采用全息光刻和二次显影的方法制备了柱形二维光子晶体.在此过程中,二维点状的周期结构首先在正性光刻胶上直接形成,然后经由Si3N4硬掩模转移到衬底材料上.利用二次显影的方法,曝光强度最强和曝光强度中等区域的光刻胶能够被同时充分显影,而曝光强度最弱区域的光刻胶则可以完全被保留下来.通过调节入射角,可以方便地调节二维结构的周期.利用此方法,在相对较大的面积上制备了不同周期的二维结构,二维结构具有很好的均匀性和重复性.文章对有关的工艺参数进行了详细讨论.
A simple and cost effective method to fabricate column shape two dimensional photonic crystals by holographic li- thography technique using double development has been reported. In the process two dimensional big-dot-type periodic structures have been generated directly on positive photoresist, and then transferred to the substrate through the Si3N4 hard mask. By using double development, the photoresist exposed to high and medium intensity can be developed away effective- ly, while those exposed to low intensity can still be preserved. The period of the two dimensional structures can be easily controlled by adjusting the angle of two incident beams. The structures in a large period range over a relative large area have been generated with good uniformity and reproducibility. The processing parameters are discussed in detail.