Comparison of measurement methods of interface trap density for n-MOSFETs with Si-implanted gate-SiO{sub}2

摘要

Effects of channel B-implantation before gate oxidation and heavy Si-implantation into the gate-SiO{sub}2 on interface trap density D{sub}(it) distribution in the energy gap for n-MOSFETs are analyzed by the following three different measurement methods; (I) high-low frequency capacitance, (II) subthreshold current, and (III) charge pumping. These threee methods produce the similar results of D{sub}(it). They indicate that the channel B{sup}+-dose scarcely has much effect on D{sub}(it) at midgap and increases as the larger amount of Si-dose gives the increase of the D{sub}(it). The method I can provide D{sub}(it) distribution across the majority of the bandgap and may cause an underestimation of D{sub}(it). The method II is convenient with a reasonable accuracy due to the simple DC measurement.