Preparation And Characterization Of Micro-nano Film Thickness Standard Samples

Micro-nano film materials are widely used in nano-fabrication,microelectronics,new materials,environmental monitoring,ultra-precision processing and other fields.With the rapid development of precision engineering and micro-nano technology,more and more micro-nano technology has been transferred from research to industrial production and application,and the requirement of quantitative and high-precision measurement for micro-nano structure has been put forward.The wide application of thin film technology promotes the development of thin film testing technology.In this paper,based on the measurement requirement of film thickness parameters,the research on the development of micro-nano film thickness standard sample,the establishment of calibration device,the calibration analysis of standard sample and the traceability of film thickness are carried out.Firstly,this paper compares the development status of thin film thickness standard samples at home and abroad and the common measurement methods of micro-nano thin film structure.In view of the advantages of ellipsometry,such as high accuracy,non-contact and fast measurement speed,a calibration device for micro-nano thin film thickness standard samples is established by using spectral ellipsometer.Comparing the single point wavelength measured by MATLAB software fitting ellipsometer with that measured by VLSI standard sample,the accuracy of the calibration device is verified,and the traceability of the standard device is verified by multiple loop comparison methods.Secondly,a set of multi-size and highly integrated film thickness standard samples for micro-nano film thickness measurement is designed and developed,including shape film thickness measurement workspace A,physical film thickness measurement workspace B and design pattern identification area C,which can trace and calibrate the film thickness measurement instruments based on different measuring principles.Then,the thermal oxidation process of several kinds of micro-nano film thick standard brick samples was analyzed.Dry oxygen oxidation method was selected to produce 10 nm-100 nm silicon dioxide thin films.For 200 nm-1000 nm silicon dioxide thin films,dry oxygen oxidation combined with wet oxygen oxidation was used to prepare the process.This method can not only ensure the quality of thin films,but also reduce the growth time of thin films.The fabrication process of ultrathin films was improved from 2 nm-10 nm.The ultrathin films were prepared by rapid heat treatment(RTP)method,and the accuracy of the quantities of ultrathin films was verified.Finally,from the analysis of processing technology,preservation environment and other external factors,the physical structure model of film thickness standard sample was optimized,and the ideal three-phase structure model was established to calibrate the developed film thickness standard sample,and the uniformity,stability and repeatability were evaluated.Based on the measuring principle of calibration device,the improvement scheme of measuring instrument is put forward to improve the measuring accuracy of measuring instrument.The traceability of the standard micron-nano film thickness sample was studied.The traceability system was established for different measuring instruments in different measuring areas of the standard sample.