High Breakdown Voltage in RF AlN/GaN/AlN Quantum Well HEMTs

In evaluating GaN high-electron mobility transistors (HEMTs) for high-power applications, it is crucial to consider the device-level breakdown characteristics. This letter replaces the conventional AlGaN barrier and common AlGaN backbarrier with unstrained AlN, and it assesses the breakdown voltage of AlN/GaN/AlN quantum well HEMTs for gate-drain spacings in the range of 0.27–<inline-formula> <tex-math notation="LaTeX">$5.1~\mu \text{m}$ </tex-math></inline-formula>. The results are highlighted by a high breakdown voltage of 78 V for a gate-drain spacing of 390 nm, among the best reported for submicron-channel devices. In addition, small-signal RF measurements showed record performance for HEMTs on the AlN platform, with <inline-formula> <tex-math notation="LaTeX">$\text {f}_{\text {t}}/\text {f}_{\text {max}} = {161}/{70}$ </tex-math></inline-formula> GHz. The cut-off frequency and corresponding drain bias are benchmarked against the state-of-the-art GaN HEMTs using the Johnson figure of merit, with measured devices highlighted by a JFoM value of 2.2 THz <inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula> V. These results illustrate the potential for AlN/GaN/AlN quantum well HEMTs as a future platform for high-power RF transistors.

[1]  A. Schmitz,et al.  Self-aligned-gate GaN-HEMTs with heavily-doped n+-GaN ohmic contacts to 2DEG , 2012, 2012 International Electron Devices Meeting.

[2]  D. Boroyevich,et al.  Evaluation of the switching characteristics of a gallium-nitride transistor , 2011, 2011 IEEE Energy Conversion Congress and Exposition.

[3]  P. M. Asbeck,et al.  Electron Velocity Enhancement in Laterally Scaled GaN DH-HEMTs With $f_{T}$ of 260 GHz , 2011, IEEE Electron Device Letters.

[4]  Xiang Gao,et al.  InAlN/AlN/GaN HEMTs With Regrown Ohmic Contacts and $f_{T}$ of 370 GHz , 2012, IEEE Electron Device Letters.

[5]  D. Jena,et al.  Strained GaN quantum-well FETs on single crystal bulk AlN substrates , 2016, 1611.08914.

[6]  U. Mishra,et al.  N-polar GaN/InAlN MIS-HEMT with 400-GHz ƒmax , 2012, 70th Device Research Conference.

[7]  S. Keller,et al.  High-performance E-mode AlGaN/GaN HEMTs , 2006, IEEE Electron Device Letters.

[8]  D. Jena,et al.  Terahertz spectroscopy of an electron-hole bilayer system in AlN/GaN/AlN quantum wells , 2017, 1708.04752.

[9]  U. Mishra,et al.  Design of High-Aspect-Ratio T-Gates on N-Polar GaN/AlGaN MIS-HEMTs for High $f_{\max}$ , 2012, IEEE Electron Device Letters.

[10]  U. K. Mishra,et al.  N-polar GaN/InAlN/AlGaN MIS-HEMTs with 1.89 S/mm extrinsic transconductance, 4 A/mm drain current, 204 GHz fT and 405 GHz fmax , 2013, 71st Device Research Conference.

[11]  Adele E. Schmitz,et al.  Ultrahigh-Speed GaN High-Electron-Mobility Transistors With f T / f max of 454/444 GHz , 2015 .

[12]  Yu Cao,et al.  InGaN Channel High-Electron-Mobility Transistors with InAlGaN Barrier and fT/fmax of 260/220 GHz , 2012 .

[13]  W. E. Hoke,et al.  AlGaN/GaN HEMT With 300-GHz $f_{\max}$ , 2010 .

[14]  Xiang Gao,et al.  Gate-Recessed InAlN/GaN HEMTs on SiC Substrate With $ \hbox{Al}_{2}\hbox{O}_{3}$ Passivation , 2009, IEEE Electron Device Letters.

[15]  Yu Cao,et al.  Polarization-Induced GaN-on-Insulator E/D Mode p-Channel Heterostructure FETs , 2013, IEEE Electron Device Letters.

[16]  U. K. Mishra,et al.  Self-Aligned N-Polar GaN/InAlN MIS-HEMTs With Record Extrinsic Transconductance of 1105 mS/mm , 2012, IEEE Electron Device Letters.

[17]  D. Jena,et al.  First demonstration of strained AlN/GaN/AlN quantum well FETs on SiC , 2016, Device Research Conference.

[18]  A. Schmitz,et al.  Deeply-scaled self-aligned-gate GaN DH-HEMTs with ultrahigh cutoff frequency , 2011, 2011 International Electron Devices Meeting.

[19]  Dong Seup Lee,et al.  317 GHz InAlGaN/GaN HEMTs with extremely low on‐resistance , 2013 .

[20]  Toru Nagashima,et al.  Thermal conductivity of single-crystalline AlN , 2018, Applied Physics Express.

[21]  Yu Cao,et al.  Ultrathin Body GaN-on-Insulator Quantum Well FETs With Regrown Ohmic Contacts , 2012, IEEE Electron Device Letters.

[22]  Yugang Zhou,et al.  AlGaN/GaN/InGaN/GaN DH-HEMTs with an InGaN notch for enhanced carrier confinement , 2006, IEEE Electron Device Letters.

[23]  G. Snider,et al.  A self‐consistent solution of Schrödinger–Poisson equations using a nonuniform mesh , 1990 .

[24]  D. Muller,et al.  A polarization-induced 2D hole gas in undoped gallium nitride quantum wells , 2018, Science.

[25]  G. Snider,et al.  Ultrascaled InAlN/GaN High Electron Mobility Transistors with Cutoff Frequency of 400 GHz , 2013 .

[26]  Xiang Gao,et al.  InAlN/GaN HEMTs With AlGaN Back Barriers , 2011, IEEE Electron Device Letters.

[27]  A. Fung,et al.  220GHz fT and 400GHz fmax in 40-nm GaN DH-HEMTs with re-grown ohmic , 2010, 2010 International Electron Devices Meeting.

[28]  Umesh K. Mishra,et al.  Demonstration of Constant 8 W/mm Power Density at 10, 30, and 94 GHz in State-of-the-Art Millimeter-Wave N-Polar GaN MISHEMTs , 2018, IEEE Transactions on Electron Devices.

[29]  L. Largeau,et al.  Ultrathin AlN‐Based HEMTs Grown on Silicon Substrate by NH3‐MBE , 2018 .

[30]  G. Snider,et al.  Time delay analysis in high speed gate-recessed E-mode InAlN HEMTs , 2013 .

[31]  D. Jena,et al.  Two-dimensional electron gases in strained quantum wells for AlN/GaN/AlN double heterostructure field-effect transistors on AlN , 2014 .

[32]  Nidhi,et al.  N-polar GaN-based highly scaled self-aligned MIS-HEMTs with state-of-the-art fT.LG product of 16.8 GHz-µm , 2009, 2009 IEEE International Electron Devices Meeting (IEDM).

[33]  D. Muller,et al.  Gate-Recessed E-mode p-Channel HFET With High On-Current Based on GaN/AlN 2D Hole Gas , 2018, IEEE Electron Device Letters.

[34]  S. Keller,et al.  Ge-spacer technology in AlGaN/GaN HEMTs for mm-wave applications , 2005, IEEE InternationalElectron Devices Meeting, 2005. IEDM Technical Digest..