近年來，非揮發性記憶體受到尺寸持續微縮的影響，造成元件產生非理想
效應。傳統浮動閘極(Floating gate)記憶體在操作過程中，若穿遂氧化層產生漏電
途徑，會使得儲存電荷藉由漏電途徑回到矽基板，造成儲存電荷流失。隨著元件
尺寸持續微縮，此情況會更加嚴重。為了提升記憶體性能，許多新型態的記憶體
逐漸被開發出來。其中，電阻式非揮發性記憶體(Resistive Random Access Memory,
RRAM)具有結構上的優勢，且擁有低耗能、高速率操作、良好的可靠度等優點，
可望能取代傳統浮動閘極記憶體。然而，電阻轉換效應的機制眾說紛紜，其研究
發展受到學術界及業界眾多矚目。
在本論文中，我們使用的介電質材料分為氧化鎵(GaOx)及氧化銦鎵(InGaOx,
IGO)。在二氧化矽的矽晶圓上沈積一層氮化鈦(TiN)當作下電極，接著利用靶磁
控濺鍍系統( Multi-Target Sputter )，分別鍍製300Å 的GaOx 與IGO 薄膜於TiN
電極上方，最後再沈積白金(Pt)作為上電極，形成Pt/GaOx/TiN 及Pt/IGO/TiN 三
明治結構之電阻式記憶體元件。藉由電性量測，我們可以觀察到Pt/GaOx/TiN 的
電阻轉換特性為雙極性轉換效應(Bipolar resistance switching)，而Pt/IGO/TiN 的
電阻轉換特性為雙極性轉換效應跟單極性轉換效應(Unipolar resistance switching)
Pt/GaOx/TiN 跟Pt/IGO/TiN 在升溫持久度(Retention)量測及一萬次連續寫入抹除
的抗劣化性(Endurance)都可以維持不錯的穩定度。並且利用變溫量測來觀察電阻
在高、低阻態的變化情形，並驗證其導電路徑的機制。
同樣地，我們在薄膜製程中通入氧氣，達到氧化層俢補作用及降低薄膜缺
陷。藉由XPS 分析，我們發現在製程中通入氧氣的薄膜，可補足鍵結不完全的
部分，使得薄膜的穩定度增加。根據後續的電性量測，在製程中通入氧氣的GaOx
跟IGO 薄膜，電阻切換特性是穩定的。
我們成功找尋到新的電阻式記憶體材料：GaOx及IGO薄膜，而它們都確實擁
有電阻式記憶體的電流特性，並且在電流切換特性上有相當程度的穩定度。由於
鎵、銦廣泛的運用在光電半導體中，其製造技術可以直接應用於現階段積體電路
製程。

Recently, the development of nonvolatile memory (NVM) is influence by scaling
down. When the device is miniaturized continuously, the tunnel oxide layer of the
floating gate will get thinner. In consequence the charges could leak into the substrate
and lead to loss all of stored information. In order to enhance the performance of the
non-volatility memory, the new generation non-volatile memories have been
developed. Advantages of the resistive random access memory (RRAM) are simple
structure, lower consumption of energy, higher operating speed and higher endurance.
RRAM might be expected to replace the memory of traditional floating gate. However,
the mechanisms of RRAM were controversial and more investigations were needed.
The aim of this study is to develop new material and theory by using the
insulator of GaOx and IGO (InGaOx, IGO). The bottom electrode (TiN) was deposited
on the substrate of Si2O3. The GaOx (300Å) and IGO (300Å) thin film were deposited
on the bottom electrode of TiN by Multi-Target Sputter. Then, the top electrode (Pt)
was deposited on the insulator. The sandwiched structure of Pt/GaOx/TiN and
Pt/IGO/TiN device was completed. Based on electrical measuring, the resistance
switching feature of Pt/GaOx/TiN is bipolar. The resistance switching features of
Pt/IGO/TiN are both bipolar and unipolar. The reliability of the device of
Pt/GaOx/TiN and Pt/IGO/TiN were maintained by retention at 85°C and 104 cycles
endurance. In order to study the device switching mechanisms, we measured the
resistance of the Rlow state and Rhigh state and observed the change of the resistance in
different temperature.
In the similar process, we sputter GaOx and IGO target with Ar gas mixes O2 gas,
in order to decrease the defect of thin film. By XPS analyzing, the thin film was stable
because the insulator sputter with Ar gas mixed O2 gas has sufficient oxygen. Based
on electrical measuring, the resistance switching of Pt/GaOx/TiN and Pt/IGO/TiN
which was sputter with Ar gas mixes O2 gas was stable.
We succeeded to find new material of RRAM which is GaOx and IGO. They
have the characteristics of stable resistance switching. Wide application of In and Ga
in modern optoelectronic semiconductor industry. These fabrication techniques can be
applied to the manufacture process of semiconductor industry.

Abstract (Chinese) ……………………………………………………...I
Abstract (English) …………………………………………………….III
Acknowledgement ……………………………………………………...V
Contents …………………………………………………………….....VI
Table Captions ………………………………………………………...IX
Figure Captions ………………………………………………………...X
Chapter 1 Introduction ………………………………………………...1
Chapter 2 Literature
2.1 Introduction of memory ……………………………………………2
2.2 Emerging non-volatile memories
2.2.1 FeRAM (Ferroelectric RAM) .....................................................3
2.2.2 MRAM (Magnetic RAM) ..........................................................3
2.2.3 PCRAM (Phase change RAM) ...................................................4
2.2.4 RRAM (Resistance RAM) .........................................................4
2.3 The materials of Resistive RAM
2.3.1 Perovskite................................................................................5
2.3.2 Transition metal oxide................................................................6
2.3.3 Organic materials......................................................................6
2.4 The switching mechanism of Resistive RAM
2.4.1 Filamentary model.....................................................................7
2.4.2 Charge-trap in small domain.......................................................7
2.4.3 Conducting path........................................................................8
2.5 The mechanism of current conduction
2.5.1 Ohmic conduction.....................................................................8
2.5.2 Tunneling conduction.................................................................9
2.5.3 Schottky emission.....................................................................9
2.5.4 Frenkel -Poole emission...........................................................10
2.5.5 Space charge limited current.....................................................10
Chapter 3 Resistive RRAM characteristics of GaOx
3.1 Results for GaOx without O2 flow
3.1.1 Experimental procedures..........................................................17
3.1.2 Basic characteristics of GaOx....................................................18
3.1.3 Endurance and Retention..........................................................19
3.1.4 Multi-level characteristic..........................................................19
3.1.5 Current-Voltage curve fitting.....................................................20
3.2 Results for GaOx with O2 flow
3.2.1 Experimental procedures..........................................................21
3.2.2 Basic characteristics of GaOx....................................................21
3.2.3 Endurance and Retention..........................................................22
3.2.4 Current-Voltage curve fitting.....................................................22
3.3 Discussion
3.3.1 Change Temperature................................................................23
3.3.2 Calculate the real switch thickness.............................................23
3.3.3 Chemical analysis by XPS........................................................24
3.3.4 Basic characteristic of mechanism..............................................25
Chapter 4 Resistive RRAM characteristics of IGO
4.1 Results for IGO without O2 flow
4.1.1 Experimental procedures..........................................................47
4.1.2 Basic characteristics of IGO......................................................48
4.2 Results for IGO with O2 flow
4.2.1 Experimental procedures..........................................................49
4.2.2 Basic characteristics of IGO......................................................50
4.2.3 Endurance and Retention..........................................................51
4.2.4 Current- Voltage curve fitting....................................................52
4.3 Discussion
4.3.1 Change Temperature................................................................52
4.3.2 Basic characteristic of mechanism..............................................53
Chapter 5 Conclusion.............................................................................74
References................................................................................................76

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