ALD growth of Al 2 O 3 on GaAs: Oxide reduction, interface structure and CV performance

Physica Status Solidi (a)

2012

The (NH4)2S treatment can reduce native oxides and passivate GaAs. Atomic‐layer‐deposited (ALD‐Al2O3) can further remove the residue native oxides by self‐cleaning. For the first time, native oxides can be sufficiently removed by the combination of (NH4)2S treatment and ALD‐Al2O3. Stacked with high dielectric constant TiO2 prepared by atomic‐layer deposition on a Al2O3/(NH4)2S‐treated GaAs MOS capacitor, the leakage current densities can reach 1.9 × 10−8 and 3.1 × 10−6 A/cm2 at ±2 MV/cm. The dielectric constant is 25 and the interface state density is about 2.4 × 1011 cm−2 eV−1.

Section: Resultsmentioning

confidence: 94%

Low interface state density and low leakage current of atomic‐layer deposited TiO₂/Al₂O₃/sulfur‐treated GaAs

Physica Status Solidi (a)

2012

“…Figure 2(a) shows a large accumulation capacitance frequency dispersion of 18.9% for SiO 2 /InP from the weak Fermi-level pinning at a certain D it (6.1 © 10 12 cm ¹2 eV ¹1 ). 34,35) This result shows that residual native oxides existed on InP only with HF in-situ cleaning and passivation. Figure 2(b) shows a smaller frequency dispersion of 14.2% for SiO 2 /S-InP.…”

Section: Resultsmentioning

confidence: 84%

Reduction in interface state density of SiO₂/Si-IPL/InP by fluorine and sulfur passivations

2014

Jpn. J. Appl. Phys.

The characteristics of a liquid-phase-deposited SiO 2 film on InP were investigated. The mixture of H 2 SiF 6 and H 3 BO 3 aqueous precursors was used as the growth solution. SiO 2 on InP with (NH 4 ) 2 S treatment showed good electrical characteristics owing to the reduction of native oxides and sulfur passivation. The electrical characteristics were further improved with an ultrathin Si interface passivation layer (IPL) through reductions in Fermi-level pinning and interface state density. Moreover, during the SiO 2 deposition, the HF in the growth solution simultaneously and effectively removed native oxides from the Si-IPL and provided fluorine passivation on it. The Al/SiO 2 /Si-IPL/(NH 4 ) 2 S-treated InP MOS capacitor showed superior electrical properties. The leakage current density reached 6.9 ' 10 %9 and 1.6 ' 10 %7 A/cm 2 at +2 V. The interface state density reached 3.6 ' 10 11 cm %2 eV %1 with low frequency dispersion of 12.3%.

“…Figure 3(a) shows a large accumulation capacitance frequency dispersion of 19% for SiO 2 /GaAs from the weak Fermi-level pinning by a certain extent of D it (5.24 © 10 12 cm ¹2 eV ¹1 ). 23,24) This result shows that residual native oxides existed on GaAs only with HF in situ cleaning and passivation. Figure 3(b) shows a smaller frequency dispersion of 12% for SiO 2 /S-GaAs.…”

Section: Resultsmentioning

confidence: 84%

Characteristics of liquid phase deposited SiO₂ on (NH₄)₂S-treated GaAs with an ultrathin Si interface passivation layer

2014

Jpn. J. Appl. Phys.

The characteristics of liquid-phase-deposited SiO2 film on GaAs were investigated. A mixture of H2SiF6 and H3BO3 aqueous precursors was used as the growth solution. SiO2 on GaAs with (NH4)2S treatment shows good electrical characteristics owing to the reduction of native oxides and sulfur passivation. The electrical characteristics are further improved with an ultrathin Si interface passivation layer (Si IPL) from the reduction of Fermi-level pinning and interface state density. Moreover, during the SiO2 deposition, HF in the growth solution can simultaneously and effectively remove native oxides on Si IPL and provide fluorine passivation on it. The Al/SiO2/Si IPL/(NH4)2S-treated GaAs MOS capacitor shows superior electrical properties. The leakage current densities can reach 7.4 × 10−9 and 6.83 × 10−8 A/cm2 at ±2 V. The interface state density can reach a 2.11 × 1011 cm−2 eV−1 with low frequency-dispersion of 8%.