A normally-off GaN double-implanted vertical MOSFET (DMOSFET) with an atomic layer deposition (ALD)-Al2O3 gate dielectric film on a free-standing GaN substrate fabricated by triple ion implantation is presented. The DMOSFET was formed with Si ion implanted source regions in a Mg ion implanted p-type base with N ion implanted termination regions. A maximum drain current of 115 mA/mm, maximum transconductance of 19 mS/mm at a drain voltage of 15 V, and a threshold voltage of 3.6 V were obtained for the fabricated DMOSFET with a gate length of 0.4 μm with an estimated p-type base Mg surface concentration of 5 × 1018 cm−3. The difference between calculated and measured Vths could be due to the activation ratio of ion-implanted Mg as well as Fermi level pinning and the interface state density. On-resistance of 9.3 mΩ·cm2 estimated from the linear region was also attained. Blocking voltage at off-state was 213 V. The fully ion implanted GaN DMOSFET is a promising candidate for future high-voltage and high-power applications.

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Articles you may be interested inPreparation of Y0.5Bi2.5Fe5O12 films on glass substrates using magnetic iron garnet buffer layers by metalorganic decomposition method J. Appl. Phys. 113, 17A926 (2013); 10.1063/1.4798480Comment on "The role of Bi3+ ions in magneto-optic Ce and Bi comodified epitaxial iron garnet films" [Appl.Development of liquid phase epitaxy-grown (Bi, Gd, Lu)-substituted thin-film iron garnets Epitaxial ͑Y,Bi͒ 3 ͑Fe, Ga͒ 5 O 12 garnet thin films have been prepared on Gd 3 Ga 5 O 12 (111) substrates by a metal-organic decomposition (MOD) method using carboxylic acids. The chemical compositions of the films prepared in this study are Y 2 BiFe 5 O 12 (YBFO), Y 3 Fe 4 GaO 12 (YFGO), and Y 2 BiFe 4 GaO 12 (YBFGO). Epitaxy of these films was confirmed by x-ray diffraction and Rutherford backscattering (RBS) measurements. Full width of half maximum values of the 444 diffraction peaks of YFGO and YBFGO were 0.4°and 0.04°, respectively. RBS channeling was clearly observed for the YFGO film with a minimum yield min along the [111] direction of ϳ7.5%. These garnet films could also be reproducibly obtained by the MOD method without any deterioration in the MOD solutions over two years.

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The lattice distortion and the transmuted-Ge related luminescence in neutron-transmutation-doped (NTD) GaN are studied by combining Rutherford backscattering spectroscopy/channeling, Raman scattering, and photoluminescence methods. The lattice displacement of Ga atoms of ∼0.12 Å from the 〈0001〉 row is estimated from the normalized angular yield profiles, preserving the single crystallinity in as-irradiated GaN with a minimum yield (χmin) of 7%. A 2.84 eV emission band observed in 600 °C annealed NTD-GaN is associated with the Ga interstitial, supporting the lattice distortion. Two emission bands at 2.90 eV and 2.25 eV observed in 1000 °C annealed NTD-GaN are assigned to a negatively charged DX-like center of Ge at Ga site and a complex defect attributed to Ge at Ga site and Ga vacancy, respectively.