本文主要建立二維有限元素分析模型，模擬雷射輔助式奈米壓印過程中，雷射照射於矽底材使之熔融並因為預施壓力使矽底材與石英模具接觸產生變形。在此二維耦合溫度-位移之模型中，雷射照射於矽底材使矽底材熔融後，我們針對液態矽及固態矽分別計算其吸收之熱源大小，利用自設副程式將熱源與分析模型結合。同時以雙層黏塑材料模型描述矽底材在高溫及熔融後之黏滯性質。利用此數值模型，可探討石英模具對熱傳導行為及熔融情形的影響；模型中分別利用體熱通量與表面熱通量來設定熱源，並探討此兩種設定情形對模擬溫度場變化及壓印過程之影響。本文之數值模擬結果可作為實驗結果之比對，亦可提供將來實驗參數設定之參考。

We developed a two-dimensional finite element model to simulate the melt of silicon substrate caused by the excimer laser, and the deformation of molten silicon due to the contact between the pre-loaded quartz mold and silicon in Laser-Assisted Direct Imprinting (LADI) process. In this two-dimensional coupled temperature-displacement model, we calculate the heat source absorbed by solid silicon and liquid silicon after the melting of silicon substrate caused by irradiation of the excimer laser. A user subroutine was used to incorporate the heat source into the model. A two-layer viscoplasticity model was used to describe the viscosity of silicon at the high temperature and at the molten state. Using this model, the effects of quartz mold on the transient process of heat transfer and molten depth were studied. The heat source provided by the excimer laser was incorporated through the body heat flux and surface heat flux respectively into the FEM model, and the effects of these two types of heat source on the temperature filed and deformation during LADI process were studied. The results of our simulation can be used to compare with the experimental results, and provide more information for better parameter setting in experiments.

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