The performance of n-type metal-oxide-semiconductor HEMTs with an InAs-channel using atomic-layer-deposited Al2O3 as gate dielectric has been fabricated and evaluated. The device performances of a set of scaled transistors with different gate dielectric thicknesses of 3, 5 and 7 nm have been investigated to determine whether the architecture of Al2O3 dielectric on InAs-channel HEMT can demonstrate good properties at low bias conditions for high-speed, high performance CMOS applications. The results indicate that the high-performance InAs-channel MOS-HEMTs with an ALD Al2O3 gate dielectric are promising candidates for advanced post-Si CMOS applications.