Research On The Measurement Technology And Reference Material Of The Phase Transition Temperature Of Thin Film Materials

The phase change characteristics of thin film materials play an important role in high and new technology industry such as information storage,photocatalysis,and light display.Among them,the phase changes generated by changing the temperature of the material are the most common and the most widely used.With the continuous improvement of application requirements,how to measure the phase transition temperature of thin film materials more accurately has become an urgent bottleneck problem.At present,foreign countries have long studied the precise measurement of the phase transition temperature of thin film materials.Among them,the National Institute of Standards and Technology has carried out the development of related measurement technology and reference materials,but there is still no domestic research.The reliability of the measurement results is poor.The lack of credibility has seriously restricted the development of related industries.For this reason,this thesis mainly focuses on the measurement methods of the phase transition temperature of thin film materials and the development of reference materials.The thesis first measures and calibrates the optical power thermal analysis technology,which is an in-situ measurement method specifically used for the measurement of the phase transition temperature of thin film materials.The calibration procedure of the optical power thermal analyzer was studied,and the collimation of the optical system was verified through measurement.The temperature traceability and reliability analysis of the K-type thermocouple that measured the film temperature were carried out.The thermocouple calibration model was designed based on the finite element.The method compares the temperature difference between the thermocouples in the model,analyzes the feasibility of the model,and discusses the evaluation of thin film standard substance candidates.On this basis,the low phase transition temperature reference material GeTe and the high phase transition temperature reference material TiO₂ were developed respectively.By optimizing the test plan,the film samples of the same batch were divided into regions,the film phase transition temperature was repeatedly measured,and the homogeneity within and between groups was compared and analyzed.Further F-test and uncertainty analysis of the measurement results show that the measurement repeatability and uniformity meet the requirements of the reference material.The thermal resistance effect of the contact between the film and the thermocouple is simulated,and the sources of measurement errors are analyzed:(1)the error introduced by repeated measurements;(2)the error of the S-type thermocouple and the temperature fluctuation of the furnace cavity.The instruments and meters used for the measurement were traced upwards,and finally the phase transition temperature of the GeTe film and TiO₂ was fixed.