Depletion region

About: Depletion region is a research topic. Over the lifetime, 9393 publications have been published within this topic receiving 145633 citations.

The potential in a charge coupled device with no mobile minority carriers and zero plate separation

Abstract: A two-dimensional analysis of the potential in charge coupled devices is presented. It is assumed that there are no mobile minority carriers, that the plate separation is zero, and that the plate voltage does not vary with time. The depletion layer approximation is used to linearize the equations, which are then solved exactly with the use of Fourier series. Both surface and buried channel devices are analyzed. These solutions can typically be evaluated on a computer in less than a tenth of the time it takes to obtain a solution by the method of finite differences. The solutions obtained here provide an important tool for the designer of charge coupled devices. In addition to describing the method of obtaining the solutions, we evaluate them to show the effects of a number of different design parameters, and compare the cost of these solutions with the cost of obtaining finite difference solutions.

The barrier height change and current transport phenomena with the presence of interfacial layer in MIS Schottky barrier solar cells

Abstract: In this comprehensive study, several interesting results which are different from those previous are reported. We find the barrier height decreases for n -type and increases for p -type when positive ions are introduced into the insulating layer. The increase of open circuit voltage can be traced to the suppression of the dark saturation current by the depletion field induced by the positive charge, and to the diminution of the majority tunneling current by the oxide potential barrier. The tunneling probabilities for majority and minority carriers are different; there are only a finite amount of majority carriers with thermionic energy greater than q ( V bi − V s ) which can surmount the depletion potential and tunnel into the metal, whereas the photogenerated minority carriers derive kinetic energy in the depletion layer making tunneling easier. Transport coefficients for electrons to transmit from metal to semiconductor and from semiconductor to metal are different for the departure of built in potentials during illumination.

Modeling Inductive Switching Characteristics of High-Speed Buffer Layer IGBT

Abstract: In this study, a physics-based compact model for high-speed buffer layer insulated gate bipolar transistor (IGBT) is proposed. The model utilizes the 1-D Fourier-based solution of ambipolar diffusion equation (ADE) implemented in MATLAB and Simulink. Based on the improved understanding on the inductive switching behavior of a high-speed buffer layer IGBT, the ADE is solved for all injection levels instead of high-level injection only as usually done. Assuming high-level injection condition in the buffer layer, the excess carrier transport, redistribution and recombination in the buffer layer are redescribed. Moreover, some physical characteristics such as the low conductivity of N-base at turn-on transient and free holes appeared in the depletion layer during turn-off process are also considered in the model. Finally, the double-pulse switching tests for a commercial field stop IGBT and a light punch-through carrier-stored trench bipolar transistor are used to validate the proposed model. The simulation results are compared with experiment results and good agreement is obtained.

Investigations on the Degradations of Double-Trench SiC Power MOSFETs Under Repetitive Avalanche Stress

Abstract: The degradations of electrical parameters for double-trench silicon carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs) under repetitive avalanche stress are investigated in this paper. The injection of hot holes into the bottom oxide of the gate trench during avalanche process is demonstrated to be the dominant degradation mechanism, while the channel is rarely influenced by the stress. The injected holes attract extra electrons in the SiC layer along the SiC/SiO2 interface, decreasing the ON-state drain–source resistance ( ${R}_{{dson}}$ ). Due to this reason, the threshold voltage ( ${V}_{{th}}$ ) of the device also reduces slightly. Moreover, other than static electrical parameters, dynamic characteristics including the gate–drain capacitance ( ${C}_{{gd}}$ ) and the switching characteristics of the device also degrade. After being stressed by repetitive avalanche stress, the depletion region beneath the bottom of the gate trench gets thinner, leading to the increase in ${C}_{{gd}}$ , which further influences the switching behaviors. The turn- ON and turn- OFF switching times of the device are calculated. It illustrates that the repetitive avalanche stress results in an obvious delay in the turn- OFF procedure, but hardly influences the turn- ON behaviors of the double-trench SiC MOSFET.