Formation of metal structures in solar cells
AssigneeSunPower Corporation
InventorJoseph Frederick Behnke
Life of this patent
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Abstract
A metal contact of a solar cell is formed by electroplating copper using an electroplating seed that is formed on a dielectric layer. The electroplating seed includes an aluminum layer that connects to a diffusion region of the solar cell through a contact hole in the dielectric layer. A nickel layer is formed on the aluminum layer, with the nickel layer-aluminum layer stack forming the electroplating seed. The copper is electroplated in a copper plating bath that has methanesulfonic acid instead of sulfuric acid as the supporting electrolyte.
Claims20
A method of fabricating a solar cell, the method comprising:
- forming an aluminum layer on a dielectric layer to connect to a diffusion region of the solar cell through a contact hole in the dielectric layer;
- forming an electroplating seed, wherein said forming the electroplating seed includes forming a nickel layer on the aluminum layer;
- and
- forming a metal contact that connects to the diffusion region of the solar cell, wherein said forming the metal contact includes electroplating a copper layer on a backside of the solar cell, wherein the copper layer is electroplated in a copper plating bath comprising methanesulfonic acid with no sulfuric acid.
A method of fabricating a solar cell, the method comprising:
- forming a dielectric layer on a solar cell substrate;
- forming a contact hole through the dielectric layer to expose a diffusion region of the solar cell;
- forming an aluminum layer on the dielectric layer and into the contact hole to connect to the diffusion region;
- and
- electroplating a copper layer using the aluminum layer as an electroplating seed in a copper electroplating bath comprising methanesulfonic acid.
A method of fabricating a solar cell, the method comprising:
- forming an aluminum layer on a dielectric layer of the solar cell;
- and
- electroplating a copper layer using the aluminum layer as an electroplating seed in a copper plating bath having a supporting electrolyte comprising methanesulfonic acid.
Dependencies are inferred from the claim text.