On-wafer fabrication of etched-mirror UV-C laser diodes with the ALD-deposited DBR

Tadayoshi Sakai,Naoharu Sugiyama,Chiaki Sasaoka,Yoshio Honda,Hiroshi Amano,Leo J. Schowalter,Maki Kushimoto,Ziyi Zhang

doi:10.1063/1.5145017

Tadayoshi Sakai, Naoharu Sugiyama + Show 6 more

Open Access

https://doi.org/10.1063/1.5145017

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Journal: Applied Physics Letters	Publication Date: Mar 23, 2020
Citations: 43	License type: cc-by

Affiliation: Nagoya University, Asahi Kasei (Japan)

Abstract

We have demonstrated an on-wafer fabrication process for AlGaN-based UV-C laser diodes (LDs) with etched mirrors and have achieved lasing for 100 ns pulsed current injection at room temperature. A combined process of dry and wet etching was employed to achieve smooth and vertical AlGaN (11¯00) facets. These etched facets were then uniformly coated with a distributed Bragg reflector by atomic layer deposition. A remarkable reduction of the lasing threshold current density to 19.6 kA/cm2 was obtained owing to the high reflectivity of the etched and coated mirror facets. The entire laser diode fabrication process was carried out on a whole 2-in. wafer. We propose this mirror fabrication process as a viable low-cost AlGaN-based UV-C LD production method that is also compatible with highly integrated optoelectronics based on AlN substrates.

Highlights

Scitation.org/journal/apl a vertical, dry-etched facet, which results in a low mirror quality, and (ii) difficulty in depositing a high-quality, distributed Bragg reflector (DBR) on the etched facet
We have demonstrated an on-wafer fabrication process for AlGaN-based UV-C laser diodes (LDs) with etched mirrors and have achieved lasing for 100 ns pulsed current injection at room temperature
The entire laser diode fabrication process was carried out on a whole 2-in. wafer. We propose this mirror fabrication process as a viable low-cost AlGaN-based UV-C LD production method that is compatible with highly integrated optoelectronics based on AlN substrates

Summary

Introduction

Scitation.org/journal/apl a vertical, dry-etched facet, which results in a low mirror quality, and (ii) difficulty in depositing a high-quality, distributed Bragg reflector (DBR) on the etched facet. We have demonstrated an on-wafer fabrication process for AlGaN-based UV-C laser diodes (LDs) with etched mirrors and have achieved lasing for 100 ns pulsed current injection at room temperature.

Results

Conclusion