Abstract
Hafnium silicate (HfSiOx) has been applied to AlGaN/GaN high-electron-mobility transistors (HEMTs) as a high κ gate dielectric. The (HfO2)/(SiO2) laminate structure was deposited on the AlGaN surface by a plasma-enhanced atomic layer deposition, followed by a post-deposition annealing at 800 °C. The HfSiOx-gate HEMT showed good transfer characteristics with a high transconductance expected from its κ value and a subthreshold swing of 71 mV/decade. For the metal–oxide-semiconductor (MOS) HEMT diode, we observed excellent capacitance–voltage (C–V) characteristics with negligible frequency dispersion. The detailed C–V analysis showed low state densities on the order of 1011 cm−2 eV−1 at the HfSiOx/AlGaN interface. In addition, excellent operation stability of the MOS HEMT was observed at high temperatures up to 150 °C.
Highlights
GaN high-electron-mobility transistors (HEMTs) with highfrequency and high-power performances are very attractive for the fifth generation communication system, where the W- and E-band frequency operations with an output power of over 1 W will be required for power amplifier transistors
We carried out comparative characterization of AlGaN/GaN MOS HEMTs with HfSiOx- and Al2O3-gate dielectrics
For the HfSiOx-gate HEMT, the (HfO2)/(SiO2) laminate structure was deposited on the AlGaN surface by plasma-enhanced atomic layer deposition (ALD), followed by PDA at 800 ○C
Summary
GaN high-electron-mobility transistors (HEMTs) with highfrequency and high-power performances are very attractive for the fifth generation communication system, where the W- and E-band frequency operations with an output power of over 1 W will be required for power amplifier transistors. At present, because of several advantages including simplicity, ease of fabrication, and high transconductance, the Schottky-gate (SG) structure is generally used in GaN HEMTs. Because of several advantages including simplicity, ease of fabrication, and high transconductance, the Schottky-gate (SG) structure is generally used in GaN HEMTs. In the high input RF power regime, the SG GaN HEMT may suffer from marked leakage currents due to input swings high enough to drive the gate to forward bias.. Gao et al. recently reported that the forward gate-bias stress applied to the SG AlGaN/GaN HEMT significantly increased gate leakage currents. Li and coworkers applied the HfSiOx gate to the AlGaN/GaN HEMT structure on Si. Li and coworkers applied the HfSiOx gate to the AlGaN/GaN HEMT structure on Si They reported polycrystalline HfSiOx without a composition ratio and high interface state densities in the MOS structure.. HfSiOx/AlGaN/GaN HEMTs and carried out electrical characterization of the MOS HEMTs, focusing on gate controllability and MOS interface properties
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
