Investigation of angstrom-thick aluminium oxide passivation layers to improve the gate lag performance of GaN HEMTs

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Gulseren M. E., Kurt G., Ghobadi T. G. U., Ghobadi A., Salkim G., Ozturk M., ...Daha Fazla

MATERIALS RESEARCH EXPRESS, cilt.6, sa.9, 2019 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 6 Sayı: 9
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1088/2053-1591/ab2f68
  • Dergi Adı: MATERIALS RESEARCH EXPRESS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: AlGaN, atomic layer deposition, dielectric, GaN, gate lag, HEMT, passivation, SURFACE PASSIVATION, ALGAN/GAN HEMTS
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Ankara Üniversitesi Adresli: Hayır

Özet

In this paper, we report an angstrom-thick atomic layer deposited (ALD) aluminum oxide (Al2O3) dielectric passivation layer for an AlGaN/GaN high electron mobility transistor (HEMT). Our results show a 55% improvement in the gate lag performance of the design and a decrease by half in interface state density upon coating with two cycles of ALD Al2O3. DC characteristics such as current density, threshold voltage, and leakage currents were maintained. ALD Al2O3 passivation layers with thicknesses up to 10 nm were investigated. XPS analyses reveal that the first ALD cycles are sufficient to passivate GaN surface traps. This study demonstrates that efficient passivation can be achieved in atomic-scale with dimensions much thinner than commonly used bulk layers.