Development Of A High-throughput Characterization Platform For Thin Film Material Resistivity

Resistivity is an important indicator reflecting electrical conductivity and carrier concentration of electronic materials.Resistivity characterization is an important procedure in the development of photovoltaic thin film materials.The idea of material genome project is applied to the development of photovoltaic thin film materials,which puts forward higher requirements for the rapid and accurate high-throughput test of resistivity of large quantities of thin film samples.Traditional test equipment has the problem of low degree of automation because of manual operation,and in order to meet the correction accuracy,the sample specification should meet higher requirements.In view of this,the development and design of a more automated equipment for resistivity characterization of mass thin film samples has important application meaning.This paper mainly completed the following work on this project:Firstly,the main methods of film resistivity measurement as well as their basic principles and application are described.In particular,the linear four-point probe method and the Dual-Configuration Four-Probe Method based on this method are described in detail which are taken as the basic theory for the development of this test equipment.In this paper,the modified algorithm of Dual-Configuration Four-Probe Method was simplified and improved for the small-size thin film samples,and the optimization method of the heterogeneity of the resistivity of the samples was put forward.Secondly,based on the basic testing principle of Dual-Configuration Four-Probe Method,the automatic test equipment is constructed.The system was designed and integrated based on the virtual instrument platform.A digital source meter and a relay module was used to complete the overall electrical signal circuit.The stepper motor driving motion module and the sample platform with a pressure sensor are used to switch samples and ensure probe contact stable.In the data processing stage,the upper computer program processes the signals collected by the instrument,calls the solver program to calculate the square resistance value of the sample and to make corrections,so that the resistivity automatic test of small-size film sample array was realized.ITO film,carbon black film and carbon nanotube film were selected as the test samples for the experiment,and the characterization equipment was used to test the sample resistance respectively.it can be seen that under the premise of considering the test environment and other boundary conditions,the test results of this test system are in good agreement with the theoretical values,which also shows the effectiveness of the correction algorithm for small samples.Finally,high-throughput scanning tests were performed on the array of carbon black film samples with different concentration ratios to obtain the block resistance distribution of the samples in the array.