Method of fabricating a VCSEL device and VCSEL device

A method of fabricating a Vertical Cavity Surface Emitting Laser (VCSEL) device, the method comprising:

• providing a first structure comprising a VCSEL layer structure on a wafer, the first structure including the wafer comprising one or more semiconductor materials, the first structure having a non-planar first structure top surface with varying height levels along the non-planar top surface, wherein the non-planar first structure top surface comprises one or more electrical contact areas at different height levels above the wafer;
• applying one or more layers of a cover material that is different from the one or more semiconductor materials on the non-planar first structure top surface with a thickness such that a lowest height level of a cover material top surface is equal to or above the highest height level of the non-planar first structure top surface, to obtain a second structure comprising the first structure and the one or more layers of cover material, the second structure having a second structure top surface;
• planarizing the second structure top surface;
• and
• producing one or more first electrical vias from the second structure top surface through the one or more layers of cover material for electrical connection to the one or more electrical contact areas.