Fabrication of CdTe quantum dot arrays on GaAs utilizng nanoporous alumina masks

The uniformity and reproducibility of the CdTe QD arrays on the GaAs substrates can be improved by using a nanoporous mask. The CdTe QDs on the GaAs substrate were grown by a molecular beam epitaxy (MBE) method. The nanoporous alumina masks used for the fabrication of QD arrays have the thickness from 0.3 μm to 5 μm with the nanochannels of ∼ 80 nm diameter and the pore density of ∼ 10¹⁰ cm^-2. When the thickness of the alumina mask used for the CdTe QD growth was about 300 nm, the CdTe QD arrays formed as a replica of the nanochannels of the mask. Smaller self-assembled CdTe QDs located randomly were produced by using the thicker nanochannel mask than 0.5 μm. The thickness of the nanochannel mask controls the size of the CdTe/GaAs QDs.