Charge Decay Time Research Articles

A dynamical constraint on particulate sizes for Saturn's B ring spokes

A dynamical time scale for the evolution of spokes in Saturn's B ring has been interpreted as the exponential charge decay time for particulates which comprise the spokes. The investigation of solar UV photoemission as the charge decay mechanism has allowed a dynamical constraint to be placed on the particulate sizes. The mean particulate radius is determined to be 0.10 ± 0.03 μm.

Switching characteristics of amorphous silicon Schottky barrier diodes

The dynamic as well as static characteristics of molybdenum/hydrogenated amorphous-silicon Schottky barrier diode were investigated. We obtained the rectification ratio of 10 9 and steady current densities of up to 1.5A/cm 2 at ±2V bias voltage. The breakdown voltage was more than 20V. Switching operation was observed even at 10MHz without appreciable distortion. It was estimated that the charge-up time and charge-decay time of a liquid crystal pixel with 1mm×1mm area in series with a diode having a junction area of 15μm×15μm were less than 1μsec and 100sec, respectively.

Measurement of Electrical Resistivity of CVD-BN Passivation Film from Gate Charge Decay Time of a MOS Transistor

The electrical resistivity of a passivation film used on integrated circuits can be determined from the gate charge decay time of a MOS transistor, where the edge wall of the gate insulator films is covered with a passivation film. For example, we determined the electrical resistivity of CVD-BN (boron nitride), which can be used as a diffusion source of boron into Si in the fabrication process and as a surface passivation of the edge wall of gate insulator films to improve device reliability. The electrical resistivity obtained is between 1011 and 1015 ohm-cm depending on the deposition temperature in the range of 400 to 550°C, although heat treatment at 720°C for Si3N4 deposition and at 1200°C for boron diffusion were also carried out during the fabrication of a test p-MOS transistor.

Production and Charge Decay of Film Electrets

The object of this work has been to obtain charged dielectric films, electrets, that retain their charge over periods of years when left open circuited. Such films are receiving increasing attention because of their potential use in practical devices such as condenser microphones, electrostatic recorders, air filters, etc. Procedures have been devised to form highly charged thin films and to measure their decay rates. Charge decay comparisons are made among different materials at various temperatures, charged in different ways. A procedure is developed that enables long lifetimes of electrets at room temperature to be predicted by extrapolating short charge decay times at elevated temperatures. A number of materials are identified as suitable for very longlived electrets.