臺灣博碩士論文加值系統

本論文共分為兩個部分：第一部分為探討薄膜厚度對金屬有機裂解法(MOD)鉭酸鍶鉍 (SrBi2Ta2O9)鐵電薄膜微結構以及鐵電特性的影響。實驗後發現以RTA高溫退火處理SBT薄膜的鐵電特性明顯地會受薄膜厚度改變所影響。若薄膜厚度小於120nm厚，發現有fluorite中間相，且漏電流過大。而在某一厚度(165nm)具有會有比較好的顯微結構以及鐵電特性。當薄膜厚度增加到250nm厚，發現整體晶粒尺寸變小，導致SBT薄膜鐵電特性比較差。所以，在一定的RTA高溫退火處理下，SBT薄膜厚度太小或太大都會影響結晶特性及鐵電特性，只有在特定範圍的厚度才具有最佳的結果，
本文的第二個部分是改變SBT薄膜中鉭(Ta)成分比率來瞭解鉭成分對SBT薄膜的微結構與極化特性的影響。本實驗結果發現改變鉭成分比率會明顯影響之後微結構及鐵電特性的表現，當鉭成分比率較化學計量比低時，本實驗採用SrBi2Ta1.8O9，可以發現其大晶粒成核與成長較快，且經過RTA750℃60s的處理後，顯微結構幾乎由均勻大晶粒組成，具有很好的殘留極化值18.37μC/cm2。而當鉭成分比率較化學計量比高時，本實驗採用SrBi2Ta2.2O9，發現有fluorite中間相，且細小晶粒所佔體積百分比很高，導致鐵電特性明顯降低。由此結果，減少SBT薄膜鉭成分比率具有改善鐵電性質與提升殘留極化值的效益。

第一章 緒論…………………………………………………………….1
1-1 前言…………………………………………………………………1
1-2 研究方向...…………………….……………………………………2
第二章 文獻回顧……………………………………………………….3
2-1鐵電材料……………..……………………………………………...3
2-1-1 鐵電材料結構及特徵……………………………………………3
2-1-2 鐵電特性…………………………………………………………5
2-2 鐵電薄膜之發展與製程……………………………………………6
2-2-1　歷史…………………………………………………………..6
2-2-2薄膜的製程…………………….………………………………….7
2-2-2-1配方溶液的研製與調配……………………………………..7
2-2-2-1-1有機金屬裂解法(Metal-Organic Decomposition，MOD)..8
2-2-2-1-2有機金屬裂解法的基本原理……………………………...9
2-2-2-2薄膜披覆製程………………………………………………..9
2-2-2-3低溫焦化熱處理……………………………………………10
2-2-2-4高溫結晶與緻密化處理…………………………………….11
2-3 SBT鐵電薄膜之相變化…………………………………………...11
2-4 鐵電薄膜於記憶體元件上的應用………………………………..12
2-5 鐵電薄膜文獻中有關size effect的已有研究……………………15
第三章 實驗程序……………………………………………………….26
3-1 基板之準備………………………………………………………..26
3-1-1 擴散阻絕層及黏著層的製備…………………………………..26
3-1-2 白金底電極的製備……………………………………………..27
3-2 晶種層的製備………………………………………………..……28
3-3 SBT鐵電薄膜製備………………………………………….…......28
3-3-1 SBT溶液之TG/DTA分析………………………………………28
3-3-2以有機金屬裂解法製備SBT薄膜……………………………...29
3-4 薄膜性質之量測分析……………………………………….….....30
3-4-1 電性量測………………………………………………………..30
3-4-2 薄膜物性分析…………………………………………………..32
第四章 結果與討論…………………………………………………….40
4-1不同薄膜厚度對於以金屬有機裂解法製備之鉭酸鍶鉍薄膜鐵電性質的影響……………………………………………………...40
4-1-1 實驗流程………………………………………………………..40
4-1-2 不同薄膜厚度對於SBT薄膜結晶的影響………….…………41
4-1-3不同薄膜厚度對鉭酸鍶鉍薄膜表面及剖面形貌的影響……...42
4-1-4 鐵電特性……………………………………………….……….43
4-1-5漏電流特性…………………….……………………….………..44
4-1-6電容-電壓特性……………………………………….………….45
4-1-7結論……………………………………………….……………...45
4-2探討改變鉭(Ta)成分對SBT薄膜鐵電特性的影響…..….……….47
4-2-1 實驗流程………………………………………………………..48
4-2-2 SBT中不同Ta成分對於薄膜結晶的影響……………....…….49
4-2-3改變Ta成分對於SBT薄膜表面與剖面形貌的影響..………..49
4-2-4改變Ta成分對SBT薄膜鐵電特性的影響……………….……51
4-2-5漏電流分析……………………………………………….……..52
4-2-6電容對電壓分析…………………………………………….…..53
4-2-7 結論…………………………………………………………….53
第五章 結論…………………………………………………………...74
參考文獻…………………………………………………………..…...76

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