Low-Frequency noise investigation of AlGaN/GaN high-electron-mobility transistors
Introduction
HEMTs are very attractive candidates for 5G and millimeter-wave applications due to their distinctive high electron mobility in the two-dimensional electron gas (2DEG), power density and high breakdown voltage [1], [2]. The working principle of the device is that in the vicinity of a semiconductor heterojunction electrons are transferred from the material with the higher conduction band energy (Ec) to the material with the lower Ec where they can occupy a lower energy state. A high density of electrons can be achieved, especially if the semiconductor with the high Ec barrier is doped [3], [4].
Near the interface there exists a 2DEG, forming the conductive channel. Therefore, it is possible to separate the electrons in the channel from their donor atoms which reduces Coulomb scattering and, hence, increases the mobility of the conducting electrons [3], [4].
In the last decade it became clear that LF noise analysis is a very powerful and sensitive tool to reveal and quantify the material/device quality, to identify material defects, trapping effects and for studying reliability of GaN-based HEMTs [5], [6], [7], [8], [9]. The 1/f noise characteristics in AlGaN/GaN HEMTs can be explained by using either the Carrier Number Fluctuations (CNF) and the Hooge Mobility Fluctuations (HMF) models [10], [11], [12].
The CNF model explains the fluctuations in carrier number due to the interactions of channel carriers with traps in the gate dielectric and/or in the semiconductor body, while the HMF model explains the fluctuations in carrier mobility in the channel due to scattering of mobile charges. A further refinement in the number of fluctuations 1/f noise is the so-called correlated mobility fluctuations (CMF) model which explains that the number of fluctuations caused by trapping/detrapping of carriers in the channel can simultaneously cause fluctuations in the carrier mobility [13].
In this work, the LF noise behavior of AlGaN/GaN HEMTs on silicon substrates is investigated for different channel lengths, widths and at different temperatures (T). It is shown that 1/f noise dominates and follows the number fluctuations model.
Section snippets
Experimental
The investigated HEMTs based on GaN/AlGaN heterostructures were grown by metal–organic chemical vapor deposition (MOCVD) on a high resistivity 200 mm Si (1 1 1) substrate. Devices were processed up to Metal 1 using an Au-free, gate-first process. In order to reduce the RF losses, high resistivity Si substrates were used, combined with a careful buffer design, a C-doping process at a lower growth temperature to form a semi-insulating GaN buffer and the strict control of the thermal budget during
Results and discussion
Fig. 2 shows the drain current (ID) and transconductance (gm) versus gate voltage (VG) for a HEMT with W = 1 μm and L = 0.2 μm, at different temperatures. (All measurements results were performed on the same device, varying only the temperature). As expected, the drain current and maximum transconductance decrease with an increase of T due to the reduction of the 2DEG electron mobility with higher temperature [15], [16], [17].
The corresponding LF noise PSD spectra are represented in Fig. 3,
Conclusions
This work presents an experimental study of the LF noise in AlGaN/GaN HEMTs on silicon with different widths and channel lengths. The measurements suggest that the 1/f noise is due to trapping in the AlGaN barrier, and the noise drops for higher temperature. GR noise can be originated from electron traps in the GaN bulk.
The device miniaturization leading to a reduction of the number of carriers available for transport, gives rise to a great sensitivity to inevitable device variations. In other
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
This work has been performed within imec’s Partner Program on high-speed analog and RF devices.
Maria Glória Caño de Andrade was born in Bauru, Brazil. She received the degree in electronic engineering from (UNESP) Paulista State University, Ilha Solteira, Brazil, in 1994, the M.S. degree from the University Center of FEI, Sao Bernardo do Campo, Brazil, in 2007 and Ph.D. degree in microelectronics from University of Sao Paulo, Brazil in 2012. For two years, she was a Researcher at IMEC and Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium, (2010 and 2012, respectively) for the
REFERENCES (23)
- et al.
2DEG modulation in double quantum well enhancement mode nitride HEMT
Physica E
(2015) - et al.
Improved DC and RF performance of AlGaN/GaN HEMTs grown by MOCVD on sapphire substrates
Solid State Electron.
(2005) - et al.
1/f noise characteristics of AlGaN/GaN HEMTs with periodically carbon-doped GaN buffer layer
Microelectron Eng
(2019) - et al.
Influence of polarization Coulomb field scattering on high-temperature electron mobility in AlGaN/AlN/GaN heterostructure field-effect transistors
Superlattices Microstruct
(2018) - et al.
Physics-based numerical simulation and device characterizations of AlGaN/GaN HEMTs with temperature effects
Microelectron J
(2011) - et al.
Low frequency noise assessment in n- and p-channel sub-10 nm triple-gate FinFETs: Part II: Measurements and results
Solid-State Electron.
(2017) - et al.
High Electron Mobility Transistor: A Review on Analytical Models, International Journal for Innovative Research in
Science & Technology
(2016) - et al.
High Electron Mobility Transistors: Performance Analysis, Research Trend and Applications, Different Types of Field-Effect Transistors
Different Types of Field-Effect Transistors Theory and Applications.
(2017) - Silvestri M., Uren M., Killat N., Marcon D., Kuball M. Localization of off-stress-induced damage in AlGaN/GaN high...
- et al.
Schottky gate of AlGaN/GaN HEMTs: Investigation with DC and low frequency noise measurements after 7000 hours HTOL test
International Conference Noise and Fluctuations. Xian, China
(2015)
Device reliability study of high gate electric field effects in AlGaN/GaN high electron mobility transistors using low frequency noise spectroscopy, Journal
Applied Physics.
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Maria Glória Caño de Andrade was born in Bauru, Brazil. She received the degree in electronic engineering from (UNESP) Paulista State University, Ilha Solteira, Brazil, in 1994, the M.S. degree from the University Center of FEI, Sao Bernardo do Campo, Brazil, in 2007 and Ph.D. degree in microelectronics from University of Sao Paulo, Brazil in 2012. For two years, she was a Researcher at IMEC and Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium, (2010 and 2012, respectively) for the experimental part of Ph.D. related to electrical characterization and Postdoctoral Researcher in semiconductor devices. She collaborated in the implantation and technical support of the telephony system Alcatel S12, acted in Brazil the international group Dates Diagnosis Team, which was responsible for the quality and control of mistakes in data, bringing agility in the software updating’s. She was responsible for the system of voice locution for several operators of Brazilian telephony, optimizing the maintenance and the operation, and she consequently won awards for the companies. Since October 2013, she has become full professor at São Paulo State University (UNESP), Institute of Science and Technology, Sorocaba, Brazil.
Luis Felipe de Oliveira is a brazilian Control and Automation engineer graduated in 2019 at Instituto de Ciência e Tecnologia - Câmpus de Sorocaba. Since the beginning of his graduation, he started his academic life in scientific initiations in semiconductor devices and transistors area. Luis was awarded a scientific initiation scholarship for two FAPESP projects in microelectronics area and was considered the best student in 2019 Control and Automation engineer class. Luis is currently a software developer at the Flextronics Institute of Technology (FIT). He is currently finishing his master's degree in electrical engineering at Instituto de Ciência e Tecnologia - Câmpus de Sorocaba focusing on transistors with high electron mobility.