Passivation of GaSb by sulfur treatment

Pérotin, M.; Coudray, Paul; Gouskov, L.; Luquet, H.; Llinarès, C.; Bonnet, J.; Soonckindt, L.; Lambert, B.

doi:10.1007/bf02651260

Cited by 53 publications

(36 citation statements)

References 17 publications

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“…5,6 The remarkable enhancement in the photoluminescence (PL) yield from S-or Se-treated GaAs indicates that the chalcogenide-terminated GaAs surface exhibits an improved electronic surface structure relative to the native oxidized surface. 7,8 In particular, Se-based treatments result in GaAs surfaces more chemically stable than those prepared by S-based aqueous treatments.…”

Section: Introductionmentioning

confidence: 99%

Modifications of the electronic structure of GaSb surface by chalcogen atoms: S, Se, and Te

Liu

Gokhale

Mavrikakis

et al. 2004

Journal of Applied Physics

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Modifications to the electronic properties and chemical structures of the GaSb surface using the chalcogen atoms S, Se, and Te were investigated theoretically and experimentally. A self-consistent density-functional theory study indicates that an adsorption of a full monolayer coverage of chalcogen atoms on a Ga-terminated surface reduces the density of gap region states significantly. A greater photoluminescence enhancement was observed from GaSb samples treated by chalcogenide (Na 2 S, Na 2 Se, or Na 2 Te) in a nonaqueous than in an aqueous passivation medium. X-ray photoelectron spectroscopy reveals a Ga-rich surface after a nonaqueous passivation, with sulfidization providing a higher concentration of Ga͑Sb͒-chalcogen bonds than does a passivation with Na 2 Se or Na 2 Te. The uptake of chalcogen during the passivation is accompanied by the loss of surface antimony. The formation of Sb-X(X = S, Se, or Te) bonds competes with X displacing surface Sb, which dominates Se or Te incorporation in the GaSb surface lattice. The passivation kinetics was analyzed on basis of a single precursor-mediated coverage-dependent chemisorption proces.

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Section: Introductionmentioning

confidence: 99%

Modifications of the electronic structure of GaSb surface by chalcogen atoms: S, Se, and Te

Liu

Gokhale

Mavrikakis

et al. 2004

Journal of Applied Physics

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“…34 When exposed to an oxygen-containing environment such as air, the GaSb surface will form a native oxide layer and free Sb. 35 Both the oxide layer and free Sb strongly diminish the device performance. While the free Sb can act as metallic low resistance shunt, the oxide layer creates additional interface states promoting generation-recombination centers, charge accumulation centers, or trap levels.…”

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confidence: 99%

Room temperature operation of GaSb-based resonant tunneling diodes by prewell injection

Pfenning

Knebl

Hartmann

et al. 2017

Applied Physics Letters

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We present room temperature resonant tunneling of GaSb/AlAsSb double barrier resonant tunneling diodes with pseudomorphically grown prewell emitter structures comprising the ternary compound semiconductors GaInSb and GaAsSb. At room temperature, resonant tunneling is absent for diode structures without prewell emitters. The incorporation of Ga 0.84 In 0.16 Sb and GaAs 0.05 Sb 0.95 prewell emitters leads to room temperature resonant tunneling with peak-to-valley current ratios of 1.45 and 1.36 , respectively. The room temperature operation is attributed to the enhanced Γ -L-valley energy separation and consequently depopulation of L-valley states in the conduction band of the ternary compound emitter prewell with respect to bulk GaSb. a) Electronic mail to: Andreas. Pfenning@physik.uni-wuerzburg.de b) Electronic mail to: Fabian.Hartmann@physik.uni-wuerzburg.de The three semiconductors GaSb, InAs and AlSb of the so-called 6.1 Å family cover a wide range of bandgap energies and unique material properties, which make them particularly suitable for applications in high-speed electronics and as mid-infrared optoelectronic semiconductor devices. 1,2 During the past few years, application related research focused on mid-infrared light sources and detectors. 3,4 Especially the progress on interband cascade lasers (ICLs) and interband cascade detectors (ICDs) with type-II superlattice absorbers has driven the field. [5][6][7] In a recent publication we proposed an alternative mid-infrared photodetector concept based on resonant tunneling diodes (RTDs) with 6.1 Å family semiconductors. 8 RTDs can be exploited as highspeed and low-noise amplifiers of weak, optically excited electrical signals. 9-11 Unlike avalanche photodiodes, in which the multiplication gain originates from impact ionization, the RTD photodetection principle is based on the modulation of the resonant tunneling current via Coulomb interaction in presence of photogenerated minority charge carriers. [12][13][14] This mechanism provides very high amplification factors exceeding several hundred thousand at considerably low operation voltages. 10,11,15,16 The GaSb/InAs/AlSb material system has brought forth resonant tunneling structures (RTS) with unique and enhanced characteristics. prewell emitters leads to room temperature resonant tunneling with peak-to-valley current ratios of 1.45 and The HR-XRD spectrum of RTD 1 shows a single peak at Δ 0°, which indicates a good and high quality latticematched crystal growth of the RTD and the AlGaAsSb contact region. For RTD 2 and RTD 3, compressive and tensile strain secondary patterns arise at smaller and higher angles, respectively, caused by the incorporation of the pseudomorphically GaInSb and GaAsSb regions. The secondary pattern of RTD 2 is more pronounced compared to RTD 3 due to the three times higher In compared to As concentration.Circular RTD mesa structures with diameters from 2 µm up to 13 µm are defined by optical lithography and dry-chemical etching. The etching depth is about 50 nm below the dou...

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“…[5][6][7] Previous studies of the sulfurbased passivation using a ͑NH 4 ͒ 2 S-water solution have shown improved Schottky characteristics with a Au-GaSb barrier of 0.52-0.57 eV being reported. 8,9 The use of an aqueous process however, with and without S passivation, leads to a variety of results in the formation of a Au-GaSb Schottky diode with a wide range of the barrier height values being reported, even exceeding the band-gap energy. 10 Further improvements in the reproducibility and stability of the Au-GaSb diodes require a thorough removal of surface oxides and elemental Sb which entails a nonaqueous environment.…”

mentioning

confidence: 99%

Improved characteristics for Au∕n-GaSb Schottky contacts through the use of a nonaqueous sulfide-based passivation

Liu

Saulys

Kuech

2004

Applied Physics Letters

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The influence of nonaqueous sulfide passivation (using Na 2 S in the inert solvent benzene) on Au/ n-GaSb Schottky junction behavior was studied. The junction parameters, Schottky barrier height and ideality factor, were derived and compared with those of as-received GaSb surfaces as well as surfaces treated with aqueous sulfide solutions. The Schottky junction made on as-received GaSb is highly nonideal, while S-based passivation treatment of the GaSb surface before contact formation improves the rectifying behavior, and markedly reduces the reverse current. A benzene-based nonaqueous sulfide treatment results in GaSb surfaces with lower oxide and elemental antimony content than does the aqueous sulfide treatment. The produced Schottky barrier height increases to 0.61 eV and the Au/ n-GaSb contact is close to an ideal Schottky junction. GaSb is an important III-V compound semiconductor for high-speed and optoelectronic devices operating in the infrared and near-infrared region. 1 Due to its small band gap, there is often difficulty in achieving a high-quality metalGaSb Schottky contact with near-ideal current-voltage ͑I -V͒ characteristics. Surface and interface properties are critical in determining metal-semiconductor contact behavior, and the existence of an interfacial layer, or a high density of defect states at the metal and semiconductor interface, can lead to highly nonideal characteristics. Air oxidation of GaSb at room temperature results in a thick overlayer of native oxide and a high concentration of elemental antimony at the oxideGaSb interface. [2][3][4] The presence of elemental Sb at the surface can lead to device degradation. Due to its metallic nature, Sb can increase the surface leakage current and lead to the generation of gap-region surface states, reducing the minority carrier lifetime and limiting device performance. Surface passivation using sulfide-based solutions can effectively remove the native oxide and improve the surface electronic and electrical properties. [5][6][7] Previous studies of the sulfurbased passivation using a ͑NH 4 ͒ 2 S-water solution have shown improved Schottky characteristics with a Au-GaSb barrier of 0.52-0.57 eV being reported. 8,9 The use of an aqueous process however, with and without S passivation, leads to a variety of results in the formation of a Au-GaSb Schottky diode with a wide range of the barrier height values being reported, even exceeding the band-gap energy. 10 Further improvements in the reproducibility and stability of the Au-GaSb diodes require a thorough removal of surface oxides and elemental Sb which entails a nonaqueous environment. Nonaqueous passivation using an inert solvent, such as benzene, as the sulfidization medium results in a GaSb surface with decreased amounts of oxide residue and elemental Sb content compared to that generated by aqueous sulfide treatment. 7 In this work, the impact of a nonaqueous S-based passivation treatment on the Au/ n-GaSb Schottky junction behavior was studied. In particular, a nonaqueous sulfide passivat...

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Passivation of GaSb by sulfur treatment

Cited by 53 publications

References 17 publications

Modifications of the electronic structure of GaSb surface by chalcogen atoms: S, Se, and Te

Modifications of the electronic structure of GaSb surface by chalcogen atoms: S, Se, and Te

Room temperature operation of GaSb-based resonant tunneling diodes by prewell injection

Improved characteristics for Au∕n-GaSb Schottky contacts through the use of a nonaqueous sulfide-based passivation

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