Method of forming a composite substrate and growing a III-V light emitting device over the composite substrate
View Patent ↗A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions.
1. A method comprising:
providing a substrate comprising:
a host; and
a seed layer bonded to the host, the seed layer comprising a plurality of regions, wherein each region is completely separated from nearest neighbor regions at interfaces between the regions;
relaxing the seed layer, wherein adjacent regions of the seed layer are in direct contact with each other at interfaces between adjacent regions after relaxing the seed layer;
growing on the substrate a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
wherein a top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than or equal to each of the plurality of seed layer regions;
connecting the semiconductor structure to a mount;
removing the host; and
removing the seed layer.
2. The method of claim 1 wherein the light emitting layer is a III-nitride layer.
3. The method of claim 1 wherein the interfaces extend through an entire thickness of the seed layer.
4. The method of claim 1 wherein the interfaces are substantially free of chemical bonds between adjacent regions of the seed layer.
5. The method of claim 1 wherein each region has a lateral extent between 1 and 10 microns.
6. A method comprising:
providing a substrate comprising:
a host; and
a seed layer bonded to the host, the seed layer comprising a plurality of regions separated by interfaces, wherein adjacent regions are connected to form a continuous web of seed layer material, wherein gaps between seed layer regions at interfaces are less than one micron wide;
growing on the substrate a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
wherein a top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than or equal to each of the plurality of seed layer regions;
connecting the semiconductor structure to a mount;
removing the host; and
removing the seed layer.
7. The method of claim 6 wherein the light emitting layer is a III-nitride layer.
8. A method comprising:
providing a substrate comprising:
a host; and
a seed layer bonded to the host, the seed layer comprising a plurality of regions, wherein the seed layer is a crystalline material having a crystalline unit cell, wherein each seed layer region is shaped to have a rotational symmetry that is the same as a rotational symmetry of the crystalline unit cell, wherein each seed layer region is completely separated from nearest neighbor seed layer regions by a gap or interface;
growing on the substrate a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;
wherein a top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than or equal to each of the plurality of seed layer regions;
connecting the semiconductor structure to a mount;
removing the host; and
removing the seed layer.
9. The method of claim 8 wherein the light emitting layer is a III-nitride layer.
10. The method of claim 8 wherein the seed layer is wurtzite and each seed layer region is shaped as a triangle or a hexagon.