High sensitivity Ga2O3 ultraviolet photodetector by one-step thermal oxidation of p-GaN films

Li, Peigang; Ji, Xueqiang; Yan, Zuyong; Xu, Yan; Lü, Chao; Li, Zhitong; Song, Qi; Li, Shan; Qi, Xiaohui; Zhang, Sai; Hu, Shengrun; Li, Peigang

doi:10.1016/j.mssp.2023.107372

Cited by 15 publications

(7 citation statements)

References 58 publications

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“…As the annealing time initially increased, the film resistance rapidly increased. However, with prolonged annealing time, the resistance of the Ga 2 O 3 began to decrease 35 . Consequently, a sufficiently long and appropriate annealing duration was considered essential for improving the oxide insulation and reducing micro-LED leakage current in this work, as will be demonstrated in our subsequent device characterization.…”

Section: Device Fabrication Processmentioning

confidence: 99%

Etching-free pixel definition in InGaN green micro-LEDs

Liu,

Lu,

Cao

et al. 2024

Light Sci Appl

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The traditional plasma etching process for defining micro-LED pixels could lead to significant sidewall damage. Defects near sidewall regions act as non-radiative recombination centers and paths for current leakage, significantly deteriorating device performance. In this study, we demonstrated a novel selective thermal oxidation (STO) method that allowed pixel definition without undergoing plasma damage and subsequent dielectric passivation. Thermal annealing in ambient air oxidized and reshaped the LED structure, such as p-layers and InGaN/GaN multiple quantum wells. Simultaneously, the pixel areas beneath the pre-deposited SiO2 layer were selectively and effectively protected. It was demonstrated that prolonged thermal annealing time enhanced the insulating properties of the oxide, significantly reducing LED leakage current. Furthermore, applying a thicker SiO2 protective layer minimized device resistance and boosted device efficiency effectively. Utilizing the STO method, InGaN green micro-LED arrays with 50-, 30-, and 10-µm pixel sizes were manufactured and characterized. The results indicated that after 4 h of air annealing and with a 3.5-μm SiO2 protective layer, the 10-µm pixel array exhibited leakage currents density 1.2 × 10−6 A/cm2 at −10 V voltage and a peak on-wafer external quantum efficiency of ~6.48%. This work suggests that the STO method could become an effective approach for future micro-LED manufacturing to mitigate adverse LED efficiency size effects due to the plasma etching and improve device efficiency. Micro-LEDs fabricated through the STO method can be applied to micro-displays, visible light communication, and optical interconnect-based memories. Almost planar pixel geometry will provide more possibilities for the monolithic integration of driving circuits with micro-LEDs. Moreover, the STO method is not limited to micro-LED fabrication and can be extended to design other III-nitride devices, such as photodetectors, laser diodes, high-electron-mobility transistors, and Schottky barrier diodes.

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Section: Device Fabrication Processmentioning

confidence: 99%

Etching-free pixel definition in InGaN green micro-LEDs

Liu,

Lu,

Cao

et al. 2024

Light Sci Appl

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“…19 Among them, β-Ga 2 O 3 shows increasing interest from the scientific community as a result of its exclusive thermodynamically stable structure. 1 Recent studies have shown excellent performance of β-Ga 2 O 3based SBPDs with high responsivity, 4,20 high sensitivity, 21 and fast response, 12,22 as a result of their high ultraviolet (UV) transmittance, economic efficiency, radiation resistance, and thermal and chemical stability. This means that β-Ga Ga 2 O 3 includes the Czochralski method, vertical Bridgman growth method, floating zone growth method, and various epitaxial growth methods.…”

Section: ■ Introductionmentioning

confidence: 99%

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga₂O₃ Thermally Oxidized from Nonpolar (110)-Plane GaN

Zhao,

Yin,

et al. 2024

ACS Appl. Mater. Interfaces

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A high-performance planar structure metal−semiconductor−metal-type solar-blind photodetector (SBPD) was fabricated on the basis of (010)-plane β-Ga 2 O 3 thermally oxidized from nonpolar (110)-plane GaN. A full width at half maximum of 0.486°was achieved for the X-ray rocking curve associated with (020)-plane β-Ga 2 O 3 , which is better than most reported results for the heteroepitaxially grown (−201)-plane β-Ga 2 O 3 . As a result of the relatively high crystalline quality, a dark current as low as 6.30 × 10 −12 A was achieved at 5 V, while the photocurrent reached 1.86 × 10 −5 A under 254 nm illumination at 600 μW/cm 2 . As a result, the photo-to-dark current ratio, specific detectivity, responsivity, and external quantum efficiency were calculated to be 2.95 × 10 6 , 2.39 × 10 12 Jones, 3.72 A/W, and 1815%, respectively. Moreover, the SBPD showed excellent repeatability and stability in the time-dependent photoresponse characteristics with fast relaxation time constants for the rise and decay processes of only 0.238 and 0.062 s, respectively. This study provides a promising approach to fabricate the device-level (010)-plane β-Ga 2 O 3 film and a new way for the epitaxial growth of (010)-plane β-Ga 2 O 3 and (110)-plane GaN as mutual substrates.

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“…Among them, Ga 2 O 3 with an ultra-wide bandgap of 4.4-5.3 eV corresponding to the solar-blind spectrum region between 238 and 280 nm is a natural material used for solar-blind ultraviolet photodetectors because it does not exist on the surface of the earth due to the strong absorption of deep ultraviolet light by stratospheric ozone. 2,[5][6][7] As a significant member of wide band gap semiconductors, Ga 2 O 3 exhibits five polymorphs, namely, a-, b-, g-, d-, and e-Ga 2 O 3 . Each phase possesses a different bandgap, which can be utilized in various types of SBPDs.…”

Section: Introductionmentioning

confidence: 99%

Regulation of oxygen vacancies in nitrogen-doped Ga₂O₃ films for high-performance MSM solar-blind UV photodetectors

Wang

Song

et al. 2023

J. Mater. Chem. C

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High sensitivity Ga2O3 ultraviolet photodetector by one-step thermal oxidation of p-GaN films

Cited by 15 publications

References 58 publications

Etching-free pixel definition in InGaN green micro-LEDs

Etching-free pixel definition in InGaN green micro-LEDs

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga₂O₃ Thermally Oxidized from Nonpolar (110)-Plane GaN

Regulation of oxygen vacancies in nitrogen-doped Ga₂O₃ films for high-performance MSM solar-blind UV photodetectors

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High sensitivity Ga2O3 ultraviolet photodetector by one-step thermal oxidation of p-GaN films

Cited by 15 publications

References 58 publications

Etching-free pixel definition in InGaN green micro-LEDs

Etching-free pixel definition in InGaN green micro-LEDs

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga2O3 Thermally Oxidized from Nonpolar (110)-Plane GaN

Regulation of oxygen vacancies in nitrogen-doped Ga2O3 films for high-performance MSM solar-blind UV photodetectors

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Product

Resources

About

High-Performance Solar-Blind Photodetector Based on (010)-Plane β-Ga₂O₃ Thermally Oxidized from Nonpolar (110)-Plane GaN

Regulation of oxygen vacancies in nitrogen-doped Ga₂O₃ films for high-performance MSM solar-blind UV photodetectors