Principle And Experiment Investigation Of Surface Plasmons Direct-writing Nanolithography

With the rapid development of electronic information industry,the feature sizes of integrated circuit get smaller.Lithography technique,especially low-cost,simple and efficient nanoscale lithography have taken an important role in nanoscale manufacturing.As the existence of optical diffraction limit,it limits the development of modern high-resolution lithography to a large extent.With the rapid development of SPs direct-writing nanolithography,which has shown great advantages in maskless,simple system structure,flexible way of writing and overcoming the diffraction limit.Therefore,It is potential to be a kind of new micro-nano manufacturing technology.The topic is derived from the national key laboratory open fund "research of the experiment platform with nano-direct writing".According to the requirements of the project,we need to manufacture a macroscopical plasmonic contact probe based on bowtie nano-structure.Meanwhile,the effect of series parameters such as polarization direction and exposure amount on lithography is also systematically studied.It will lay the foundation for low-cost,higher resolution and higher repetitive rate direct-writing nanolithography.The main contents of the article are as follows:1.we put forward an enhanced nanolithography structure which combines the bowtie aperture with insulator-metal(BIM).Numerical simulations show the FWHM of plasmonic spot is 49 nm,which reduces by 62% compared to traditional structure(BI).Compared with the nanolithography structure combining the bowtie aperture with metal-insulator-metal(BMIM),BIM rnanolithography structure can avoid the residuary upper Ag film contaminating the target area.2.To further study the factors of influencing the focused spot size,we use software to analyze BIM structure under different polarized 365-nm-wavelenth plane wave.Fornormal incident light with polarization parallel to the gap(along y direction),the electric field is strongly concentrated in two triangle regions.For normal incident light with 45-degree polarization relative to x direction,the electric field is emphatically concentrated in gap region,and the shape of focused spot is same as bowtie aperture.CST calculations provide a guide for the design of recording structure and the arrangement of placing polarizer.3.We manufacture a macroscopical plasmonic contact probe based on bowtie nano-structure and Pr-Ag recording structure.4.In order to form a set of complete lithography system,we need to test the experimental device and optimize the lithography process.5.The experiments show that the polarization direction does affect the quality of lithography,which is consistent with the theoretical data trend.Finally,focal spots with effective focal spot size of less than 100 nm is obtained by experimental results.It is proved that the lithography system designed by the paper is promising for practical applications.