Browsing by Author "Sarkar, Ritam"

Filter results by typing the first few letters
Now showing 1 - 1 of 1
  • Epi-Gd2O3/AlGaN/GaN MOS HEMT on 150 mm Si wafer: A fully epitaxial system for high power application
    (2019-08-05) Sarkar, Ritam; Bhunia, S.; Nag, D.; Barik, B. C.; Das Gupta, K.; Saha, D.; Ganguly, S.; Laha, Apurba; Lemettinen, Jori; Kauppinen, Christoffer; Kim, Iurii; Suihkonen, Sami; Gribisch, Philipp; Osten, Hans Jörg
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    In this letter, we report the impact of epitaxial Gd2O3 on the electrical properties of an AlGaN/GaN high electron mobility transistor (HEMT) grown on a 150 mm diameter Si (111) substrate. Incorporation of epitaxial Gd2O3 grown by the molecular beam epitaxy technique under a metal gate (metal/Gd2O3/AlGaN/GaN) causes six orders of magnitude reduction in gate leakage current compared to metal/AlGaN/GaN HEMT. We observe that epi-Gd2O3 undergoes complete structural changes from hexagonal to monoclinic as the thickness of the layer is increased from 2.8 nm to 15 nm. Such structural transformation is found to have a strong impact on electrical properties whereby the gate leakage current reaches its minimum value when the oxide thickness is 2.8 nm. We find a similar trend in the density of interface traps (Dit) having a minimum value of 2.98 × 1012 cm-2 eV-1 for the epioxide layer of thickness 2.8 nm. Our measurements also confirm a significant increase in the two dimensional electron gas (2DEG) density (∼40%) at AlGaN/GaN interface with epioxide grown on AlGaN, thus confirming the contribution of epitaxial lattice strain on 2DEG modulation.