Background: To increase the resolution and depth of focus (DOF) of flat panel display (FPD) exposure systems, off-axis illumination (OAI) conditions are used extensively. OAI using narrowband wavelength illumination has been studied sufficiently. In contrast, new techniques that consider broadband wavelength illumination are needed because the effects of OAI differ between broadband and narrowband illumination. Aim: This paper presents a divided spectrum illumination (DSI), a new design concept that achieves both high resolution and a large DOF. Approach: The source wavelength is optimized according to the illumination angle. Results: Experimental imaging results for line and space patterns with a line width of 1.0 and a pitch of 2.0 μm demonstrate that the DSI design provides improved resolution. Exposure results also indicate that resist profiles using DSI are sufficiently sharp to retain pattern fidelity at the top of the resist. The DOF with DSI is also improved by 21% compared to that obtained with traditional OAI. Conclusions: DSI achieves both high resolution and a large DOF while maintaining high productivity.

中文翻译：

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光刻中根据照射角度通过源波长优化提高分辨率

背景技术：为了提高平板显示器（FPD）曝光系统的分辨率和景深（DOF），广泛使用了轴外照明（OAI）条件。已经充分研究了使用窄带波长照明的OAI。相反，由于宽带和窄带照明的OAI效果不同，因此需要考虑宽带波长照明的新技术。目的：本文介绍了一种分光光谱照明（DSI），这是一种既可以实现高分辨率又可以实现大自由度的新设计概念。方法：根据照射角度优化光源波长。结果：线宽为1.0且间距为2.0μm的线和间隔图案的实验成像结果表明DSI设计可提供更高的分辨率。曝光结果还表明，使用DSI的抗蚀剂轮廓足够清晰，可以在抗蚀剂顶部保留图案保真度。与传统OAI相比，具有DSI的自由度也提高了21％。结论：DSI在保持高生产率的同时实现了高分辨率和大DOF。