本研究主要是利用奈米壓痕的技術測量矽單晶的機械性質並探討奈米壓痕荷載及加熱溫度對其巨觀機械性質與壓痕影響區微觀之影響，透過所發展之定位陣列技術，可快速、準確且有效率的來搜尋微小奈米壓痕，並利用聚焦離子束顯微鏡切割出穿透式電子顯微鏡之觀測試片。首先，本實驗利用半導體製程於 (100) 方向之矽單晶分別先加熱至250℃、350℃、450℃，並持溫2分鐘，再分別進行30mN、50 mN、70mN的荷載，接著對未加熱的矽單經分別進行30 mN、40 mN、70 mN，藉此比較未加熱及不同加熱條件下，其微觀組織之變化及壓痕影響區之奈米結晶結構(nano-crystalline)與完全非結晶型(amorphous)結構混合結構形成之特徵與機制。
巨觀機械性質的量測結果顯示，硬度(H)曲線與楊氏模數(E)曲線受壓痕尺寸效應、表面粗糙度(壓痕深度小於10 nm)所影響，楊氏模數約為178GPa，硬度值約為16GPa。從微觀結果顯示，矽單晶受奈米荷載及快速退火溫度之影響，造成壓痕器正下方之高應力塑性變形區的原子重新排列，單晶矽由原本的鑽石立方結構轉變為奈米結晶結構(nano-crystalline)與完全非結晶型(amorphous)結構混合結構。本研究發現，經過相同快速退火溫度後，荷載愈大時，壓痕影響區的底部產生愈多nano-crystalline與amorphous的混合結構；對未經過及經過250℃、350℃、450℃快速退火溫度後的矽單晶分別進行最大荷載為30 mN的奈米壓痕試驗，發現其壓痕影響區皆為amorphous結構；對未經過及經過250℃、350℃、450℃快速退火溫度後的矽單晶分別進行最大荷載為50 mN、70 mN的奈米壓痕試驗，發現其壓痕影響區為奈米結晶結構(nano-crystalline)與完全非結晶型(amorphous)結構混合結構，crystalline結構皆位在壓痕影響區底部，且隨著溫度的增加其分布的區域由底部逐漸往壓痕表面方向擴增。

The study investigates the nano-mechanical properties of single-crystal silicon using a nanoindentation technique. The indented position is accurately identified using a proprietary position array system, and TEM specimens are extracted by the focused ion beam microscope technique quickly. The effects of indentation load and the annealing temperature on the microstructural evolution are also evaluated. The single-crystal silicon is annealed at the temperature of 250℃, 350℃, 450℃ for 2 min respectively,and then indented to the maximum load of 30 mN, 50mN, 50mN respectively.
The overall tendencies of the hardness and Young’s modulus curves are governed by the indentation size effect and surface roughness for indentation depths of less than 10 nm, and by the substrate effect for indentation depths greater than 10% of the substrate. The hardness and Young’s modulus are measured about 16GPa and 178GPa respectively. The microstructural observations reveal that nanoindentation induces an atoms reorganization, and results in the formation of high-stress plastic deformation regions beneath the indenter. The microstructure of indentation affected zone of silicon substrate transfers from diamond cubic structure to mixed structure of nano-crystalline and amorphous.A complete amorphous phase within the indentation zone is produced at 30mN. However, in the specimens loaded at 40mN and 70mN, the microstructure of the indentation zone is characterized by a mixed structure comprising amorphous phase and nanocrystalline phase. The microstrucutral results also confirmed that the load-dependent nature of the unloading curves, namely pop-out events, is related to the different phase transformation mechanisms at various indentation loads.

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