Shi Lei, Zeng Lijiang
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China.
Opt Express. 2011 May 9;19(10):8985-93. doi: 10.1364/OE.19.008985.
We propose and demonstrate a self-referencing alignment technique to conveniently enlarge fabricated grating area. The latent image gratings are used as the reference objects to align (adjust and lock) the attitude and position of the substrate relative to the exposure beams between and during consecutive exposures. The adjustment system and the fringe-locking system are combined into the exposure system, eliminating the drift errors between them and making the whole system low-cost and compact. For the fabricated 1 × 4 mosaics of 50 × (30 + 30 + 30 + 30) mm(2) area and 1 × 2 mosaics of 90 × (80 + 80) mm(2) area, the typical peak-valley -1st-order wavefront errors measured by a 100-mm-diameter interferometer are not more than 0.06 λ and 0.09 λ, respectively.
我们提出并演示了一种自参考对准技术，以方便地扩大制造的光栅面积。潜像光栅用作参考对象，以在连续曝光之间和曝光期间对准（调整和锁定）基板相对于曝光光束的姿态和位置。调整系统和条纹锁定系统被集成到曝光系统中，消除了它们之间的漂移误差，使整个系统低成本且紧凑。对于制造的面积为50×(30 + 30 + 30 + 30)mm²的1×4镶嵌光栅和面积为90×(80 + 80)mm²的1×2镶嵌光栅，用直径100mm的干涉仪测量的典型峰谷 - 一阶波前误差分别不超过0.06λ和0.09λ。
