Depletion region

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

MOS semiconductor device and method of manufacturing the same

Abstract: The object of the present invention is to suppress a short channel effect on a threshold voltage. A channel region 5 , a pair of source-drain regions and an isolating film 2 having a trench isolation structure are selectively formed in a main surface of a semiconductor substrate 1 . An upper surface of the isolating film 2 recedes to be lower than an upper surface of the channel region 5 in a trench portion adjacent to side surfaces of the channel region 5 and to be almost on a level with the upper surface of the channel region 5 in other regions. Consequently, a part of the side surfaces of the channel region 5 as well as the upper surface thereof are covered by a gate electrode 4 with a gate insulating film 3 interposed therebetween. A channel width W of the channel region 5 is set to have a value which is equal to or smaller than a double of a maximum channel depletion layer width Xdm. Moreover, a width of the trench adjacent to the side surfaces of the channel region 5 is set to be equal to or smaller than a double of a thickness of the gate electrode 4.

Parameter determination from resistance-voltage curve for long-wavelength HgCdTe photodiode

Abstract: A data-processing approach has been developed to obtain device parameters from resistance-voltage (R-V) curves measured on long-wavelength HgCdTe n-on-p photodiodes. The physical model used for R-V curve fitting includes the dark current mechanisms induced by diffusion, generation recombination, trap-assisted tunneling, and band-to-band tunneling. Moreover, the series resistance effect is also taken into account. Six parameters, which include the dopant density Nd in the n region, the ratio of mobility to lifetime of electrons μn∕τn in the p region, the effective lifetime τ0 in the depletion region, the relative energy position of trap level Et∕Eg and its density Nt in the depletion region, and the series resistance Rs, can be extracted from measured R-V curves. The fitting procedure has been presented in detail and the error ranges of the extracted parameters have been discussed. By fitting to the R-V characteristics of three long-wavelength devices with different Cd compositions, the applicability of ou...

Theory of photocurrent in semiconductor‐electrolyte junction solar cells

Abstract: Expressions are derived for the current‐voltage characteristics of semiconductor‐electrolyte junctions. Charge transfer kinetics, surface recombination, recombination in the quasineutral region and in the depletion region as well as the effect of the incident illumination on the minority carrier distribution in the semiconductor are included in the model. It is shown that surface transfer velocity for minority carriers is a very important parameter that determines the photocurrent of the cell. The dependence of the photoresponse on the light intensity is shown to be a diagnostic tool in determining the efficiency of charge transfer at the surface.

Technique for suppression of edge current in semiconductor devices

Abstract: A passive mechanism suppresses injection, into any active guard regions interposed between the edge (170) of a photodiode array chip and the outer photodiode pixels or into the outer pixels themselves, of minority carrier (180) current generated in the physically disrupte region at the egde of the semiconductor die created by cleaving, sawing or otherwise separating the chip from the remainder of the wafer on which the die was fabricated A thin metallic layer covers all or part of the edge region, thereby creating a Schottky barrier This barrier generates a depletion region in the adjacet semiconductor material The depletion region (160) inherently creates an energy band distribution which preferentially accelerates minority carriers generated or near the metal-semiconductor interface towards the metal, thereby suppressing collection of these carriers by any active regions of the guard structure or by the photodiode pixels

Depletion layer studies in organic films: Temperature dependence studies of low frequency capacitance measurements in tetracene and magnesium phthalocyanine

Abstract: The voltage dependence of capacitance in two photovoltaic sandwich cells, (Al ‖ tetracene ‖ Nesatron) and (Al ‖ magnesium phthalocyanine ‖ Nesatron), is reported as a function of temperature. The tetracene cell shows a voltage independent (geometric) capacitance at room temperature which upon heating to 120 °C changes to a depletion layer type capacitance at 10−1 Hz. Values for depletion width, carrier concentration, and barrier voltage are consistent with those reported in a previous publication where carriers in tetracene were mobilized by light. Magnesium phthalocyanine cells, on the other hand, show a depletion layer capacitance at room temperature and upon cooling revert to a geometric capacitance at some lower temperature depending on the frequency of the measurement. A theoretical treatment is presented which describes the frequency and temperature dependence of the depletion layer capacitance. From this analysis a method for measuring activation energies and rate constants for detrapping is obtain...