本論文目標是在矽基板上以射頻磁控濺鍍法製備鐵電性質良好的鐵酸鉍(BiFeO3)薄膜，為了量測鐵酸鉍薄膜的鐵電性質，需要在矽基板和鐵酸鉍之間鍍上一層底電極，然而，矽基板在空氣中表面常會自然形成非晶二氧化矽，造成底電極不易沉積在矽基板上，因此，有時候會需要在矽基板和底電極之間再成長一層緩衝層(Buffer layers)幫助薄膜成長。綜合上述，本實驗根據文獻找到三種不同的緩衝層，並分別濺鍍於矽基板上。首先是以金屬鈦靶材通入氮氣進行反應濺鍍合成出氮化鈦(TiN)薄膜，XRD分析結果可以觀察到TiN有(200)擇優取向，並且以四點探針量測，其電阻率為4.05*10-5 Ω·cm，擁有非常好的導電性，可以作為底電極兼緩衝層；接下來找到另一個金屬氧化物材料鎳酸鑭(LaNiO3)，LaNiO3(~3.84Å)與BiFeO3(~3.96Å)晶格匹配度很高，且LaNiO3製程完後在氧氣環境下退火，其電阻率為6.00*10-4 Ω·cm，也很適合當作底電極以及緩衝層；最後是用金屬鋱靶材以1.4 nm/min鍍率沉積出具有(222)擇優取向的氧化鋱(Tb2O3)薄膜，其表面非常平坦，Ra值為0.83 nm，Rq值為1.06 nm，而氧化鋱本身不導電，若要使用需要在上方再鍍一層底電極，但是它在矽基板上很好成長且有優異的取向，作為緩衝層還是非常有潛力的。三種緩衝層中，於LaNiO3/Si(100)基板上成長的BiFeO3薄膜，經過調控濺鍍參數，在成長溫度700℃、BiFeO3靶材功率100 W、氧分壓1.2 mTorr時有好的鐵電性質，有98 μC/cm2的殘餘極化量和475 kV/cm的矯頑電場。此外還嘗試在量測電滯曲線時，將BiFeO3/LaNiO3/Si(100)薄膜上的頂電極白金(Pt)換成鍍黃金(Au)，可以得到最良好的鐵電性質，有131 μC/cm2的殘餘極化量和528 kV/cm的矯頑電場。

The aim of this paper is to fabricate high quality BiFeO3 (BFO) thin films with excellent ferroelectric properties on silicon substrates using radio frequency magnetron sputtering. However, amorphous silicon dioxide is often formed on the surface of the silicon substrate in air, making it difficult for the bottom electrode to be deposited on the silicon substrate. Therefore, sometimes it is necessary to grow a buffer layer between the silicon substrate and the bottom electrode to help the film grow. Based on the above, this experiment found three different buffer layers according to the literature, and sputtered them on the silicon substrate respectively. Firstly, TiN thin films were synthesized by sputtering using a titanium metal target and nitrogen gas. X-ray diffraction analysis showed a (200) preferred orientation for TiN, and four-point probe measurements revealed a resistivity of 4.05*10-5 Ω·cm, indicating excellent conductivity, making it suitable as a buffer layer and bottom electrode. Secondly metal oxide material, LaNiO3 (LNO), was found to have a high lattice matching with BFO (LNO ~ 3.84 Å, BFO ~ 3.96 Å), and its resistivity is 6.00*10-4 Ω·cm, which is also suitable as the bottom electrode and buffer layer. Finally, Tb2O3 thin films with a (222) preferred orientation were deposited using a terbium metal target at a deposition rate of 1.4 nm/min. The Tb2O3 film exhibited a very flat surface with an Ra value of 0.83 nm and Rq value of 1.06 nm. However, it is not conductive by itself , and if it is to be used, a bottom electrode needs to be deposited on top of it. Nevertheless, it grows well on the silicon substrate and has an unique orientation, so it still has great potential as a buffer layer. The BFO thin film grown on the LNO/Si(100) substrate demonstrated good ferroelectric properties, with a remnant polarization of 98 μC/cm2 and coercive field of 475 kV/cm. Additionally, when the platinum top electrode was replaced by gold, best ferroelectric properties were observed, with a remnant polarization of 131 μC/cm2 and coercive field of 528 kV/cm.

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