- 學位論文
以奈米壓痕及有限元素法研究硒化鎵薄膜沉積於矽基板之機械性質與變形行為
A combined nanoindentation and finite element analysis for determining the mechanical properties of GaSe thin films
摘要
本研究利用奈米壓痕結合有限元素法探討硒化鎵薄膜之機械性質與變形行為。硒化鎵薄膜以脈衝雷射沉積於矽(111)基板上。透過奈米壓痕儀結合連續性勁度量測系統，量測出硒化鎵薄膜硬度與楊氏模數分別為2.8與93.5 GPa，並由顯微結構觀察到裂紋及隆起現象。藉由有限元素法探討壓痕實驗產生應力對薄膜與基板之影響。實驗結合模擬之結果表明：對硒化鎵薄膜下壓薄膜深度的30%時無基板效應產生，隨著下壓深度的增加，當達到下壓薄膜深度的60%時，應力開始對基板產生影響導致基板效應產生，第一點pop-in現象之最大剪切應力模擬結果為0.3 GPa與實驗值0.29 GPa接近，並透過等效應力分布結果證明Si-III相與Si-XII相之產生，說明硒化鎵奈米壓痕實驗成功與有限元素法結合。
並列摘要
The GaSe thin films were deposited on Si(111) substrates by pulsed laser deposition. The mechanical properties of gallium selenide thin films on Si(111) substrates were analyzed using nanoindentation. The hardness and Young's modulus of gallium selenide films are measured by Continuous Stiffness Measurement. The hardness and young’s modulus measured by the Berkovich nanoindenter are 2.8 GPa and 93.5 GPa, respectively. The cracks and plie-ups were observed from the scanning electron microscope microstructure. Investigate the effect of stress generated by indentation experiments on films and substrates by finite element method. The results of experiments combined with simulations show that. There is no substrate effect when the GaSe film is indentation to 30% of the film depth, which is consistent with the theoretical value. As the depth of depression increases. When reaching 60% of the depth of the film, the stress begins to affect the substrate, resulting in a substrate effect. The simulation result of the maximum shear stress of the pop-in phenomenon at the first point is 0.3 GPa, which is close to the experimental value of 0.29 GPa. And through the equivalent stress distribution results to prove the generation of Si-III phase and Si-XII phase. This shows that the nanoindentation experiment of GaSe was successfully combined with the finite element method.