Fundamental electrical noises and nondestructive testing of electronic devices

Abstract

Aim. The research of potential wide applications of electrical noises in nondestructive testing of electronic devices and theoretic justification of their use for such purposes. To that effect, fundamental electrical noises are examined and the types of those that in principle can be used for nondestructive testing are analyzed. Methods. The article contains theoretical research finding regarding fluctuation processes behind several types of electrical noise and degradation processes in electronic devices. The connection between the spectral properties of the fluctuations with the characteristics of the degradation processes in electronic devices is analyzed. On this basis, conclusions are made regarding the opportunities of using electrical noises for non-destructive testing of electronic devices. Electrical fluctuation phenomena caused by capture and emission of charge carriers by traps created by structural defects in the solid body structure. The processes of capture and emission of charge carriers by traps are a fundamental cause of the following fundamental types of electrical noise: excess, generationrecombination and burst. Various types of noise significantly differ in terms of the parameters and statistical properties of fluctuation processes. That is the reason for the analysis of electrical fluctuations caused by traps in order to provide a sufficiently general description of such fluctuation phenomena. The work resulted in a rigorous description of the electrical fluctuations caused by traps. A general expression for the fluctuation spectrum was calculated. In special cases, from it we can pass to the spectrums of excess, generation-recombination and bursts noises. The findings regarding the electric fluctuations causes by traps can be used for identification of spectral properties of fluctuations in solid materials and solid-state electronic devices. A rigorous quantitative analysis was made of the degradation processes that occur in solid-state electronic devices in order to establish associations between the spectral characteristics of noises caused by capture and emission of charge carriers by structural defects with the degree of materials defectiveness in order to be able to better exploit the noises in the evaluation of the quality and dependability of electronic devices. It was established that the noise spectral density is associated with the degree and rate of the structure’s degradation. Thus, noises in electronic devices contain information on the degree and rate of degradation. The following practical conclusions were made. The noise spectral density is associated with the number of defects in the device at the baseline, as well as the rate of defect formation and, consequently, the ageing rate of the electronic device. Therefore, noise contains information on the quality of the manufactured device and its characteristics change rate. Accordingly, the noise spectrum can be used in evaluation of an electronic device’s deficiencies, both those occurring during the manufacturing process, and those that manifest themselves in operation. Conclusions. The paper substantiates the potential wide applications of electrical noises in non-destructive testing of electronic devices, shows the feasibility of using fundamental types of electrical noises for the above purposes. The rigorous substantiation of the use of electrical noises for nondestructive testing of electronic devices, feasibility of evaluation of the devices’ defects caused by various factors, use of common frequently prevailing types of noise, high sensitivity of fluctuation spectroscopy highlight the efficiency of electrical noise in nondestructive testing of electronic devices.