Ion implantation for isolation of III-V semiconductors

Current-voltage characteristics of Pd2Si/p-Si(111) Schottky barrier diodes studied over a wide temperature range (60-201 K) are shown to follow a thermionic emission-diffusion mechanism under both the forward and the reverse bias conditions. The barrier parameters as evaluated from the forward I-V data reveal a decrease of zero-bias barrier height ( phi b0) but an increase of ideality factor ( eta ) and series resistance (Rs) with decrease in temperature. Moreover, the changes in phi b0, eta and Rs become quite significant below ~100 K. An In(Is/T2) versus 1/T plot is found to fit well with two straight lines in different temperatures regimes giving an activation energy of 0.33 eV (201-107 K) and 0.24 eV (below 107 K) and an effective Richardson constant of 33 A cm-2 K-2. However, the activation energy of 0.33 eV corresponds to the zero-bias barrier height at absolute zero. An In(Isf/T2) versus 1/ eta T plot is suggested to obtain the flat-band barrier height and the effective Richardson constant; the corresponding values obtained are 0.401 eV and 32.2 A cm-2 K-2 respectively. It is shown that the `T0 effect` cannot account for the apparent increase in ideality factor and decrease of barrier height at low temperatures. Finally, the decrease of barrier height with voltage under the reverse bias condition is attributed mainly to interfacial layer effects with a small contribution due to image force lowering.

http://iopscience.iop.org/article/10.1088/0268-1242/10/12/019/pdf

Current-voltage characteristics and barrier parameters of Pd2Si/p-Si(111) Schottky diodes in a wide temperature range

Selective growth of InP/GaInAs in LP-MOVPE and MOMBE/CBE

We present the experimental study of an optical isolator with a semiconductor guiding layer that was obtained by use of a nonreciprocal phase shift. The isolator is equipped with an optical interferometer composed of tapered couplers, nonreciprocal phase shifters, and a reciprocal phase shifter. The nonreciprocal phase shifter was constructed by wafer direct bonding between the semiconductor guiding layer and the magneto-optic cladding layer. The isolator, designed for the 1.55-µm wavelength, was fabricated to investigate the characteristics of each component. By applying an external magnetic field to the nonreciprocal phase shifter, we achieved an isolation ratio of approximately 4.9 dB in the interferometric isolator.

Demonstration of an Optical Isolator with a Semiconductor Guiding Layer that was Obtained by Use of a Nonreciprocal Phase Shift.

Metalorganic precursors for vapour phase epitaxy

Code: A novel MOVPE technique for the single stage growth of buried ridge double heterostructure lasers and waveguides

High quality Al0.48In0.52As layers with specular morphology and narrowest reported X-ray linewidths of 24 seconds of arc have been grown on InP substrates by LP MOVPE at temperatures of 680-710 degrees C. Background carrier concentrations were in the range 8*1515-4*1016 cm-3 with room temperature mobilities as high as 1900 cm2 V-1 s-1 for growth under optimum conditions. Doping in the range 1017-2*1018 cm-3 was achieved using a H2S/H2 mixture. Improvements in structural and electrical quality were concurrent with successful Schottky barrier measurements where barrier heights of up to phi B=0.73 eV were obtained from C-V measurements on diodes using evaporated PtAu. These results have important implications in the development of Ga0.47In0.53As/Al0.48As HEMTS and InP-based opto-electronic devices.

https://iopscience.iop.org/article/10.1088/0268-1242/3/3/011/pdf

Improvements in the structural quality of Al0.48In0.52As grown by low pressure metal-organic vapour-phase epitaxy

We report for the first time, the metalorganic vapor phase epitaxy (MOVPE) growth of the quaternary alloy GaxAlyIn1−x−yAs, lattice matched to InP. Single epitaxial layers were prepared showing specular morphologies and lattice matching within Δa/a=10−3. Epilayers showed a high degree of crystallinity with routine x‐ray linewidths of 20–40 seconds of arc. The lowest linewidth achieved was 22 seconds of arc. Room temperature and 4 K photoluminescence (PL) studies demonstrated very narrow excitonic transitions with ΔE at 4 K down to 5.4 meV. Band‐gap energies, obtained from the absorption edge and PL peak energies, plotted against Al composition showed that the alloy was best described by a straight line relationship between the ternary end points, Ga0.47In0.53As and Al0.48In0.52As with no bowing observed.

Structural and optical properties of GaAlInAs lattice matched to InP grown by low‐pressure metalorganic vapor phase epitaxy

The authors report room-temperature measurements of the quantum confined Stark effect in single InGaAs/InP quantum wells grown by low-pressure MOVPE. Photocurrent measurements on pin diodes containing single quantum wells have been used to demonstrate strong excitonic absorption features which exhibit substantial spectral shift in an applied electric field. These excitonic absorption features remain well resolved for values of electric field up to 4*105 V cm-1. The observed field dependence of the excitonic transition energies and their oscillator strengths is in good agreement with the predicted dependence obtained from an effective-mass mode over a range of well thicknesses from 45 to 110 AA. Integration of the spectra over a wide wavelength range shows a constant integrated absorption as a function of electric field in confirmation of the absorption sum rule.

Quantum confined Stark effect in InGaAs/InP single quantum wells investigated by photocurrent spectroscopy

The effects of surface pretreatment and a variety of metallisation techniques on the characteristics of Schottky diodes fabricated on AlxIn1-xAs grown by low-pressure and atmospheric-pressure MOCVD have been investigated. Barrier heights have been determined from I-V, C-V and I-T measurements and have been found to be in good agreement. Barrier heights of about 0.69 eV were measured for Al0.48In0.52As using Pt as the Schottky barrier contact.

A.C. Marshall

Papers

Code: A novel MOVPE technique for the single stage growth of buried ridge double heterostructure lasers and waveguides

Improvements in the structural quality of Al0.48In0.52As grown by low pressure metal-organic vapour-phase epitaxy

Structural and optical properties of GaAlInAs lattice matched to InP grown by low‐pressure metalorganic vapor phase epitaxy

Quantum confined Stark effect in InGaAs/InP single quantum wells investigated by photocurrent spectroscopy

Characteristics of Schottky diodes on AlxIn1-xAs grown by MOCVD