The growth conditions of low-dimensional dot structures of strained InxGa1-xAs on Si substrates using the Stranski–Krastanov growth mode by metal–organic chemical vapor deposition are optimized. Atomic force microscopy measurement has been performed to characterize the dot structures. The dot density and their size are found to be strongly dependent on the substrate temperature, In content, and V/III ratio. The optimized growth condition was further used to fabricate quantum dot-like laser diodes on Si. The characteristics of the laser diode with an InxGa1-xAs quantum dot-like active region are analyzed. © 2001 American Institute of Physics.