本論文利用自製曝光機並以灰階光罩的方式來製作微光學元件。灰階光罩能提供不同的曝光強度，所造成的曝光差異會產生不同的光阻厚度，並具有只需一次的曝光步驟的優點，可適用於具有灰階度或連續曲面形狀的光學元件。我們所使用的自製灰階曝光機為結合電腦輸入的影像，經由數位光源處理投影技術將圖案投影在基板上即可曝光，這樣可以方便變換不同的光罩圖案。 以灰階光罩製作光學元件之微影製程與一般半導體製程大致相同，主要包含基板清洗、光阻塗佈、曝光、顯影等步驟，而元件分別有二元式繞射光柵、閃耀式繞射光柵、利用電腦產生全像片、菲涅耳透鏡以及莫爾透鏡，再利用自製灰階曝光機以及黃光微影製程來製作出所需的元件。 ;In this thesis, we produce various micro optical elements by the self-made maskless aligner and gray-level masks. The gray-level masks provide different exposure intensities during the photolithography process. The resulting intensity differences penetrate photoresists at different depths and produce different photoresist thicknesses. Furthermore, it can be used to fabricate the optical elements with grayscale or continuous curved surface by one-step photolithography exposure. The self-made gray-level maskless aligner combines the pattern by computer and digital light processing technology. Under this setup, the pattern of masks can be changed easily. The photolithography process with gray-level mask is roughly the same as that of semiconductor fabrication process, which including the substrate cleaning, photoresist coating, exposure, and development. Our system can pattern the optical elements including binary diffraction grating, blazed diffraction grating, computer generate hologram, Fresnel lens and Moiré lens.
