Methods for producing light extraction structures for semiconductor devices
Aspects of the disclosure provide for mechanisms for fabricating light extraction structures for semiconductor devices (e.g., light-emitting devices). In accordance with some embodiments, a semiconductor device is provided. The semiconductor device may include: a first semiconductor layer including an epitaxial layer of a semiconductor material; a second semiconductor layer comprising an active layer; and a light-reflection layer configured to cause at least a portion of light produced by the active layer to emerge from the semiconductor device via a surface of the second semiconductor layer, wherein the light-reflection layer is positioned between the first semiconductor layer and the second semiconductor layer. In some embodiments, the semiconductor material includes gallium nitride. In some embodiments, the light-reflection layer includes a layer of gallium.
1. A method for producing a semiconductor device, comprising:
forming, on a first semiconductor layer comprising a first epitaxial layer of a group III-V material, a light-reflection layer for reflecting at least a portion of light produced by a second semiconductor layer of the semiconductor device, wherein the group III-V material comprises a first group III material, and wherein forming the light-reflection layer further comprises:
forming an intermediate layer comprising the first group III material and a second group III material; and
removing at least a portion of the second group III material from the intermediate layer; and
forming the second semiconductor layer on the light-reflection layer.
2. The method of claim 1 , wherein the first semiconductor layer comprises a semiconductor material having a first refractive index, wherein the light-reflection layer comprises a reflective material having a second refractive index, and wherein the first refractive index is different from the second refractive index.
3. The method of claim 1 , further comprising forming the first semiconductor layer using at least one of a metal organic chemical vapor deposition (MOCVD) process or a molecular beam epitaxy (MBE) process.
4. The method of claim 1 , wherein the first group III material comprises gallium, and wherein the second group III material comprises indium.
5. The method of claim 4 , wherein forming the intermediate layer comprises adjusting a temperature in a processing chamber to a first temperature, and wherein removing at least the portion of the second group III material comprises adjusting the temperature in the processing chamber to a second temperature.
6. The method of claim 5 , wherein the second temperature is higher than the first temperature.
7. The method of claim 6 , wherein the first temperature is between 300° C. and 800° C.
8. The method of claim 6 , wherein the second temperature is higher than 800° C.
9. The method of claim 5 , wherein forming the intermediate layer further comprises:
flowing a first precursor comprising the first group III material in the processing chamber; and
flowing a second precursor comprising the second group III material in the processing chamber.
10. The method of claim 9 , wherein removing at least the portion of the second group III material from the intermediate layer further comprises:
flowing a gas flow comprising hydrogen in the processing chamber.
11. The method of claim 10 , wherein removing at least the portion of the second group III material from the first semiconductor layer further comprises:
stopping flowing the second precursor in the processing chamber.