散射式極紫外光光罩檢測系統設計及高解析度與高場強之極紫外光波帶片設計

Abstract

極紫外光微影術是下一世代微影製程的候選技術之一。然而，極紫外光微影在商業大量製造上還有許多障礙尚未克服，其中之一為無缺陷光罩的製造。在本文中，為了檢測光罩上缺陷的狀況，我們以同步輻射做為光源，建構了同調散射顯微鏡，並探討利用散射訊號重建光罩圖像的演算法。 在極紫外光波段中，菲涅耳波帶片為一重要之繞射聚光元件，其解析度與最外圈線寬大小相關，因此聚焦效果受到製程技術的限制。我們提出額外圈數的概念，克服最外圈受製程限制的影響，提升解析度。在本文中，我們在製程限制及極紫外光波段的情形下，利用菲涅耳－克希荷夫繞設公式探討改良式的菲涅耳波帶片。

Extreme ultraviolet (EUV) lithography is currently the leading next generation lithography candidate for high-volume manufacturing. However, several technical hurdles obstruct the commercialization of EUV lithography. One of the problems is the difficulty to fabricate the EUV masks free of printable defects. To inspect the defect profile, we construct a coherent scattering microscopy (CSM) using synchrotron source. Also, the algorithm which is used for the reconstruction of mask image is studied in this thesis. In EUV wavelength, Fresnel zone plate (FZP) is one of the most important diffractive optical elements for imaging and focusing. The resolution of FZP depends on the line width of outermost zone, that is, resolution is limited by the fabrication. We propose a concept of additional zones to overcome the limit of line width. The Modified FZP are discussed by Fresnel-Kirchhoff diffraction formula in EUV wavelength with the fabrication limit of line width.