Vertical-cavity surface-emitting laser with bottom dielectric distributed bragg reflector

A method for fabricating a VCSEL structure, comprising the steps of:

• (a) epitaxially growing:
• an etch stop layer on the substrate, a top current-spreading layer on the etch stop layer, a semiconductor active region on the top current-spreading layer, and a bottom current-spreading layer on the active region, said active region being capable of stimulated emission at a lasing wavelength;
• (b) forming an annular contact metal layer on said bottom current-spreading layer, said annular contact metal layer having a central opening;
• (c) depositing a bottom dielectric DBR on said annular contact metal layer and, through the central opening of the annular contact metal layer, on said bottom current-spreading layer;
• (d) removing a portion of the bottom dielectric DBR to expose an annular surface of the annular contact metal layer and forming a bottom dielectric DBR mesa having side walls;
• (e) depositing a metal bonding layer covering the bottom dielectric DBR mesa and contacting the exposed annular surface of the annular contact metal layer;
• (f) applying heat to bond the metal bonding layer to a metal surface of a submount;
• and
• (g) applying selective etching to remove the substrate and then the etch stop layer.