Lam Research Corporation

Kari Thorkelsson

Steven T Mayer

Bryan L Buckalew

Aaron Berke

Richard G Abraham

Justin Oberst

Thomas Anand Ponnuswamy

Stephen J Banik, Ii

Direct copper-copper bonding at low temperatures is achieved by electroplating copper features on a substrate followed by electroplanarizing the copper features. The copper features are electroplated on the substrate under conditions so that nanotwinned copper structures are formed. Electroplanarizing the copper features is performed by anodically biasing the substrate and contacting the copper features with an electrolyte so that copper is electrochemically removed. Such electrochemical removal is performed in a manner so that roughness is reduced in the copper features and substantial coplanarity is achieved among the copper features. Copper features having nanotwinned copper structures, reduced roughness, and better coplanarity enable direct copper-copper bonding at low temperatures.

Low temperature direct copper-copper bonding

Sequential electrodeposition of metals into through-mask features on a semiconductor substrate is conducted such as to reduce the deleterious consequences of lipseal's pressure onto the mask material. In a first electroplating step, a first metal (e.g., nickel) is electrodeposited using a lipseal that has an innermost point of contact with the semiconductor substrate at a first distance from the edge of the substrate. In a second electroplating step, a second metal (e.g., tin) is electrodeposited using a lipseal that has an innermost point of contact with the semiconductor substrate at a greater distance from the edge of the substrate than the first distance. This allows to at least partially shift the lipseal pressure from a point that could have been damaged during the first electrodeposition step and to shield from electrolyte any cracks that might have formed in the mask material during the first electroplating step.

Lipseal edge exclusion engineering to maintain material integrity at wafer edge

In one implementation a cathode for electrochemical metal removal has a generally disc-shaped body and a plurality of channels in the generally disc-shaped body, where the channels are configured for passing electrolyte through the body of the cathode. The channels may be fitted with non-conductive (e.g., plastic) tubes that in some embodiments extend above the body of the cathode to a height of at least 1 cm. The cathode may also include a plurality of indentations at the edge to facilitate electrolyte flow at the edge of the cathode. In some embodiments the cathode includes a plurality of non-conductive fixation elements on a conductive surface of the cathode, where the fixation elements are attachable to one or more handles for removing the cathode from the electrochemical metal removal apparatus.

Electro-oxidative metal removal in through mask interconnect fabrication

The embodiments herein relate to methods and apparatus for electroplating one or more materials onto a substrate. Typically, the embodiments herein utilize a channeled plate positioned near the substrate, creating a cross flow manifold between the channeled plate and substrate, and on the sides by a flow confinement ring. A seal may be provided between the bottom surface of a substrate holder and the top surface of an element below the substrate holder (e.g., the flow confinement ring). During plating, fluid enters the cross flow manifold through channels in the channeled plate, and through a cross flow inlet, then exits at the cross flow exit, positioned opposite the cross flow inlet. The apparatus may switch between a sealed state and an unsealed state during electroplating, for example by lowering and lifting the substrate and substrate holder as appropriate to engage and disengage the seal.

Dynamic modulation of cross flow manifold during elecroplating

In one implementation a wafer processing method includes filling a plurality of through-resist recessed features with a metal, such that a ratio of fill rate of a first feature to a fill rate of a second feature is R1; followed by electrochemically removing metal such that a ratio of metal removal rate from the first feature to the metal removal rate from the second feature is greater than R1, improving the uniformity of the fill. In some embodiments the method includes contacting an anodically biased substrate with an electrolyte such that the electrolyte has a transverse flow component in a direction that is substantially parallel to the working surface of the substrate. The method can be implemented in an apparatus that is configured for generating the transverse flow at the surface of the substrate. In some implementations the method makes use of distinct electrochemical regimes to achieve improvement in uniformity.

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Portland, OR, United States of America

Kari Thorkelsson