- 學位論文
赭尼客式靜電式相位板之製造及其於相位穿透式電子顯微鏡之應用
The Fabrication of the Zernike Electrostatic Phase Plate and its application on the Phase TEM
摘要
穿透式電子顯微鏡是分析試片內部結構的強力工具。但對於主要由輕元素，如碳、氮、氧組成的生物樣本或對於半導體中佈植了與基材原子量相近元素的佈植層，其過弱的影像對比使得試片無法被精確分析。 穿透式電子顯微鏡的影像對比來自於電子束的強度和穿透電子束及繞射電子束的相位差。赭尼客式靜電式相位板是一個在穿透式電子顯微鏡中改變穿透電子束及繞射電子束的相位差的新元件。赭尼客式相位差是增加影像對比最有效率的方法，且不降低解析度。 赭尼客式靜電式相位板的主體結構是一個五層的環狀結構—三層電極，兩層介電層各夾在每兩層電極中間。中間電極被施加一偏壓，而頂部及底部電極接地。如此一來，在相位板的環狀結構中間的圓柱形成一個靜電場，相當於一個靜電透鏡。當未被繞射的穿透束通過此靜電場，其相位被改變。 本論文中利微機電技術製造赭尼客式靜電式相位板，以完成微米尺寸等級的相位板設計之製程。及討論利用赭尼客式靜電式相位板所增加相位對比的穿透束電子顯微鏡相位對比影像。
並列摘要
Abstract Transmission Electron Microscopy (TEM) is a powerful tool to analyze the inner structure of the specimen. However, for the biological samples which mainly compose of low atomic number elements such as C, N and O or for the doping layer a the semiconductor which has doped elements of atomic numbers close to the matrix, the contrast of the image is too poor to analyze precisely. The contrast of TEM images come from the intensity of the electron beams and the phase difference between the direct and scattered electron wave. The Zernike Electrostatic Phase Plate (ZEPP) is a novel device in TEM altering the phase shift between the direct electron wave and the scattered electron wave to obtain Zernike phase contrast. The Zernike phase contrast is the most effective way to increase the image contrast without loss of resolution. The main structure of a ZEPP is a 5-layer ring shape structure—3 layers of electrode and 2 dielectric layers between each electrode. A voltage is applied to the middle electrode and the top and bottom electrodes are grounded. In this way an electrostatic field is constructed in the inner cylinder of the phase plate ring structure and is effective as an electrostatic lens. As the direct electron wave passes through the electrostatic field, its phase is shifted. The ZEPP is fabricated by Micro-Electro Mechanical System (MEMs) techniques for it is able to handle the micro-meter scale dimension design of the phase plate.