Ru中間層與Cu底層對Co80Pt20合金薄膜之顯微結構與磁性質研究

Investigating the influence of Ru intermediate layer and Cu underlayer on the microstructures and magnetic properties of Co80Pt20 alloy thin film

王健名(Chien-Ming Wang)

指導教授 ： 郭博成

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10879

摘要

本研究在常溫下利用dc磁控濺鍍沈積具有顆粒狀奈米晶之Co80Pt20(50nm)薄膜於Ru(30nm)/Cu(100nm)/Glass基板上，初鍍薄膜之垂直方向頑磁力Hc⊥值高達5460 Oe且垂直方向角型比S⊥可達0.85。研究發現，若直接將Co80Pt20薄膜成長於未引入Cu底層之Ru(30nm)/glass基板上，薄膜會呈現水平磁異向性，其水平方向頑磁力Hc//值僅1560 Oe。這是因為FCC Cu(111)底層可以促進HCP Ru(0002)中間層之磊晶成長，進而誘發HCP Co80Pt20磁性層之(0002)從優取向，使整體薄膜呈現垂直磁異向性及高垂直硬磁性質。橫截面TEM影像顯示，Co80Pt20磁性層呈現奈米晶柱狀結構，平均柱寬約為10 nm，此與平面TEM影像所觀察之晶粒大小大致吻合。
進一步將Co80Pt20/Ru/Cu/Glass 多層膜置於1 mTorr的真空度下施以300℃低溫退火30分鐘後，薄膜之垂直方向頑磁力Hc⊥及垂直方向角型比S⊥可進一步提升至6980 Oe及0.88，這些性質具備應用於超高密度垂直磁記錄媒體(PMR)的潛力。

關鍵字

Cu底層 ； Ru中間層 ； Co-rich Co-Pt合金薄膜 ； 垂直磁異向性 ； 奈米柱狀晶 ； 退火

並列摘要

Granular Co80Pt20 nano-grains with perpendicular coercivity of 5460 Oe and perpendicular squareness of 0.85 has been successfully prepared by dc sputtering Co80Pt20 (50nm) film onto Ru(30nm)/Cu(100nm)/Glass substrate at ambient temperature. The Co80Pt20 film deposited directly onto Ru layer in the absence of a Cu underlayer exhibits an in-plane magnetic anisotropy with a low in-plane coercivity of 1560 Oe. This is because a fcc Cu (111) underlayer can promote hcp Ru (0002) seed layer to help induce (002) texture in hcp Co80Pt20 magnetic layer, leading to good perpendicular magnetic anisotropy and high perpendicular hard magnetic properties of the Co80Pt20 films. TEM cross-sectional images show that the columnar nano-grains with average width of 10 nm are observed in Co80Pt20 magnetic layer, which is consistent with the observation of TEM plane-view images.
When post-annealed the Co80Pt20/Ru/Cu/Glass multi-layer films in a vacuum of 1 mTorr at a lower temperature of 300°C for 30 min, both the perpendicular coercivity and perpendicular squareness of the film can be further increased to 6980 Oe and 0.88 respectively. The film may serve as an excellent candidate for perpendicular magnetic recording (PMR) media.

並列關鍵字

Cu underlayer ； Ru intermediate layer ； Co-rich Co-Pt alloy thin film ； perpendicular magnetic anisotropy ； annealing

參考文獻

參考文獻

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