[20a-PA5-1~14] 13.3 Insulator technology

[20a-PA5-10] Relationship between interface state generation and substrate hole current in InGaAs n- MOSFETs

〇(D)SANghee YOON¹, Daehwan Ahn¹, Mitsuru Takenaka¹, Shinichi Takagi¹ (1.Tokyo Univ.)

Keywords:reliability, interface states, substrate hole current

Relationship between substrate hole currents and interface state generation in Al2O3/InGaAs n-channel MOSFETs is experimentally studied for the MOSFETs with Al2O3 thicknesses of 3nm. The constant positive gate bias stress is applied. Then, the substrate hole current, monitored in the carrier separation setup, is clearly observed for the InGaAs n-channel MOSFETs. It is found that the density of thegenerated interface states is uniquely represented as a function of the total hole fluence , given by integrating the substrate hole current over time, not the total electron fluence. This experimental result strongly supports that interface state generation is triggered by holes induced by electrical stress. It is also found that the feature of Isub/Ig as a function of Vg in Al2O3/InGaAs n-channel MOSFET is similar as that of SiO2/Si n-channel MOSFET which suggesting the mechanism of generation hole current is valence band electron tunneling. Judging from the similarity of these features in SiO2/Si n-MOSFETs reported previously, the Al2O3/InGaAs interfaces have the similiar physical origin of interface states generation with SiO2/Si interfaces.