應用於高頻螺旋型電感性能增益之陽極氧化鋁/四氧化三鐵奈米複合薄膜製程技術開發

Abstract

在此篇論文中，我們研究以四氧化三鐵-陽極氧化鋁奈米複合薄膜於高頻平面螺旋型電感應用的可行性，希冀透過增加空間中的相對磁導率且提升電感值，以達到無線通訊應用中晶片面積微小化的目標。奈米複合薄膜之合成是利用磁吸引的方式，將四氧化三鐵奈米粒子填入直徑為 200 奈米、厚度為 60 微米的奈米陽極氧化鋁濾膜之中。而奈米化的四氧化三鐵粒子，因其超順磁與低導電率之特性，除了可以有效降低電感在高頻操作時產生在磁性材料中的渦電流損耗與磁滯損耗之外，更可以利用奈米陽極氧化鋁濾膜之高深寬比的特徵，將重組後之四氧化三鐵薄膜產生較佳之磁性異相性，以提升其鐵磁共振頻率，並增益電感在高頻之感值表現。在本研究中，除開發奈米複合薄膜之合成製程外，也導入高頻平面螺旋型電感結構，並且量測該電感之高頻特性。研究發現三圈半之平面螺旋型電感在分別在有無加入磁性複合薄膜情況比較下，約有 11.4 % 的增加且感值增益持續到達 7.3 GHz 為止。而四圈半之電感在分別在有無加入磁性複合薄膜情況比較下，約有 10.8 % 的增加且感值增益持續到達 5.9 GHz 為止。而最大品質因子在2.5 GHz時，分別為26.6和25.4。此外，因奈米磁性粒子於磁場作用下，由鬆弛機制所造成之熱損耗使得電感品質因子並無明顯增益。

In this thesis, the feasibility study on the size reduction and cost down of wireless communication applications via increasing the relative permeability in space and inductance enhancement of aluminum anodic oxide(AAO)-Fe3O4 nanocomposite thin film is proposed. The synthesis of nanocomposite thin film was accomplished by magnetic attraction method. The Fe3O4 nanoparticles were filled and isolated into AAO thin film with diameter of 200 nm and thickness of 60 μm. The Fe3O4 nanoparticles have superparamagnetic and low conductivity characteristics that can effective reduce the magnetic loss when applied them at high frequency. Besides, AAO thin film has high aspect ratio characteristic, the Fe3O4 nanoparticles filled into it can have higher anisotropy magnetic field, which can promote the ferromagnetic resonance (FMR) frequency and enhance the performance of inductors. In the experiment, we also present the fully CMOS compatible RF on-chip spiral inductors with AAO-Fe3O4 nanocomposite thin film and characterized them from 0.1 GHz to 20 GHz. Experimental results show that the 3.5 and 4.5-turns spiral inductors with AAO-Fe3O4 nanocomposite thin film can have 11.4% and 10.8% inductance (L) enhancement than that of inductors without the Fe3O4 nanoparticles at 1.4 GHz, respectively. Meanwhile, the operation frequency of 3.5 and 4.5-turns spiral inductor is up to 7.3 GHz and 5.9 GHz, and the quality factor (Q) is 26.6 and 25.4 at 2.5 GHz, respectively.