Memory effect in nitrogen based on experimental data of electrical breakdown time delay as a function of afterglow period in the presence of additional electrons has been investigated. The additional electrons were supplied as a result of extraction from the auxiliary electrode pair or nitrogen irradiation with the radioactive sourceof low activity. The results show that these electrons have an important role in the recombination of positive ions formed in mutual metastable molecules' collisions and collisions between metastable and highly vibrationally excited molecules in the early afterglow. As a consequence of the ion–electron recombination N(4S) atoms are formed which, as well as N(4S) atoms formed in previous discharge, have a significant influence on the memory effect in late afterglow. The presence of N(4S) atoms in the late afterglow is tracked by monitoring the secondary emission which they induce via catalytic recombination on the cathode of a nitrogen-filled tube. Also, it has been shown that the contribution of secondary electrons which originate from N(4S) atoms and Compton electrons when the radioactive source is and isn't present can be distinguished.
This study aimed to comprehensively understand the performance and degradation of both p- and n-channel vertical double diffused MOS (VDMOS) transistors under bias temperature stress. Conducted experimental investigations involved various stress conditions and annealing processes to analyze the impacts of BT stress on the formation of oxide trapped charge and interface traps, leading to threshold voltage shifts. Findings revealed meaningful threshold voltage shifts in both PMOS and NMOS devices due to stresses, and the subsequent annealing process was analyzed in detail. The study also examined the influence of stress history on self-heating behavior under real operating conditions. Additionally, the study elucidated the complex correlation between stress-induced degradation and device reliability. The insights contribute to optimizing the performance and permanence of VDMOS transistors in practical applications, advancing semiconductor technology. This study underscored the importance of considering stress-induced effects on device reliability and performance in the design and application of VDMOS transistors.
The results presented in this article relate to the study of the impact of gamma radiation on the breakdown voltage of gas-filled surge arrester manufactured by CITEL, Littelfuse and EPCOS at an operating voltage of 230 V. Radium was considered as a source of gamma radiation in this research. The stability of breakdown voltage as well as the reliability of gas-filled surge arresters of different manufacturers were investigated using different statistical methods. This gas component operation was based on processes that lead to electrical breakdown and discharge in gas. The breakdown voltage has a stochastic nature, and it is a subject of certain distribution. One thousand voltage measurements of breakdown voltage were carried out for each value of the voltage increase rate, from 1 V/s up to 10 V/s, with and without the presence of additional gamma radiation. The detailed statistical analysis of the obtained experimental data was performed for both cases for all three GFSA types. Moreover, the cumulative distribution functions of breakdown voltage were presented with the applied Weibull distribution fit. The coefficient of correlation as well as Pearson χ2 test showed the strength of the relationship between the experimental distribution functions and the Weibull distribution fits. The values of the Weibull distribution coefficients for all voltage increase rates and for all components were also analyzed with and without gamma radiation.