Methods for growing light emitting devices under ultra-violet illumination
Described herein are methods for growing light emitting devices under ultra-violet (UV) illumination. A method includes growing a III-nitride n-type layer over a III-nitride p-type layer under UV illumination. Another method includes growing a light emitting device structure on a growth substrate and growing a tunnel junction on the light emitting device structure, where certain layers are grown under UV illumination. Another method includes forming a III-nitride tunnel junction n-type layer over the III-nitride p-type layer to form a tunnel junction light emitting diode. A surface of the III-nitride tunnel junction n-type layer is done under illumination during an initial period and a remainder of the formation is completed absent illumination. The UV light has photon energy higher than the III-nitride p-type layer's band gap energy. The UV illumination inhibits formation of Mg—H complexes within the III-nitride p-type layer resulting from hydrogen present in a deposition chamber.
1. A method for forming a light emitting diode (LED), the method comprising:
epitaxially growing a III-nitride n-type layer over a growth substrate;
epitaxially growing an active layer over the III-nitride n-type layer;
epitaxially growing a III-nitride p-type layer over the active layer in the presence of hydrogen and magnesium;
annealing at least the III-nitride p-type layer in situ to activate magnesium dopants in the III-nitride p-type layer;
ceasing the anneal;
epitaxially forming a first portion of a III-nitride tunnel junction n-type layer over the III-nitride p-type layer to form a tunnel junction light emitting diode;
illuminating a surface of the first portion of the III-nitride tunnel junction n-type layer with light having a photon energy higher than the III-nitride p-type layer's band gap energy during growth; and
epitaxially forming a remainder of the III-nitride tunnel junction n-type layer absent light illumination during growth.
2. The method of claim 1 , wherein illuminating the surface of the III-nitride tunnel junction n-type layer with the light inhibits the formation of Mg—H complexes within the III-nitride p-type layer.
3. The method of claim 2 , wherein the light is UV light.
4. The method of claim 1 , further comprising:
applying the light through a window in a deposition chamber.
5. The method of claim 4 , wherein the deposition chamber is a MOCVD chamber.
6. The method of claim 1 , further comprising:
illuminating with the light during the annealing.