We report on the growth of In0.30Ga0.70As channel high-electron mobility transistor (HEMT) epi-layers on a 200 mm silicon wafer by metal organic chemical vapor deposition (MOCVD). The device epi-layers were grown on a silicon substrate by using a ~ 3 µm thick buffer comprising a Ge layer, a GaAs layer and an InAlAs compositionally graded, strain relaxation layer. The achieved epitaxy has a threading dislocation density of (1 – 2) × 107 cm-2 and a root mean square surface roughness of 6-7 nm. The device active layers include a delta-doped InAlAs bottom barrier, a 15 nm thick InGaAs channel, a 15 nm InGaP top barrier layer and a heavily doped InGaAs contact layer. Long channel MOS-HEMT devices (LG ~ 20 µm), were fabricated achieving a peak effective electron mobility of ~ 3700 cm2/V·s.