Gillgrass, S. J., Baker, J., Allford, C. P. ![]() ![]() ![]() ![]() |
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Abstract
To reduce material usage and minimise device cost the use of reduced substrate thickness is considered in high volume vertical-cavity surface-emitting laser (VCSEL) manufacturing. For large-diameter VCSEL wafers, germanium (Ge) is emerging as an alternative substrate solution. In this work, VCSEL structures designed for 940 nm emission are grown by metal–organic vapour-phase epitaxy on 150 mm (6 inch) germanium substrates of thickness 675, 450 and 225 µm. Using on-wafer testing of fabricated devices, threshold current density, differential resistance, and emission wavelength are compared across the three substrate thicknesses, with results demonstrated for the first time on a Ge wafer thickness of 225 µm. These results underline the potential of thin Ge substrates for reduced material usage in VCSEL manufacturing.
Item Type: | Article |
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Date Type: | Published Online |
Status: | Published |
Schools: | Schools > Physics and Astronomy |
Additional Information: | License information from Publisher: LICENSE 1: URL: https://creativecommons.org/licenses/by/4.0/, Type: cc-by |
Publisher: | IOP Publishing |
Date of First Compliant Deposit: | 4 August 2025 |
Date of Acceptance: | 13 July 2025 |
Last Modified: | 04 Aug 2025 11:00 |
URI: | https://orca.cardiff.ac.uk/id/eprint/180229 |
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