摘要
The band alignment of HfO2 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 In2O3 and InPO4 at the interface.Ultraviolet spectrophotometer (UVS) was employed to obtain the band gap value of HfO2.In 3d and Hf 4f core-level spectra and valence spectra were employed to obtain the valence band offset of HfO2/InP.Experimental results show that the (5.88 ± 0.05) eV band gap of HfO2 is aligned to the band gap of InP with a conduction band offset (△Ec) of (2.74 ± 0.05) eV and a valence band offset (△Ev) of (1.80 ± 0.05) eV.Compared with HfO2 on Si,HfO2 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 HfO2 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 In2O3 and InPO4 at the interface.Ultraviolet spectrophotometer (UVS) was employed to obtain the band gap value of HfO2.In 3d and Hf 4f core-level spectra and valence spectra were employed to obtain the valence band offset of HfO2/InP.Experimental results show that the (5.88 ± 0.05) eV band gap of HfO2 is aligned to the band gap of InP with a conduction band offset (△Ec) of (2.74 ± 0.05) eV and a valence band offset (△Ev) of (1.80 ± 0.05) eV.Compared with HfO2 on Si,HfO2 on InP exhibits a much larger conduction band offset (1.35 eV larger),which is beneficial to suppress the tunneling leakage current.
基金
financially supported by the National Natural Science Foundation of China(Nos.50932001,51102020,and 51202013)