First attainment of interface trap density of 3x1011 eV-1cm-2 on oxide/p-InGaAs by in-situ Y2O3 deposition
Yen-Hsun Lin1*, Hsien-Wen Wan1, Yu-Jie Hong1, Lawrence Bo-Yu Young1, Yi-Ting Cheng1, Chien-Ting Wu2, Jueinai Kwo3, Minghwei Hong1
1Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei, Taiwan
2Taiwan Semiconductor Research Institute, Hsinchu, Taiwan
3Department of Physics, National Tsing Hua Univerisity, Hsinchu, Taiwan
* Presenter:Yen-Hsun Lin,
III-V InGaAs semiconductors have been in a wide variety of research fields and device applications. Studies of high mobility two-dimensional electron gas (2DEG) in InGaAs have focused on fundamental physics such as Rashba-type spin-orbit interaction, and also searching Majorana fermions with the combination of high-mobility 2DEG and adjacent superconducting thin films. InGaAs device applications include high-speed electronic devices for wireless telecommunications and short-wavelength infrared optoelectronic devices. Nonetheless, one major obstacle to realize high-performance InGaAs devices is the high interface trap density (Dit) at oxide/InGaAs interface, giving strong carrier scattering effect and high surface recombination velocity. Passivating InGaAs surface with low Dit is vital to preserve its high carrier mobility and high quantum efficiency for high-performance InGaAs devices. Studies on InGaAs surface passivation over the past decades have produced the Dit’s below 1012 eV-1cm-2 from the mid-gap to conduction band, but not from the mid-gap to the valence band edge, where the Dit’s remain high of 1012 or over 1013 eV-1cm-2.
In this work, by perfecting the InGaAs surface preparation and utilizing in-situ Y2O3 deposition, we have attained record-low Dit down to 3x1011 eV-1cm-2 at the lower-half bandgap of InGaAs for the first time. Moreover, we have achieved high-temperature thermal stability up to 800oC. These achievements have paved the way for solving fundamental problems in the III-V surface passivation. Moreover, they will lead to high-performance InGaAs devices for many fundamental physics studies and novel technologies.

Keywords: III-V semiconductors, device physics, passivation, interface trap density (Dit), in-situ