寬頻抗反射表面結構於光電半導體元件之研製

Abstract

本研究論文主要探討使用自組小球顯影技術，利用旋轉塗佈法，於基板表面鋪設單層週期性的小球結構。透過二維嚴格耦合波模擬設計，我們在不同基板表面鋪設單層100nm的二氧化矽小球，在400nm ~700nm的可見光波段中，量測到穿透率皆有提升之效果。即便入射光於60度斜向入射基板下，鋪設單層小球之基板穿透率仍可提升10%以上，展現抗反射表面週期性奈米結構具寬頻，大角度之優勢。本方法並實際鋪設於大面積基板表面，驗證低成本，高產出之量產優勢。 此外，我們也以自組小球顯影技術，利用小球作為蝕刻遮罩，結合乾式蝕刻與濕式蝕刻，製作出抗反射表面結構於半導體基板表面。我們並利用此抗反射半導體基板具高穿透率，以及半導體基板表面奈米結構之電場呈現空間梯度變化之特性，結合液晶分子研製出消雷射光斑元件。我們更進一步利用弦波偏壓驅動液晶分子，來量測元件去光斑之效果，由原本62.5%下降至24.3%，降低雷射光斑對比值，以達到降低雷射光斑之目的。

This dissertation focuses on the use of self-assembled lithography by using a spin-coating method to form periodic monolayer structures on the substrate surface. We applied two-dimensional rigorous coupled-wave analysis (2D-RCWA) to simulate the nanostructure surface, and then spread out monolayer-thick 100nm silica particles. The periodic nanostructure can dramatically increase transmittance in the visible spectrum range. Even with oblique incidence angle at 60 degrees, the sample with 100nm surface structure can still maintain 10% more increase in the optical transmittance compare with sample of flat surface showing the characteristics of broadband and wide-angle. Moreover, we also successfully developed a wafer-scale substrate surface the periodic monolayer structure to verify the advantage of low-cost and mass production. In addition, we use the self-assembled sphere mask to fabricate an antireflective surface on semiconductors by combining dry etching and wet etching. The antireflective nanostructure surface not only increased transmittance but also formed a gradient field distribution effect due to the surface structure. Meanwhile, we used the electro-optical characteristics of liquid crystal to fabricate laser despeckle device and applied sine wave bias to drive the liquid crystal. The speckle contrast is reduced from 62.5% to 24.3% at pulse bias compared with device without surface modification. It greatly reduced the laser speckle contrast, and achieved the purpose of reducing laser speckle phenomenon.