C. Vaudry

Pseudomorphic GaInP Schottky diode and high electron mobility transistor on InP

GaInP material has been used as a high‐gap semiconductor on InP to fabricate Schottky diodes. The experimental results show that the devices exhibit good electrical properties when the ternary strained layer is below the critical thickness. The best device is obtained with a gallium composition of 100% and a GaP thickness of 11 A, and exhibits a barrier height of 0.8 eV, an ideality factor of 1.1, and a reverse current of 0.1 nA at −1 V. A high electron mobility transistor has been fabricated on an InP substrate by molecular beam epitaxy using a high‐gap GaInP material, and a transconductance of 300 mS/mm has been measured on a device of 1.3 μm gate length.

Epitaxial liftoff microcavities for 1.55-μm quantum-well spatial light modulators

Microcavities operating at 1.55 /spl mu/m have been realized according to the epitaxial liftoff (ELO) technique. The process is described and characterized. No significant variation of the optical properties of the grafted devices has been found. The technique is then applied to a spatial light modulator made by inserting a 3-/spl mu/m multiple-quantum-well device in a short asymmetric Fabry-Perot microcavity. An enhancement by a factor 1000 of the performances of the switching component is obtained. The input diffraction efficiency reaches 2% in a degenerated four wave mixing configuration with a pulse energy of 1 /spl mu/J/cm/sup 2/ and without any applied electric field.

InP substrate etched with methane reactive ion etching technique: surface characterization and epitaxial growth

The authors have characterized the surface defects and determined the growth conditions that permit the fabrication of high-quality InP epitaxial layers. After etching, InP epitaxial layers have been grown by gas-source molecular beam epitaxy. The surface damage has been characterized by angle-resolved X-ray photoelectron spectroscopy, photoluminescence, and secondary ion mass spectroscopy. It has been found that reactive ion etching with methane, hydrogen, and argon mixtures induces a surface damaged layer that is phosphorus depleted and contains a high concentration of hydrogen atoms. Annealing under cracked phosphine restores the surface and permits the growing of high-quality InP epitaxial layers.<<ETX>>

Lateral diffusion of carriers and screening measurements in GaInAsP/GaInAs MQW photorefractive devices at 1.55 /spl mu/m

We demonstrate the performance of a semiconductor photorefractive p-i-n diode operating at 1.55 /spl mu/m in the longitudinal quantum-confined Stark geometry. The device structure consists of a semi-insulating GaInAsP/GaInAs multiple quantum well, sandwiched between two trapping regions, and embedded in a p-n junction. On this structure, we investigated the carrier lateral diffusion, the applied electric field screening and the diffraction efficiency.

Influence of the well composition and thickness in the GaInP/InP/GaInAs/InP structure for HEMT

Photoluminescence, Hall effect, and I-V characteristics of heterostructure InP/GaInAs/InP grown by gas source molecular beam epitaxy (MBE) are presented. The structure is chosen as an alternative to AlInAs/GaInAs/AlInAs to avoid the problems related to the presence of aluminum in HEMT structures. An extremely high indium concentration is used in the well to improve its performance. The InAs well degrades above 10 AA thickness. It is shown that the best experimental results are obtained with a 60 AA GaInAs well (82% InAs) with 2% lattice mismatch.<<ETX>>

Low temperature DC characteristics of pseudomorphic Ga/sub 0.18/In/sub 0.82/P/InP/Ga/sub 0.47/In/sub 0.53/As HEMT

A high-gap strained GaInP material has been used to increase Schottky barrier height on InP. This is the first time GaInP has been used for high-electron-mobility transistor (HEMT) fabrication of InP. For these devices the best g/sub m/ for a 1.3- mu m gate HEMT is 300 mS/mm. Transistors of 3- mu m gate length have been studied at low temperature (100 K to 293 K). Their DC electrical characteristics improve upon cooling. The best improvement is obtained at the lowest temperature (+54% for g/sub m/ at 105 K). The structure is stable and does not undergo g/sub m/ or I/sub ds/ collapse at lower temperature, unlike AlGaAs/GaAs heterostructures.<<ETX>>