Study of interface and oxide defects in high-k/In0.53Ga0.47As n-MOSFETs

Interface and oxide defects in surface-channel In_0.53Ga_0.47As n-MOSFETs, featuring a threshold voltage, V_T, of 0.43 V, a subthreshold swing, SS, of 150 mV/dec, an I_ON/I_OFF of ~ 10⁴ and a source/drain resistance, R_SD, of 103 Ω, have been investigated using “split C-V” measurements and self-consistent Poisson-Schrödinger quasi-static C-V simulations. An integrated density of traps across the In_0.53Ga_0.47As band gap at the Al₂O₃/In_0.53Ga_0.47As interface, N_Trap, of ~ 7.8 × 10¹² /cm², has been obtained from a comparison of the theoretical and experimental quasi-static C-V responses, where N_Trap reflects the combined contribution of interface traps and border traps. An equivalent surface density of fixed positive oxide charges, N⁺, of 1.4 × 10¹² /cm² is also reported. Finally, the application of the Maserjian Y-function to the Al₂O₃/In_0.53Ga_0.47As MOS system is briefly discussed.