Successive ionic layer adsorption and reaction process for depositing epitaxial ZnO on III-nitride-based light emitting diode and light emitting diode including epitaxial ZnO

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• mesa etching the substrate to expose the first GaN layer;
• forming a passivation layer on the mesa-etched substrate;
• forming a first photoresist layer on the passivation layer;
• etching the substrate using the first photoresist layer as a mask, to expose the second GaN layer;
• forming a ZnO layer on the exposed second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process;
• increasing the thickness of the ZnO layer using a low-temperature aqueous deposition process;
• and
• annealing the substrate.

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• forming a ZnO layer on the second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process;
• forming a first photoresist layer on the ZnO layer,
• etching the ZnO layer using the first photoresist layer as a mask;
• mesa etching the substrate to expose the first GaN layer;
• and
• forming electrode pads on the ZnO layer and the first GaN layer.

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• forming a ZnO layer on the second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process;
• forming a passivation layer on the substrate and that exposes a portion of the ZnO layer;
• increasing the thickness of the exposed portion of the ZnO layer using a low-temperature aqueous ZnO deposition method;
• forming a first photoresist layer on the substrate and that exposes a portion of the passivation layer;
• etching the substrate using the first photoresist layer as a mask, to remove the exposed portion of the passivation layer;
• mesa etching the substrate to expose a portion of the first GaN layer;
• forming a second photoresist layer on the substrate that exposes portions of the ZnO layer and the first GaN layer;
• and
• forming electrode pads on the ZnO layer and the first GaN layer.

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• forming a ZnO layer on the second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process;
• forming a first photoresist layer on the ZnO layer and that exposes a portion of the ZnO layer;
• increasing the thickness of the exposed portion of the ZnO layer using a low-temperature aqueous ZnO deposition method;
• forming a second photoresist layer on the substrate and that covers the thicker portion of the ZnO layer;
• etching the substrate using the second photoresist layer as a mask, to expose a portion of the first GaN layer;
• and
• forming electrode pads on the ZnO layer and the exposed portion of the first GaN layer.

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• forming a first photoresist layer on the second GaN layer;
• mesa etching the substrate, using the first photoresist layer as a mask, to expose the first GaN layer;
• forming a second photoresist layer on the substrate and that exposes the second GaN layer;
• forming a ZnO layer on the second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process that uses second photoresist layer as a mask;
• forming an electrode pad on the first GaN layer;
• forming a third photoresist layer on the substrate and that exposes the ZnO layer;
• increasing the thickness of the ZnO layer using a low-temperature aqueous ZnO deposition method;
• and
• forming an electrode pad on the ZnO layer.

A method of forming a III-Nitride based LED, the method comprising:

• forming a first GaN layer on a substrate, an active layer on the first GaN layer, and a second GaN layer on the active layer, the first and second GaN layers having different ones of a P-type dopant and an N-type dopant;
• forming a passivation layer on the substrate and that exposes a portion of the second GaN layer;
• forming a ZnO layer on the exposed portion of the second GaN layer using a Successive Ionic Layer Adsorption and Reaction (SILAR) process;
• etching the passivation layer to expose a portion of the second GaN layer;
• mesa etching the substrate to expose portions of the first GaN layer;
• forming a first photoresist layer on the substrate and that exposes portions of the first GaN layer and the ZnO layer;
• and
• forming electrodes on the exposed portions of the first GaN layer and the ZnO layer.

A III-Nitride LED comprising:

• a substrate;
• a first GaN layer disposed on the substrate;
• an active layer disposed on the first GaN layer;
• a second GaN layer disposed on the active layer;
• and
• a ZnO composite layer disposed on the second GaN layer, the composite layer comprising:
• a first ZnO layer disposed on the second GaN layer and having a first conductivity;
• and
• a second ZnO layer disposed on the first ZnO layer and have a second conductivity that is higher than the first conductivity.