由於氧化銦鎵錫在半導體領域有相當廣的應用，故使用氧化銦鎵錫以射頻磁控濺鍍設備製作非揮發性可變電阻式隨機存儲記憶體的轉換層，本研究所使用的材料中，氧化鎵具有較大能隙，而氧化銦及氧化錫則具有高導電性，三種氧化物的比例則固定不變（銦：鎵：錫＝1：2：1）。
首先，以氧化銦鎵錫作為轉換層，鉑作為下電極，使用鈦(Ti)、銀(Ag)、鋁(Al)作為上電極，觀察其直流特性後，發現使用之元件特性均為雙極性元件，使用不同上電極會對元件的電阻轉換特性產生影響，而產生影響的原因體現在傳導方式上。使用鈦電極之元件，具有電阻轉換超過1700次的同時，開關比保持在10以上，是三種電極中具有最多操作次數，而使用銀電極之元件，其操作電壓是三種電極之間最低，而鋁電極的開關比則能夠達到10⁴，為三種電極中最大，但其形成電壓及設置電壓會變大。而這三種電極製作出的元件都能夠在室溫，讀取電壓為0.1伏特的條件下，維持高、低阻態各10⁴秒的資料殘留時間。
此外，本研究欲探究在使用氧化銦鎵錫進行射頻磁控濺鍍的過程中，改變氧氣通量比(O2/O2+Ar)對元件特性之影響，故以鉑作為下電極鈦作為上電極，分別製作出氧氣通量為0%、10%、20%的氧化銦鎵錫轉換層。由結果可以發現10%的氧氣通量比雖然會使元件的操作電壓上升，但同時會使元件的開關比略為上升，並且增加元件的操作電壓穩定度，而20%的氧氣通量比也會使元件的操作電壓及開關比略微上升，但卻會使元件的操作電壓的穩定度下降，並且隨著氧氣通量比的上升，元件可操作的次數會有所下降，未通氧的元件可以操作超過1700次，氧氣通量比10%的元件可操作次數則下降到了297次，而氧氣通量比20%之元件更是下降到了243次，配合XPS的分析結果可以得出結論，隨著氧氣通量比的上升，氧化銦鎵錫薄膜中的的晶格缺陷，也就是氧空缺比例會逐漸下降，使導絲路徑的生成較為簡化，適量的氧氣通量比可以幫助改善元件之操作電壓穩定度，但會使導絲較難生成，導致操作電壓上升，而過多氧氣通量比則會造成導絲過於難生成，除了會使操作電壓上升外，也會產生較為不穩定之導絲，導致操作電壓較為不穩定，雖然特性較為不穩定，但這些元件都能夠擁有在室溫，讀取電壓為0.1伏特的條件下，維持高、低阻態各10⁴秒的資料殘留時間。
再者，本研究欲探討不同轉換層之厚度對元件特性之影響，使用鋁作為上電極，再以20、60、100奈米厚度之氧化銦鎵錫作為轉換層，觀察其電性發現隨著轉換層厚度增加，會使開關比增加，但同時操作電壓會上升。而這些元件都能在室溫，讀取電壓為0.1伏特的條件下，維持高、低阻態各10⁴秒的資料殘留時間
接下來，本研究會探討不同退火溫度對於元件之影響，使用鋁作為上電極，鉑作為下電極，氧氣通量比為0%的氧化銦鎵錫轉換層，分別進行300℃/1hr、400℃/1hr的退火，鋁電極未退火的元件之操作電壓約在2.82V/-0.5V，退火過後的操作電壓會逐漸下降，當退火溫度為400℃時，有著最小的操作電壓約為1.41V/-0.49V，能看出操作電壓有明顯下降。而這些元件都能在室溫，讀取電壓為0.1伏特的條件下，維持高、低阻態各10⁴秒的資料殘留時間。
最後，本研究對於Ag/IGTO (10%)/Pt 非揮發性可變電阻式隨機存儲記憶體進行脈衝測試，代表氧化銦鎵錫作為轉換層之非揮發性可變電阻式隨機存儲記憶體具有在現代電腦科技中使用的潛力。

Due to the wide applications of indium gallium tin oxide (IGTO) in the semiconductor field, IGTO was used as the switching layer to fabricate non-volatile resistive random access memory (RRAM) using radio frequency (RF) magnetron sputtering. In the materials used in this study, gallium oxide has a large band gap, while indium oxide and tin oxide have high conductivity. The ratio of the three oxides remained constant (In2O3:Ga2O3: SnO2 = 1:2:1).
First, with IGTO as the switching layer and platinum as the bottom electrode, titanium, silver, and aluminum were used as top electrodes to observe their DC sweep characteristics. The results showed that all fabricated devices exhibited bipolar switching behavior. Different top electrodes influenced the resistance switching characteristics of the devices, and the underlying reason lies in the conduction mechanisms. The device with the titanium electrode exhibited resistance switching for over 1700 cycles while maintaining an ON/OFF ratio above 10, showing the highest endurance among the three electrodes. The device with the silver electrode had the lowest operating voltage among the three electrodes. The aluminum electrode device achieved the largest ON/OFF ratio of 10⁴, but its forming and set voltages were higher. Notably, all three types of devices have the ability to maintain data retention times of 10⁴ seconds for both high-resistance state (HRS) and low-resistance state (LRS) at room temperature with a read voltage of 0.1 V.
Furthermore, this study aimed to investigate the effect of the oxygen flow ratio (O2/(O2+Ar)) of depositing IGTO on the device during the RF magnetron sputtering. Therefore, IGTO switching layers were deposited with oxygen flow ratios of 0%, 10%, and 20%, using platinum as the bottom electrode and titanium as the top electrode. The results revealed that while a 10% oxygen flow ratio increased the operating voltage of the device, it also slightly improved the on/off ratio and enhanced the stability of the operating voltage. A 20% oxygen flow ratio also slightly increased the operating voltage and on/off ratio, but it reduced the stability of the operating voltage. Additionally, the number of switching cycles decreased with an increasing oxygen flow ratio. The device fabricated without oxygen flow exhibited over 1700 switching cycles, while the devices with 10% and 20% oxygen flow ratios showed a decrease to 297 and 243 cycles, respectively. Combined with XPS analysis, it was concluded that as the oxygen flow ratio increased, the concentration of lattice defects (oxygen vacancies) in the IGTO thin film gradually decreased, simplifying the formation of conductive filaments. An appropriate oxygen flow ratio could help improve the operating voltage stability of the device but made the formation of conductive filaments more difficult, leading to an increase in operating voltage. Conversely, an excessive oxygen flow ratio made the formation of conductive filaments too difficult, resulting in both increased and unstable operating voltages. Despite these variations in switching characteristics, all these devices exhibited data retention times of 10⁴ seconds for both HRS and LRS at room temperature with a read voltage of 0.1 V.
Moreover, this study explored the impact of different switching layer thicknesses on device characteristics. Using aluminum as the top electrode and IGTO as the switching layer with thicknesses of 20, 60, and 100 nm, electrical measurements showed that increasing the switching layer thickness led to an increase in the on/off ratio but also increased the operating voltage. Importantly, all these devices have the ability to maintain data retention times of 10⁴ seconds for both HRS and LRS at room temperature with a read voltage of 0.1 V.
Next, this research investigated the effect of different annealing temperatures on the devices. Using aluminum as the top electrode, platinum as the bottom electrode, and an IGTO switching layer deposited with a 0% oxygen flow ratio, annealing was performed at 300℃ for 1 hour and 400℃ for 1 hour. The unannealed device with the aluminum electrode exhibited operating voltages around 2.82 V/-0.5 V. After annealing, the operating voltage gradually decreased. The device annealed at 400℃ showed the lowest operating voltages of approximately 1.41 V/-0.49 V, indicating a significant reduction in operating voltage. Furthermore, all these devices can maintain data retention times of 10⁴ seconds for both HRS and LRS at room temperature with a read voltage of 0.1 V.
Finally, this study conducted pulse testing on the Ag/IGTO (10%)/Pt non-volatile resistive random access memory, demonstrating the potential of IGTO as the switching layer in non-volatile resistive random access memory for applications in modern computer technology.

Chen, “A review of emerging non-volatile memory (NVM) technologies and applications,” Solid-State Electronics, vol. 125, pp. 25–38, Nov. 2016.
C. Ye et al., “Physical Mechanism and Performance Factors of Metal Oxide Based Resistive Switching Memory: A Review,” vol. 32, no. 1, pp. 1–11, Jan. 2016.
Win-San Khwa, D. Lu, C.-M. Dou, and M.-F. Chang, “Emerging NVM Circuit Techniques and Implementations for Energy-Efficient Systems,” Springer eBooks, pp. 85–132, Aug. 2018.
A. Toriumi et al., "Material perspectives of HfO2-based ferroelectric films for device applications," 2019 IEEE International Electron Devices Meeting (IEDM), San Francisco, CA, USA, 2019, pp. 15.1.1-15.1.4.
S. Raoux, Matthias Wuttig, and Springerlink (Online Service, Phase Change Materials : Science and Applications. New York, Ny: Springer Us, 2009.
S. Raoux et al., "Phase-change random access memory: A scalable technology," in IBM Journal of Research and Development, vol. 52, no. 4.5, pp. 465-479, July 2008.
W. Banerjee, A. Kashir, and S. Kamba, “Hafnium Oxide (HfO2 ) – A Multifunctional Oxide: A Review on the Prospect and Challenges of Hafnium Oxide in Resistive Switching and Ferroelectric Memories,” Small, vol. 18, no. 23, p. 2107575, May 2022.
Dmytro Apalkov, B. Diény, and J. M. Slaughter, “Magnetoresistive Random Access Memory,” Proceedings of the IEEE, vol. 104, no. 10, pp. 1796–1830, Oct. 2016.
F. Zahoor, T. Z. Azni Zulkifli, and F. A. Khanday, “Resistive Random Access Memory (RRAM): an Overview of Materials, Switching Mechanism, Performance, Multilevel Cell (mlc) Storage, Modeling, and Applications,” Nanoscale Research Letters, vol. 15, no. 1, Apr. 2020.
K. Y. Cheong, I. A. Tayeb, F. Zhao, and J. M. Abdullah, “Review on resistive switching mechanisms of bio-organic thin film for non-volatile memory application,” Nanotechnology Reviews, vol. 10, no. 1, pp. 680–709, Jan. 2021.
T.-C. Chang, K.-C. Chang, T.-M. Tsai, T.-J. Chu, and S. M. Sze, “Resistance random access memory,” Materials Today, vol. 19, no. 5, pp. 254–264, Jun. 2016.
H.-S. . P. Wong et al., “Metal–Oxide RRAM,” Proceedings of the IEEE, vol. 100, no. 6, pp. 1951–1970, Jun. 2012.
F.-C. Chiu, “A Review on Conduction Mechanisms in Dielectric Films,” Advances in Materials Science and Engineering, vol. 2014, pp. 1–18, 2014.
E. Lim and R. Ismail, “Conduction Mechanism of Valence Change Resistive Switching Memory: A Survey,” Semantic Scholar, 2015.
‌Yi-Sheng Lai, Chia-Hsun Tu, Dim-Lee Kwong and J. S. Chen, "Charge-transport characteristics in bistable resistive Poly(N-vinylcarbazole) films," in IEEE Electron Device Letters, vol. 27, no. 6, pp. 451-453, June 2006.
W. S. Lau, “An Extended Unified Schottky-Poole-Frenkel Theory to Explain the Current-Voltage Characteristics of Thin Film Metal-Insulator-Metal Capacitors with Examples for Various High-k Dielectric Materials,” ECS journal of solid state science and technology, vol. 1, no. 6, pp. N139–N148, Jan. 2012.
A. Yildiz, N. Serin, T. Serin, and Mehmet Kasap, “Crossover from Nearest-Neighbor Hopping Conduction to Efros–Shklovskii Variable-Range Hopping Conduction in Hydrogenated Amorphous Silicon Films,” Japanese Journal of Applied Physics, vol. 48, no. 11, pp. 111203–111203, Nov. 2009.
W. N. Shafarman and T. G. Castner, “Critical behavior of Mott variable-range hopping in Si: As near the metal-insulator transition,” Physical Review B, vol. 33, no. 5, pp. 3570–3572, Mar. 1986.
Ilia Valov and M. N. Kozicki, “Cation-based resistance change memory,” vol. 46, no. 7, pp. 074005–074005, Feb. 2013.
M. L. Dalal, S. Sivaraman, and Y. V. G. S. Murti, “Space charge limited current (SCLC) in alkali halide crystals during electrolytic coloration,” Journal of Physics and Chemistry of Solids, vol. 49, no. 2, pp. 223–232, Sep. 2002.‌
M. P. Houng, Y. H. Wang, and W. J. Chang, “Current transport mechanism in trapped oxides: A generalized trap-assisted tunneling model,” Journal of Applied Physics, vol. 86, no. 3, pp. 1488–1491, Aug. 1999.
E. V. Amadi, A. Venkataraman, and C. Papadopoulos, “Nanoscale self-assembly: concepts, applications and challenges,” Nanotechnology, Dec. 2021.
J. L. Vossen, “Control of Film Properties by rf-Sputtering Techniques,” Journal of Vacuum Science and Technology, vol. 8, no. 5, pp. S12–S30, Sep. 1971.
J. W. Coburn and E. Kay, “PLASMA DIAGNOSTICS OF AN rf-SPUTTERING GLOW DISCHARGE,” Applied Physics Letters, vol. 18, no. 10, pp. 435–438, May 1971.
Li-Yang Chang, “Investigation of Indium Gallium Oxide Thin Film Fabricated by RF Sputtering System and Their Applications,” Master D.thesis, NCKU, Jun. 2017.
The Editors of Encyclopaedia Britannica, “Bragg law. Encyclopedia Britannica”, March 4, 2025.
Binnig, Gerd, Calvin F. Quate, and Ch Gerber. "Atomic force microscope." Physical review letters 56.9 (1986): 930.
D. B. Williams and C. B. Carter, Transmission Electron Microscopy. Boston, MA: Springer US, 2009.
F. A. Stevie and C. L. Donley, “Introduction to x-ray photoelectron spectroscopy,” Journal of Vacuum Science & Technology A, vol. 38, no. 6, p. 063204, Dec. 2020.
L. J. Allen, A. J. D’Alfonso, B. Freitag, and D. O. Klenov, “Chemical mapping at atomic resolution using energy-dispersive x-ray spectroscopy,” MRS Bulletin, vol. 37, no. 1, pp. 47–52, Jan. 2012.
S. I. Inamdar and K. Y. Rajpure, “High-performance metal–semiconductor–metal UV photodetector based on spray deposited ZnO thin films,” Journal of Alloys and Compounds, vol. 595, pp. 55–59, May 2014
Wang, X.T.; Qian, H.L.; Guan, L.; Wang, W.; Xing, B.R.; Yan, X.Y.; Zhang, S.C.; Sha, J.; Wang, Y.W. Influence of metal electrode on the performance of ZnO based resistance switching memories. J. Appl. Phys. 2017, 122, 5.
Lee, K.J.; Wang, L.W ; Chiang, T.K.; Wang, Y.H. Effects of Electrodes on the Switching Behavior of Strontium Titanate Nickelate Resistive Random Access Memory. Materials 2015, 8, 7191–7198.
Lee, C.B.; Kang, B.S.; Benayad, A.; Lee, M.J.; Ahn, S.E.; Kim, K.H.; Stefanovich, G.; Park, Y.; Yoo, I.K. Effects of metal electrodes on the resistive memory switching property of NiO thin films. Appl. Phys. Lett. 2008, 93, 3.
Vijay, H M, and V N Ramakrishnan. “A Novel Approach to Analyze the Resistance of the RRAM Based on the Conductive Nano Filament Length and Width Variation.” Transactions on Electrical and Electronic Materials, vol. 23, no. 5, 17 Dec. 2021, pp. 476–482.
Wu, Lei, et al. “Self-Compliance and High Performance Pt/HfOx/Ti RRAM Achieved through Annealing.” Nanomaterials, vol. 10, no. 3, 4 Mar. 2020, pp. 457–457.
Shen, Zongjie, et al. “Effect of Annealing Temperature for Ni/AlOx/Pt RRAM Devices Fabricated with Solution-Based Dielectric.” Micromachines, vol. 10, no. 7, 2 July 2019, pp. 446–446.
Choi, Kihwan, and James Jungho Pak. “Improved Resistive Switching Characteristics of Solution Processed ZrO2/SnO2 Bilayer RRAM via Oxygen Vacancy Differential.” Semiconductor Science and Technology, vol. 39, no. 4, 20 Feb. 2024, pp. 045012–045012.
Sun, Kai, et al. “Temperature Dependence of Resistive Switching Behavior in α-Ga2O3-Based RRAM Devices.” IEEE Transactions on Electron Devices, vol. 71, no. 12, Dec. 2024, pp. 7935–7942.
Wu, Cheng-Hsien, et al. “Inert Pt Electrode Switching Mechanism after Controlled Polarity-Forming Process in in2O3-Based Resistive Random Access Memory.” Applied Physics Express, vol. 10, no. 9, 31 Aug. 2017, pp. 094102–094102.
D. Li, D. Li, and C. Zou, “Stabilizing electric switching of ferromagnetism in In2O3:Cu thin films,” Journal of Alloys and Compounds, vol. 650, pp. 912–917, Aug. 2015.
C.-H. Wu et al., “Inert Pt electrode switching mechanism after controlled polarity-forming process in In2O3-based resistive random access memory,” Applied Physics Express, vol. 10, no. 9, pp. 094102–094102, Aug. 2017.
W.-L. Huang, Y.-Z. Lin, S.-P. Chang, and S.-J. Chang, “Investigation of Conductive Mechanism of Amorphous IGO Resistive Random-Access Memory with Different Top Electrode Metal,” Coatings, vol. 10, no. 5, pp. 504–504, May 2020.
Z. Yang et al., “Resistive random access memory based on gallium oxide thin films for self-powered pressure sensor systems,” Ceramics International, vol. 46, no. 13, pp. 21141–21148, May 2020.