軟磁鐵鈷鉿氧/氧化鋁多層膜與鐵鉿氮薄膜之開發及其磁性質對功率電感特性之影響

Soft magnetic FeCoHfO/AlOx multilayers and FeHfN thin films for applications in power inductors

郭于銘(Yu-Ming 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/博士(2011年)

https://doi.org/10.6843/NTHU.2011.00090

摘要

隨著無線通訊與可攜式產品之微型化，傳統的電感元件已無法滿足微小化的需求。為了縮小電感尺寸並提升直流-直流轉換器之轉換效率，需利用高的感值與飽和電流來達成此一目標。因此本研究藉由高導磁率鐵磁薄膜來提升功率電感之感值與飽和電流。
本研究運用dc-反應磁控濺鍍鍍製FeCoHfO/AlOx多層膜與FeHfN薄膜。在FeCoHfO/AlOx系統中，由於AlOx的置入提高了多層膜之導磁率進而提升功率電感的感值。此外FeHfN薄膜中，N2流量的增加會造成FeHfN薄膜從非晶相轉變成結晶相，因而影響FeHfN薄膜本身之磁特性與導磁率。在N2流量為1.2 sccm時，具有較高的導磁率(μ’ > 600 在100 MHz)。將此FeHfN薄膜與功率電感整合後，感值大幅提升將近13 %，飽和電流有超過2 A的表現。
為了進一步與直流-直流轉換器整合，因而挑選較高導磁率之FeHfN薄膜與功率電感結合。整合後高感值及高飽和電流之表現有效的抑制電流漣波，並提升直流-直流轉換器之轉換效率。因此FeHfN薄膜在電感與直流-直流轉換器之微型化應用上具有相當的潛力，可望被廣泛運用。

關鍵字

多層膜 ； 磁異向性場 ； 微結構 ； 導磁率 ； 電感值 ； 飽和電流 ； 電流漣波 ； 直流-直流轉換器

並列摘要

Driven by the modern trend for miniaturization of the wireless communication and portable products, conventional inductors fail to fulfill the requirement. In order to miniaturize the dimension of power inductors and to increase conversion efficiency of DC-DC converters, high inductance and saturation current are necessary. Hence, it is crucial to employ high-permeability films to enhance the inductance and saturation current of power inductors.
In this study, FeCoHfO/AlOx multilayers and FeHfN films were fabricated by dc reactive magnetron co-sputtering. Inserting the AlOx layers increases the permeability of the multilayers, which is beneficial to raise the inductance nearly 5 %. In addition, increasing N2 flow alters the structure of FeHfN films from amorphous-like to crystalline phases, affecting magnetic properties and permeability. With the optimum N2 flow of 1.2 sccm, high permeability (μ’ > 600 at 50 MHz) was obtained. The inductance and saturation current made of FeHfN films were greatly enhanced around 13 % and exceeded 2 A, respectively.
To further integrate into DC-DC converters, FeHfN films were selected alongside with the power inductors. After integration, the higher inductance and saturation current efficiently suppresses the current ripple and enhanced the conversion efficiency of DC-DC converters. Therefore, the FeHfN films are promising for miniaturization of the inductors and DC-DC converters.

並列關鍵字

Multilayers ； Anisotropy ； Microstructure ； Permeability ； Inductance ； Saturation current ； Current ripple ； DC-DC converter

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