An In0.9Ga0.1P/In0.75Ga0.25As/In0.53Ga0.47As/InP heterostructure grown by low-pressure metal-organic chemical vapor deposition exhibits a mobility as high as 7910 cm2 V-1 s-1 with a two-dimensional electron gas (2DEG) concentration of 3.35 x 10(12) cm-2 at 300 K (99 300 cm2 V-1 s-1, 1.76 x 10(12) cm-2 at 77 K). Photoluminescence analysis shows good carrier confinement in this structure.