Here is the abstract you requested from the IMAPS_2008 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Electrochemical Process for Through via/Bump Formation without CMP and Lithographic Processes|
|Keywords: electropolishing, electroless copper plating, electroless tin plating|
|In conventional flip chip interconnection, CMP and lithographic processes were used in Cu/Sn bumps fabrication. During CMP process, copper via substrates were easily damaged and lithographic process is high cost process. Series of electropolishing, electroless copper plating, electroless tin plating followed by reflow were suggested to replace CMP and lithographic process. The 50 and 20 micrometer diameter copper via were fabricated by electroplating method. Overplated copper were successfully removed by electropolishing method in suppressor and accelerator added phosphoric acid. 5 micrometer height copper bumps were formed on electropolished via by electroless plating method. Suppressor added electroless copper bath can promote selectivity of copper bump formation on via after proper acid cleaning. 9 micrometer height tin bumps were formed on electroless copper bump. Finally uniform sized Cu/Sn bumps were fabricated after reflow process.|
|Jae-Ho Lee, Professor