本研究設計的多片環形背向散射電子偵檢器，只需收集背向散射電子，即可顯示試片的原子序對比以及表面形貌分辨率。相較於典型的多片扇形背向散射電子偵檢器，具有更好的原子序敏感度以及表面形貌對比。多片環形背向散射電子偵檢器考慮入射電子束與不同的試片傾斜角度，產生不同的背向散射電子的角度分佈，設計了多片環形的空乏區，使多片環形背向散射電子偵檢器可收集不同分佈角度的背向散射電子，故可提升表面形貌對比。

The multi-annular backscattered electron detector (BSED) proposed in this thesis has been evolved so that collecting BSEs is already adequate for the display of Z-contrast as well as surface topography. Compared with the traditional multi-fan shaped BSED, the BSED proposed in this thesis can provide higher sensitivity of Z-contrast and better surface topography contrast. With the consideration that different angular distribution of BSEs can be resulted from different tilt angles between the BSEs and specimens, a multi-annular BSED has been proposed in this thesis. Benefited by this structure, BSEs from different angular distribution can also be collected, improving the quality of the surface topography contrast.