[20p-P02-1~29] 9 Applied Materials Science (Poster)

English Presentation

[20p-P02-11] Hole gas accumulation and fabrication of SWIR photodetector
using Ge/Si core-shell nanostructure

〇(D)Guanghui WANG^1,2, Chao Le^1,2, Wipakorn JEVASUWAN², Naoki Fukata^1,2 (1.Univ. of Tsukuba, 2.NIMS)

Keywords:

semiconductor,silicon/germanium,nanosheets

The Ge/Si core-shell nanostructures such as nanowire (NWs) and nanosheets (NSs) have attracted considerable attention for next generation high performance semiconductor devices due to its ability to separate the carrier transport region from the impurity-doped region. However, both the controlled fabrication of Ge/Si core-shell NWs arrays and detailed studies on the collective behaviors related to their integration density remain largely unexplored. Therefore, in this study, Ge core NW and NS arrays with different size were fabricated by top-down method combined with chemical vapor deposition (CVD) to growth Si shell, Ge/Si NW and NS array were produced, and a detailed quantitative analysis using Raman scattering was conducted to investigate hole gas accumulation. Furthermore, compared with i-Ge/i-Si, i-Ge/p-Si was formed by doping of Si shell layer with boron (B) atoms, which led to an increase in hole gas accumulation as the electrical activity of the B atoms was activated. In addition, Ge/Si core-shell photodetectors were fabricated to study their SWIR detection performance. Aside from this, for traditional single-crystal Ge materials, their photodetectors can detect the short-wave infrared (SWIR) region, making them widely used in optical communications and military fields. However, since their maximum detectable wavelength is 1.8 μm, which does not fully cover the SWIR range (1-3 μm), their applications are significantly limited. The Ge/Si core-shell nanostructure can extend the detectable range of the detector to 3 μm or even reach the mid-infrared detection region by controlling the band structure of the heterojunction. Based on the point, we plan to fabricate and research SWIR photodetector performance for Ge/Si core-shell nanostructure in the future.