大F数硅微透镜阵列的制作及光学性能测试研究

提出了一种补偿刻蚀法 :在经过常规光刻热熔成形和离子束刻蚀技术制成的硅微透镜阵列上再涂敷几层光刻胶 ,以降低各单元微透镜的曲率 ,然后再次进行加热固化和离子束刻蚀。扫描电子显微镜 ( SEM)显示微透镜阵列为表面极为平缓的球冠形阵列 ,表面探针测试结果显示用补偿刻蚀法制作的微透镜的 F数和 F′数分别可达到 31.62和 35.88,而常规光刻热熔法很难制作出 F数和 F′数分别超过 1.0 0和 4 .0 0的微透镜阵列。光学填充因子也由常规方法的 64.3%提高至78.5% ,并且微透镜的点扩散函数也更接近理想值

Research on Fabrication and Optical Performance Testing of Silicon Microlenses Array with Large F/ Number

A new method,named curvature compansation milling,is proposed to increase F/ of refractiave microlenses array (MLA).It is described as follows: in order to decrease curvature of MLA fabricated by the conventional method of photolithography/melting/ion beam milling,several new layers of photoresist are coated on MLA,then heated and consolidated,at last milled again.Scanning electron microscope (SEM) shows that microlens is gently spherical,and surface stylus measurement shows that F/ number and F′/ number of MLA,fabricated by the new method,is promoted to 31.62 and 35.88,respectively,compared with 1.00 and 4.00,hardly obtained by use of conventional way.And the filling factor is promoted from 64.3% to 78.5%.Using the new method,point spread funtions of MLAs are more ideal,and their image quality is improved.