scholarly journals Current Understanding of Bias-Temperature Instabilities in GaN MIS Transistors for Power Switching Applications

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1153
Author(s):  
Milan Ťapajna
Keyword(s):  
High Electron Mobility Transistors ◽  
High Electron ◽  
Power Switching ◽  
Metal Insulator ◽  
Electron Mobility Transistors ◽  
Gate Structure ◽  
Power Frequency ◽  
Leakage Characteristics ◽  
Further Development ◽  
Bias Temperature Instabilities

GaN-based high-electron mobility transistors (HEMTs) have brought unprecedented performance in terms of power, frequency, and efficiency. Application of metal-insulator-semiconductor (MIS) gate structure has enabled further development of these devices by improving the gate leakage characteristics, gate controllability, and stability, and offered several approaches to achieve E-mode operation desired for switching devices. Yet, bias-temperature instabilities (BTI) in GaN MIS transistors represent one of the major concerns. This paper reviews BTI in D- and E-mode GaN MISHEMTs and fully recess-gate E-mode devices (MISFETs). Special attention is given to discussion of existing models describing the defects distribution in the GaN-based MIS gate structures as well as related trapping mechanisms responsible for threshold voltage instabilities. Selected technological approaches for improving the dielectric/III-N interfaces and techniques for BTI investigation in GaN MISHEMTs and MISFETs are also outlined.

scholarly journals Effects of Recessed-Gate Structure on AlGaN/GaN-on-SiC MIS-HEMTs with Thin AlOxNy MIS Gate

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1538 ◽  
Author(s):  
Hyun-Seop Kim ◽  
Myoung-Jin Kang ◽  
Jeong Jin Kim ◽  
Kwang-Seok Seo ◽  
Ho-Young Cha
Keyword(s):  
High Electron Mobility Transistors ◽  
Gate Insulator ◽  
High Electron ◽  
Aluminum Oxynitride ◽  
Characterization Methods ◽  
Field Plate ◽  
Electron Mobility Transistors ◽  
Gate Structure ◽  
Recessed Gate ◽  
Gate Recess

This study investigated the effects of a thin aluminum oxynitride (AlOxNy) gate insulator on the electrical characteristics of AlGaN/GaN-on-SiC metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs). The fabricated AlGaN/GaN-on-SiC MIS-HEMTs exhibited a significant reduction in gate leakage and off-state drain currents in comparison with the conventional Schottky-gate HEMTs, thus enhancing the breakdown voltage. The effects of gate recess were also investigated while using recessed MIS-HEMT configuration. The Johnson’s figures of merit (= fT × BVgd) for the fabricated MIS-HEMTs were found to be in the range of 5.57 to 10.76 THz·V, which is the state-of-the-art values for GaN-based HEMTs without a field plate. Various characterization methods were used to investigate the quality of the MIS and the recessed MIS interface.

scholarly journals Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2760 ◽  
Author(s):  
Pedro J. Martínez ◽  
Enrique Maset ◽  
Pedro Martín-Holgado ◽  
Yolanda Morilla ◽  
David Gilabert ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Wide Band ◽  
High Electron Mobility Transistors ◽  
Dynamic Resistance ◽  
High Electron ◽  
Power Switching ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Free Current ◽  
60Co Gamma Radiation

GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (RON_dyn) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (RDSON) characteristics under 60Co gamma radiation of two different commercial power GaN HEMT structures. Different bias conditions were applied to both structures during irradiation and some static measurements, such as threshold voltage and leakage currents, were performed. Additionally, dynamic resistance was measured to obtain practical information about device trapping under radiation during switching mode, and how trapping in the device is affected by gamma radiation. The experimental results showed a high dependence on the HEMT structure and the bias condition applied during irradiation. Specifically, a free current collapse structure showed great stability until 3.7 Mrad(Si), unlike the other structure tested, which showed high degradation of the parameters measured. The changes were demonstrated to be due to trapping effects generated or enhanced by gamma radiation. These new results obtained about RON_dyn will help elucidate trap behaviors in switching transistors.

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