A two-axis Lloyd's mirrors interferometer based optical fabrication system was theoretically investigated and constructed for patterning high-uniformity nanoscale crossed grating structures over a large area with a high throughput. The current interferometer was configured with two reflected mirrors and a grating holder, which are placed edge by edge and orthogonal with each other. In such a manner, the two beams reflected from the two mirrors interfere with the incident beam, respectively, forming a crossed grating patterns with only one exposure. Differing from the conventional solution for elimination of unexpected interference between the two reflected beams, a systematical analysis, that is based on the proposed index indicating the non-orthogonality between the two beams at different incident angles, was conducted by using a spatial full polarization tracing method. Without polarization modulation to eliminate the additional interference, an optimal exposure condition with small non-orthogonality between reflected beams was found at a certain incident angle range, while the two required interferences to construct cross grating still remain high. A pattern period of ∼1 µm-level crossed grating structure could be obtained through balancing the structure area and the non-orthogonality. Finally, the exposure setup with orthogonal two-axis Lloyd's mirrors interferometer is established, and the crossed grating structure with the periods of 1076 nm along X-direction and 1091 nm along Y-direction was successfully fabricated on a silicon substrate via microfabrication technology over a large area of 400 mm2. The uniformity of crossed grating array over the whole area was evaluated by an atomic force microscope, and the standard deviations of structure periods along X- and Y-directions smaller than 0.3% are achieved. It is demonstrated that the orthogonal two-axis Lloyd's mirrors interferometer based on single-beam single-exposure scheme with non-orthogonality systematic analysis is an effective approach to fabricate crossed grating patterns of 1 µm-level period with high uniformity over a large area.

中文翻译：

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使用基于两轴劳埃德反射镜的干涉光刻技术，以高均匀度对纳米级交叉光栅进行构图。

理论上研究和构建了基于两轴劳埃德镜干涉仪的光学制造系统，用于在大面积上以高通量图案化高均匀度纳米尺度交叉光栅结构。当前的干涉仪配置有两个反射镜和一个光栅架，它们被并排放置并且彼此正交。以这种方式，从两个镜反射的两个光束分别与入射光束干涉，从而形成仅具有一次曝光的交叉光栅图案。与消除两个反射光束之间的意外干扰的常规解决方案不同，基于建议的指标进行系统分析，该指标表明两个光束在不同入射角之间的非正交性，通过使用空间全极化跟踪方法进行。没有偏振调制来消除额外的干扰，在一定的入射角范围内发现了反射光束之间具有小的非正交性的最佳曝光条件，而构成交叉光栅所需的两个干扰仍然很高。通过平衡结构面积和非正交性，可以获得〜1 µm级交叉光栅结构的图案周期。最后，建立了正交的两轴劳埃德镜干涉仪的曝光设置，并通过微细加工技术在硅衬底上成功地在硅衬底上制造了沿X方向的周期为1076 nm，沿Y方向的周期为1091 nm的交叉光栅结构。 400平方毫米的大面积。用原子力显微镜评估了交叉光栅阵列在整个区域上的均匀性，并获得了结构周期沿X和Y方向的标准偏差小于0.3％。结果表明，基于单光束单曝光方案的正交二轴劳埃德镜干涉仪具有非正交系统分析方法，是一种在大面积上制造均匀度高且周期为1 µm的交叉光栅图形的有效方法。