Degradation of bipolar transistor current gain by hot holes duringreverse emitter-base bias stress

Experimental evidences are given which demonstrate that degradation of the common-emitter forward current gain h_FE of submicron silicon npn bipolar transistors at low reverse emitter-base junction applied voltage is caused by primary hot holes of the n⁺ /p emitter tunneling current rather than secondary hot electrons generated by the hot holes or thermally-generated hot electrons. Experiments also showed similar kinetic energy dependence of the generation rate of oxide/silicon interface traps by primary hot electrons and primary hot holes. Significant h_FE degradation was observed at stress voltages less than 2.4 V     

Improving Usability Perception of Error-Prone AI Speakers: Elaborated Feedback Mitigates Negative Consequences of Errors

ABSTRACT

Users of voice user interface (VUI) often encounter errors, such as when a VUI attempts to recognize a user’s voice inputs or execute tasks. Conversation is prone to errors, and in the collaborative perspective, communicators manage common ground together to handle erroneous situations. Adopting a collaborative view of conversation, we propose that a VUI can address different types of errors by providing users with feedback to aid them in developing common ground to communicate more effectively. To test this proposal, we conducted a 2 (error type: recognition vs. execution error) × 2 (feedback elaboration: present vs. absent) mixed-design experiment in which users interacted with a VUI speaker and evaluated its usability in these four modes. Participants reported greater acceptance of feedback and higher usability perception for a speaker returning execution errors than for one returning recognition errors, particularly when the speaker presented feedback articulating reasons for the errors. This finding indicates that a VUI can employ feedback explaining the causes of errors to facilitate the development of common ground and to minimize the negative consequences of errors.     

Cathodic pulse breakdown of anodic films on aluminium in alkaline silicate electrolyte – Understanding the role of cathodic half-cycle in AC plasma electrolytic oxidation

Sequential anodic and cathodic pulse voltages were applied on anodised Al micro-electrodes in alkaline silicate electrolyte to explore the role of cathodic pulse in AC or bipolar plasma electrolytic oxidation (PEO) process. SEM observation was carried out to observe the sites of anodic and cathodic breakdown and their morphologies. The prior anodic breakdown accelerated the cathodic breakdown at ?50 V, and the acceleration was associated with the preferential cathodic breakdown at the anodic breakdown sites. However, the succeeding anodic breakdown during applying anodic pulse of 420 V for 2 ms was highly suppressed at the cathodic breakdown sites. This would randomise the anodic breakdown sites. Such role may contribute to the formation of rather uniform coatings on aluminium in this electrolyte without large discharge channels when larger cathodic current is applied with respect to the anodic current in AC PEO.     

Exact capacitance of a lossless MOS capacitor

First order Ricatti equations are obtained for the capacitive 3-wire transmission line of a one-dimensional MOS capacitance which give an order of magnitude improvement in numerical computation time over the transmission matrix solution of the lumped section equivalent circuit model of the transmission line.     

Direct-current measurements of oxide and interface traps onoxidized silicon

A direct-current current-voltage (DCIV) measurement technique of interface and oxide traps on oxidized silicon is demonstrated. It uses the gate-controlled parasitic bipolar junction transistor of a metal-oxide-silicon field-effect transistor in a p/n junction isolation well to monitor the change of the oxide and interface trap density. The dc base and collector currents are the monitors, hence, this technique is more sensitive and reliable than the traditional ac methods for determination of fundamental kinetic rates and transistor degradation mechanisms, such as charge pumping     

双极场引晶体管:VI.CMOS电压倒相电路(双MOS栅纯基)

本文报告了硅互补金属氧化层硅（CMOS）电压倒相电路的直流稳态电压和电流转移特性和功率耗散. 这电路用一只实际的﹑纳米尺度的双极场引晶体管(BiFET)实现. 通过数字求解五个偏微分方程,可获得这些电学特性. 方程是基于这种器件结构：在薄纯硅基层的两表面上各有一个MOS栅,在这薄基的两端都有电子和空穴接触. 内部条件和CMOS边界条件用于三种势（静电势和电子及空穴电化学势）. 用一台装有Windows XP-PRO下的64位FORTRAN语言的双核个人计算机,快速地计算出一系列曲线.     

Influence of temperature on threshold stress for reorientation of hydrides and residual stress variation across thickness of Zr-2.5Nb alloy pressure tube

Threshold stress, σ_th, for reorientation of hydrides in cold worked and stress-relieved (CWSR) Zr-2.5Nb pressure tube material was determined in the temperature range of 523-673 K. Using tapered gage tensile specimen, mean value of σ_th was experimentally determined by two methods, half thickness method and area compensation method. The difference between local values of σ_th measured across the thickness of the tube and the mean σ_th values yielded the residual stress variation across the tube thickness. It was observed that both the mean threshold stress and residual stress decrease with increase in reorientation temperature. Also, the maximum value of residual stresses was observed near the midsection of the tube.     

Interface edge effect and its contribution to the frequency dispersion of metal-oxide-semiconductor admittance

Room temperature frequency dispersion of the admittance of Metal-Oxide-Semiconductor (MOS) capacitors made on non-degenerate n-type silicon substrate with (111) surface orientation was studied. A simplified lumped equivalent circuit model which takes into account the interface edge effect, i.e. carrier generation-recombination-trapping via interface states near the edge of the surface inversion region, is proposed and found to be in good agreement with experimental data. Our model also suggests another method of calculating the density of interface states. Fundamental properties of interface states are estimated from experimental data. A self-consistency check is made among the values of equivalent circuit elements to substantiate our model.     

Theory of concentration profiling technique for semiconductors with many deep levels

A general theory is developed to obtain the spatial variations of the concentrations of the deep levels and free carrier from constant-capacitance voltage-transient (CCVT) measurements on semiconductor junctions containing many deep energy levels. In order to measure the deep-level densities near the junction boundary, two methods of edge region correction are also analyzed: the integral equation method and an experimental three-frequency capacitance-voltage method. Conditions under which these methods are easily applicable in experiments are discussed. Applications of these methods are published elsewhere.     

Physicochemical characterization of diclofenac sodium-loaded poloxamer gel as a rectal delivery system with fast absorption

Rectal poloxamer gel systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and were mucoadhesive to the rectal tissues without leakage after the dose. However, a poloxamer gel containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a poloxamer gel using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength, and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers, and sodium chloride were investigated. Furthermore, the pharmacokinetic study of diclofenac sodium delivered by the poloxamer gel was performed. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. The poloxamer gels with less than 1.0% sodium chloride, in which the drug was not precipitated, were inserted into the rectum without difficulty and leakage, and were retained in the rectum of rats for at least 6 hr. Furthermore, poloxamer gel gave significantly higher initial plasma concentrations and faster T_max of diclofenac sodium than did solid suppository, indicating that drug from poloxamer gel could be absorbed faster than that from the solid one in rats. Our results suggested that a rectal poloxamer gel system with sodium chloride and poloxamers was a more physically stable, convenient, and effective rectal dosage form for diclofenac sodium.