Advanced seed layer of Cu wiring for printed circuit board with sputtering method

To realize fine pitch and high density Cu wiring pattering on printed circuit board, seed layer sputtering method with high productivity is necessary. ULVAC developed new sputtering system for seed layer of fine pitch and high density Cu wiring [1]. Thin thickness seed layer controllability is important in terms of prevention over etching and deterioration of Cu wiring shape at seed layer etching step to achieve below 5um/5um line and space pattern. And throwing power improvement with thin seed layer thickness is also important to fill Via with Cu electro plating. ULVAC developed directional sputtering method to improve throwing power and then we could suppress surface seed layer thickness. On the other hand, ULVAC has developed Cu alloy material and deposition process with high adhesion and barrier characteristics as Cu wiring technique for flat panel display [2][3]. We arranged this Cu alloy material composition for Cu wiring seed layer of printed circuit board and developed advanced Cu alloy material. With this advanced Cu alloy material, manufacturing process step can be reduced. By applying these new techniques, we can provide advanced seed layer of Cu wiring for printed circuit board.