光学精密工程
光學精密工程
광학정밀공정
OPTICS AND PRECISION ENGINEERING
2000年
2期
124-127
,共4页
软X射线多层膜%曲面基片%误差分析
軟X射線多層膜%麯麵基片%誤差分析
연X사선다층막%곡면기편%오차분석
soft X-ray multilayer%figured substrate%error
软X射线光学系统需要在超光滑曲面上均匀镀膜。我们将超光滑曲面看作由若干个小平面拼接而成,通过小角衍射仪测量出各个小平面的周期膜厚,并拟和出整个曲面的镀膜速率。为提高控制精度,我们对同一片多层膜进行等精度多次测量,去除其中的粗大误差、系统误差,最后得到多层膜厚度的最佳估计值。
軟X射線光學繫統需要在超光滑麯麵上均勻鍍膜。我們將超光滑麯麵看作由若榦箇小平麵拼接而成,通過小角衍射儀測量齣各箇小平麵的週期膜厚,併擬和齣整箇麯麵的鍍膜速率。為提高控製精度,我們對同一片多層膜進行等精度多次測量,去除其中的粗大誤差、繫統誤差,最後得到多層膜厚度的最佳估計值。
연X사선광학계통수요재초광활곡면상균균도막。아문장초광활곡면간작유약간개소평면병접이성,통과소각연사의측량출각개소평면적주기막후,병의화출정개곡면적도막속솔。위제고공제정도,아문대동일편다층막진행등정도다차측량,거제기중적조대오차、계통오차,최후득도다층막후도적최가고계치。
Recent advances in multilayer mirror technology meet many of the stringent demands of soft X-ray projection lithography (SXPL). The maximum normal-incident reflectivity achieved to data, is 66% for Mo/Si multilayers at 13.4 nm, which is sufficient to satisfy the X-ray throughput requirements of SXPL. These high-performance coatings must be deposited on figured optics with layer-thickness error controled in ～0.5%. Uniform multilayr coatings are required for SXPL imaging optics, so maintaining the surface figure is critical to achieve diffraction-limited performance. In this paper, the figured substrate is considered as small super polished planes on the figured curve. By measuring the periods of multilayer on every small plane with small angle diffraction, the deposition speed of the figured substrate can be obtained. For improving the accuracy, every multilayer is measured repeatedly to wipe off the crude and systematic errors, acquire the best value, and calculate limiting error.
