添加物對鈦酸鍶鋇薄膜特性之影響

Effect of Dopants on the Properties of (Ba,Sr)TiO3 Thin Films

粘斯韋(Siu-Wen Nien)

指導教授 ： 王宏文

中原大學/理學院/化學研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200270

摘要

本研究利用金屬有機分解法 (MOD) 在Pt/Ti/SiO2/Si 基板上製備 (Ba0.7Sr0.3)TiO3 薄膜，並添加 金 及共添加物 鎂-鑭 、鎂-鈮 ，最後利用 XRD 、SEM 、TEM 研究添加物對薄膜顯微結構的影響﹔再利用 LCR meter 及 HP4155C 來量測介電常數、漏電流，如此便可確知添加物對 BST 薄膜電性的影響。
實驗發現隨著金的添加量增加其晶粒變小 , 並有助於 BST 薄膜的成相，並使其起始結晶溫度降低至570℃。
在電性方面的研究︰單一添加物(金)的添加會使介電常數及漏電流都隨著金的添加量增加而降低。但在低溫退火（570℃、600℃）時 , 介電常數則隨著Au的添加量增加而微幅增加 , 因為在低溫時添加Au有幫助BST薄膜結晶的效果 , 故其介電常數隨之增加。
在共添加系列( 鎂-鑭 、鎂-鈮 ) 中，漏電流同樣也隨著添加量增加而降低，在鎂=5 mol% ，鑭(或鈮) =10 mol%時，漏電流降到最低點，但在隨著添加量繼續增加時，漏電流反而又再上升。

關鍵字

添加物 ； 鈦酸鍶鋇 ； 薄膜

並列摘要

In this study, (Ba0.7Sr0.3)TiO3 thin films added with Au particles were prepared on Pt/Ti/SiO2/Si substrate by metal-organic deposition methods (MOD). Mg-La, Mg-Nb co-doped BST films were also investigated in this work. XRD, SEM, and TEM were used to characterize the effects of dopants on microstructures of the thin films. LCR meter and HP4155C measured the dielectric constant and leakage current of the films.
Additions of gold to the BST films enhance crystallization and to lower crystal temperature to 570℃.
Regarding electric properties, it was found that both dielecric constant and leakage current decreased while doping levels of single dopant (Au) increased. On the other hand, for Mg-La/Mg-Nb co-doped BST films, even though the dielectric constant also decreased with increasing the doping levels, the leakage current reversed. A minimum of the leakage current occurred at Mg=5 mol%, La(Nb)=10 mol%, above that the leakage current would increase with higher doping levels.

並列關鍵字

BST ； Dopant ； thin films

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