Monitoring surface oxide on seed layers during electroplating
First Claim
1. A method of determining whether a substrate includes an unacceptable amount of oxide on a surface of the substrate, the method comprising:
- (a) receiving the substrate in an electroplating chamber;
(b) immersing the substrate in electrolyte, wherein during and/or immediately after immersing the substrate, either;
(i) a current applied to the substrate is controlled, or(ii) a voltage applied between the substrate and a reference is controlled;
(c) measuring either a voltage response or a current response during and/or immediately after immersion, wherein;
(i) the voltage response is measured if the current applied to the substrate is controlled in (b)(i), or(ii) the current response is measured if the voltage applied to the substrate is controlled in (b)(ii);
(d) comparing the voltage response or current response measured in (c) to a threshold voltage, a threshold current, or a threshold time, wherein the threshold voltage, threshold current, or threshold time is selected to distinguish between (1) cases where the substrate includes the unacceptable amount of oxide present on the surface of the substrate and (2) cases where the substrate includes an acceptable amount of oxide present on the surface or no oxide present on the surface of the substrate;
(e) determining, based on the comparison in (d), whether the substrate includes the unacceptable amount of oxide on the surface of the substrate; and
(f) electroplating the substrate in the electroplating chamber during and/or after immersing the substrate, wherein immersing the substrate at (b) and electroplating the substrate at (f) occur in the electrolyte.
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Abstract
Methods and apparatus for determining whether a substrate includes an unacceptably high amount of oxide on its surface are described. The substrate is typically a substrate that is to be electroplated. The determination may be made directly in an electroplating apparatus, during an initial portion of an electroplating process. The determination may involve immersing the substrate in electrolyte with a particular applied voltage or applied current provided during or soon after immersion, and recording a current response or voltage response over this same timeframe. The applied current or applied voltage may be zero or non-zero. By comparing the current response or voltage response to a threshold current, threshold voltage, or threshold time, it can be determined whether the substrate included an unacceptably high amount of oxide on its surface. The threshold current, threshold voltage, and/or threshold time may be selected based on a calibration procedure.
144 Citations
14 Claims
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1. A method of determining whether a substrate includes an unacceptable amount of oxide on a surface of the substrate, the method comprising:
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(a) receiving the substrate in an electroplating chamber; (b) immersing the substrate in electrolyte, wherein during and/or immediately after immersing the substrate, either; (i) a current applied to the substrate is controlled, or (ii) a voltage applied between the substrate and a reference is controlled; (c) measuring either a voltage response or a current response during and/or immediately after immersion, wherein; (i) the voltage response is measured if the current applied to the substrate is controlled in (b)(i), or (ii) the current response is measured if the voltage applied to the substrate is controlled in (b)(ii); (d) comparing the voltage response or current response measured in (c) to a threshold voltage, a threshold current, or a threshold time, wherein the threshold voltage, threshold current, or threshold time is selected to distinguish between (1) cases where the substrate includes the unacceptable amount of oxide present on the surface of the substrate and (2) cases where the substrate includes an acceptable amount of oxide present on the surface or no oxide present on the surface of the substrate; (e) determining, based on the comparison in (d), whether the substrate includes the unacceptable amount of oxide on the surface of the substrate; and (f) electroplating the substrate in the electroplating chamber during and/or after immersing the substrate, wherein immersing the substrate at (b) and electroplating the substrate at (f) occur in the electrolyte. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification