In this paper, we investigate the effects of growth temperature and growth rate on the formation of InAs/GaAs quantum dots (QDs) grown by metalorganic chemical vapor deposition. These QDs are formed with large InAs coverage (3.0 MLs) and periodic growth interruption via the Stranski-Krastanow epitaxial growth mode. The photoluminescence (PL) spectra at 300 K exhibit a red shift in peak wavelength by decreasing the InAs growth temperature from 540degreesC to 500degreesC. As the growth rate increases from 0.05 to 0.2ML/s at a growth temperature of 500degreesC, the PL linewidth decreases and the PL intensity increases. These results are related to the In clusters and uniformity of InAs/GaAs QDs, which are observed by scanning electron microscopy (SEM). Finally, the room-temperature PL spectrum of InAs/GaAs QDs directly capped with GaAs layer shows an emission wavelength at 1.35 mum and a narrow linewidth of 30.8 meV. (C) 2004 Elsevier B.V. All rights reserved.