Negative Differential Resistance Observation and a New Fitting Model for Electron Drift Velocity in GaN-Based Heterostructures

Abstract

The aim of this paper is an investigation of electric field-dependent drift velocity characteristics for Al 0.3 Ga 0.7 N/AlN/GaN heterostructures without and with in situ Si 3 N 4 passivation. The nanosecond-pulsed currentvoltage (I -V ) measurements were performed using a 20-ns applied pulse. Electron drift velocity depending on the electric field was obtained from the I -V measurements. These measurements show that a reduction in peak electron velocity from 2.01 × 10 7 to 1.39 × 10 7 cm/s after in situ Si 3 N 4 passivation. Also, negative differential resistance regime was observed which begins at lower fields with the implementation of in situ Si 3 N 4 passivation. In our samples, the electric field dependence of drift velocity was measured over 400 kV/cm due to smaller sample lengths. Then, a wellknown fitting model was fitted to our experimental results. This fitting model was improved in order to provide an adequate description of the field dependence of drift velocity. It gives reasonable agreement with the experimental drift velocity data up to 475 kV/cm of the electric field and could be used in the device simulators. ). T. V. Malin and V. G. Mansurov are with the Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia. K. S. Zhuravlev is with the Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia, and also with the

Influence of Parasitic Effects in Negative Differential Resistance Characteristics of Resonant Tunneling

“…The design and fabrication of resonant tunneling system using practice resonant tunneling electronic (PRTE) structure with NDR characteristics have been proposed in literatures [1,12,13], which have been applied in voltage-controlled oscillators (VCOs), MVLLs, and MFDs. Basic practice resonant tunneling electronic (BPRTE) structure was defined with two parallel transistors and four resistances.…”

Evolution of the surface states during the in situ SiN layer formation on AlN/GaN heterostructures

“…In many cases passivation films are deposited ex situ onto the surface of the AlGaN/GaN heterostructure, but this does not solve the problem of oxidation and contamination [15][16][17]. The in situ deposition of the SiN film immediately after the growth of the transistor structure prevents the direct exposure of AlN surface to air improving HEMTs performances [18]. This method was used in metal-organic chemical vapor deposition, where a high growth temperature can promote the formation of high-quality SiN films.…”