Method of fabricating a merged P-N junction and schottky diode with regrown gallium nitride layer
View Patent ↗A method for fabricating a merged p-i-n Schottky (MPS) diode in gallium nitride (GaN) based materials includes providing an n-type GaN-based substrate having a first surface and a second surface. The method also includes forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate, and forming a p-type GaN-based epitaxial layer coupled to the n-type GaN-based epitaxial layer. The method further includes removing portions of the p-type GaN-based epitaxial layer to form a plurality of dopant sources, and regrowing a GaN-based epitaxial layer including n-type material in regions overlying portions of the n-type GaN-based epitaxial layer, and p-type material in regions overlying the plurality of dopant sources. The method also includes forming a first metallic structure electrically coupled to the regrown GaN-based epitaxial layer.
1. A method for fabricating a merged p-i-n Schottky (MPS) diode in gallium nitride (GaN) based materials, the method comprising:
providing an n-type GaN-based substrate having a first surface and a second surface;
forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate;
forming a p-type GaN-based epitaxial layer coupled to the n-type GaN-based epitaxial layer;
removing portions of the p-type GaN-based epitaxial layer to form a plurality of dopant sources;
regrowing a GaN-based epitaxial layer including n-type material in regions overlying portions of the n-type GaN-based epitaxial layer and p-type material in regions overlying the plurality of dopant sources; and
forming a first metallic structure electrically coupled to the regrown GaN-based epitaxial layer.
2. The method of claim 1 wherein the first metallic structure comprises Schottky contacts electrically coupled to the n-type material in the regions overlying portions of the n-type GaN-based epitaxial layer and ohmic contacts electrically coupled to the p-type material in the regions overlying the plurality of dopant sources.
3. The method of claim 1 further comprising forming a second metallic structure electrically coupled to the second surface of the n-type GaN-based substrate.
4. The method of claim 1 wherein regrowing the GaN-based epitaxial layer comprises using a blanket regrowth process.
5. The method of claim 1 wherein the n-type GaN-based substrate is characterized by a first n-type dopant concentration and the n-type GaN-based epitaxial layer is characterized by a second n-type dopant concentration less than the first n-type dopant concentration.
6. The method of claim 1 wherein at least one of the regions overlying the plurality of dopant sources is configured to provide edge termination to the MPS diode.
7. The method of claim 1 wherein at least one of the regions overlying the plurality of dopant sources is configured to provide a junction termination extension to the MPS diode.