InGaAs quantum wells (QWs) cladded by InAlAs barriers were grown on Si by metalorganic chemical vapor deposition. InP/GaAs/Si buffer templates were first prepared using a two-step growth method. We were able to significantly reduce the dislocation density in the upper InP buffer and obtain smooth surface morphology by fine-tuning the growth parameters and inserting an InGaAs interlayer in the InP buffer. On these InP/GaAs/Si compliant substrates, we investigated InGaAs QWs with various well/barrier parameters and Si-delta doping. We obtained two-dimensional electron gas mobilities over 10,000 cm2 V−1 s−1 at 300 K and above 39,000 cm2 V−1 s−1 at 77 K on Si substrates.