Self-assembled In/sub 0.22/Ga/sub 0.78/As quantum dots grown on GaAs/Ge/Si/sub x/Ge/sub 1-x//Si substrate

Self-assembled In/sub 0.22/Ga/sub 0.78/As quantum dots (QDs) fabricated on Si substrate with Ge buffer by metal organic vapor phase epitaxy (MOVPE) were investigated. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) images were used to observe the size and distribution of the In/sub 0.22/Ga/sub 0.78/As QDs grown on the GaAs/Ge/GeSi/Si layer structure. The influence of the growth temperature on the QDs density and distribution was investigated. For QDs grown at 430 /spl deg/C, the density of the In/sub 0.22/Ga/sub 0.78/As dots was estimated to be 1/spl times/10/sup 11/ cm/sup -2/ and the In/sub 0.22/Ga/sub 0.78/As QDs thickness was 5 monolayer thick.