顯微鏡之功能開發與教學演示

Abstract

在本實驗室成功開發了研究版掃描穿隧式電子顯微鏡，配備自動進針功能且得到了高品質的奈米級解析度地貌後，希望進一步的開發奈米材料的量測功能以及在不同環境下掃描的功能。首先在掃描環境部分，突破了原本只能在大氣下掃描的限制，開發液態下掃描的功能，能在液體當中進行表面的量測或地貌的改造。另外，也藉由控制探針與樣品間的偏壓，成功地改變樣品地貌，達到奈米書寫的目的。最後開發量測不同電壓下的穿隧電流值的功能，來測量樣品穿隧能譜。此外也透過結構上的改良以及材料的改變，針對步進器做了效能上的優化，讓步進器更輕便及更好校正。掃描器方面也新增了大範圍模式以及高解析度模式。 為了解決低電壓掃描器掃描範圍不足的情形，以及為了日後跨足原子力顯微鏡需要的更大掃描範圍做準備，本實驗室利用層疊式結構設計了新型的低電壓大範圍掃描器，在十伏特的低電壓驅動下，達到大於15微米的掃描範圍，相較於傳統的掃描器掃描範圍增加了四倍，且在增加掃描範圍的情形下，維持高結構穩定度以及高解析度的表現。 為了演示穿透式電子顯微鏡(TEM)的運作原理，本實驗室致力於開發TEM模擬器，藉由雷射光束取代穿透式電子顯微鏡中的電子束，配合二維晶格樣品，在不同的透鏡組合之下分別得到了晶格樣品的實空間放大圖形以及繞設圖形，成功演示穿透式電子顯微鏡的運作原理。

We developed a portable scanning tunneling microscope (STM) equipped with a stepper. The tip can automatically approach the sample surface and the microscope can describe the morphology of nanomaterials with a high spatial resolution in ambient conditions. In this work, we improved the STM to be operated under different environments and we developed several new functions to detect characteristics of samples. We designed a liquid cell and fabricated a tip coated with a thin insulator so we could scan images in liquid. Further, the lithography function is introduced by applying high voltage pulses, thus we can deposit nanostructures on sample surfaces. Moreover, we developed an additional function of scanning tunneling spectroscopy. To enlarge the scanning area, we designed a new scanner which is driven by 10 volt. The scanning range of the scanner is up to 15 micrometers which is 4 times larger in comparison with previous designs, while maintaining the same spatial resolution. On the other hand, we developed a TEM simulator. We use the laser to simulate the electron beam of TEM. We can obtain real diffraction images of crystalline samples. The simulator can demonstrate the operation mechanism of a TEM machine.