Quantitative investigation of localized ion irradiation effects in n-channel metal-oxide-semiconductor field-effect transistors using single ion microprobe

Localized ion irradiation effects in n-channel metal-oxide-semiconductor field-effect transistor (n-ch MOSFET) have been investigated quantitatively by means of both the single ion microprobe (SIMP) and single ion beam induced charge (SIBIC) imaging. An extremely large leakage current in the subthreshold gate voltage Vg-drain current Id characteristics (Vg< threshold voltage Vth) have been induced by exposing a small fraction of the MOSFET gate area to MeV He single ions, while the turn-on Vg-Id characteristics (Vg≳Vth) have scarcely been affected. The causes of the large leakage current in the subthreshold region induced by the localized ion irradiation have been discussed.