Depletion region

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

Design of edge termination for GaN power Schottky diodes

Abstract: The GaN Schottky diodes capable of operating in the 300–700-V range with low turn-on voltage (0.7 V) and forward conduction currents of at least 10 A at 1.4 V (with corresponding forward current density of 500 A/cm2) are attractive for applications ranging from power distribution in electric/hybrid electric vehicles to power management in spacecraft and geothermal, deep-well drilling telemetry. A key requirement is the need for edge-termination design to prevent premature breakdown because of field crowding at the edge of the depletion region. We describe the simulation of structures incorporating various kinds of edge termination, including dielectric overlap and ion-implanted guard rings. Dielectric overlap using 5-µm termination of 0.1–0.2-µm-thick SiO2 increases the breakdown voltage of quasi-vertical diodes with 3-µm GaN epi thickness by a factor of ∼2.7. The use of even one p-type guard ring produces about the same benefit as the optimized dielectric overlap termination.

Influence of Surface Defects on the Characteristics of GaN Schottky Diodes

Abstract: We have studied the fabrication of Pt/Au Schottky diodes on n-type GaN. We show that the electrical characteristics of the diodes are strongly dependent on the surface chemical treatment before the metal deposition. Lowest leakage currents were obtained by the use of a HC1 solution. We also show that annealing the diode at a moderate temperature (400°C) leads to reduced reverse currents. In order to explain these results, we measured the density of deep levels in the Schottky diode depletion region before and after the annealing process. We did not observe any significant difference in the bulk density of defects due to the anneal. We also studied the temperature dependence of the reverse currents and found a low activation energy. Our results are interpreted in terms of electrical defects at the metal-GaN surface.

Approximate analytical solution to the space charge problem in nanosized Schottky diodes

Abstract: An analysis is given of the space charge region that is induced in a semiconductor by a circular Schottky contact Using the depletion approximation, the resulting free-boundary problem for Poisson’s equation is formulated and approximately solved in oblate spheroidal coordinates Expressions are derived for the boundary of the space charge region and the related depletion potential Calculations of the thickness of the Schottky barrier as a function of the diode size, down to the nanometer range, show good agreement with published results obtained numerically

Deep depletion concept for diamond MOSFET

Abstract: A stable deep depletion regime is demonstrated in metal oxide semiconductor capacitors using p-type oxygen-terminated (100) diamond as a semiconductor and Al2O3 deposited by Atomic Layer Deposition at 380 °C. Current voltage I(V) and capacitance voltage C(V) measurements were performed to evaluate the effectiveness of diamond semiconductor gate control. An effective modulation of the space charge region width is obtained by the gate bias, where the deep depletion regime is demonstrated for a positive gate bias. The deep depletion concept is described and proposed for MOSFET devices. Finally, a proof of concept of diamond deep depletion MOSFETs is presented.

Quantum Detection Efficiency in Geiger Mode Avalanche Photodiodes

Abstract: The fabrication of silicon shallow junction photodiodes is a relevant topic for the detection of blue and near ultraviolet weak photon fluxes. In this paper we present a simple model to calculate the quantum detection efficiency (QDE) of a Geiger mode avalanche photodiode (GMAP) as a function of the dead layer thickness above the junction depletion layer. A comparison between calculated and experimental data is also presented. Moreover, by using the same model, an analysis of the QDE at 420 nm wavelength of conventional GMAPs based on shallow N+-P and P+-N junctions is given.