNiCu films. Based on the etching morphology test results of profilometer and atomic force microscopy, it is proved that the PrAlNiCu metallic glass film is a very promising photoresist for PCL.