The Journal of China Universities of Posts and Telecommunications ›› 2024, Vol. 31 ›› Issue (2): 17-27.doi: 10.19682/j.cnki.1005-8885.2024.0006

Special Issue: 集成电路

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Performance study of vertical MSM solar-blind photodetectors based on β-Ga2O3 thin film


  • Received:2023-12-04 Revised:2024-02-25 Online:2024-04-30 Published:2024-04-30
  • Supported by:
    Natural Science Basic Research Program in Shaanxi Province of China;National Natural Science Foundation of China


In this work, β-Ga2O3 thin films were grown on SiO2 substrate by atomic layer deposition (ALD) and annealed in N2 atmosphere to enhance the crystallization quality of the thin films, which were verified from X-rays diffraction (XRD). Based on the grown β-Ga2O3 thin films, vertical metal-semiconductor-metal (MSM) interdigital photodetectors (PDs) were fabricated and investigated. The PDs have an ultralow dark current of 1.92 pA, ultra-high photo-to-dark current ratio (PDCR) of 1.7×106, and ultra-high detectivity of 4.25×1014 Jones at a bias voltage of 10 V under 254 nm deep ultraviolet (DUV). Compared with the horizontal MSM PDs under the same process, the PDCR and detectivity of the fabricated vertical PDs are increased by 1 000 times and 100 times, respectively. In addition, the vertical PDs possess a high responsivity of 34.24 A/W and an external quantμm efficiency of 1.67×104%, and also exhibit robustness and repeatability, which indicate excellent performance. Then the effects of electrode size and external irradiation conditions on the performance of the vertical PDs continued to be investigated.

Key words:

Ga2O3, atomic layer deposition, annealing, vertical metal-semiconductor-metal (MSM) interdigital photodetectors