在本論文中, 我們成功地利用原子層沉積系統(ALD)成長之氧化鋁薄膜作為介電層(Insulator)應用於非揮發性電阻式記憶體(RRAM)中，在鍍製氧化鋁薄膜時採用TMA(Trimethylaluminum)作為鋁的前驅物(precursor)及H2O作為反應時的氧化劑來提供氧原子來反應，接著分別以鈦金屬以及鉑金屬分別作為上、下電極，其結構為鉑-氧化鋁薄膜-鈦三層結構。藉由外部提供電場，使得記憶體可在高阻態、低阻態間來回切換，其高阻態、低阻態的電流值可經由一個較小的讀取電壓得知。
本論文中所製作之氧化鋁薄膜記憶體具有相當大的開關電流比值(on/off ratio>103)，在高阻態、低阻態之電流值分別都可以保持長時間的穩定性(retention>104秒)，並且有超過10次以上的開關切換次數。一般電阻式記憶體的開關特性可以用燈絲傳導機制(Filamentary conduction theory)來解釋，當絕緣層與金屬電極為歐姆接觸時，一般在其高阻態、低阻態之導通機制分別為空間電荷侷限電流(Space charge limit current)理論及歐姆定律。
氧化鋁為high k材料，擁有高介電常數(k=10)，大的電子能隙(9 eV)，高崩潰電場(5-10 MV cm-1)以及良好的熱和化學穩定性等等。因此，在氧化鋁薄膜中，當氧離子藉由外部電場的影響而遷移到上電極，其所留下的氧空缺(oxygen vacancy)形成之燈絲導通路徑可作為電子的穩定傳導路線，所以氧化鋁及許多其他二元金屬氧化物薄膜很適合作為電阻式記憶體之介電層。

In this thesis, aluminum oxide thin film, deposited by an atomic layer deposition (ALD) system, is utilized as the dielectric film for the fabrication of resistive random access memory (RRAM) with a titanium (Ti) layer as the top electrodes and platinum (Pt) as the bottom electrodes. The RRAM with a metal-insulator-metal (MIM) structure of Ti/Al2O3/Pt is switched between the high resistance state (HRS; OFF state) and its low resistance state (LRS; ON state) by the external electrical stimulation. The HRS or LRS are probed by applying a low applied voltage across two counter electrodes and measuring its conduction current.
It is observed that the Ti/Al2O3/Pt structure shows good ON/OFF conduction current ratio >103 with measured, retention time >104 s and switching cycles >10 times. The trap-controlled space charge limit current (SCLC) might have dominated the conduction current of the HRS while the conduction current of the LRS might be dominated by the Ohmic conduction.
Al2O3 is known as a high-k material, with a dielectric constant k=10, a large energy band gap (9 eV), high breakdown strength (5-10 MV cm-1) and has good thermal and chemical stability. When oxygen ions migrate to the top electrode by external electrical stimulation, the conductive filamentary channel composed of oxygen vacancy is stable in the Al2O3 thin film. Therefore, Al2O3 and some other binary metal oxide thin films are suitable dielectric materials for RRAM.

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