一維陣列抗反射矽奈米結構

材料表面的反射是因為光線通過折射率不同的界面所致，因此在表面製作奈米結構，例如奈米洞，奈米線，奈米柱等，可減少光學電子元件的光損耗與反射。對矽太陽能電池而言，奈米結構具有能以低反射表面增加光的捕獲，以及提供光生少數載子所需較短的擴散距離，以利增加載子收集的效率等優點，將可降低太陽能電池所要求的矽晶圓品質，進而降低成本。在本研究中，我們以i-line光學微影與電漿蝕刻，快速地製作大面積高均勻性的矽奈米柱狀陣列結構。首先利用電子束微影製程製作出光罩，再以光學微影製程透過光罩將氧化矽／矽晶圓表面上的光阻曝光顯影出直徑與間距400奈米的奈米柱圖案，接著以電漿蝕刻，藉由控制蝕刻時間，製作出梯形、柱形、鉛筆形等奈米結構，以利用不同的高寬比的奈米柱結構，來量測表面反射率的變化。結果顯示，所有的奈米結構反射率皆比平面晶圓低，其中長度2 μm鉛筆狀的奈米柱陣列，可將矽晶圓表面反射率在可見光波段降至10%以下。

關鍵字

光學微影；矽奈米柱陣列；抗反射

並列摘要

As the light passes through the interface between air and materials, the surface reflection will arise from the change of refractive indices. To reduce the reflection and the optical loss of the optical electronic components, we can create nanostructures, such as creating nanopores, nanowires, and nanopillars, on their surfaces. For silicon solar cell, these nanostructures have the advantages of enhanced light trapping by lower reflection and higher collection efficiency of photogenic minority carriers by shorter diffusion length, so that the quality requirement on silicon crystals can be reduced for cost down purpose. In this study, we used i-line lithography and plasma etching to efficiently fabricate silicon nanopillar array with high uniformity over large area. A reticle was firstly prepared by electron-beam lithography, which was then used to expose the resist on silicon oxide/silicon substrate for creating the nanopillar array pattern with 400 nm in pillar diameter and pillar spacing. To measure the reflection variation of different aspect-ratio nanostructures, plasma etching time was controlled to obtain trapezoidal, columnar and pencil-like nanostructures. The results show that the reflectivity of each nanostructured sample is lower than that of bare silicon wafer. For 2-μm pencil-like nanopillar array, the reflectance can be reduced down to less than 10% over 300-800 nm.

並列關鍵字

Optical Lithography ； Silicon Nanopillar Array ； Antireflection

國際替代計量

一維陣列抗反射矽奈米結構

全文下載

主題瀏覽