Electroless copper deposition method for preparing copper seed layers
First Claim
1. A method of forming a copper seed layer on a substrate surface, the method comprising:
- providing a substrate having dielectric layer on its surface and recesses in said dielectric layer, the substrate further comprising a partially complete copper seed layer formed in at least some recesses of the substrate surface;
contacting the substrate surface with an electroless plating bath comprising a reducing agent and a source of copper ions, to deposit additional copper on the substrate surface; and
monitoring the plating rate via a potential between the substrate and a reference electrode.
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Accused Products
Abstract
Disclosed is a procedure for deposition of a thin and relatively continuous electroless copper film on the substrate of sub-micron integrated circuit features. The electroless copper film is deposited onto a previously deposited PVD copper film, which may be discontinuous. The continuous film formed by electroless deposition allows for sufficient filling of the sub-micron integrated circuit features by electrodeposition. The electroless bath employed to form the continuous electroless copper film may be composed of a reducing agent, a complexing agent, a source of copper ions, a pH adjuster, and optionally one or more surfactants and/or stabilizers. In one example, the reducing agent contains an aldehyde moiety.
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Citations
34 Claims
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1. A method of forming a copper seed layer on a substrate surface, the method comprising:
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providing a substrate having dielectric layer on its surface and recesses in said dielectric layer, the substrate further comprising a partially complete copper seed layer formed in at least some recesses of the substrate surface;
contacting the substrate surface with an electroless plating bath comprising a reducing agent and a source of copper ions, to deposit additional copper on the substrate surface; and
monitoring the plating rate via a potential between the substrate and a reference electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A process by which a substrate with a non-continuous physical vapor deposited seed layer is plated with an electroless copper layer comprising:
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placing the substrate in an electroless plating bath in a face down orientation while rotating;
allowing the substrate to undergo electroless plating while flow to the substrate surface is controlled, at least in part, by the rotation rate of the substrate; and
monitoring the resistivity of the copper layer to determine the thickness of the copper layer during electroless plating. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
drying the substrate; and
electroplated the substrate at a later time.
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33. The process of claim 31, further comprising electroplated the substrate immediately after electroless deposition and rinsing.
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34. The process of claim 21, further comprising annealing the substrate to thereby stabilize the electroless copper layer.
Specification