鈷60鐵20硼20之晶粒尺寸對於奈米壓痕性質的影響

Effect of grain size on nano-indentation property of Co60Fe20B20 thin film

吳佳紋(Chai-Wen Wu)

指導教授 ： 陳元宗

義守大學/理工學院/材料科學與工程學系/碩士(2014年)

https://doi.org/10.6343/ISU.2014.00047

摘要

本實驗主要研究鈷鐵硼的奈米機械性質與其晶粒尺寸的效應。將鈷鐵硼薄膜濺鍍於玻璃基板上，其厚度分別為1000 Å、2000 Å、3000 Å、4000 Å與5000 Å，而以下有四種濺鍍溫度條件：(1) 濺鍍溫度為室溫、(2) 熱處理150 ˚C，持溫1個小時、(3) 熱處理250 ˚C，持溫1個小時、(4) 熱處理350 ˚C，持溫1個小時。首先，我們利用高解析穿透式電子顯微鏡 (High-resolution Transmission Electron Microscope, HRTEM) 觀察鈷鐵硼薄膜的晶粒分布狀態，並且利用軟體圈選計算平均晶粒尺寸，再利用擇區繞射 (Selected-Area-Diffraction, SAD) 功能觀察鈷鐵硼薄膜具有體心立方 (Body-centered cubic, BCC) 奈米鈷鐵硼結晶結構且具有明顯的鈷鐵硼 (110) 方向的結晶。根據平均晶粒尺寸的結果發現，熱處理溫度越高，鈷鐵硼的晶粒尺寸會變大，且隨著鈷鐵硼薄膜的厚度增厚，平均晶粒尺寸也會隨之增加。再利用奈米壓痕測量鈷鐵硼薄膜的硬度與楊式模數。根據晶粒尺寸與奈米壓痕的量測結果顯示，硬度與楊式模數會因較小晶粒尺寸的關係而增加，這結果是符合 Hall-petch 理論。利用掃描式電子顯微鏡 (Scanning Electron Microscope, SEM) 觀察鈷鐵硼薄膜表面的奈米壓痕微結構，結果發現經熱處理後的鈷鐵硼薄膜在奈米壓痕量測後的壓痕面積會變大，這結果也與先前的硬度與楊式模數的結果符合。

關鍵字

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並列摘要

This study investigates the nano-mechanical properties of Co60Fe20B20 thin films and the effect of the size of the grains on them. These films were sputtered onto glass substrates to thicknesses from 1000 Å to 5000 Å under the following conditions: (a) substrate temperature maintained at RT, (b) post-annealing at a treatment temperature of 150 ˚C for 1 h, (c) post-annealing at a treatment temperature of 250 ˚C for 1 h, and (d) post-annealing at a treatment temperature of 350 ˚C for 1 h. A plane-view image was captured under a high-resolution transmission electron microscope (HRTEM) to determine the distribution of grains. The selected-area-diffraction (SAD) pattern was obtained using HRTEM. The electron diffraction pattern revealed that the CoFeB thin film had a nano-crystallization body-centered cubic (BCC) CoFeB structure and strong CoFeB (110) crystallization. A higher annealing temperature resulted in a larger grain. The average grain size increased with the thickness of the CoFeB thin film. The hardness and Young’s modulus were obtained using nano-indentation. Results concerning the grain size and the nano-indentation measurement an increase in hardness and Young’s modulus are reasonably inferred from a smaller grain size, consistent with the ‘‘Hall-Petch’’ effect. The nano-indentation microstructure was obtained by scanning electron microscopy (SEM). Annealing increased the area of the nano-indentation triangle. This result is consistent with the results concerning hardness and Young’s modulus. The nanomechanical properties of the post-annealed CoFeB thin film are worse than those of the as-deposited film.

並列關鍵字

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參考文獻

[33]. 奈米科技研發中心，國立中山大學。

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