Gallium nitride containing laser device configured on a patterned substrate

A structure for a gallium and nitrogen containing laser diode device, the structure comprising:

• a gallium and nitrogen containing substrate material comprising a surface region;
• a plurality of migration blocking regions (MBRs) within the substrate material, each of the MBRs including a recessed region, and each pair of adjacent MBRs forming a mesa region therebetween, the mesa region having a width of at least 0.5 microns, the pair of adjacent MBRs being configured to block a plurality of defects from migrating into the mesa region;
• an epitaxial gallium and nitrogen containing material overlying the substrate material, the epitaxial gallium and nitrogen containing material overlying the mesa region being substantially free from defects migrating from regions outside the pair of adjacent MBRs to the mesa region;
• an active region overlying the epitaxial gallium and nitrogen containing material and the mesa region, wherein the epitaxial gallium and nitrogen containing material and the active region overlie sidewalls and bottoms of the plurality of MBRs;
• and
• a p-type region overlying the active region, wherein a top surface of a portion of the epitaxial gallium and nitrogen containing material that extends over the bottoms of at least some of the plurality of MBRs is below a top surface of the surface region so that the epitaxial gallium and nitrogen containing material does not completely fill at least some of the plurality of MBRs, and a top surface of a portion of the p-type region that extends over the bottoms of the plurality of MBRs is substantially planar and coalesces to fill depressions above the plurality of MBRs.

A method for fabricating a gallium and nitrogen containing laser diode device, the method comprising:

• providing a gallium and nitrogen containing substrate material comprising a surface region;
• forming a plurality of migration blocking regions (MBRs) within the substrate material, each of the MBRs including a recessed region, and each pair of adjacent MBRs forming a mesa region therebetween, the mesa region having a width of at least 0.5 microns, the pair of adjacent MBRs being configured to block a plurality of defects from migrating into the mesa region;
• forming an epitaxial gallium and nitrogen containing material overlying the substrate material, the epitaxial gallium and nitrogen containing material overlying the mesa region being substantially free from defects migrating from regions outside the pair of adjacent MBRs to the mesa region;
• forming an active region overlying the epitaxial gallium and nitrogen containing material and the mesa region, wherein the epitaxial gallium and nitrogen containing material and the active region overlie sidewalls and bottoms of the plurality of MBRs;
• and
• forming a p-type region overlying the active region, wherein a top surface of a portion of the epitaxial gallium and nitrogen containing material that extends over the bottoms of at least some of the plurality of MBRs is below a top surface of the surface region so that the epitaxial gallium and nitrogen containing material does not completely fill at least some of the plurality of MBRs, and a top surface of a portion of the p-type region that extends over the bottoms of the plurality of MBRs is substantially planar, the p-type region coalescing to fill depressions above the plurality of MBRs.