Faraday Technology Marketing Group, LLC

Faraday Technology Corporation

Chengdong Zhou

E Jennings Taylor

Jenny J Sun

Robert P Renz

Lawrence E Gebhart

Mahendra K Sunkara

Eric C Stortz

A smooth layer of a metal is electroplated onto a microrough electrically conducting substrate by immersing the substrate and a counterelectrode in an electroplating bath of the metal to be electroplated and passing a modulated reversing electric current between the electrodes. The current contains pulses that are cathodic with respect to said substrate and pulses that are anodic with respect to said substrate. The cathodic pulses have a duty cycle less than about 50% and said anodic pulses have a duty cycle greater than about 50%, the charge transfer ratio of the cathodic pulses to the anodic pulses is greater than one, and the frequency of said pulses ranges from about 10 Hertz to about 12000 Hertz. The plating bath is substantially devoid of levelers and may be devoid of brighteners.

Pulse reverse electrodeposition for metallization and planarization of semiconductor substrates

A layer of a metal is electroplated onto an electrically conducting substrate having a generally smooth surface with a small recess therein, having a transverse dimension not greater than about 350 micrometers, typically from about 5 micrometers to about 350 micrometers, by immersing the substrate and a counterelectrode in an electroplating bath of the metal to be electroplated and passing a modulated reversing electric current between the electrodes. The current contains pulses that are cathodic with respect to said substrate and pulses that are anodic with respect to said substrate. The cathodic pulses typically have a duty cycle less than about 50% and the anodic pulses have a duty cycle greater than about 50%, the charge transfer ratio of the cathodic pulses to the anodic pulses is greater than one, and the frequency of the pulses ranges from about 10 Hertz to about 12000 Hertz. The on-time of the cathodic pulses may range from about 0.83 microseconds to about 50 milliseconds. The anodic pulse is longer than the cathodic pulse and may range from about 42 &mgr;s to about 99 milliseconds. The plating bath may be substantially devoid of levelers and/or brighteners.

Electrodeposition of metals in small recesses using modulated electric fields

Electrochemical machining of metals and alloys is accomplished by using a pulsed electric current incorporating modulated reverse electric current. Reverse (cathodic) pulses are interposed between forward (anodic) pulses. The process is useful for electrochemical shaping of metals, electrochemically polishing metal surfaces, and electrochemical deburring of metal articles. The process is especially useful for electrochemical processing of metals and alloys that readily form passive surface layers.

Electrochemical machining using modulated reverse electric fields

A layer of a metal is electroplated onto an electrically conducting substrate having a generally smooth surface with a small recess therein, having a transverse dimension not greater than about 350 micrometers, by immersing the substrate and a counterelectrode in an electroplating bath of the metal to be electroplated and passing a modulated reversing electric current between the electrodes. The current contains pulses that are cathodic with respect to said substrate and pulses that are anodic with respect to said substrate. The cathodic pulses have a duty cycle less than about 50% and said anodic pulses have a duty cycle greater than about 50%, the charge transfer ratio of the cathodic pulses to the anodic pulses is greater than one, and the frequency of said pulses ranges from about 10 Hertz to about 12000 Hertz. The plating bath may be substantially devoid of levelers and/or brighteners.

A layer of a metal is electroplated onto an electrically conducting substrate having a generally smooth surface with a small recess therein, having a transverse dimension not greater than about 350 micrometers, typically from about 5 micrometers to about 350 micrometers, by immersing the substrate and a counterelectrode in an electroplating bath of the metal to be electroplated and passing a modulated reversing electric current between the electrodes. The current contains pulses that are cathodic with respect to said substrate and pulses that are anodic with respect to said substrate. The cathodic pulses have a duty cycle less than about 50% and said anodic pulses have a duty cycle greater than about 50%, the charge transfer ratio of the cathodic pulses to the anodic pulses is greater than one, and the frequency of said pulses ranges from about 10 Hertz to about 5000 Hertz.

Electrodeposition of metals in small recesses for manufacture of high density interconnects using reverse pulse plating

A smooth layer of a metal is electroplated onto a microrough electrically conducting substrate by immersing the substrate and a counterelectrode in an electroplating bath of the metal to be electroplated and passing a modulated reversing electric current between the electrodes. The current contains pulses that are cathodic with respect to said substrate and pulses that are anodic with respect to said substrate. The cathodic pulses have a duty cycle less than about 50% and said anodic pulses have a duty cycle greater than about 50%, the charge transfer ratio of the cathodic pulses to the anodic pulses is greater than one, and the frequency of said pulses ranges from about 10 Hertz to about 5000 Hertz.

Pulse reverse electrodeposition for metallization and planarization of a semiconductor substrates

Metal salts are removed from solution in an electrolyte by subjecting the solution to electrolysis in a cell having an anode that has an anion exchange membrane closely associated therewith which sequesters the anion of the salt. The cathode may also be provided with a closely associated cation exchange membrane that sequesters, at least partially, the cation of the salt. A metal salt solution can be regenerated by reversing the polarity of the electrodes and conducting an electrolysis using fresh electrolyte.

Method of removing metal salts from solution by electrolysis an

A waste solution containing electroactive species, e.g., metal ions, can be remediated to very low levels of contaminant by an electrolysis method including the steps of introducing an electrolyte containing an electroactive species into an electrolytic cell having a cathode and an anode, producing a flow of the electrolyte past at least one of the electrodes at an electrolyte flow rate, and passing an electric current through the solution between the anode and the cathode whereby the electroactive species undergoes an electrochemical reaction at one of the electrodes at an electrochemical reaction rate, using an electric current pulsed at a frequency of 0.5 to 1000 Hertz and a duty cycle of not greater than 50%, and adjusting the electrolyte flow rate for the pulsed current electrolysis such that the electrochemical reaction rate for pulsed current electrolysis is greater than the electrochemical reaction rate for direct current electrolysis. The method is especially useful in increasing the efficiency of electrolytic remediation of metal-containing waste solutions to low levels of metal ion contaminants. The method is preferably conducted using electrodes having very high surface area, optionally coated with an ion exchange resin.

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Salem, OR, United States of America

Chengdong Zhou