提高奈米壓印均勻性之模具構造研究

Increasing uniformity in nano-imprint lithography by designing mold structure

徐偉軒(Wei-Hsuan Hsu)

指導教授 ： 賀陳弘

國立清華大學/工學院/動力機械工程學系/碩士(2006年)

摘要

相較於光學微影技術，奈米轉印技術提供了另一個製造奈米等級結構的製造方式。於進行大面積壓印時，壓印結構的完整性容易受壓印力分布的均勻性以及模具與基板表面的品質所影響。因此，如何提高壓印結構的均勻性對奈米壓印技術實用化而言是一重要關鍵。
為了改善大面積壓印的瓶頸，本論文中提出一個新的製程─控制局部變形之奈米轉印技術。此技術不同於一般奈米轉印技術之處在於基板或模具背面切割200µm~300µm深度的溝槽，利用此結構產生微量變形，使模具與基板更容易貼合進而提升有效轉印之面積，同時使壓印過程中所產生的變形量集中於溝槽結構處，因此具有控制不均勻轉印發生於無圖案區域之能力，進而提升圖樣區域之均勻性。
本論文中，此概念以有限元素分析以及實際轉印實驗加以證明。模擬結果顯示增加壓印面積或壓印力會導致基板的扭曲進而影響轉印結構的品質，此外，溝槽結構確實能夠改善圖樣(Pattern）區域之基板扭曲情形，對於改善轉印結構品質有實質幫助。另一方面，本研究成功地利用此技術於4吋矽晶圓上成功轉印出50奈米寬、200奈米高之100奈米周期性光柵結構，證明溝槽結構確實有助於提升轉印品質。此技術有效地提升了大面積轉印小於100nm結構的可能性，對於奈米轉印技術跨出實驗室研究階段具有實質的幫助。

關鍵字

奈米轉印 ； 模具變形 ； 溝槽結構

並列摘要

Nano-imprint technique has the advantage of high throughput, sub-10nm resolution and low cost. In the printing process, however, the mold deformation often occurs and causes a great concern of the quality of pattern transfer, such as the uniformity. This paper presents a uniform printing method across the wafer by introducing the local mold deformation along the block boundaries. This method is simple and effective with the grooves cut on the backside within the non-patterned area of mold. The grooves lead the mold to lie and to close fit easily on substrate and obtains more uniform pattern on large surface.
Both analytical and experimental investigations were conducted to verify the proposed approach. The analytical results reveal that increasing the imprinting force or mold area will cause the substrate distortion and affect the imprinted quality significantly. The grooves can improve the defects and increase the uniform stress distribution in the patterned area. Using the proposed technique to fabricate 50nm grates with the aspect ratio as high as 4 on 4” silicon wafers are successful. The results demonstrate a new imprint method of introducing the controlled local mold deformation for more uniform imprint across large area. This technique enhances the nano-imprint performance in practice.

並列關鍵字

nano-imprint lithography ； mold deformation ； grooves

參考文獻

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