本論文揭示相位對比的來源與重要性，從電子顯微鏡的理論出發，假設透鏡之相差與成像原理。由於弱相位物的低影像對比，造成生物試片或是輕元素材料試片不易在穿透式電子顯微鏡下觀察，故發展靜電式相位板來改善影像上相位對比。此靜電式相位板由三層金屬層與兩層介電層所組成，經由外加電壓的控制，將於相位板內部形成均勻靜電場，並且改變穿透電子束的相位，進而提升影像上的對比，此相位板的結構相當於一個單透鏡。
所有關於靜電式相位板的參量，例如：靜電場的中電位分佈、電子束經相位板之軌跡、相位板所改變電子束的相位量、相位板孔徑尺寸的影響，以及相位板寬度所阻斷的頻率分量，在此論文中都有詳盡的理論與計算。同時利用原子力顯微鏡(AFM)來量測靜電場強度分佈，並與模擬的電場強度分佈作為比較，以證明靜電場分佈的真實性。由這些參量的計算來決定靜電式相位板的尺寸，以便於往後在微機電製程上作適當的評估與調整。最後，將展示相位板的裝載系統與其應用在穿透式電子顯微鏡JEOL2000FXII之情況，以及使用相位板之後的影像對應於外加電壓之變化。由此初步的結果，可以對未來發展相位對比顯微鏡與低頻區之相位回復提供一項嶄新的指標，同時影像對比的提升有助於生物與材料方面的研究。

This thesis examines the origin and the importance of phase in transmission electron microscopy. Because the low contrast of weak phase object, we develop the electrostatic phase plate to improve the phase contrast. The phase plate consists of three electrode layers and two dielectric layers, which forms a uniform electrostatic field and shifts the phase of electron beam. The structure of the phase plate is the same as an Einzel lens.
All the parameters of phase plate, such as electrostatic field distribution, electrons trajectory, phase change from phase plate, and the frequencies blocked by the ring, were calculated. The simulation of electrostatic field distribution is also compared to the results measured by Atomic Force Microscopy (AFM). With these parameters, the profile of the phase plate can be determined, and the factors for fabrication are easily controlled. At last, the images taken after using a phase plate are shown and key points and suggestions are given.

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