Fabrication of microlens array on 6H-SiC mold by an integrated microcutting-etching process

Precision glass molding (PGM) is an efficient method to mass-produce glass microlens arrays with high-precision, the key to which is the high-quality mold. Silicon carbide (SiC) is considered to be an ideal mold material, but microstructures are difficult to machine in SiC because of its high hardness and strength. In this study, a microcutting-etching method involving the combination of single-point diamond cutting with inductively coupled plasma (ICP) etching is proposed to fabricate microlens arrays on 6H-SiC. The research described in this paper focuses on the use of the proposed method for controllable processing of a microlens array mold made of 6H-SiC. The microcutting process of the mask material and the etching process of the substrate material 6H-SiC are studied. The techniques to control the accuracy of the microlens array on 6H-SiC are managed by studying the cutting process, selectivity ratio and etching condition. In this manner, a ring-shaped microlens array with excellent accuracy and consistency is generated.