MOVPE and its future production challenges

•VCSEL Wafer diameters on GaAs were initially developed at 100 mm and rapidly expanded to 150 mm.•Improved uniformity in reflectivity, thickness and composition.•150 mm VCSELs on GaAs were qualified from a newly constructed state-of-the-art epi-foundry.•New substrate material was considered – Ge demonstrated significantly reduced wafer bow, zero EPD substrate with minimal slip.•Growth of VCSELs on 200 mm wafers.