Comparison of interface trap density measured by capacitance/subthreshold/charge-pumping methods for n-MOSFETs with Si-implanted gate-SiO2

Effects of channel B-implantation before gate oxidation and heavy Si-implantation into the gate-SiO₂ on interface trap density D_it distribution in the energy gap for n-MOSFETs are analyzed by three different measurement methods: (I) high-low frequency capacitance, (II) subthreshold current, and (III) charge pumping. These three methods produce similar results for D_it. They indicate that the channel B⁺-dose scarcely has any effect on D_it at midgap and increases as larger Si-doses give an increase in D _it. Method I can provide the D_it distribution across the majority of the bandgap and may cause an underestimation of D _it. Method II is convenient with reasonable accuracy due to the simple DC measurement