连续型平面衍射聚光透镜掩模的制作

Fabrication of continuous relief mask for diffractive plane focus lens

针对目前二元光学元件掩模制作工艺过程的诸多不足,对连续型平面衍射聚光透镜掩模的激光直写制作工艺进行了研究。基于基尔霍夫标量衍射理论,采用光线追迹法设计了连续型平面衍射聚光透镜掩模。采用激光直写技术,利用CLW S-300M/C极坐标激光直写设备、S1830光刻胶和M ICROPO S IT-351显影液,进行了刻写实验。实验表明,激光能量、预烘烤温度、显影液浓度以及预曝光对掩模微结构的制作均有影响。最后制作了掩模。与二元光学元件掩模的制作工艺相比,该技术具有工艺简单、制作周期短且易于操作的优点。

The fabrication technology of continuous relief mask for diffractive plane focus lens is studied in the paper. According to Kirchhoff＇s scalar diffraction theory, with the ray tracing method, a continuous relief mask for diffractive focus lens has been designed. Using the technology, some experiments on the writing of the mask were carried out with the help of CLWS-300M/C. The results show that the laser energy, prebake temperature, developer concentration and pre-exposure will affect the microstructure of the mask. The mask was fabricated with such technology after a lot of efforts. Compared with the technology for binary optical mask, the technology has the following strong points： process simplification, short period of fabrication and easy operation.