發展電子束微影鄰近效應之修正方法

Abstract

微影技術是積體電路IC製程的關鍵技術，也是讓摩爾定律能夠繼續前進的重要推手，半導體工業之所以能夠快速發展，晶片能夠越做越小且價格越來越便宜都與微影技術的發展息息相關，一直以來光學微影是半導體製程的主流，其優點為可大量生產且速度快成本低廉，相較於其他微影技術有很大的優勢，然而隨著晶片越來越小傳統的光學微影技術已經面臨了極限，需要新的微影技術研究，目前電子束微影(E-beam, Electron Beam Lithography)及極紫外光微影(EUV, Extreme Ultraviolet Lithography)是未來顯影技術研究的主流。 隨著半導體製程的發展，許多重要的固態元件得以將尺度縮小且提高效能，諸如：天線元件與近日炙手可熱的3-D元件 –多閘二極體（FIN-FET）等，以上元件皆需要極高精準度的顯影圖形品質才能確保天線陣列訊號的穩定性，與漏電流的產生；如何製作出精準而微小的奈米結構左右著整體元件的穩定性與效能。 本論文主要研究如何改善電子束微影中的鄰近效應。為了改善鄰近效應我們使用了計算機模擬光阻顯影的過程；有別於傳統方法-格點移除法（Cell-removal Method），一種透過反覆地進行嘗試錯誤法的方法；我們提出兩種假設，所有顯影路徑中必定存在一關鍵顯影路徑、將顯影路徑問題轉換成圖論問題，且利用粒子群智能式最佳化演算法（Particle Swarm Intelligence Optimism Method），是一種模仿群居動物行為趨近最佳結果的演算法最為最佳化策略，透過以上兩種假設加速演算流程。 本論文採用U型圖形的開口深度做為實驗的最佳化指標，製作出極為精準的U型結構，並將圖形誤差由51%降低到3%，有望能改善傳統U-shape split-ring resonator的功率與訊號品質等。

Lithography is the key technology in integrated circuits manufacturing process, and the improvement of it is the main reason that Moore's law can keep going. The rapid development of semiconductor industry and chips can become smaller and cheaper are closely related to the progress of lithography.For a long time, optical lithography is the mainstream in semiconductor industry, it is superior to other lithography method because of its mass production with high speed and low cost. However, with chips size become smaller and smaller optical lithography has reached its limit, it is necessary to investigate a new method for lithography, E-beam (Electron Beam Lithography) and EUV (Extreme Ultraviolet Lithography) are the main research direction lithography method in the future. As the development of semiconductor process, many important solid state device could be smaller and more efficient. For example: attena device and current trend of the 3-D device FIN-FET. All the device mentioned above need extremely high accurate and high developing quality to make sure that the stability of the attena array and avoid leakage current in the FIN-FET. The stability and efficiency depends on how to fabricate the pattern with high quality and extremely small size. In this thesis, we focus on how to improve the proximity effect in the e-beam lithography. We used the computer to simulate the developing process of the resist for improving proximity effect. The method we used is different from the traditional method including finding-all-possible method and cell-removal method, this two method take too much time because of the repeated trial-and-error process. we have proposed two hypothesis, one is there exists a critical path in developing environment, another one is we transform the developing path problem into a graph theory problem.Then we apply the particle swarm intelligence optimism which mimics the natural collective behavior of animals to reduce the computational cost. In this paper, we employ the depth of U-shape pattern to be a index of optimism level, and we have fabricated the U-shape structure with high quality and accuracy. It is helpful for improving the power and quality of signals U-shape split-ring resonator est.