We have applied the modified droplet epitaxy method using sulfur terminatio
n to fabricate InAs quantum dots on GaAs(001) substrates for the first time
. It is observed that the S-terminated surface effectively prevents the two
-dimensional growth of InAs, forming InAs nanocrystals. From the magneto-ph
otoluminescence measurements of this structure, three-dimensional quantum c
onfinement effect was confirmed. This modified droplet epitaxy method is pr
omising for the fabrication of quantum dots, not only in the lattice-matche
d system but also in the lattice-mismatched system.