Excimer laser micromachining for 3D microstructure

A new 3D micromachining method, called Hole Area Modulation (HAM), has been introduced to enhance the current micromachining technology. In this method, information on the machining depth is converted to the sizes of holes on the mask. The machining is carried out with a simple 2D movement of the workpiece or the mask. This method can be applied for machining various kinds of microcavities in various materials. In this paper, a mathematical model for excimer laser micromachining based on HAM and determination of the optimal laser ablation conditions (hole diameter, step size, mask movement velocity, etc.) are described. The simulation and experiment of the HAM-based laser ablation were carried out successfully to create microlens.