Dependence of structural and electrical properties of AlGaN/GaN HEMT on Si(111) on buffer growth conditions by MBE

Abstract

Multiple AlGaN/GaN heterostructure has been grown on Si(111) substrate by molecular beam epitaxy with different buffer growth conditions. Its influence on physical and electrical properties of two-dimensional electron gas (2DEG) has been investigated. Correlation between growth temperature variation in AlN intermediate layer and thick GaN buffer layer on 2DEG transport property has been observed. Besides the variation in growth temperatures, dissimilar partial doping in the thick GaN buffer has also been studied. Impact of different silicon substrate doping has been examined to inspect the electrical properties of high electron mobility transistors (HEMT). DC characteristics of large area fabricated HEMT have been compared in terms of current, transconductance, and linearity for power amplifier applications.

Effects of threading dislocations on drain current dispersion and slow transients in unpassivated AlGaN/GaN/Si heterostructure field-effect transistors

“…For that purpose, the growth temperature (calibrated by emissivity corrected pyrometry with two colour reflectometry, SVTA-IS4K) of AlN nucleation layer was kept at either 800 C (for wafer A and B) or 950 C (wafer C), whereas the final GaN buffer layer was grown at 715, 740, and 750 C for wafer A, B, and C, respectively. 13 It is well documented that in material systems having large lattice mismatches (such as $19% between AlN and Si in present case), epitaxy supposedly commences with nucleation of hexagonal pyramids, faceted on low energy {1 100} and (0001) planes. These pyramids eventually coalesce giving rise to TDs at each coalescence boundary.…”

High Figure‐of‐Merit Gallium Oxide UV Photodetector on Silicon by Molecular Beam Epitaxy: A Path toward Monolithic Integration

“…Further surface cleaning was performed by a Ga treatment, as described elsewhere. [ 16 ] In situ reflection high energy electron diffraction (RHEED) reconstruction patterns were used to confirm the complete removal of SiO 2 from the surface. Prior to opening the MBE oxygen plasma shutter, metallic Ga was pre‐deposited for several minutes to form a thin layer of Ga at a substrate temperature of 500 °C.…”

Observation of in‐situ reciprocal lattice evolution of AlGaN/InGaN on Si (111) through GaN and AlN interlayers by RHEED and reflectance

“…A thick GaN buffer has been grown on these interlayers platform at the temperature of 780 °C (initial) and 740 °C (final). While initial GaN buffer has been grown under the N-rich condition, Ga-rich condition has been maintained for final GaN to achieve a smoother surface for above quantum well layers [7]. InGaN with ~16 % of In mole fraction has been grown on GaN using metal-modulated epitaxy at 500 °C [8].…”