排序方式: 共有40条查询结果,搜索用时 46 毫秒
1.
2.
针对传统接触式曝光过程中掩模版因自身重力产生形变从而引入不可忽视的线宽误差和位置误差的问题,提出了一种大口径石英基底衍射透镜的高精度制备方法.采用背面具有真空道的高平面度、高强度金属校正工装吸附在掩模版上,利用掩模版上下表面的压强差使其与工装高度贴合,确保掩模版的高平面度.待石英基底所有区域均与掩模版结构面紧密贴合后取下工装.完成接触式曝光和显影后,采用反应离子刻蚀技术对大口径石英基底进行刻蚀,最终得到高精度微纳米结构.经有限元分析,使用该校正工装后,掩模版的形变量由28.85μm减小为0.88μm.实验结果表明,采用该方法制备的口径430mm两台阶石英基底菲涅尔衍射透镜波像差优于1/25λ,平均衍射效率为38.24%,达到理论值的94.35%,具有良好的聚焦和光学成像效果. 相似文献
3.
4.
5.
6.
7.
8.
9.
The full aperture complex amplitude transmittance function of a multi-level diffraction lens with maskalignment errors was derived based on scalar diffraction theory. The point spread function(PSF) was calculated by the Kirchhoff diffraction integral. It is found that the radius of the Airy disk increases with the increase of the error in the direction of misalignment, and the image center shifts along the direction of misalignment. A fourlevel diffractive lens with a diameter of 80 mm was fabricated, and its PSF and diffraction efficiency of +1 st order were calculated and measured. The distribution of PSF is consistent with the calculated results, and the tested diffraction efficiency is slightly smaller than the calculated value; the relative error is 5.71%. 相似文献
10.
范斌 《理化检验(化学分册)》1994,30(5):296-297
高含量钾测定,一般采用NaB(C_6H_5)_4-Hg(Ⅱ)-EDTA容量法。由于使用金属指示剂指示滴定终点,就要求溶液无色,无沉淀物等,而且终点不甚清晰。交流示波极谱滴定法则可克眼指示剂法的不足之处。本试验于强酸性介质中,加入NaB(C_6H_5)_4,使K~ 与(C_6H_5)_4B-生成沉淀,用丙酮溶解。加入过量Hg(Ⅱ)- 相似文献