Modulated Al2O3-Alloyed Ga2O3 Materials and Deep Ultraviolet Photodetectors

作者：Lee Hsin Ying; Liu Jyun Ting; Lee Ching Ting^*

来源：IEEE Photonics Technology Letters, 2018, 30(6): 549-552.

DOI：10.1109/LPT.2018.2803763

• Aluminum oxide-alloyed gallium oxide films
• deep ultraviolet photodetectors
• flicker noise
• metal-semiconductor-metal structure
• photoresponsivity

To modulate the cutoff wavelength of the metal-semiconductor-metal deep ultraviolet photodetectors (MSM DUV-PDs), the aluminum content of the aluminium oxide-alloyed gallium oxide (Ga2O3:Al2O3) absorption layers was deposited using radio frequency (RF) magnetron cosputter system with dual targets, in which the Ga2O3 target was sputtered with an RF power of 100 W and the Al2O3 target sputtered with various RF powers. The optical bandgap energy of the Ga2O3:Al2O3 films increased with an increase of the Al content deposited with a larger sputtered RF power of the Al2O3 target. In view of the suppression effect of the oxygen vacancy and the defect by the more Al-O bonds in the Ga2O3:Al2O3 absorption layer, the noise performances and the detectivity of the MSM DUV-PDs were improved. For depositing the Al atomic percentage of 5.9% in the Ga2O3:Al2O3 absorption layer, the resulting MSM DUV-PDs revealed the cutoff wavelength of 230 nm, the noise equivalent power of 2.80 x 10(-12) W, and the detectivity of 1.37 x 10(11) cmHz(0.5)W(-1). Furthermore, the dominant low-frequency noise source was the flicker noise.

• 出版日期2018-3-15