[en] Negative bias temperature instability (NBTI) has become a serious reliability issue, and the interface traps and oxide charges play an important role in the degradation process. In this paper, we study the recovery of NBTI systemically under different conditions in the P-type metal–oxide–semiconductor field effect transistor (PMOSFET), explain the various recovery phenomena, and find the possible processes of the recovery. (paper)

[en] The influence of PMOSFET gate length on the parameter degradation relations under negative bias temperature instability (NBTI) stress is studied. The threshold voltage degradation increases with reducing the gate length. By calculating the relations between the threshold voltage and the linear/saturation drain current, we obtain their correlation coefficients. Comparing the test result with the calculated linear/saturation current value, we obtain the ratio factors. The ratio factors decrease differently when the gate length diminishes. When the gate length reduces to some degree, the linear ratio factor decreases from greater than 1 to nearly 1, but the saturation factor decreases from greater than 1 to smaller than 1. This results from the influence of mobility and the velocity saturation effect. Moreover, due to the un-uniform distribution of potential damages along the channel, the descending slopes of the curve are different. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

[en] This study investigated the transformation of triclosan (TCS) following co-exposure to UV irradiation and ClO₂. Special attention was given to understand the influencing of water quality parameters and toxicity changes during the co-exposure process. The results show that the co-exposure process prompted TCS elimination quickly and effectively, with more than 99% of TCS degraded under the experimental conditions. The molar yield ratios of 2,4-dichlorophenol/TCS (2,4-DCP/TCS) were calculated to be 35.81–74.49%; however, the by-product of 2,8-dichlorodibenzop-dioxin (2,8-Cl₂DD) was not detected. The TCS degradation was sensitive to ClO₂ dosage, pH, H₂O₂, and natural organic matter (NOM), but not to the carbonate (CO₃²⁻) concentration. Neutral and slightly alkaline condition were favorable to TCS elimination. The TCS removal rate increased from 85.33 to 99.75% when the ClO₂ concentration increased from 0.25 to 1.5 mg L⁻¹. TCS degradation can be promoted at low NOM level (1, 3, and 5 mg L⁻¹), whereas was inhibited at high NOM concentrations of 7 and 9 mg L⁻¹. While adding H₂O₂, the degradation rate of TCS increased with increasing H₂O₂ concentration from 1 to 3 mg L⁻¹; however, too low or overdosed H₂O₂ (0.5 and 5 mg L⁻¹) hindered TCS degradation. Based on the results of a microtox bioassay, the toxicity did not change following the co-exposure process.

[en] The performance degradation of gate-recessed metal–oxide–semiconductor high electron mobility transistor (MOS-HEMT) is compared with that of conventional high electron mobility transistor (HEMT) under direct current (DC) stress, and the degradation mechanism is studied. Under the channel hot electron injection stress, the degradation of gate-recessed MOS-HEMT is more serious than that of conventional HEMT devices due to the combined effect of traps in the barrier layer, and that under the gate dielectric of the device. The threshold voltage of conventional HEMT shows a reduction under the gate electron injection stress, which is caused by the barrier layer traps trapping the injected electrons and releasing them into the channel. However, because of defects under gate dielectrics which can trap the electrons injected from gate and deplete part of the channel, the threshold voltage of gate-recessed MOS-HEMT first increases and then decreases as the conventional HEMT. The saturation phenomenon of threshold voltage degradation under high field stress verifies the existence of threshold voltage reduction effect caused by gate electron injection. (paper)