Work

AlGaAs VSCELs grown on thin 150 mm germanium substrates

Year: 2025

Type: article

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.

Source: Journal of Physics Photonics

DOI: 10.1088/2515-7647/adef1f

Authors: S J Gillgrass, J Baker, C P Allford, J I Davies, S Shutts, P M Smowton

Institutions: Cardiff University, IQE (United Kingdom)

Language: English

Topic: Semiconductor Lasers and Optical Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,700

Funders: UK Research and Innovation, Cardiff University, Engineering and Physical Sciences Research Council