當矽受到高壓(11~12 GPa)時，會由一大氣壓下穩定的鑽石結構，相變化為具有白錫(β-tin)結構且為金屬性的矽第二相(Si-II)。當壓力釋放後，隨著壓力卸載的速率不同，轉變成介穩定態的半金屬矽第三相(Si-III)、半導體性的矽第十二相(Si-XII)與非晶質相(amorphous)，而對於矽高壓相變化的研究數據，大部分是巨觀下（X-ray繞射分析、拉曼光譜等等）量測的結果，對於在奈米區域下相變化的實驗結果仍不多。
本實驗利用導電性原子力顯微術(CAFM)研究矽在奈米壓痕後所產生高導電性第三相的特性。在荷重3~90 mN之間，荷重-位移曲線具有因為第三、十二相出現時體積膨脹所造成不連續現象，與文獻結果符合。從表面形貌與電流影像中，顯示壓痕內有任意分佈的高電流區域，大小約數十至數百 nm。從定點量測高電流區域的電流-電壓曲線，以Fowler-Nordheim穿隧電流理論分析，得到第三相與氧化矽之接面能障為0.39 eV，推算其功函數為1.51 eV。

At atmospheric pressure, semiconductor silicon (Si-I) has the stable diamond structure. Under hydrostatic pressures of 11~12 GPa, the Si-I phase undergoes a phase transformation to the phase, which has a β-tin structure. During the release of pressure, metastable phases semi-metallic Si-III, semiconductive Si-XII and amorphous silicon are produced from Si-II at different unloading rates. Although most experimental results reveal various properties of phases, less informations about the nanoscale properties have been explored.
In the experiment, conducting atomic force microscopy is used to study the high conductivity Si-III phase under nanoindentation. With loading forces of 3~90 mN, discontinuities in the load-displacement curves are observed, which are caused by the volume expansion effect when the Si-III and Si-XII phases are produced. In the simultaneously obtained topography and current images, high current regions are found to be randomly distributed in the indented region. These regions have sizes ranging from several tens to several hundreds of nm with a smallest diameter of around 25 nm. Current-voltage curves in the high current site have also been measured and fitted with Fowler-Nordheim equation. Barrier height between Si-III and SiO2 and work function of Si-III were determined to be 0.39 and 1.51 eV, respectively.

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