1. Structural and Electrical Properties of Grafted Si/GaAsSb Heterojunction
- Author
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Abbasi, Haris Naeem, Lee, Seunghyun, Jung, Hyemin, Gajowski, Nathan, Lu, Yi, Wang, Linus, Kim, Donghyeok, Zhou, Jie, Gong, Jiarui, Chae, Chris, Hwang, Jinwoo, Muduli, Manisha, Nookala, Subramanya, Ma, Zhenqiang, and Krishna, Sanjay
- Subjects
Physics - Applied Physics ,Condensed Matter - Materials Science - Abstract
The short-wave infrared (SWIR) wavelength, especially 1.55 um, has attracted significant attention in various areas such as high-speed optical communication and LiDAR systems. Avalanche photodiodes (APDs) are a critical component as a receiver in these systems due to their internal gain which enhances the system performance. Silicon-based APDs are promising since they are CMOS compatible, but they are limited in detecting 1.55 um light detection. This study proposes a p-type Si on n-type GaAs0.51Sb0.49 (GaAsSb) lattice matched to InP substrates heterojunction formed using a grafting technique for future GaAsSb/Si APD technology. A p+Si nanomembrane is transferred onto the GaAsSb/AlInAs/InP substrate, with an ultrathin ALD-Al2O3 oxide at the interface, which behaves as both double-side passivation and quantum tunneling layers. The devices exhibit excellent surface morphology and interface quality, confirmed by atomic force microscope (AFM) and transmission electron microscope (TEM). Also, the current-voltage (I-V) of the p+Si/n-GaAsSb heterojunction shows ideal rectifying characteristics with an ideality factor of 1.15. The I-V tests across multiple devices confirm high consistency and yield. Furthermore, the X-ray photoelectron spectroscopy (XPS) measurement reveals that GaAsSb and Si are found to have type-II band alignment with a conduction band offset of 50 meV which is favorable for the high-bandwidth APD application. The demonstration of the GaAsSb/Si heterojunction highlights the potential to advance current SWIR PD technologies., Comment: 14 pages, 6 figures
- Published
- 2024