skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Novel cubic phase III-nitride complementary metal-oxide-semiconductor transistor technology
Here we propose a new wide band gap logic circuitry providing emerging power electronics with reliable logic control capabilities with 500 MHz+ switching speeds and withstanding 300V+. Particularly, a three-stage ring oscillator composed of NMOS (μe = 1000 cm2/V-s) and PMOS (μh = 250 cm2/V-s) cubic phase GaN devices (with VT of 0.77 V and –0.84 V, respectively) is simulated. The propagation delay is minimized by optimizing the width-to-length ratio (W/L) between the NMOS and PMOS devices. Transient response of the simulation illustrates the ability of the CMOS inverter to operate at a maximum frequency of 1.22 GHz with a full voltage swing between VDD of 2.5 V and 0 V. The proposed cutting-edge p-channel GaN high hole mobility transistor (HHMT) solves one of the most longstanding problems in power electronics and constitutes the basis of an innovative reduced total life cycle cost that will serve as the cornerstone of the next generation of integrated, scalable, and reliable power systems.  more » « less
Award ID(s):
1652871
PAR ID:
10082124
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Quantum Sensing and Nano Electronics and Photonics XV
Volume:
10540
Issue:
105401G
Page Range / eLocation ID:
1-8
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; (, Applied Physics Letters)
    The polarization difference and band offset between Al(Ga)N and GaN induce two-dimensional (2D) free carriers in Al(Ga)N/GaN heterojunctions without any chemical doping. A high-density 2D electron gas (2DEG), analogous to the recently discovered 2D hole gas in a metal-polar structure, is predicted in a N-polar pseudomorphic GaN/Al(Ga)N heterostructure on unstrained AlN. We report the observation of such 2DEGs in N-polar undoped pseudomorphic GaN/AlGaN heterostructures on single-crystal AlN substrates by molecular beam epitaxy. With a high electron density of ∼4.3 ×1013/cm2 that maintains down to cryogenic temperatures and a room temperature electron mobility of ∼450 cm2/V s, a sheet resistance as low as ∼320 Ω/◻ is achieved in a structure with an 8 nm GaN layer. These results indicate significant potential of AlN platform for future high-power RF electronics based on N-polar III-nitride high electron mobility transistors. 
    more » « less
  2. ; ; ; ; ; ; ; (, Applied Physics Letters)
    Polarization-induced carriers play an important role in achieving high electrical conductivity in ultrawide bandgap semiconductor AlGaN, which is essential for various applications ranging from radio frequency and power electronics to deep UV photonics. Despite significant scientific and technological interest, studies on polarization-induced carriers in N-polar AlGaN are rare. We report the observation and properties of polarization-induced two-dimensional electron gases (2DEGs) in N-polar AlGaN/AlN heterostructures on single-crystal AlN substrates by systematically varying the Al content in the 8 nm top layers from x = 0 to x = 0.6, spanning energy bandgaps from 3.56 to 4.77 eV. The 2DEG density drops monotonically with increasing Al content, from 3.8 × 1013/cm2 in the GaN channel, down to no measurable conductivity for x = 0.6. Alloy scattering limits the 2DEG mobility to below 50 cm2/V s for x = 0.49. These results provide valuable insights for designing N-polar AlGaN channel high electron mobility transistors on AlN for extreme electronics at high voltages and high temperatures, and for UV photonic devices. 
    more » « less
  3. ; ; ; ; ; ; ; ; (, Applied Physics Letters)
    AlScN is attractive as a lattice-matched epitaxial barrier layer for incorporation in GaN high electron mobility transistors due to its large dielectric constant and polarization. The transport properties of polarization-induced two-dimensional (2D) electron gas of densities of ∼2×1013/cm2 formed at the AlScN–GaN interface is studied by Hall-effect measurements down to cryogenic temperatures. The 2D electron gas densities exhibit mobilities limited to ∼300 cm2/V s down to 10 K at AlScN/GaN heterojunctions. The insertion of a ∼2 nm AlN interlayer boosts the room temperature mobility by more than five times from ∼300 cm2/V s to ∼1573 cm2/V s, and the 10 K mobility by more than 20 times to ∼6980 cm2/V s at 10 K. These measurements provide guidelines to the limits of electron conductivities of these highly polar heterostructures. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, ACS Applied Materials & Interfaces)
    Ultra-wide band gap semiconductor devices based on β-phase gallium oxide (Ga2O3) offer the potential to achieve higher switching performance and efficiency and lower manufacturing cost than that of today’s wide band gap power electronics. However, the most critical challenge to the commercialization of Ga2O3 electronics is overheating, which impacts the device performance and reliability. We fabricated a Ga2O3/4H–SiC composite wafer using a fusion-bonding method. A low-temperature (≤600 °C) epitaxy and device processing scheme was developed to fabricate MOSFETs on the composite wafer. The low-temperature-grown epitaxial Ga2O3 devices deliver high thermal performance (56% reduction in channel temperature) and a power figure of merit of (∼300 MW/cm2), which is the highest among heterogeneously integrated Ga2O3 devices reported to date. Simulations calibrated based on thermal characterization results of the Ga2O3-on-SiC MOSFET reveal that a Ga2O3/diamond composite wafer with a reduced Ga2O3 thickness (∼1 μm) and a thinner bonding interlayer (<10 nm) can reduce the device thermal impedance to a level lower than that of today’s GaN-on-SiC power switches. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Applied Physics Letters)
    Wide and ultrawide-bandgap semiconductors lie at the heart of next-generation high-power, high-frequency electronics. Here, we report the growth of ultrawide-bandgap boron nitride (BN) thin films on wide-bandgap gallium nitride (GaN) by pulsed laser deposition. Comprehensive spectroscopic (core level and valence band x-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman) and microscopic (atomic force microscopy and scanning transmission electron microscopy) characterizations confirm the growth of BN thin films on GaN. Optically, we observed that the BN/GaN heterostructure is second-harmonic generation active. Moreover, we fabricated the BN/GaN heterostructure-based Schottky diode that demonstrates rectifying characteristics, lower turn-on voltage, and an improved breakdown capability (∼234 V) as compared to GaN (∼168 V), owing to the higher breakdown electrical field of BN. Our approach is an early step toward bridging the gap between wide and ultrawide-bandgap materials for potential optoelectronics as well as next-generation high-power electronics. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email