Defects at the surface of β-Ga2O3 produced by Ar plasma exposure

Abstract

Films of β-Ga2O3 grown by halide vapor phase epitaxy on native substrates were subjected to Ar inductively coupled plasma treatment. As a result, the built-in voltage of Ni Schottky diodes deposited on the plasma treated surfaces decreased from 1 V to −0.02 V due to the buildup of deep trap concentration in the near surface region. Deep level spectra measurements indicate a strong increase in the top ∼200 nm of the plasma treated layer of the concentration of E2* (Ec − 0.8 eV) and especially E3 (Ec − 1.05 eV) deep electron traps. Capacitance-voltage profiling with monochromatic illumination also indicated a large increase in the upper ∼100 nm of the film in the concentration of deep acceptors with optical threshold for an ionization of ∼2.3 eV and 3.1 eV. Such defects at the surface led to a significant increase in reverse current, an increase in the ideality factor in forward current, and a dramatic decrease in the diffusion length of nonequilibrium charge carriers from 450 nm to 150 nm.

Transferable Ga2O3 Membrane for Vertical and Flexible Electronics via One-Step Exfoliation

“…We observed slightly higher resistance and Schottky behavior of exfoliated n-Ga 2 O 3 +etching sample compared with the as-grown n-Ga 2 O 3 /mica. This phenomenon could be attributed to (i) material quality difference between the top n-Ga 2 O 3 layer and exfoliated bottom n-Ga 2 O 3 , which may contain polycrystal interfacial layer, , and (ii) plasma damages after Ar dry etching. , …”

Low Temperature Modeling of Ni/β-Ga2O3 Schottky Barrier Diode Interface

“…This effect is shown in Figures a,b, where it is observed that the traps had a negligeable effect in contrast with our previous study, where these traps have a pronounced effect at higher temperatures (greater than 300 K). This result is due to the high electron concentration on the surface of Si-doped β-Ga 2 O 3 and the tunneling current domination in addition to the fact that a higher temperature results in more activated traps …”

“…This result is due to the high electron concentration on the surface of Sidoped β-Ga 2 O 3 and the tunneling current domination in addition to the fact that a higher temperature results in more activated traps. 8 Temperature-Dependent SBD Current. Now, the temperature dependence of the J−V characteristics and comparison with measurement for the mentioned model are carried out, as shown in Figure 8.…”

“…The basic optical properties are related to its ultrawide bandgap; hence, β-Ga 2 O 3 is transparent in UV, visible, and near-infrared spectra , with no absorption bands . Furthermore, transport and electrical properties such as electron mobility and resistivity can be easily controlled. , Improving and interpreting β-Ga 2 O 3 Schottky barrier diode (SBD) characteristics at different temperatures are of prime interest and focus. Because the current–voltage ( J–V ) characteristics of Schottky diodes measured at room temperatures do not provide satisfactory information about the conduction process and the nature of the barrier, the low-temperature dependent J – V characteristics facilitate understanding the different aspects of the conduction mechanisms.…”

Identification and Suppression of Majority Surface States in the Dry-Etched β-Ga2O3

“…Figure c shows the summarized Arrhenius space of the majority carrier traps in this work and refs and . The DLTS peaks at 310, 350, and 410 K have been assigned to the E2* traps related to intrinsic defects (V Ga or V Ga –V O ), the unintentional doped impurity E2 traps related to Fe substituting for Ga (Fe Ga ), and E3 traps in the HVPE-grown β-Ga 2 O 3 , respectively. − ,− Table summarizes the detailed trap parameters. The E3 trap has been reported to be related to surface contaminants (e.g., Ti, Fe, and Co) with an energy level of E C – 1.09 eV and a capture cross section of σ E3 = 4.30 × 10 –14 cm 2 , which are completely removed by the dry etching, together with the reduced E2 trap ( E C – 0.83 eV and σ E2 = 2.56 × 10 –15 cm 2 ) in concentration ( N TE2 ).…”