衍射干涉光刻研究

光刻就是将掩模版上的图形转移到基底的过程,广泛应用于微电子、微机械领域。衍射现象是光刻工艺无法避免的问题,当掩模图形尺寸接近光源波长时,就会产生衍射干涉现象。利用这一现象,可以产生小于掩模图形尺寸的图形。采用严格耦合波分析算法对光刻过程中的衍射干涉做了仿真分析;并用karl suss MA6光刻机实现了基于掩模的干涉光刻实验,通过增加滤光片得到相干光源,增强光刻过程的衍射,形成衍射干涉,掩模版透光区域和部分不透光区域下方的光刻胶得到曝光,利用微米尺度的光栅图形,在光刻胶上产生亚微米的光栅;最后利用干法刻蚀工艺,在硅基底上加工出亚微米尺度光栅。

Research on Coherent Diffraction Lithography

Lithography is a process of transferring patterned mask to the basal and is widely used in microelectronics,micro-mechanical field.The diffraction phenomenon cannot be avoided in the lithography process.When the patterned size on the mask close to the optical source wavelength,it will produce coherent diffraction phenomenon.The graphics less than the size of patterned mask can be produced by this phenomenon.The coherent diffraction lithography in lithography process was simulated by rigorous coupled wave analysis(RCWA)algorithms.Interference lithography based mask was realized on the karl suss MA6 aligner.Through increased filters,the coherent optical source was achieved to increase the diffraction,produce the coherent diffraction phenomenon.Therefore,the photoresist under the transparent and part of opaque area of the mask is exposed.Sub-micron gratings are produced via micron scale gratings pattern.Finally,sub-micron gratings are fabricated on silicon substrate by dry etching process.