本論文中，以射頻磁控共濺鍍製備氧化鋅鎵作為非揮發性電阻式隨機存取記憶體的電阻轉換層。本文欲結合有高導電性的氧化鋅和較大能隙的氧化鎵，以單靶及共靶濺鍍的方式製備氧化鋅鎵薄膜作為電阻轉換層。另外通過製程的調整，製作不同品質的氧化鋅鎵電阻式記憶體樣品，並探討不同樣品特性差異。
首先，我們探討在上電極為銅、鎳、鈦、氧化銦錫，鉑作為下電極的情況下，氧化鋅鎵記憶體的製備方式及其電特性。實驗結果顯示這些樣品在直流操作下，有著雙極性特性，而不同接面對於元件電阻轉換特性以及傳導機制有不同之影響。以銅為上電極的電阻式記憶體具有最高的981 次高低組態轉換次數，以及高達10^4 的開關比。以氧化銦錫為上電極的電阻式記憶體具有最低的操作電壓，以及cycle 間最小的高組態變動。以鈦為上電極的電阻式記憶體具有最高的操作電壓，以及cycle 間最大的高組態變動。另外，這些元件具有在室溫、0.02 伏特讀取電壓下，保持高低阻態各10^4 秒的穩定記憶能力。
再來，以氧化銦錫作為上電極，鉑作為下電極，藉由改變氧化鋅鎵電阻轉換層的厚度，欲研究不同電阻轉換層的厚度對於電阻式記憶體特性之影響。結果顯示元件皆為雙極性之電阻轉換操作，樣品的電阻轉換層越厚，開關比與高低組態轉換次數隨之提高。電阻轉換層40 奈米厚的樣品具有489 次高低組態轉換次數，以及10^1 的開關比，以及能在室溫、 0.02伏特讀取電壓下，保持高低阻態各 10^4 秒的穩定記憶能力。
接著，以氧化銦錫作為上電極，鉑作為下電極，藉由改變氧化鋅鎵電阻轉換層的氧氣通量比（O2/O2+Ar），欲研究不同氧通量比例的氧化鋅鎵薄膜對於電阻式記憶體特性之影響。結果顯示元件皆為雙極性之電阻轉換操作，隨著濺鍍中通氧比例的增加，使得電阻轉換更加穩定，高低阻態轉換的次數也隨之增加。10%, 20%, 30% 通氧比之樣品的高低阻態轉換次數均超過3000 次，且具有在室溫、0.02 伏特的讀取電壓下，保持高低阻態各 10^4 秒的穩定記憶能力。其中30% 通氧比的樣品更可達到 4903次的高低阻態轉換次數與相當低的操作電壓，分別是0.92 伏特和 -0.9 伏特。我們由量測結果搭配XPS 分析發現，射頻濺鍍製程中適當的增加氧通量比例，可以減少氧化鋅鎵薄膜中的先天缺陷（氧空缺），降低了導通路徑的複雜度，使得操作電壓顯著下降，進而提升電阻記憶體的穩定性與耐久度。
最後，以氧化銦錫作為上電極，鉑作為下電極，我們進行射頻磁控共濺鍍的功率調變，欲研究不同共濺鍍功率比例的氧化鋅鎵薄膜對於電阻式記憶體特性之影響。首先固定ZGO 靶材功率為80W 和0%的氧通量，將氧化鎵靶材之功率由20W 遞增至60W，製備不同功率比之氧化鋅鎵電阻式記憶體樣品。在室溫、0.02 伏特的讀取電壓下，三種樣品的高低阻態的記憶保持力均能達10^4 秒以上的穩定。另外，可以發現當氧化鎵的濺鍍功率提高，薄膜中氧化鎵成分比例較高時，能適當的減少薄膜中的本質缺陷與導電細絲路徑，使得80W+60W 功率比之樣品的高低阻態轉換次數提升到7035 次、操作電壓顯著下降，同時也因為氧化鎵具有較高的能隙，開關比從10^1 提升到10^2，有效改善元件的電性。

In this thesis, a RF magnetron sputtering method was used to prepare ZnGaO as the resistive switching layer for non-volatile resistive random-access memory (RRAM). The aim of this study is to combine highly conductive zinc oxide with wide bandgap gallium oxide to fabricate ZnGaO thin films as the resistive switching layer using both sputtering and co-sputtering methods.Additionally, by adjusting the fabrication process, RRAM samples with different qualities of ZnGaO were produced, and the differences in sample characteristics were investigated.
First, we investigated the fabrication methods and electrical properties of ZnGaO RRAM samples using various materials for the top electrode, including copper, nickel, titanium, and indium tin oxide, with platinum as the bottom electrode. Experimental results showed that these samples exhibited bipolar characteristics under direct current (DC) operation, and different interfaces had different effects on the device's resistive switching behavior and conduction mechanism. Copper-based sample showed the highest number of 981 endurance cycles and an on/off ratio up to 10^4. Indium tin oxide-based sample exhibited the lowest operating voltage and the smallest HRS variation between cycles. Titanium-based sample had the highest operating voltage and the largest HRS variation between cycles. Furthermore, these samples demonstrated stable memory retention with high and low resistance states maintained for 10^4 seconds at room temperature under a read voltage of 0.02V.
Next, using indium tin oxide as the top electrode and platinum as the bottom electrode, we investigated the influence of varying the thickness of the ZnGaO resistive switching layer on the characteristics of RRAM. The results showed that all samples exhibited bipolar resistive switching behavior, and as the thickness of the resistive switching layer increased, the on/off ratio and the number of endurance cycle also increased. The sample with a resistive switching layer thickness of 40 nm showed 489 endurance cycles and an on/off ratio of 10^1, with stable memory retention of high and low resistance states for 104 seconds at room temperature under a read voltage of 0.02V.
Then, using indium tin oxide as the top electrode and platinum as the bottom electrode, we studied the influence of different oxygen flow ratios (O2/O2+Ar) of the ZnGaO resistive switching layer on the characteristics of RRAM at room temperature. The results showed that all samples exhibited bipolar resistive switching behavior, and as the oxygen flow ratio in the sputtering process increased, the resistive switching became more stable, and the number of endurance cycles increased. Samples with oxygen flow ratios of 10%, 20%, and 30% showed endurance cycles exceeding 3000, and they exhibited stable memory retention of high and low resistance states for 10^4 seconds at room temperature under a read voltage of 0.02V. Among them, the sample with a 30% oxygen flow ratio achieved 4903 endurance cycles and operated at significantly low voltages, namely 0.92V and -0.9V. We found from the measurement results combined with XPS analysis that appropriately increasing the oxygen flow ratio during the RF sputtering process can reduce the inherent defects (oxygen vacancies) in the ZnGaO thin film, reduce the complexity of conduction paths, significantly decrease the operating voltage, and thereby improve the stability and reliability of resistive memory.
Finally, using indium tin oxide as the top electrode and platinum as the bottom electrode, we performed power modulation in RF magnetron sputtering to investigate the influence of power ratios during co-sputtering on the characteristics of ZnGaO thin films for RRAM at room temperature. Initially, we fixed the power of the ZGO target at 80W and the oxygen flow at 0%, and varied the power of the Ga2O3 target from 20W to 60W to fabricate RRAM samples with different power ratios. Under a read voltage of 0.02V and at room temperature, all three samples exhibited stable memory retention of high and low resistance states for more than 104 seconds. Furthermore, it was observed that increasing the sputtering power of Ga2O3 resulted in a higher proportion of gallium oxide in the thin film, effectively reducing intrinsic defects and the complexity of conduction filament paths within the film. This led to significant improvements in the sample with an 80W+60W power ratio, including an increased number of endurance cycles up to 7035, a notable decrease in operating voltage, and an enhanced on/off ratio from 10^1 to 10^2 due to the wider bandgap of gallium oxide. The overall electrical performance of the RRAM device was effectively improved.

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