臺灣博碩士論文加值系統

近年來人工智慧、物聯網、大數據處理蓬勃發展，對於記憶體的運算速度及儲存容量具有更高要求，在非揮發記憶體中以電阻式記憶體(RRAM)最具潛力，其具備讀寫速度快、儲存容量高及可與半導體製程進行整合等優點。本論文利用氮化鈦為下電極製備Cu/SiOx/TiN元件，探討其電阻切換及記憶特性，並藉由快速熱退火氧化TiN電極改善其轉態穩定性及利用元件結構微縮以降低其操作電壓。
第一部分探討Cu/SiO2/TiN與Cu/SiO2/TiOxNy/TiN改善元件，由於施加電壓會使氮化鈦下電極形成不均勻的氧化層，因此於氧氣下進行快速熱退火使下電極預先形成一層薄氧化層，以減少絲狀路徑的不穩定形成。透過電壓掃描確認元件電阻切換特性，並將電流電壓曲線進行擬合以得知其傳導機制，元件高電阻狀態(HRS)為蕭特基發射而低電阻狀態(LRS)為歐姆傳導。接著量測耐久度及記憶特性，相較於Cu/SiO2/TiN元件，Cu/SiO2/TiOxNy/TiN改善元件的耐久度可穩定達到500個週期，記憶特性達到104秒且高低電阻倍率約為100倍。第二部分則是探討將Cu/SiO2/TiOxNy/TiN改善元件進行微縮，直徑從100 μm縮小至1.2 μm，面積縮小不易受微粒汙染，因尺寸效應產生更高的電場強度使絲狀路徑較容易形成，轉態特性較為穩定，耐久度可穩定達到1000個週期且記憶特性達104秒，高低電阻倍率約為10倍。

In recent years, with the rapid development of artificial intelligence, Internet of Things, and big data processing, there are higher requirements for the computing speed and storage capacity of memory. Among various non-volatile memory devices, resistive random access memory (RRAM) is a promising candidate due to its fast read/write speed, high storage capacity, and integration with semiconductor processes. This thesis used titanium nitride (TiN) to fabricate Cu/SiOx/TiN devices and investigated its resistive memory characteristics. Furthermore, the switching stability was improved by applying rapid thermal annealing to oxidize the TiN electrode, and device scaling was utilized to reduce the operating voltage.
The first part studied Cu/SiO2/TiN and Cu/SiO2/TiOxNy/TiN improved devices. Due to the application of voltage, the titanium nitride (TiN) bottom electrode may form an uneven oxide layer. To address this issue, the device was subjected to rapid thermal annealing in the presence of oxygen, and the bottom electrode can be pre-form a thin oxide layer. This process can reduce the instability in the formation of conductive filament.These RRAM devices can be continuously switched their resistance with applied voltages and the conduction mechanisms was determined by fitting the current-voltage curves. The conduction mechanisms of the high-resistance state (HRS) and low-resistance state (LRS) are dominated by Schottky emission and Ohmic conduction, respectively.Compared with the Cu/SiO2/TiN device, the Cu/SiO2/TiOxNy/TiN device exhibited stable resistance switching characteristics with endurance of 500 times and retention of 104 seconds. The high-to-low resistance ratio approximately 100 times.The second part studied scaling down of Cu/SiO2/TiOxNy/TiN improved devices, reducing the diameter from 100 μm to 1.2 μm. The device became less susceptible to particle contamination. The higher electric field intensity generated due to size effects makes it easier to formation of conductive filament,and the scaled-down device exhibited stable resistance switching characteristics with endurance of 1000 times and retention of 104 seconds. The high-to-low resistance ratio approximately 10 times.

中文摘要 I
英文摘要 II
誌謝 IV
目錄 V
圖目錄 VII
表目錄 X
第一章 緒論 1
1-1 前言 1
1-2 研究動機與目的 1
1-3 論文架構 2
第二章 文獻回顧與基礎理論 3
2-1 非揮發性記憶體介紹 3
2-2 電阻式記憶體簡介及發展 6
2-3 材料及界面探討 7
2-4 電阻式記憶體切換機制 10
2-5 電阻式記憶體記憶特性介紹 17
2-6 電流傳導機制 18
第三章 實驗步驟 22
3-1 實驗流程說明 22
3-2 實驗設備 23
3-3 元件製備流程 26
3-4 材料分析 29
3-5 電性量測 29
第四章 結果與討論 32
4-1 氧化處理對TiN薄膜所造成之特性差異 32
4-1-1 元件製備流程與材料化學分析 32
4-1-2 元件電阻切換特性與電流傳導機制 37
4-1-3 元件耐久度及記憶時間分析 41
4-1-4 元件之絲狀路徑形成及斷裂 44
4-2 元件微縮所造成之特性改善 45
4-2-1 元件製備流程 45
4-2-2 元件電阻切換特性與電流傳導機制 46
4-2-3 元件耐久度及記憶時間分析 51
第五章 結論與未來展望 54
5-1 結論 54
5-2 未來展望 55
參考文獻 56

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