The comprehensive study and the reduction of contact resistivity on the n-InGaAs M-I-S contact system with different inserted insulators

Five different kinds of insulators including BaTiO3, TiO2, Al2O3, CdO and ZnO on the n-type InGaAs metal-insulator-semiconductor (M-I-S) ohmic contact structure are studied. The effect for the dielectric constant (ε) of inserted insulator and the conduction band offset (CBO) between an insulator and semiconductor substrate is analyzed by a unified M-I-S contact model. Based on the theoretical model and experimental data, we demonstrates that the inserted ZnO insulator with the high electron affinity and the low CBO (∼0.1 eV) to the InGaAs substrate results in ∼10 times contact resistivity reduction, even the ε of ZnO is not pretty high (∼10).