This paper reports on an investigation of interface state densities, low frequency noise and electron mobility in surface channel In0.53Ga0.47As n-MOSFETs with a ZrO2 gate dielectric. Interface state density values of Dit ∼ 5 × 1012 cm−2 eV−1 were extracted using sub-threshold slope analysis and charge pumping technique. The same order of magnitude of trap density was found from low frequency noise measurements. A peak effective electron mobility of 1200 cm2/Vs has been achieved. For these surface channel In0.53Ga0.47As n-MOSFETs, it was found that η parameter, an empirical parameter used to calculate the effective electric field, was ∼0.55, and is to be comparable to the standard value found in Si device.Graphical abstractThe investigation of interface state densities, low frequency noise and electron mobility in surface channel In0.53Ga0.47As n-MOSFETs with a ZrO2 gate dielectric is presented using sub-threshold slope analysis, charge pumping technique, low frequency noise measurements, and Y-function method. Electron mobility has been measured as high as of 1200 cm2/Vs at density 1.8 × 1012 cm−2 and CET ∼ 2.4 nm.Highlights► We extract high interface density values from various measurement techniques. ► We extract h parameter of III-V MOSFET which is comparable with Si device. ► We compare mobility extraction by using split CV and Y function method. ► III-V MOSFET devices suffer the influence of (remote) Coulomb scattering.