觀察文獻中電阻式記憶體(RRAM)操作的方式多半是利用從小電壓慢慢加大的Double Sweep，本研究認為Reset應該是一個動態的過程，推測在慢慢升壓的過程應該會影響氧離子與阻絲的反應，因此，改變RRAM的量測手法，採用直接給予最大電壓的Single Sweep進行Reset行為，發現此量測手法可以得到更好的高阻態(HRS)電阻值，並利用快速量測(Fast IV)技術對元件進行脈衝Reset，設計不同波型以改變升壓時間(Rising time)模擬Single/Double Sweep，發現升壓時間短的波型，能夠以更少的能量得到更高的阻值，在經由COMSOL模擬能夠發現，若直接施加最大電壓，能夠擁有最大的等效電場範圍，可以吸引更多氧離子進行Reset行為，而得到更好的高阻態阻值[1]。
根據以上實驗，可以得知當升壓時間(Rising time)越短，能夠得到更高的阻值，但是根據先前實驗室的研究成果，發現在Rising time越長，能夠得到更高的阻值[2]。經過比較後可以發現，兩者Rising time的範圍不同，本研究利用Fast IV改變升壓時間以包含兩者實驗數據，認為升壓時間(Rising time)對於Reset行為的影響，可以分為兩種機制:熱效應、電場效應。
在Rising time極短的情況下，由電場效應主導，在這個區間Rising time越短能夠得到較高的HRS阻值；在Rising time極長的情況下，由熱效應主導，在這個階段Rising time越長能夠得到較高的阻值。
接著，利用不同Rising time以及降壓時間(Falling time)的搭配，進行Reset行為，得到在電場效應下，Falling time的長短能夠影響HRS的大小，而在熱效應下，Falling time的長短則沒有影響。藉此，得到對於Reset行為而言，理想的三角脈衝波是需要短的升壓時間(Rising time)以及長的降壓時間(Falling time)。

In this study, we demonstrate completely different characteristics with different operating modes and analyze the electrical field effect to confirm the filament dissolution behavior. Compared with traditional double sweep method, the device exhibited a larger memory window when using a single voltage sweep method during reset process. The phenomenon was verified by using fast I–V measurement to simulate the two operating methods. In this work, the device applied with a very short rising time pulse was found to get a better high resistance state (HRS) and lower power consumption. Furthermore, we proposed the electrical field effect to explain the phenomenon and demonstrate distribution by COMSOL simulation.
During operation with gradually increased voltage, range of effective electric field is limited due to the filament dissolution, caused by attracted oxygen ions under electric field. In the contrast, better high resistance state (HRS) can be acquired when directly applying the max voltage of device because the device obtains the biggest range of effective field and more oxygen ions could be drawn to undergo reset process.
According to the above experiments, shorter rising time leads to higher resistance state of device. However, the result we’ve got before was contrast; longer rising time can get a higher resistance. Therefore, we tried to figure out the differences between two experiments. After comparison, we found that the ranges of rising time of two experiments are different. We used Fast IV system to change the Rising time, including both experimental data, and discovered that the resistance state of device is not only resulted from one mechanism. It is considered that the effect of Rising time on Reset behavior can be divided into two mechanisms: thermal effect and electric field effect.
In the case of extremely short rising time, the oxygen ions of device dominated by electric filed effect, leading to switching to better HRS at shorter pulse rising time. Contrast, in the case of extremely long rising time, the oxygen ions of device dominated by thermal effect. At this condition, longer rising time can control more oxygen ions, achieving the better resistance.
Moreover, this work found out that the effects of falling time at two cases (electric field effect and thermal effect) are different. Under electric field effect, the variation of falling time would change the values of HRS of RRAM, which achieving higher HRS of RRAM at longer falling time. However, this phenomenon doesn’t exist under the condition of thermal effect. Therefore, both of extremely short rising time and long enough falling time are needed for an ideal triangle pulse waveform.

論文審定書 i
致謝 ii
摘要 iii
Abstract iv
目錄 vi
圖目錄 ix
表目錄: xii
第一章 序論 1
1.1. 前言 1
1.2. 研究目的與動機 2
第二章 文獻回顧 3
2.1 次世代非揮發性記憶體 3
2-1-1 鐵電式隨機存取記憶體(FeRAM) 3
2-1-2 磁阻式記憶體(MRAM) 5
2-1-3 相變化記憶體(PCRAM) 6
2-1-4 電阻式記憶體(RRAM) 6
2.2 電阻式記憶體材料 10
2-2-1 高分子材料 10
2-2-2 過渡金屬氧化物 10
2-2-3 鈣鈦礦 10
2.3 電阻式記憶體切換機制 11
2-3-1 阻絲理論(Filament-type theory) 11
2-3-2 介面效應 (Interface-type theory) 13
2.4 絕緣體載子傳導機制 13
2-4-1 歐姆傳導(Ohmic conduction) 14
2-4-2 普爾-法蘭克發射(Poole-Frenkel emission) 15
2-4-3 蕭基發射(Schottky emission) 16
2-4-4 空間電荷限制電流(Space charge limited current) 17
2-4-5 穿隧(Tunneling) 19
第三章 實驗設備 20
3.1. 製程設備 20
3-1-1 多靶磁控濺鍍系統 (Multi-Target Sputter) 20
3.2. 材料分析設備 21
3-2-1 傅立葉轉換紅外光譜儀 (Fourier-Transform Infrared Spectrometer) 21
3-2-2 N&K薄膜特性分析儀 (N & K Analyzer) 23
3.3. 電性量測設備 25
3-3-1 半導體精準電性量測系統 25
第四章 1T1R元件量測方法 27
4.1. 1T1R元件 27
4.2. 電性量測方式 27
第五章 改變電性量測手法對Reset過程的影響 29
5.1 實驗動機 29
5.2 電性量測結果比較 30
5.3 Fast IV電性分析 36
5.4 COMSOL模擬以及物理機制分析 38
第六章 Rising Time對Reset行為的影響與分析 40
6.1 實驗動機 40
6.2 Rising Time對Reset行為與HRS的關係 44
6.3 實驗結果與討論 54
第七章 Rising and Falling time對於Reset行為的物理意義 56
7.1 Falling time對於Reset行為的影響 56
7.2 三角脈衝波形的mapping 56
7.3 實驗結果及討論 58
第八章 結論 69
參考文獻 71

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