MONITORING SURFACE OXIDE ON SEED LAYERS DURING ELECTROPLATING
First Claim
1. A method of determining whether a substrate includes an unacceptably high 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 unacceptably high amount of oxide present on the surface of the substrate and (2) cases where the substrate includes an acceptably low amount of oxide present on the surface or no oxide present on the surface of the substrate; and
(e) determining, based on the comparison in (d), whether the substrate includes the unacceptably high amount of oxide on the surface of the substrate.
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Accused Products
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.
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Citations
21 Claims
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1. A method of determining whether a substrate includes an unacceptably high 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 unacceptably high amount of oxide present on the surface of the substrate and (2) cases where the substrate includes an acceptably low amount of oxide present on the surface or no oxide present on the surface of the substrate; and (e) determining, based on the comparison in (d), whether the substrate includes the unacceptably high amount of oxide on the surface of the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of selecting pre-treatment conditions for removing oxide from a surface of a production substrate, the method comprising:
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(a) providing a plurality of calibration substrates; (b) pre-treating at least some of the calibration substrates to at least partially remove oxide from a surface of each calibration substrate that is pre-treated, wherein the calibration substrates that are pre-treated are pre-treated using different sets of pre-treatment conditions; (c) immersing each calibration substrate in electrolyte; (d) measuring a voltage response or a current response during and/or immediately after each calibration substrate is immersed in electrolyte; (e) analyzing the voltage responses or current responses measured in (d) to identify which sets of pre-treatment conditions resulted in adequate removal of oxide from the surface of a relevant calibration substrate; and (f) selecting pre-treatment conditions for removing oxide from the surface of a production substrate based on the analysis of (e). - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. An electroplating apparatus configured to determine whether a substrate includes an unacceptably high amount of oxide on a surface of the substrate, the apparatus comprising:
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an electroplating chamber configured to hold electrolyte; a power supply configured to (1) apply current and/or voltage to the substrate and (2) measure a voltage response and/or current response in response to the applied current and/or applied voltage; a controller comprising executable instructions for; (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 unacceptably high amount of oxide present on the surface of the substrate and (2) cases where the substrate includes an acceptably low amount of oxide present on the surface or no oxide present on the surface of the substrate; and (e) determining, based on the comparison in (d), whether the substrate includes the unacceptably high amount of oxide on the surface of the substrate.
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Specification