Characterization of Subgap Density-of-States by Sub-Bandgap Optical Charge Pumping in In0.53Ga0.47As Metal-Oxide-Semiconductor Field-Effect Transistors

Han Bin Yoo; Seong Kwang Kim; Junyeap Kim; Jintae Yu; Sung-Jin Choi; Dae Hwan Kim; Dong Myong Kim

doi:10.1166/jnn.2020.17785

Characterization of Subgap Density-of-States by Sub-Bandgap Optical Charge Pumping in In_0.53Ga_0.47As Metal-Oxide-Semiconductor Field-Effect Transistors

J Nanosci Nanotechnol. 2020 Jul 1;20(7):4287-4291. doi: 10.1166/jnn.2020.17785.

Authors

Han Bin Yoo¹, Seong Kwang Kim², Junyeap Kim¹, Jintae Yu¹, Sung-Jin Choi¹, Dae Hwan Kim¹, Dong Myong Kim¹

Affiliations

¹ School of Electrical Engineering, Kookmin University, Seoul 02701, Korea.
² School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.

PMID: 31968459
DOI: 10.1166/jnn.2020.17785

Abstract

We report an experimental characterization of the interface states (D_it(E)) by using the subthreshold drain current with optical charge pumping effect in In_0.53Ga_0.47As metal-oxide-semiconductor fieldeffect transistors (MOSFETs). The interface states are derived from the difference between the dark and photo states of the current-voltage characteristics. We used a sub-bandgap photon (i.e., with the photon energy lower than the bandgap energy, E_ph < E_g) to optically excite trapped carriers over the bandgap in In_0.53Ga_0.47As MOSFETs. We combined a gate bias-dependent capacitance model to determine the channel length-independent oxide capacitance. Then, we estimated the channel length-independent interface states in In_0.53Ga_0.47As MOSFETs having different channel lengths (L_ch = 5, 10, and 25 [μm]) for a fixed overlap length (L_ov = 5 [μm]).