Metastable quantum dot (QD) arrays were grown by submonolayer migration enhanced epitaxy (SMEE) mode on GaAs(100) singular and vicinal substrates. It has been established that two QD groups are formed on the vicinal surface. These groups — conjunct QDs (CQD) and isolated QDs (IQD) — demonstrate a basically different behavior in their photoluminescence spectra. The CQDs form chain-like structures. They lay on the wetting layer which connects them to each other. The IQDs are formed due to wetting layer rupture directly on the GaAs surface at the terrace edges. They are isolated and not connected to the rest QD array.