The band alignment of HfO_2 film on p-type(100) InP substrate grown by magnetron sputtering was investigated.The chemical states and bonding characteristics of the system were characterized by X-ray photoelectron spectroscopy(XPS).The results show that there is no existence of Hf-P or Hf-In and there are interfacial In_2O_3and InPO_4 at the interface.Ultraviolet spectrophotometer(UVS) was employed to obtain the band gap value of HfO_2.In 3d and Hf 4f core-level spectra and valence spectra were employed to obtain the valence band offset of HfO_2/InP.Experimental results show that the(5.88 ± 0.05) eV band gap of HfO_2 is aligned to the band gap of InP with a conduction band offset(ΔE_c) of(2.74 ± 0.05) eV and a valence band offset(ΔE_v) of(1.80 ± 0.05) eV.Compared with HfO_2 on Si,HfO_2 on InP exhibits a much larger conduction band offset(1.35 eV larger),which is beneficial to suppress the tunneling leakage current. The band alignment of HfO 2 film on p-type (100) InP substrate grown by magnetron sputtering was investigated. The chemical states and bonding characteristics of the system were characterized by X-ray photoelectron spectroscopy (XPS). The results show that there is no existence of Hf-P or Hf-In and there are interfacial In_2O_3and InPO_4 at the interface. Ultraviolet spectrophotometer (UVS) was employed to obtain the band gap value of HfO_2.In 3d and Hf 4f core-level spectra and valence spectra were employed to The valence band offset of HfO 2 / InP. Experimental results show that (5.88 ± 0.05) eV band gap of HfO 2 is aligned to the band gap of InP with a conduction band offset (ΔE_c) of (2.74 ± 0.05) eV and a valence band offset (ΔE_v) of (1.80 ± 0.05) eV.Compared with HfO_2 on Si, HfO_2 on InP exhibits a much larger conduction band offset (1.35 eV larger), which is beneficial to suppress the tunneling leakage current.