A Reliability Investigation of VDMOS Transistors: Performance and Degradation Caused by Bias Temperature Stress.

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.

Xenon-filled diode performance under influence of low doses of gamma radiation.

This paper presents a detailed statistical analysis of experimental results of dynamic breakdown voltage and electrical breakdown time delay for xenon-filled diode. These quantities have a stochastic nature and they were measured in the cases when the xenon-filled diode was and was not exposed to a gamma radiation source, with exposure dose rate 7.7⋅10-12 C/(kg⋅s). The static breakdown voltage was estimated based on dynamic breakdown voltage as a function of voltage increase rate. The applicability of certain distributions to experimental dynamic breakdown voltage and electrical breakdown time delay data was also analyzed.

INVESTIGATION OF XENON-FILLED TUBE BREAKDOWN VOLTAGE AND DELAY RESPONSE AS POSSIBLE DOSIMETRIC PARAMETERS FOR SMALL GAMMA RAY AIR KERMA RATES.

This paper presents experimental results of dynamic breakdown voltage and delay response as functions of gamma ray air kerma rate for xenon-filled tube at 2.7 mbar pressure. Gamma ray air kerma rate range was considered from 123 nGy h-1 up to 12.3 mGy h-1 in order to investigate the possibility of the application of this tube in gamma radiation dosimetry. It was shown that the variations of the above-mentioned parameters are considerable up to the dose rate of 1.23 µGy h-1, which points to the possibility for application in small dose rate gamma ray dosimetry. Physical processes that make dominant impact to dynamic breakdown voltage and delay response during xenon-filled tube irradiation are also discussed in the paper.