A new method for three dimensional excimer laser micromachining, Hole Area Modulation (HAM)

A new excimer laser system configuration for three dimensional (3D) micromachining, called Hole Area Modulation (HAM) method, is proposed and the feasibility of the system is experimentally confirmed. In this method, information on the depth of machining is converted to the sizes of small holes in the mask. The machining is carried out with a simple 2D movement of the workpiece. Since the total area of the targeted cavity is machined simultaneously, a 2.5-μm-deep, 800μm × 1600μm 3D cavity was machined in about 5s. This method can be applied for machining various kinds of microcavities in various materials. Owing to the short machining time, the fabrication of a mold with repeated shapes, for example a mold for a microlens array, will be a good application in the future.