Devices formed from a non-polar plane of a crystalline material and method of making the same
Materials, methods, structures and device including the same can provide a semiconductor device such as an LED using an active region corresponding to a non-polar face or surface of III-V semiconductor crystalline material. In some embodiments, an active diode region contains more non-polar III-V material oriented to a non-polar plane than III-V material oriented to a polar plane. In other embodiments, a bottom region contains more non-polar m-plane or a-plane surface area GaN than polar c-plane surface area GaN facing an active region.
1. A method comprising:
providing a first layer of a first semiconductor crystalline material over a substrate, the first layer having a polar top surface;
forming a recess in the first layer, the recess having a non-polar sidewall surface of the first semiconductor crystalline material; and
forming a second layer of a second semiconductor crystalline material along the non-polar sidewall surface of the recess, the first layer forming a first diode region, the second layer forming a second diode region, an active region being interposed between the first diode region and the second diode region, the first diode region, the active region, and the second diode region forming a diode.
2. The method of claim 1 , wherein a ratio of non-polar surface area of the first layer of the diode to polar surface area of the first layer of the diode is more than one.
3. The method of claim 1 , wherein the first semiconductor crystalline material and the second semiconductor crystalline material are a same semiconductor crystalline material.
4. The method of claim 1 , wherein the first semiconductor crystalline material and the second semiconductor crystalline material are different semiconductor crystalline materials.
5. The method of claim 1 further comprising removing at least a portion of the second layer along the polar top surface.
6. The method of claim 1 further comprising after forming the second layer, removing at least a portion of the first layer or the second layer corresponding to a bottom polar surface of the recess.
7. The method of claim 1 further comprising:
forming a first contact adjacent the substrate; and
forming a second contact adjacent the second layer.
8. A method comprising:
forming a first diode region comprising a III-N semiconductor crystalline material having a polar plane and a non-polar plane; and
forming a second diode region proximate the first diode region, an active diode region being disposed between the first diode region and the second diode region, at least a portion of the active diode region and the second diode region being along the polar plane and the non-polar plane of the III-N semiconductor crystalline material.
9. The method of claim 8 , wherein a ratio of a non-polar surface area of the first diode region to a polar surface area of the first diode region is more than one.
10. The method of claim 8 , wherein the first diode region has a recess, the non-polar plane being a sidewall of the recess.
11. The method of claim 8 , wherein the first diode region and the second diode region are a same semiconductor crystalline material.
12. The method of claim 8 , wherein the first diode region and the second diode region are a different semiconductor crystalline material.
13. The method of claim 8 further comprising removing at least a portion of the active diode region corresponding to a polar face.
14. The method of claim 8 further comprising removing at least a portion of the first diode region or the second diode region corresponding to a polar face.
15. A method comprising:
providing III-N semiconductor crystalline layer over a substrate, the III-N semiconductor crystalline layer having a polar plane top surface;
forming a bottom diode region having at least one first surface aligned in a non-polar plane of the III-N semiconductor crystalline layer and at least one second surface aligned in a polar plane of the III-N semiconductor crystalline layer;
forming an active diode region adjacent the at least one first surface and the at least one second surface of the bottom diode region; and
forming a top diode region adjacent the active diode region.
16. The method of claim 15 , wherein a ratio of non-polar surface area in the bottom diode region to polar-plane surface area is more than one.
17. The method of claim 15 , wherein the forming the bottom diode region comprises forming a recess in the III-N semiconductor crystalline layer, the at least one first surface aligned in a non-polar plane of the III-N semiconductor crystalline layer comprising a sidewall of the recess.
18. The method of claim 15 , wherein the bottom diode region is a different semiconductor crystalline material than at least the active region or the top diode region.
19. The method of claim 15 , wherein at least a portion of the active diode region corresponding to a polar face of the III-N semiconductor crystalline layer is removed.
20. The method of claim 15 , wherein at least a portion of the bottom diode region or the top diode region corresponding to a polar face of the III-N semiconductor crystalline layer is removed.