紫外光刻中部分相干光的传播及衍射效应

基于Hopkins公式,研究了接近式紫外光刻中扩展准单色光源经柯勒照明系统传播到掩模表面上任两点的复相干度,并建立相应的基于部分相干光理论的光刻模型.应用部分相干光的传播理论,研究掩模平面到光刻胶表面任意两点互强度的传播,进而得到光刻胶表面的光强分布.以此为基础,分析了由于掩模与光刻胶之间光的衍射效应而产生的光刻微结构的图形失真.给出了理论模型的计算模拟结果,并用实验对该理论模型的计算结果进行了验证.

Propagation and diffraction of partial coherent light in uv-lithography

The light source of proximity uv-lithography is extended incoherent quasi-monochronmatic.The light incident on the mask plane becomes partial coherence light after transferring through the Kohler's illumination system.Based on the Hopkins formula,the complex degree of coherence for any two points on the mask plane was discussed and a lithography model based on partial coherence theory was constructed.Then the propagation of mutual intensity from the mask to photoresist was studied to calculate the intensity distribution on its surface.The study shows that there is some graph distortion on the edges and corners of the photoresist which is caused by diffraction.The experimental results have evaluated the theoretical simulation and proved the validity of the method.