Method to metallize ohmic electrodes to P-type group III nitrides
AssigneeThe Board of Trustees of the University of Illinois
InventorsIlesanmi Adesida, Ling Zhou
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Abstract
The metallization method of the invention uses an oxide-forming metal layer to improve adhesion and getter surface contamination or oxides. A high work function metal is then formed on the oxide-forming layer. An anneal is conducted to diffuse the high work function on metal through the oxide-forming layer. One or more metal cap layers may top the high work function metal to protect the high work function metal.
Claims8
A metallization method for forming a contact electrode on p-type Group III nitride materials, the method comprising steps of:
- depositing an oxide forming layer on a surface of a p-type Group III nitride layer;
- depositing a high work function metal on the oxide forming layer;
- annealing at a temperature in the approximate range of between 700° C. and 800° C. to permit diffusion of the high work function metal through the oxide forming layer, and
- wherein said oxide forming layer comprises Ti.
A metallization method for forming a contact electrode on p-type Group III nitride materials, the method comprising steps of:
- depositing an oxide forming layer on a surface of a p-type Group III nitride layer;
- depositing a high work function metal on the oxide forming layer;
- annealing at a temperature in the approximate range of between 700° C. and 800° C. to permit diffusion of the high work function metal through the oxide forming layer;
- wherein said oxide forming layer comprises Cr;
- and
- wherein said high work function metal is one of Pt and Pd.
A metallization method for forming a contact electrode on p-type Group III nitride materials, the method comprising steps of:
- depositing a first layer from one of Ti, Cr, Pd, and Ni;
- depositing a high work function metal on the first layer;
- annealing at a temperature in the approximate range of between 700° C. and 800° C. to permit diffusion of the high work function metal through the first layer;
- and
- wherein said high function work metal is one of Pt and Pd.
Dependencies are inferred from the claim text.