The influence of ion mass and dose on the intermixing of GaAs/GaAlAs quantum-well structures using photoluminescence (PL) and secondary-ion-mass spectroscopy (SIMS) techniques has been studied. Ga, Zn, Ar, Mg, Ne, and He ions are implanted in a single-quantum-well (SQW) structure at different doses. After annealing, the amount of intermixing between Al and Ga is extracted from the PL peak energy shift of the near-band-gap emission of the SQW. The measured Al diffusion length values ΔAl for different ion species agree with a simple model which assumes that the implantation damage in conjunction with low T (T<600 °C) defect diffusion is responsible for the mixing. We observe a similar dose dependence for ΔAl for all the above ions. For high implantation doses we have studied the mixing by Ar ions after implantation and annealing with SIMS. The SIMS data indicate that at high doses collisional mixing is the dominant mechanism for the disordering. Drastic mixing effects are obtained in the above quantum-well structures after high-temperature annealing of samples implanted with electrically active impurities (S,Si).

We have fabricated GaAs/GaAlAs quantum wires with widths between 220 and 40 nm by high-dose (2×1014 cm−2) Ga implantation in a locally masked single quantum well structure. The width dependence of the emission energies indicates a steep 1D confinement determined by the lateral straggling of the implanted Ga. The external quantum efficiency of the wires increases strongly with decreasing mask width due to significant carrier capture from the lateral barrier.

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We report on investigations of dry etching in GaInP/AlGaInP. As a method of dry etching we used CCl2F2/Ar reactive ion etching (RIE) and Ar ion beam etching (IBE). The suitability of these two methods for microstructure technology with respect to etch rates in investigated. First data on damage resulting from application of these two dry etching techniques in GaInP/AlGaInP are presented. The degree of damage was detected by performing photoluminescence measurement.