Encapsulating film stacks for OLED applications
Embodiments described herein generally relate to a method and apparatus for encapsulating an OLED structure, more particularly, to a TFE structure for an OLED structure. The TFE structure includes at least one dielectric layer and at least two barrier layers, and the TFE structure is formed over the OLED structure. The at least one dielectric layer is deposited by atomic layer deposition (ALD). Having the at least one dielectric layer formed by ALD in the TFE structure improves the barrier performance of the TFE structure.
1. A thin film encapsulation structure, comprising:
a first barrier layer formed on a substrate having an OLED structure, wherein the first barrier layer is in direct contact with the OLED structure, the first barrier layer is fabricated by a chemical vapor deposition process;
a first dielectric layer in direct contact with en the first barrier layer, wherein the first dielectric layer is formed by an atomic layer deposition process;
a second barrier layer disposed on the first dielectric layer; and
a second dielectric layer disposed on the second barrier layer.
2. The thin film encapsulation structure of claim 1 , wherein the first and second barrier layers are fabricated from substantially the same material.
3. The thin film encapsulation structure of claim 2 , wherein the first dielectric layer is a metal dielectric layer.
4. The thin film encapsulation structure of claim 3 , wherein the metal dielectric layer is selected from the group consisting of aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), zirconium (IV) oxide (ZrO 2 ), aluminum titanium oxide (AlTiO), aluminum zirconium oxide (AlZrO), zinc oxide (ZnO), indium tin oxide (ITO), AlON, SiON and AlN.
5. The thin film encapsulation structure of claim 1 , further comprising a buffer layer disposed between the first dielectric layer and the second barrier layer.
6. The thin film encapsulation structure of claim 5 , wherein the buffer layer is organic.
7. The thin film encapsulation structure of claim 5 , wherein the buffer layer is a hexamethyldisiloxane layer.
8. The thin film encapsulation structure of claim 1 , wherein the second dielectric layer is formed by an atomic layer deposition process.
9. The thin film encapsulation structure of claim 1 , wherein the first and second barrier layers are inorganic.
10. The thin film encapsulation structure of claim 1 , wherein the first and second dielectric layers are inorganic.
11. The thin film encapsulation structure of claim 1 , further comprising:
a third dielectric layer formed between the first dielectric layer and the second barrier layer.
12. The thin film encapsulation structure of claim 1 , wherein the second barrier layer is formed by a chemical vapor deposition process.
13. The thin film encapsulation structure of claim 1 , further comprising:
a third barrier layer disposed on the second dielectric layer.
14. The thin film encapsulation structure of claim 13 , wherein the first, second and third barrier layers are selected from the group consisting of silicon nitride (SiN), silicon oxynitride (SiON), silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ) and aluminum nitride (AlN).
15. The thin film encapsulation structure of claim 1 , wherein the first dielectric layer is aluminum oxide (Al 2 O 3 ).