脈衝雷射鍍膜法製備鐵電薄膜之研究

Abstract

本論文主要採用脈衝雷射鍍膜法來製備各種鐵電薄膜，其中包括鈣鈦礦結 構的鈦酸鋇及鋯鈦酸鑭鉛，與鎢青銅結構的鈮酸鍶鋇。藉由氧化鈰與釔鋇 銅氧高溫超導薄膜當緩衝層，鐵電薄膜可以成功的製備在矽單晶基板上， 且具有方向的優選性及極佳的殘餘極化值，可配合半導體製程應用於鐵電 記憶體，成為新一代不怕斷電的記憶體。磊晶的鈦酸鋇、PLZT 及 SBN 薄 膜可成功的備製在鈦酸鍶與氧化鎂單晶上。其相關晶粒沿垂直薄膜方向與 沿薄膜平行方向的排列特性可由Ｘ射線繞射技術檢測驗證，且其極佳的薄 膜晶體結構特性亦可由X 射線繞射技術的搖擺角度加以驗證。CeO2薄膜在 本實驗中被用來當作緩衝層，以避免鈦酸鋇與矽單晶起反應，並經由SIMS 縱深測試檢測驗證。具Ｃ軸優選性的YBCO薄膜被選來當緩衝層，不祇是被 用來增強上層鈣鈦礦結構的鈦酸鋇、PLZT與正方晶鎢青銅結構的SBN 的形 成，同時它還可被用來當作電性測試的底電極。 This dissertation presents a systematic approach to reach the optimization deposition conditions to deposit ferroelectric thin films on Si substrates, through the use of CeO[2] and YBa[2 ]Cu[3]O[7] buffer layers. Perovskite BaTiO[3] and Pb[0.97 ]La[0.03](Zr[0.54]Ti[0.46])O[3], and quaternary tungsten- bronze Sr[0.5]Ba[0.5]Nb[2]O[6] have been deposited successfully as epitaxy-like films. Together with their high remanent polarization value on silicon substrates and semiconductor process technique, they can be used as Non-volatile random access memory NVRAM. This new devices will let our data remain exist through the electrical power went off accidentally. We believe they will be the new generation of RAM.