Fabrication of self-assembled InGaAs, GaAs, and InAs quantum dots by chemical beam epitaxy

We report on the fabrication of self-assembled GaAs, InGaAs and InAs quantum dots (QD) on GaAs(100) via droplet epitaxy and S-K mode growth by chemical beam epitaxy (CBE). Triethylgallium, trimethylindium, monoethylarsine, and arsine were applied as source materials. GaAs and InGaAs quantum dots with diameter 50 nm and density 1x10(9) cm(-2) were grown by Ga droplet formation and the successive supply of source materials without any pre-treatment steps prior to growth. InAs quantum dots were coherently assembled on a lattice-mismatched GaAs substrate without any indication of misfit dislocation in the Stranski-Krastanow (S-K) growth method. The areal density of 40 nm sized InAs islands was obtained up to 10(10) cm(-2) by changing the deposition thickness. Our results demonstrate that CBE can be a very powerful method for the growth of self-assembled quantum dots. (C) 1998 Elsevier Science B.V. All rights reserved.