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 possibility of using commercial p-channel power vertical double-diffused metal-oxide-semiconductor field-effect transistors (VDMOSFETs) as X-ray sensors is investigated in this case study. In this aspect, the dependence of sensitivity on both the gate voltage and the mean energy for three X-ray beams is examined. The eight gate voltages from 0 to 21 V are applied, and the dependence of the sensitivity on the gate voltage is well fitted using the proposed equation. Regarding X-ray energy, the sensitivity first increases and then decreases as a consequence of the behavior of the mass energy-absorption coefficients and is the largest for RQR8 beam. As the mass energy-absorption coefficients of SiO₂ are not found in the literature, the mass energy-absorption coefficients of silicon are used. The behavior of irradiated transistors during annealing at room temperature without gate polarization is also considered.

We report on a procedure for extracting the SPICE model parameters of a RADFET sensor with a dielectric HfO₂/SiO₂ double-layer. RADFETs, traditionally fabricated as PMOS transistors with SiO₂, are enhanced by incorporating high-k dielectric materials such as HfO₂ to reduce oxide thickness in modern radiation sensors. The fabrication steps of the sensor are outlined, and model parameters, including the threshold voltage and transconductance, are extracted based on experimental data. Experimental setups for measuring electrical characteristics and irradiation are described, and a method for determining model parameters dependent on the accumulated dose is provided. A SPICE model card is proposed, including parameters for two dielectric thicknesses: (30/10) nm and (40/5) nm. The sensitivities of the sensors are 1.685 mV/Gy and 0.78 mV/Gy, respectively. The model is calibrated for doses up to 20 Gy, and good agreement between experimental and simulation results validates the proposed model.

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.