复杂图案轮廓曝光版图的生成及工艺实现

Realization of complex patterns via “sketch and peel” lithography

轮廓曝光技术可大幅提高跨尺度结构电子束直写的加工效率,但对于复杂图案,前期人工绘制曝光版图的过程费时费力。为了进一步提高版图生成效率,本文提出一种利用边界追踪算法提取数字图像轮廓并将它转换为曝光版图的方法。首先,通过图像灰度化以及Otsu自适应阈值分割法将图像转换为二值图像。接着,使用MATLAB bwboundaries边界追踪函数追踪二值图像边界。最后,利用GDS工具箱将图像边界转换为曝光版图。实验结果表明,本工作提出的方法可以有效地提取树叶、数字及动物等复杂图案边缘并将它们转换为版图进行后续曝光。通过制备"枫叶"图形证实利用本文方法生成的版图在轮廓曝光中可获得从纳米尺度到亚毫米尺度下的跨尺度、高保真度图形,通过制备50μm和100μm等不同大小、不同复杂程度的金结构证实了此方法在微纳制造中的通用性。

'Sketch and Peel'lithography(SPL)has demonstrated the potential to improve the efficiency of electron beam direct writing.However,it is time-consuming to design exposure layouts for complex patterns.In this study,we proposed a method to generate SPL layouts for complex patterns using an edge tracing algorithm to extract digital image contours.First,the color image was converted to a binary image by image graying and the Otsu adaptive threshold segmentation algorithm.Then,the boundary of the binary image was traced by the MATLAB bwboundaries function.Finally,the MATLAB GDS toolbox was utilized to transform the traced boundary to layouts for exposure.The experiments confirmed that the proposed method is effective for extracting the boundaries of images and converting them to layouts.As shown by fabricating a maple leaf-like pattern,the generated layout still maintains its high graphic fidelity when applied to SPL.The versatility of the proposed method for micro-nanomanufacturing was also verified by fabricating other complex patterns of different sizes and different geometries.