基于虚拟仪器技术及Rymaszewski四探针双电测组合法设计了薄膜电阻率自动化测量系统.在虚拟仪器软件LabVIEW和数字量输出模块NI 9401的控制下,利用基于CD4052芯片的接口电路实现电流探针、电压探针的自动切换,并通过LabVIEW程序控制Keithley 2400数字源表实现两次电压测量;同时根据两次电压测量结果由LabVIEW程序完成范德堡修正因子和方块电阻的计算;最终实现薄膜电阻率自动测量、记录和显示.试验结果表明,所设计的自动测量系统不仅可以满足多种薄膜电阻率测量要求,而且提高了测量精度和自动化程度,同时精简了薄膜电阻率测量过程.
Thin film resistivity measurement system was designed based on the virtual instrumentation technology and Rymaszewski dual electro-measurement with four-point probes. Interface circuit based on CD4052 chip was designed to realize automatic switching of current probes and voltage probes under the control of virtual instrumentation software, LabVIEW and digital output module hardware, NI 9401. Keithley 2400 sourcemeter under control of LabVIEW program was used for two times voltage measurement, and then van der Pauw correction factor and sheet resistance were calculated by LabVIEW program based on results of voltage measurement. Finally, thin film resistivity was automatically measured, recorded and displayed. The results of experiments show that the proposed system can meet the needs of thin film resistivity automatic measurement, the measurement process for thin film resistivity can be simplified and the level of measurement accuracy and automation can be improved.