Experimental investigation and modeling of diffusion in the InP/(In,Ga)As heterostructures

Abstract

Articles you may be interested inArgon plasma exposure enhanced intermixing in an undoped In Ga As P ∕ In P quantum-well structure Influence of cap layer on implantation induced interdiffusion in InP/InGaAs quantum wells J. Appl. Phys. 93, 4468 (2003); 10.1063/1.1555273Transmission electron microscopy study of the InP/InGaAs and InGaAs/InP heterointerfaces grown by metalorganic vapor-phase epitaxy A comparison of spectroscopic and microscopic observations of ion-induced intermixing in InGaAs/InP quantum wells Appl.The interdiffusion of lattice-matched InP/͑In,Ga͒As superlattice structures ͑nominally undoped, p-doped and n-doped͒ has been studied by analytical electron microscopy ͑x-ray analysis͒ using a field emission gun, scanning transmission electron microscope. The point-spread function of the electron beam was used to correct the experimental data ͑obtained as x-ray maps, 50ϫ50 nm in area͒ in order to derive diffusion profiles of the group V elements ͑As, P͒ after annealing. The results, showing a marked asymmetry in the As profiles after annealing, are interpreted using a model based on the coherent diffusion of the group III and V elements on their own sublattices, each of which is treated as a regular solution. A mathematical procedure, based on the minimization of the difference between the measured and predicted concentration profiles, is employed to compute the two lattice-specific composition-dependent velocities from the experimental diffusion profiles. A good agreement is found between the experimental measurements and the predictions of the model. The role of coherency strains in the interdiffusion process is discussed.

The effect of different proximity caps on quantum well intermixing in InGaAsP/InP QW structures

“…Regions of the samples with known composition were used as a standard to convert the counts to atomic percent. The x-ray elemental maps were taken using automatic beam tracking to correct for specimen drift [8].…”

“…Photoluminescence, however, does not allow for a direct quantitative analysis of the QW since the only usable PL parameter is the wavelength change, which depends on the band-offset between the QW and barriers, and the QW thickness and shape. These parameters have been determined quantitatively using analytical electron microscopy [6][7][8] to directly obtain the compositional and morphological changes induced by QWI. On the basis of these data, it has been possible to compare the PL simulation with PL measurements.…”

Modelling and Monte Carlo simulation of the atomic ordering processes in Ni3Al intermetallics

“…Theoretical studies on binary and multicomponent Ni 3 Al based intermetallics mainly intend to analyse the kinetics of the ordering processes [6][7][8][9][10][11][12][13][14], alloy phase stability [15][16][17], lattice site occupancy of various impurities [13,14,18,19], thermodynamic properties [20] etc by means of cluster variation (CVM) and MC simulation methods, electronic theory of alloys and firstprinciple calculations in order to clarify the effects of temperature, concentration and alloying element additions on the stability of the superstructure, LRO and SRO characteristics of the alloy systems. It should be noted that the unknown parameters of both CVM and MC simulation methods [6][7][8][9][10][11][12][13][14] are the magnitudes of ordering energies at the first and second coordination spheres only or their ratio, the values of which are usually taken from the experimental studies available in the literature. However, a realistic description of the atomic ordering mechanism and order-disorder transformation phenomena requires the magnitude of ordering energies in the higher coordination spheres also.…”

High-performance phase and amplitude modulators based on GaInAsP stepped quantum wells

“…Stepped quantum wells, unlike coupled quantum wells, do not require very thin epitaxial layers or large change of material composition. Recent data 10 indicates that even at the conventional growth temperature and duration, material interdiffusion can severely deform thin potential barriers. A high degree of interdiffusion in the GaInAsP material system may complicate the attainment of enhanced electrorefraction in the coupled quantum well approach.…”