GaAs/AlGaAs quantum-well intermixing using shallow ion implantation and rapid thermal annealing

Abstract

Low-energy As+-ion implantation followed by rapid thermal annealing (RTA) was utilized to modify exciton transition energies of GaAs/AlGaAs quantum wells (QW). A variety of structures were irradiated at an energy low enough that the disordered region was spatially separated from the QWs. After RTA, exciton energies showed large increases which were dependent on QW widths and the implantation fluence with no significant increases in peak linewidths. The observed energy shifts were interpreted as resulting from the modification of the shapes of the as-grown QWs due to enhanced Ga and Al interdiffusion at heterointerfaces in irradiated areas. These results are consistent with the model of enhanced intermixing of Al and Ga atoms in depth of the material due to diffusion of vacancies generated near the surface.

Numerical solution to the general one‐dimensional diffusion equation in semiconductor heterostructures

“…6 superimposes the diffusion profiles of the top (well 1) and bottom (well 25) wells. It can be seen that, as concluded by Elman et al [13] the quantum wells have undergone similar well shape modifications. Nonetheless, this small difference is sufficient to give rise to the quite significant broadening of the photoluminescence emission.…”

“…Elman et al [13] implanted a GaAs/Ga, 7Alo AS multiple-quantum-well sample with low energy 75As ions, the depth of the lattice damage being only 160A into a 0.5pm AlGaAs top cladding layer.…”

Blueshifting of InGaAsP/InP laser diodes by low-energy ion implantation

“…These include photoabsorption induced intermixing, 1 dielectric cap disordering, 2-4 impurity induced disordering 5,6 and high energy ion implantation for vacancy induced disordering. 7,8 Low-energy ion implantation has been used in the past to produce quantum well intermixing 3,[9][10][11] in nonlaser heterostructures. In this letter, we report on blueshifted diode lasers based on quaternary InGaAsP/InGaAs/InP material with compressively strained active layers operating at a wavelength near 1.55 m. Low-energy implantation is used to create vacancies near the surface of the structure.…”

Proton implantation and rapid thermal annealing effects on GaAs/AlGaAs quantum well infrared photodetectors

“…Further research activities on intersubband physics, detector performance and optimization accelerate greatly the development of practical QWIP devices. Recently, researchers have been interested in the application of quantum well intermixing (QWI) techniques [6,7] to modify energy levels of GaAs/AlGaAs multiple quantum wells. QWI has drawn considerable interest because of its wide applicability in optoelectronics, as it can easily modify the geometric shape of the quantum well to allow postgrowth adjustments of key physical parameters such as effective bandgap, optical absorption coefficient and refractive index.…”