热压增大光刻胶光栅占宽比的方法及其应用

摘要

全息光刻-单晶硅各向异性湿法刻蚀是制作大高宽比硅光栅的一种重要方法,而如何增大光刻胶光栅的占宽比,以提高制作工艺宽容度和光栅质量是急需解决的问题.本文提出了一种热压增大光刻胶光栅占宽比的方法,该方法通过加热加压直接将光刻胶光栅线条展宽.论文详细阐述了其工艺过程,探究了占宽比增加值随施压载荷、温度的变化规律,讨论了施压垫片对光刻胶光栅质量的影响.应用此方法制作了周期为500nm的硅光栅,光栅线条的高宽比达到了12.6,氮化硅光栅掩模的占宽比高达0.72.热压增大光刻胶光栅占宽比的方法工艺简单、可靠,无需昂贵设备、成本低,能够有效增大占宽比,且获得的光栅掩模质量高、均匀性好,满足制作高质量大高宽比硅光栅的要求.%Holographic lithography combined with anisotropic wet etching of monocrystalline silicon is an important method for the fabrication of high-aspect-ratio silicon gratings.However, increasing the duty cycle of photoresist grating to improve the fabrication process tolerance and grating quality is a major problem.We present a method for increasing the duty cycle of photoresist grating by hot pressing.The principle of this method is to broaden the width of photoresist grating lines directly by heating and pressurizing.The fabrication process is described in detail.The variation of the duty cycle with pressure load and temperature was studied, and the influence of pressing gasket on the grating quality was investigated.Using this method, a silicon grating with a period of 500 nm was successful-ly fabricated.The aspect ratio of the grating line is 12.6, and the duty cycle of silicon nitride mask is as high as 0.72.This method is simple, reliable, and affordable.It can effectively increase the duty cycle, and the obtained grating mask has high quality and good uniformity, which meets the requirements of fabricating high-quality silicon gratings with high aspect ratios.