Apparatus and methods for fast chemical electrodeposition for fabrication of solar cells
OwnerKurt H. Weiner, Gaurav Vermainventors
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Abstract
The invention relates generally to electrodeposition apparatus and methods. When depositing films via electrodeposition, where the substrate has an inherent resistivity, for example, sheet resistance in a thin film, methods and apparatus of the invention are used to electrodeposit materials onto the substrate by forming a plurality of ohmic contacts to the substrate surface and thereby overcome the inherent resistance and electrodeposit uniform films. Methods and apparatus of the invention find particular use in solar cell fabrication.
Claims42
An apparatus for electrodeposition of a material onto a sample, comprising:
- a support structure including a plurality of contact pins, each contact pin of said plurality of contact pins configured to establish electrical contact with a substrate surface of a semiconductor film of a sample undergoing electrodeposition that is arranged over an underlying conductive layer of the sample undergoing electrodeposition, wherein the contact pins are individually addressable;
- and
- a controller programmed to individually apply and increase a voltage that is applied to each of the contact pins until a breakdown voltage of the semiconductor film is reached so as to establish an ohmic contact from each contact pin to the underlying conductive layer through the semiconductor film so as to cause negligible resistance from each contact pin, through the semiconductor film, to the underlying conductive layer during electrodeposition of a material onto the substrate surface of the semiconductor film while stopping a further increase in voltage that would otherwise cause a breakdown voltage to be reached in the underlying conductive layer.
An apparatus for electrodeposition of a material onto a sample, comprising:
- a support structure including a plurality of compliant contact pins, each contact pin of said plurality of compliant contact pins arranged to establish electrical contact with a substrate surface of a semiconductor film of a sample undergoing electrodeposition that is arranged over an underlying conductive layer of the sample undergoing electrodeposition;
- wherein the support structure comprises one or more pin holders, said one or more pin holders arranged to support the plurality of compliant contact pins, wherein said pin holders reside outside of the perimeter of the substrate surface during electrodeposition, and wherein the compliant contact pins are individually addressable;
- a control circuit coupled with the compliant contact pins and the control circuit being arranged to individually apply a breakdown voltage to each of the compliant contact pins;
- and
- a controller programmed to cause the control circuit to individually increase a voltage that is applied to each of the compliant contact pins until a breakdown voltage of the semiconductor film is reached so as to establish an ohmic contact from each compliant contact pin to the underlying conductive layer through the semiconductor film so as to cause an electrical flow from each compliant contact pin, through the semiconductor film, to the underlying conductive layer during electrodeposition of a material onto the substrate surface of the semiconductor film while stopping a further increase in voltage that would otherwise cause a breakdown voltage to be reached in the underlying conductive layer.
Dependencies are inferred from the claim text.