III-Nitride-based junction devices round contacts: effect of semiconductor film geometry and characteristics on the capacitance and conductance measurements


A theoretical model was developed, which allows simulating the capacitance (C) and conductance/frequency (G/f) profiles as a function of operation frequencies for a round Schottky diode, and in terms of a transfer length concept, LT(jω), which depends on the electrical characteristics of AlGaN:Si semiconductor film, dimensions and structure Schottky diode. The (C) and (G/f) measurements were performed by applying a small electrical signal far away and parallel to the planar structure of junction device, due to the impossibility of accessing perpendicularly path, since the AlGaN:Si semiconductor film was deposited over a substrate of high electrical resistivity, just as it happens with the III nitrates materials. The (C) and (G/f) profiles were measured for operating frequencies ranging from 3 kHz to 1 MHz. Comparison of experimental measurements and theoretical model were analyzed. It was found that the structure Schottky and electrical characteristics of film plays an important role as a limiting factor in the (C) and (G/f) measurements at media and high operating frequencies.

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The technical assistance of Elias Muñoz Merino, Ignacio Izpura and Moises Orduño-Gómez for sample preparation and characterization is thanked.

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Correspondence to Heberto Gómez Pozos.

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Pozos, H.G., Maldonado, A., Izpura, J.I. et al. III-Nitride-based junction devices round contacts: effect of semiconductor film geometry and characteristics on the capacitance and conductance measurements. J Mater Sci: Mater Electron 30, 11164–11170 (2019). https://doi.org/10.1007/s10854-019-01459-x

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