Methods of forming light emitting devices having current reducing structures
View Patent ↗A light emitting device includes a p-type semiconductor layer, an n-type semiconductor layer, and an active region between the n-type semiconductor layer and the p-type semiconductor layer. A non-transparent feature, such as a wire bond pad, is on the p-type semiconductor layer or on the n-type semiconductor layer opposite the p-type semiconductor layer, and a reduced conductivity region is in the p-type semiconductor layer or the n-type semiconductor layer and is aligned with the non-transparent feature. The reduced conductivity region may extend from a surface of the p-type semiconductor layer opposite the n-type semiconductor layer towards the active region and/or from a surface of the n-type semiconductor layer opposite the p-type semiconductor layer towards the active region.
1. A method of forming a light emitting device, comprising:
forming a p-type semiconductor layer, an n-type semiconductor layer, and an active region between the n-type semiconductor layer and the p-type semiconductor layer;
forming a non-transparent feature on the n-type semiconductor layer opposite the p-type semiconductor layer; and
forming a reduced conductivity region in the p-type semiconductor layer, wherein edges of the reduced conductivity region are aligned with edges of the non-transparent feature, the reduced conductivity region extending from a surface of the p-type semiconductor layer opposite the n-type semiconductor layer towards the active region.
2. The method of claim 1 , wherein forming a non-transparent feature on the n-type semiconductor layer comprises forming a wire bond pad, a current spreading finger and/or a passivation region on the n-type semiconductor layer.
3. The method of claim 1 , wherein the reduced conductivity region extends from the surface of the p-type semiconductor layer to the active region.
4. The method of claim 1 , wherein the reduced conductivity region extends from the surface of the p-type semiconductor layer into the active region.
5. The method of claim 1 , wherein the reduced conductivity region extends from the surface of the p-type semiconductor layer through the active region.
6. The method of claim 1 , wherein the reduced conductivity region extends through the active region.
7. The method of claim 1 , wherein the active region comprises a Group III-nitride based active region.
8. The method of claim 1 , wherein forming a reduced conductivity region comprises:
forming a mask layer on the surface of the p-type semiconductor layer, the mask layer having an opening corresponding to the bond pad region; and
implanting atoms into the p-type semiconductor layer through the opening in the mask layer.
9. A method of forming a light emitting device, comprising:
forming a p-type semiconductor layer, an n-type semiconductor layer, and an active region between the n-type semiconductor layer and the p-type semiconductor layer;
forming a wire bond pad on the n-type semiconductor layer opposite the p-type semiconductor layer; and
forming a metal contact on a surface of the p-type semiconductor layer opposite the n-type semiconductor layer, wherein the metal contact forms an ohmic contact to the p-type semiconductor layer in a region other than a reduced conductivity area of the surface of the p-type semiconductor layer, wherein edges of the reduced conductivity area are aligned with edges of the wire bond pad.
10. The method of claim 9 , further comprising forming a reduced conductivity region in the p-type semiconductor layer and aligned with the wire bond pad and the reduced conductivity area, the reduced conductivity region extending from the surface of the p-type semiconductor layer towards the active region.
11. The method of claim 9 , further comprising forming a reduced conductivity region in the n-type semiconductor layer and aligned with the wire bond pad, the reduced conductivity region extending from a surface of the n-type semiconductor layer opposite the p-type semiconductor layer towards the active region.
12. The method of claim 9 , further comprising forming a non-ohmic contact on the surface of the p-type semiconductor layer.
13. The method of claim 12 , wherein the non-ohmic contact comprises a metal that does not form an ohmic contact with the p-type semiconductor layer.
14. A method of forming a light emitting device, comprising:
forming a p-type semiconductor layer, an n-type semiconductor layer, and an active region between the n-type semiconductor layer and the p-type semiconductor layer;
forming a wire bond pad on the n-type semiconductor layer opposite the p-type semiconductor layer;
forming a metal contact on a surface of the p-type semiconductor layer opposite the n-type semiconductor layer, wherein the metal contact forms on ohmic contact to the p-type semiconductor layer in a region other than a reduced conductivity area of the surface of the p-type semiconductor layer that is aligned with the wire bond pad; and
forming a reduced conductivity region in the n-type semiconductor layer and aligned with the wire bond pad, the reduced conductivity region extending from a surface of the n-type semiconductor layer opposite the p-type semiconductor layer towards the active region, wherein the non-ohmic contact comprises an insulator on the surface of the p-type semiconductor layer.