Enhancement of light transmittance for wafers bonded with thin Al films using atomic diffusion bonding and subsequent laser irradiation

Ichikawa, Michio; Eboshi, N.; Kemmochi, Tatsuya; Sano, Masahiko; Mukai, Takashi; Uomoto, Miyuki; Shimatsu, T.

doi:10.23919/ltb-3d.2017.7947402

Cited by 1 publication

(2 citation statements)

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“…Laser irradiation has also been demonstrated to improve the light transmittance of wafers bonded with thin metal films using ADB. 24 We have shown that the light transmittance of synthetic quartz glass wafers bonded with 0.4-nm-thick Al films on either side using ADB is significantly enhanced by laser irradiation, particularly in the short wavelength region, as a result of the diffusion of Al into the wafers.…”

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confidence: 88%

“…Our previous work showed that laser annealing of metals at the bonding interface after ADB bonding improves transmittance, 24 as a result of increased oxidation of the metal films. Laser annealing of the bonding interface allows heat-treatment to be applied at temperatures sufficient to melt the glass only in the vicinity of the bonding interface.…”

Section: Optimization Of Bonding Metal Filmsmentioning

confidence: 99%

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Fabrication of High Power Deep Ultraviolet Light-Emitting Diodes with Glass Lenses Using Atomic Diffusion Bonding

Ichikawa

Kemmochi

Mukai

et al. 2019

ECS J. Solid State Sci. Technol.

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This work demonstrated that both the output power and external quantum efficiency of AlGaN-based deep ultraviolet light-emitting diodes (DUV-LEDs) are greatly enhanced by bonding glass lenses to the LED chips using atomic diffusion bonding (ADB). ADB is advantageous because it permits the bonding of glass to DUV-LEDs at room temperature. A Ti film was found to improve light transmittance through the bonding interface and to provide good bonding strength. In addition, hydrophilic treatment of the bonding surfaces prior to Ti film deposition during ADB and post-bonding annealing further enhanced the bonding strength. In this manner, 255 nm DUV-LEDs with glass lenses having n values almost equal to that of sapphire were fabricated, using the ADB process in conjunction with a 0.4-nm-thick Ti film on each side. Even though the glass lens exhibited some light absorption, the output power and the maximum external quantum efficiency of these glass-lens-bonded LEDs were both 2.5 times greater than the values for an LED without a lens.

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confidence: 88%

Section: Optimization Of Bonding Metal Filmsmentioning

confidence: 99%