Maskless laser plating techniques for microelectronic materials

The authors describe techniques for laser enhanced plating of gold, nickel and copper. This maskless plating results in speeds up to 103 times that of conventional plating. Mechanisms and applications are discussed. Lasers continue to have increasing applications, particularly in the field of microelectronic processing for a variety of maskless deposition and etching techniques. The maskless pattern formation makes use both of gases and liquids from which the metal atoms or ions are deposited or reacted. The physical mechanisms include photolytic, pyrolytic and chemisorption processes. Patterns are generated by motion of the focused laser beam relative to the workpiece. The processes utilizing lasers in combination with various gases are in many ways analogous to plating and etching patterning from solution