以磁控濺鍍法研製鐵鈷鉿基之軟磁薄膜及其微結構與磁性質分析

Microstructure and Magnetic Properties of Fe-Co-Hf Based Soft Magnetic Thin Films Fabricated by Magnetron Sputtering for Radio-Frequency Applications

郭政倫(Cheng-Lun Kuo)

指導教授 ： 杜正恭

國立清華大學/工學院/材料科學工程學系/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00498

摘要

被動元件-電感，在整個電子元件的整合中，體積佔了很大的部份。如果以鐵磁薄膜來增加電感的磁通量，將能有效的增加電感的感值，進而縮小電感的尺寸。這將對3C產品的尺寸與重量縮減有助益。
本實驗選用成分為Fe–Co–Hf基的鐵磁薄膜作為研究的材料。以RF-磁控濺度系統在N2與Ar的氣氛下並藉著控制槍(gun)的位置可以成功鍍製出有鉿(Hf)濃度梯度的Fe–Co–Hf–N薄膜。利用此濃度梯度的濺射，增加薄膜的內應力，進而增加磁場的異向性，使此薄膜能具有更高的操作頻率。此外，在調變O2與Ar的氣氛下，鍍製出非晶相的Fe–Co–Hf–O磁性薄膜，再經由熱處理使之形成奈米晶與非晶的混合相，增加薄膜的電阻值，進而降低渦電流損耗。
此外，利用振動樣品磁力計(VSM)對薄膜作磁性質分析。在Fe–Co–Hf–N薄膜中，不同的鉿含量下，會有不同的磁性質表現。此薄膜磁具有高的磁場異向性(HK)約150 Oe與低的矯頑場(HC)約5 Oe。在高頻性質的表現上，其鐵磁共振頻率均超過3 GHz。另外， Fe–Co–Hf–O薄膜中，在成份Fe36.5Co17.2Hf9.8O36.5時，其飽和磁化量(MS)約為12 kG，矯頑場約0.8 Oe，且電阻值高達800 □□□cm，鐵磁共振頻率也能達到2.6 GHz。

關鍵字

鐵磁 ； 薄膜 ； 電感 ； 透磁率 ； 異向性

並列摘要

Soft magnetic thin films with high saturation magnetization and resistivity are of great interest in micro-inductor for the magnetic device application.
In this study, amorphous Fe–Co–Hf–N thin films with a gradient concentration of Hf doping were fabricated by rf reactive magnetron sputtering. The evaluated magnetic properties and high-frequency characteristics were sensitive to the doping contents. A new technology was used to deposit a series Fe–Co–Hf–N thin films on which gradient concentration of Hf was present. By this new deposition technology, the films existed residual stress, and thus the stress-induced anisotropy field was enhanced. The as-deposited films without post annealing exhibited larger anisotropy field (Hk) of 150 Oe. In addition, coercivity (HC) of less than 5 Oe in both easy and hard axes, and electrical resistivity (ρ) of 500 μΩ-cm were obtained.
In addition, nano-composite Fe–Co–Hf–O thin films were developed using dc reactive magnetron sputtering. The influence of oxygen content on the microstructure, high-frequency characteristics and magnetic properties was investigated. With the increase in oxygen content from 31 to 40 at%, the films exhibited high resistivity up to 2600 μΩ-cm. A minimum coercivity (HC) value of 0.8 Oe andρ= 800 μΩ-cm was obtained for the Fe36.5Co17.2Hf9.8O36.5 film with thickness around 1300 nm.
The high frequency behavior of Fe–Co–Hf based films was also evaluated. The permeability measurement showed a permeability of Fe–Co–Hf–N films around 100 at 3 GHz and a ferromagnetic resonance frequency (fFMR) in excess of 3 GHz. In addition, the ferromagnetic resonance frequency of Fe–Co–Hf–O film was as high as 2.6 GHz, implying a high cut-off frequency. It is expected that the Fe–Co–Hf based films should be promising for practical applications as a high-frequency ferromagnetic material.

並列關鍵字

HASH(0x1c20d8a0) ； HASH(0x1c20d940) ； HASH(0x1c20d9e0) ； HASH(0x1c20da80) ； HASH(0x1c20db20)

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