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US 10,094,038 B2Granted
Monitoring electrolytes during electroplating
AssigneeLam Research Corporation
InventorsMatthew Sherman Thorum, Steven T. Mayer
Life of this patent
Estimating the term…
Abstract
Methods of and apparatuses for monitoring electroplating bath quality in electroplating cells using voltage readings are described herein. Methods involve obtaining real-time voltage readings during an electroplating process and determining whether the voltage readings are within a threshold deviation of an expected voltage reading at a given time.
Claims19
A method of controlling an electroplating cell by monitoring conditions of an electroplating bath, the method comprising:
- (a) providing a substrate to an electroplating apparatus for electrodepositing a metal from the electroplating bath, the electroplating apparatus comprising the electroplating cell configured to hold the electroplating bath, a power supply, and a second electrode;
- (b) reading an initial voltage between the substrate as a first electrode and the second electrode;
- (c) electroplating the metal onto the substrate in the electroplating cell;
- (d) during electroplating on the substrate in the electroplating cell, repeatedly reading a voltage between the substrate and the second electrode;
- (e) comparing each of the repeated readings of the voltage to a corresponding expected voltage that drifts from the initial voltage during the electroplating,
- wherein the drift is determined from substrate electroplating operations that produce satisfactory electroplating results, and
- wherein the drift comprises a three-part drift profile during the electroplating, the profile comprising (i) a negative slope of voltage over time, and (ii) a positive slope of voltage over time, and (iii) a slope of about zero of voltage over time;
- (f) determining that one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than a threshold deviation;
- and
- (g) in response to determining that the one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than the threshold deviation, suspending operation of the electroplating cell, wherein the threshold deviation depends on the drift profile and comprises one or more threshold deviations, and wherein a threshold deviation corresponding to (ii) is greater than a threshold deviation corresponding to (i).
7 more elements
A method of controlling an electroplating cell by monitoring conditions of an electroplating bath, the method comprising:
- (a) providing a substrate to an electroplating apparatus for electrodepositing a metal from the electroplating bath, the electroplating apparatus comprising the electroplating cell configured to hold the electroplating bath, a power supply, and a second electrode;
- (b) electroplating the metal onto the substrate in the electroplating cell;
- (c) waiting a delay period during the electroplating before reading an initial voltage between a substrate as a first electrode and a second electrode;
- (d) reading the initial voltage between a substrate as a first electrode and a second electrode;
- (e) during electroplating on the substrate in the electroplating cell, repeatedly reading a voltage between the substrate and the second electrode;
- (f) comparing each of the repeated readings of the voltage to a corresponding expected voltage that drifts from the initial voltage during the electroplating,
- wherein the drift is determined from substrate electroplating operations that produce satisfactory electroplating results and
- wherein the drift comprises a three-part drift profile during the electroplating, the profile comprising (i) a negative slope of voltage over time, and (ii) a positive slope of voltage over time, and (iii) a slope of about zero of voltage over time;
- (g) determining that one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than a threshold deviation;
- and
- (h) in response to determining that the one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than the threshold deviation, suspending operation of the electroplating cell, wherein the threshold deviation depends on the drift profile and comprises one or more threshold deviations, and wherein a threshold deviation corresponding to (ii) is greater than a threshold deviation corresponding to (i).
8 more elements
A method of controlling an electroplating cell by monitoring conditions of an electroplating bath, the method comprising:
- (a) providing a substrate to an electroplating apparatus for electrodepositing a metal from the electroplating bath, the electroplating apparatus comprising the electroplating cell configured to hold the electroplating bath, a power supply, and a second electrode;
- (b) reading an initial voltage between the substrate as a first electrode and the second electrode;
- (c) electroplating the metal onto the substrate in the electroplating cell;
- (d) during electroplating on the substrate in the electroplating cell, repeatedly reading a voltage between the substrate and the second electrode;
- (e) comparing each of the repeated readings of the voltage to a corresponding expected voltage that drifts from the initial voltage during the electroplating,
- wherein the drift is determined from substrate electroplating operations that produce satisfactory electroplating results,
- wherein the drift comprises a three-part drift profile during the electroplating, the profile comprising (i) a negative slope of voltage over time, and (ii) a positive slope of voltage over time, and (iii) a slope of about zero of voltage over time, and wherein the drift is a logarithmic function of time;
- (f) determining that one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than a threshold deviation;
- and
- (g) in response to determining that the one or more of the repeated readings of the voltage deviate from the corresponding expected voltage by a value greater than the threshold deviation, suspending operation of the electroplating cell.
7 more elements
Dependencies are inferred from the claim text.