The disclosed embodiments relate to methods and apparatus for immersing a substrate in electrolyte in an electroplating cell under sub-atmospheric conditions to reduce or eliminate the formation/trapping of bubbles as the substrate is immersed. Various electrolyte recirculation loops are disclosed to provide electrolyte to the plating cell. The recirculation loops may include pumps, degassers, sensors, valves, etc. The disclosed embodiments allow a substrate to be immersed quickly, greatly reducing the issues related to bubble formation and uneven plating times during electroplating.

Focused Electric Field Imprinting (FEFI) provides a focused electric field to guide an unplating operation and/or a plating operation to form very fine-pitched metal patterns on a substrate. The process is a variation of the electrochemical unplating process, wherein the process is modified for imprinting range of patterns of around 2000 microns to 20 microns or less in width, and from about 0.1 microns or less to 10 microns or more in depth. Some embodiments curve a proton-exchange membrane whose shape is varied using suction on a backing fluid through a support mask. Other embodiments use a curved electrode. Mask-membrane interaction parameters and process settings vary the feature size, which can generate sub-100-nm features. The feature-generation process is parallelized, and a stepped sequence of such FEFI operations, can generate sub-100-nm lines with sub-100-nm spacing. The described FEFI process is implemented on copper substrate, and also works well on other conductors.

Focused Electric Field Imprinting (FEFI) provides a focused electric field to guide an unplating operation and/or a plating operation to form very fine-pitched metal patterns on a substrate. The process is a variation of the electrochemical unplating process, wherein the process is modified for imprinting range of patterns of around 2000 microns to 20 microns or less in width, and from about 0.1 microns or less to 10 microns or more in depth. Some embodiments curve a proton-exchange membrane whose shape is varied using suction on a backing fluid through a support mask. Other embodiments use a curved electrode. Mask-membrane interaction parameters and process settings vary the feature size, which can generate sub-100-nm features. The feature-generation process is parallelized, and a stepped sequence of such FEFI operations, can generate sub-100-nm lines with sub-100-nm spacing. The described FEFI process is implemented on copper substrate, and also works well on other conductors.

In electroplating apparatus, a paddle or agitator agitates electrolyte in a vessel to provide high velocity fluid flow at the surface of a wafer. The agitator is designed and/or moved to also selectively shield part of the wafer, for example the edge of the wafer, from the electric field in the vessel. Selectively shielding may be achieved by temporally shifting the average position of the agitator towards one side of the wafer, by omitting or shortening slots in the agitator, and/or by synchronizing movement of the agitator with rotation of the wafer.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 m or more, diameters of 10 m or below, and inter-pillar spacing below 20 m. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 m or more, diameters of 10 m or below, and inter-pillar spacing below 20 m. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 m or more, diameters of 10 m or below, and inter-pillar spacing below 20 m. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.

A system and method of using electrochemical additive manufacturing to add interconnection features, such as wafer bumps or pillars, or similar structures like heatsinks, to a plate such as a silicon wafer. The plate may be coupled to a cathode, and material for the features may be deposited onto the plate by transmitting current from an anode array through an electrolyte to the cathode. Position actuators and sensors may control the position and orientation of the plate and the anode array to place features in precise positions. Use of electrochemical additive manufacturing may enable construction of features that cannot be created using current photoresist-based methods. For example, pillars may be taller and more closely spaced, with heights of 200 m or more, diameters of 10 m or below, and inter-pillar spacing below 20 m. Features may also extend horizontally instead of only vertically, enabling routing of interconnections to desired locations.