Electrochemical microfabrication by laser-enhanced photothermal processes

Laser-enhanced processes have found an increasingly important role as the interest in microfabrication continues to grow. An especially attractive feature of laser processing in liquids is the ability to obtain maskless patterning in the form of material deposition or dissolution, dictated by the path of the focused laser on the sample. In the present discussion we review theoretical and experimental aspects of laser-enhanced plating and etching for a variety of materials. Some of the substrates readily etched with the help of the laser are extremely difficult to process by conventional methods. Even though the laser processes can handle materials only in a serial manner, the plating and etching rates in certain instances are sufficiently rapid to make them competitive with batch processing methods. This is particularly interesting as it pertains to laser-enhanced jet plating of copper and gold, where rates as high as 50 and 20 µm/s have respectively been obtained.