Light emitting diode devices with patterned TCO layer including different thicknesses
Described are light emitting diode (LED) devices comprising a mesa with semiconductor layers, the semiconductor layers including an N-type layer, an active layer, and a P-type layer. A patterned transparent conductive oxide layer is on the top surface of the mesa. The patterned transparent conductive oxide layer has a first portion with a first thickness and a second portion with a second thickness, the second thickness less than the first thickness. Optical loss of the LED is reduced in the thinned region of the transparent conductive oxide layer.
1. A light emitting diode (LED) device comprising:
a mesa comprising semiconductor layers, the semiconductor layers including an n-type layer, an active layer, and a p-type layer;
a patterned transparent conductive oxide layer directly on a top surface of the mesa, the patterned transparent conductive oxide layer having a first portion with a first uniform thickness in a range of from 1 nm to 500 nm and a second portion with a second uniform thickness in a range of from 0 nm to 400 nm, the second thickness less than the first thickness;
a dielectric layer on a top surface of the patterned transparent conductive oxide layer, the dielectric layer comprising at least one via opening, the at least one via opening having sidewalls and a bottom exposing a top surface of the first portion of the patterned transparent conductive oxide layer; and
a contact on the dielectric layer and in electrical communication with the first portion of the patterned transparent conductive oxide layer.
2. The LED device of claim 1 , wherein the at least one via opening has a width in a range of about 1 micron to about 30 microns.
3. The LED device of claim 1 , wherein the second portion has a width in a range of about 1 microns to about 30 microns.
4. The LED device of claim 1 , wherein the dielectric layer has a thickness greater than about 300 nm.
5. The LED device of claim 1 , wherein the patterned transparent conductive oxide layer comprises one or more of indium-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, indium oxide, tin oxide, tungsten oxide, copper aluminum oxide, strontium copper oxide, gadolinium-doped zinc oxide, and zinc-doped tin oxide.
6. The LED device of claim 1 , wherein the contact comprises a material selected from one or more of silver (Ag), aluminum (Al), gold (Au), copper (Cu), palladium (Pd), and platinum (Pt).
7. The LED device of claim 1 , wherein the dielectric layer comprises one or more of silicon oxide (SiO x ), aluminum oxide (AlO x ), silicon nitride (SiN), titanium oxide (TiO x ), niobium oxide (NbO x ), tantalum oxide (TaO x ).
8. A method of manufacturing a light emitting diode (LED) device, the method comprising:
depositing a transparent conductive oxide layer directly on a semiconductor surface;
patterning the transparent conductive oxide layer to form a patterned transparent conductive oxide layer having first portion with a first uniform thickness in a range of from 1 nm to 500 nm and a second portion with a second uniform thickness in a range of from 0 nm to 400 nm, the second uniform thickness less than the first uniform thickness;
depositing a dielectric layer on the patterned transparent conductive oxide layer;
forming a via opening in the dielectric layer; and
forming a contact on the dielectric layer and in the via opening, the contact in electrical communication with the patterned transparent conductive oxide layer.
9. The method of claim 8 , wherein the via opening has at least one sidewall and a bottom surface, the bottom surface comprising a top surface of the first portion of the patterned transparent conductive oxide layer.
10. The method of claim 8 , wherein the second portion has a width in a range of about 2 microns to about 30 microns.
11. The method of claim 8 , further comprising treating the patterned transparent conductive oxide layer with one or more of a dry etch treatment and a chemical treatment.
12. The method of claim 11 , wherein the chemical treatment comprises treatment with one or more of oxygen (O 2 ), chlorine (Cl 2 ), boron trichloride (BCl 3 ), sulfur hexafluoride (SF 6 ), fluoroform (CHF 3 ), nitrogen (N 2 ), argon (Ar 2 ), hydrochloric acid (HCl), hydrofluoric acid (HF), buffered oxide etchant, ammonia (NH 4 ), hydrogen peroxide (H 2 O 2 ), and photoresist stripping chemicals.
13. The method of claim 8 , further comprising depositing a film on the patterned transparent conductive oxide layer prior to deposition of the dielectric layer, the film comprising one or more of silicon oxide (SiO x ), silicon nitride (SiN), gallium nitride (GaN), and zinc oxide (ZnO).
14. The method of claim 12 , further comprising annealing the patterned transparent conductive oxide layer.
15. The method of claim 8 , further comprising depositing a second transparent conductive oxide layer and patterning the second transparent conductive oxide layer.
16. The method of claim 8 , wherein the patterned transparent conductive oxide layer comprises one or more of indium-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, indium oxide, tin oxide, tungsten oxide, copper aluminum oxide, strontium copper oxide, gadolinium-doped zinc oxide, and zinc-doped tin oxide.
17. A light emitting diode (LED) device comprising:
a mesa comprising semiconductor layers, the semiconductor layers including an n-type layer, an active layer, and a p-type layer;
a patterned transparent conductive oxide layer on a top surface of the mesa, the patterned transparent conductive oxide layer having a first portion with a first uniform thickness and a second portion with a second uniform thickness, the second thickness less than the first thickness, the patterned transparent conductive oxide layer comprising one or more of indium-doped tin oxide, aluminum-doped zinc oxide, indium-doped cadmium oxide, indium oxide, tin oxide, tungsten oxide, copper aluminum oxide, strontium copper oxide, gadolinium-doped zinc oxide, and zinc-doped tin oxide, the first uniform thickness is in a range of from about 1 nm to about 100 nm and the second uniform thickness is in a range of from about 0 nm to about 50 nm;
a dielectric layer directly on a top surface of the patterned transparent conductive oxide layer, the dielectric layer comprising at least one via opening, the via opening having sidewalls and a bottom exposing a top surface of the first portion of the patterned transparent conductive oxide layer; and
a contact on the dielectric layer and in electrical communication with the first portion of the patterned transparent conductive oxide layer.
18. The LED device of claim 1 , wherein the via opening has a bottom surface comprising a top surface of the first portion.
19. The LED device of claim 17 , wherein the via opening has a bottom surface comprising a top surface of the first portion.
20. The LED device of claim 1 , wherein the first uniform thickness is in a range of from 1 nm to 500 nm, and the second uniform thickness is 0 nm.
21. The LED device of claim 17 , wherein the first uniform thickness is in a range of from 1 nm to 500 nm, and the second uniform thickness is 0 nm.