Automated control of the thin films electrical conductivity by the eddy current method

Abstract

The article considers the possibility of using the eddy current method of non-destructive testing for the problems of measuring the electrical conductivity of thin metal films. As the object of measurement, we used copper films of various thicknesses obtained by vacuum vapor deposition. A review of current trends in the use of copper films in modern industry and science is presented, and an analysis is made of current methods of nondestructive testing suitable for studying thin copper films. A brief description of the deposition method and the hardware-software complex for measuring the electrical conductivity of the film is presented. A calibration curve is presented, which makes it possible to restore the values of the electrical conductivity of the film from the value of the signal of the eddy current transducer. GaAs samples were selected to construct a calibration curve. The decision is explained by the proximity of the values of the electrical conductivity of this chemical compound to the calculated indicators of the obtained thin films. The results of testing films with different characteristics are presented and the distribution of the electrical conductivity of the films depending on the batch is shown. A series of practical measurements of thin films demonstrated the existence of a relationship between the mass of the initial substance that was subjected to deposition and the characteristics of the resulting films. According to different values of electrical conductivity within the same batch, it was concluded that there is a difference in the quality of deposition of different films.