外文题目: Interference pattern period measurement at picometer level
作者: Xiang, Xiansong; Wei, Chunlong; Jia, Wei; Zhou, Changhe; Li, Minkang; Lu, Yancong
刊名: Proc.SPIE
来源图书: HOLOGRAPHY, DIFFRACTIVE OPTICS, AND APPLICATIONS VII
年: 2017 卷: 10022 文章编号：100220Z
会议名称: Conference on Holography, Diffractive Optics, and Applications VII
英文关键词:
SBIL; period measurement; least square fit; sinusoid curve fit
英文摘要:
To produce large scale gratings by Scanning Beam Interference Lithography (SBIL), a light spot containing grating pattern is generated by two beams interfering, and a scanning stage is used to drive the substrate moving under the light spot. In order to locate the stage at the proper exposure positions, the period of the Interference pattern must be measured accurately. We developed a set of process to obtain the period value of two interfering beams at picometer level. The process includes data acquisition and data analysis. The data is received from a photodiode and a laser interferometer with sub-nanometer resolution. Data analysis differs from conventional analyzing methods like counting wave peaks or using Fourier transform to get the signal period, after a preprocess of filtering and envelope removing, the mean square error is calculated between the received signal and ideal sinusoid waves to find the best-fit frequency, thus an accuracy period value is acquired, this method has a low sensitivity to amplitude noise and a high resolution of frequency. With 405nm laser beams interfering, a pattern period value around 562nm is acquired by employing this process, fitting diagram of the result shows the accuracy of the period value reaches picometer level, which is much higher than the results of conventional methods.


文献类型: 会议论文
正文语种: English
收录类别: ISTP
DOI: 10.1117/12.2245946


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