scholarly journals Многообразие свойств приборных структур на основе нитридов элементов III группы, связанное с модификацией фрактально-перколяционной системы

Author(s):  
В.В. Емцев ◽  
Е.В. Гущина ◽  
В.Н. Петров ◽  
Н.А. Тальнишних ◽  
А.Е. Черняков ◽  
...  

AbstractA fractal-percolation system that includes extended defects and random fluctuations in the alloy composition is formed during the growth of device structures based on Group-III nitrides. It is established that the specific features of this system are determined not only by the growth conditions. It is shown that the diversity of the electrical and optical properties of InGaN/GaN LEDs (light-emitting diodes) emitting at wavelengths of 450–460 and 519–530 nm, as well as that of the electrical properties of AlGaN/GaN HEMT (high-electron-mobility transistor) structures, is due to modification of the properties of the fractal-percolation system both during the growth process and under the action of the injection current and irradiation. The influence exerted by these specific features on the service life of light-emitting devices and on the reliability of AlGaN/GaN HEMT structures is discussed.

2005 ◽  
Vol 483-485 ◽  
pp. 1051-1056
Author(s):  
A. Krost ◽  
Armin Dadgar ◽  
F. Schulze ◽  
R. Clos ◽  
K. Haberland ◽  
...  

Due to the lack of GaN wafers, so far, group-III nitrides are mostly grown on sapphire or SiC substrates. Silicon offers an attractive alternative because of its low cost, large wafer area, and physical benefits such as the possibility of chemical etching, lower hardness, good thermal conductivity, and electrical conducting or isolating for light emitting devices or transistor structures, respectively. However, for a long time, a technological breakthrough of GaN-on-silicon has been thought to be impossible because of the cracking problem originating in the huge difference of the thermal expansion coefficients between GaN and silicon which leads to tensile strain and cracking of the layers when cooling down. However, in recent years, several approaches to prevent cracking and wafer bowing have been successfully applied. Nowadays, device-relevant thicknesses of crackfree group-III-nitrides can be grown on silicon. To reach this goal the most important issues were the identification of the physical origin of strains and its engineering by means of in situ monitoring during metalorganic vapor phase epitaxy.


2001 ◽  
Vol 171 (8) ◽  
pp. 857 ◽  
Author(s):  
Igor L. Krestnikov ◽  
V.V. Lundin ◽  
A.V. Sakharov ◽  
D.A. Bedarev ◽  
E.E. Zavarin ◽  
...  

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 751
Author(s):  
Yu-Lin Song ◽  
Manoj Kumar Reddy ◽  
Luh-Maan Chang ◽  
Gene Sheu

This study proposes an analysis of the physics-based TCAD (Technology Computer-Aided Design) simulation procedure for GaN/AlGaN/GaN HEMT (High Electron Mobility Transistor) device structures grown on Si (111) substrate which is calibrated against measurement data. The presence of traps and activation energies in the device structure will impact the performance of a device, the source of traps and position of traps in the device remains as a complex exercise until today. The key parameters for the precise tuning of threshold voltage (Vth) in GaN transistors are the control of the positive fixed charges −5 × 1012 cm−2, donor-like traps −3 × 1013 cm−2 at the nitride/GaN interfaces, the energy of the donor-like traps 1.42 eV below the conduction band and the acceptor traps activation energy in the AlGaN layer and buffer regions with 0.59 eV below the conduction band. Hence in this paper, the sensitivity of the trap mechanisms in GaN/AlGaN/GaN HEMT transistors, understanding the absolute vertical electric field distribution, electron density and the physical characteristics of the device has been investigated and the results are in good agreement with GaN experimental data.


2021 ◽  
Author(s):  
Pawan Kumar ◽  
Sumit Chaudhary ◽  
Md Arif Khan ◽  
Sanjay Kumar ◽  
Shaibal Mukherjee

Abstract We investigate the power switching mechanism to evaluate the power loss ( P D ) and efficiency ( η ) in MgZnO/ZnO (MZO)-based power high electron mobility transistor (HEMT), and physical parameters responsible for P D in molecular beam epitaxy (MBE) and dual ion beam sputtering (DIBS) grown MZO HEMT and compare the performance with the group III-nitride HEMTs. This work extensively probes all physical parameters such as two-dimensional electron gas (2DEG) density, mobility, switching frequency, and device dimension to study their impact on power switching in MZO HEMT. Results suggest that the MBE and DIBS grown MZO HEMT with the gate width ( W G ) of ∼ 205 and ∼ 280 mm at drain current coefficient (k) of 11 and 15, respectively, will achieve 99.96 and 99.95% of η and 9.03 and 12.53 W of P D , respectively. Moreover, W G value for DIBS-grown MZO HEMT is observed to further reduce in the range of 112-168 mm by using a Y 2 O 3 spacer layer leading to the maximum η in the range of 99.98-99.97% and the minimum P D in the range of 5-7 W. This work is significant for the development of cost-effective HEMTs for power switching applications.


2018 ◽  
Vol 52 (7) ◽  
pp. 942-949 ◽  
Author(s):  
V. V. Emtsev ◽  
E. V. Gushchina ◽  
V. N. Petrov ◽  
N. A. Tal’nishnih ◽  
A. E. Chernyakov ◽  
...  

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 353 ◽  
Author(s):  
Giovanni Crupi ◽  
Antonio Raffo ◽  
Valeria Vadalà ◽  
Giorgio Vannini ◽  
Alina Caddemi

The aim of this feature article is to provide a deep insight into the origin of the kink effects affecting the output reflection coefficient (S22) and the short-circuit current-gain (h21) of solid-state electronic devices. To gain a clear and comprehensive understanding of how these anomalous phenomena impact device performance, the kink effects in S22 and h21 are thoroughly analyzed over a broad range of bias and temperature conditions. The analysis is accomplished using high-frequency scattering (S-) parameters measured on a gallium-nitride (GaN) high electron-mobility transistor (HEMT). The experiments show that the kink effects might become more or less severe depending on the bias and temperature conditions. By using a GaN HEMT equivalent-circuit model, the experimental results are analyzed and interpreted in terms of the circuit elements to investigate the origin of the kink effects and their dependence on the operating condition. This empirical analysis provides valuable information, simply achievable by conventional instrumentation, that can be used not only by GaN foundries to optimize the technology processes and, as a consequence, device performance, but also by designers that need to face out with the pronounced kink effects of this amazing technology.


2020 ◽  
Vol 19 (06) ◽  
pp. 2050011
Author(s):  
Yogesh Kumar Verma ◽  
Varun Mishra ◽  
Santosh Kumar Gupta

The two-dimensional electron gas (2DEG) at the heterointerface of AlGaN and GaN is a complicated transcendental function of gate voltage, so an analytical charge control model for AlGaN/GaN high electron mobility transistor (HEMT) is presented accounting for all the three regions of operation (i.e., sub-threshold, moderate, and strong-inversion region). In addition to it, the performance of AlGaN/GaN HEMT is highly dependent on the device geometry. Therefore, to get the optimum performance of the device it is advisable to optimize the parameters governing the device geometry. Accordingly, the output and transfer characteristics, threshold voltage, ON current, OFF current, and transconductance are calculated using numerical computations. The present design is tested to calculate the voltage transfer characteristics (VTC) and transient characteristics of the invertor circuit, after the optimization of the device parameters.


2019 ◽  
Vol 11 (31) ◽  
pp. 3981-3986 ◽  
Author(s):  
Lei Zhao ◽  
Xinsheng Liu ◽  
Bin Miao ◽  
Zhiqi Gu ◽  
Jin Wang ◽  
...  

In this study, we propose a differential extended gate (DEG)-AlGaN/GaN high electron mobility transistor (HEMT) sensor to detect ionic pollutants in solution.


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