有鑑於非揮發性記憶體在可攜式產品中的重要地位以及目前所遇到的瓶頸,研發新世代的記憶體已經成為刻不容緩的目標.電阻式記憶體無論是在操作速度.功率消耗.面積大小.以及製程整合上都明顯優於其它記憶體,因此本研究著重於電阻式記憶體.在眾多電阻式記憶體材料中,我們選用二氧化鉿(HfO2)以及上電極Ti下電極TiN來做為我們的研究材料,其原因為二氧化鉿可以直接進行製程整合無虛額外的污染考量,上電極選用Ti是因為在CMOS邏輯閘製程的多層島連線中,Ti已經廣泛的被當作吸附層再使用,而下電極選用TiN的原因也是因為在多層島連線中,TiN也已經廣泛的被當作阻障層使用,所以可以減少製程整合上的問題.而在本研究中大致上可以分成氧化鉿RRAM的基本特性探討以及單一原件多重位元儲存的可能性,並在最後找出可能的轉態時間與功率消耗.並且利用變溫的技巧成功萃取出不同電壓下的缺陷深度,以及不同限流下的導電行為.這對以後電阻式記憶體與邏輯閘結合上有重大的幫助.

In recent year, non-volatile memory has become more and more important in our life. However, as the CMOS scaling goes on, we need faster, smaller, and less power consume’s memory to use in portable merchandises. Under this condition, resistive switching random access memory (RRAM) has strong potential among next generation non-volatile memory candidates. Hence, our study will focus on RRAM and its applications.Among so many RRAM materials, we decide using HfO2 to be our dielectric layer and Ti as top electrode TiN as bottom electrode. It is because HfO2 has been broadly used in COMS process and Ti, TiN also wieldy used in via as adhesion layer and stopping layer. So our material can directly compatible with CMOS process without any other contaminations issue.Our study can be divided to two parts: one is basic HfO2 RRAM characteristic the other is studying the possibility of HfO2 RRAM application in multi-level operations. Finally, by using changetemperature technique, we can abstract the defect levels , erase/programming times ,power consumptions and device operation behavior under different compliance current. Hoping our study will give other researchers help and contributions to RRAM.

References
[1] D. Kahng and S. M. Sze, “A Floating Gate and Its application to Memory
Devises,” Bell Syst. Tech. J., 46, 1283 (1967).
[2] “International Technology Roadmap for Semiconductors, 2007 update” at
http://public.itrs.net/Files/2007Update/Home.pdf.
[3] J. C. Bruyere and B. K. Chakraverty, Appl. Phys. Lett. 16, 40(1970).
[4] Zhuang, W.W. et al“ Novel1 Colossal Magnetoresistive Thin Film Nonvolatile
Resistance Random AccessMemory (RRAM) ” sharp IEDM 2002.
[5] Peiqi Xuan, Min She, Bruce Harteneck, Alex Liddle, Jefkey Bokor, and Tsu-Jae
King, “FinFET SONOS Flash Memory for Embedded Applications”, IEEE
IEDM, p. 609-612 (2003).
[6] 張文淵, 以LaNiO3底電極開發(Pr,Ca)MnO3非揮發性電阻式記憶體特性
之研究. 清華大學, 碩士論文, 2006.
[7] H. Y. Lee et al, “ Low Power and High Speed Bipolar Switching with A Thin
Reactive Ti Buffer Layer in Robust HfO2 Based RRAM” ITRI IEEE IEDM 2008.
[8]張文淵, 以LaNiO3底電極開發(Pr,Ca)MnO3非揮發性電阻式記憶體特性
之研究. 清華大學, 碩士論文, 2006.
[9]余昭倫, 縱觀新世代記憶體-相變化記憶(PCRAM). Digitimes 技術 IT,
2006.
[10] Gerhard Muller, T.H., Micheal Kund, Gill Yong Lee, Nicolas Nagel, and
Recai Sezi, Status and outlook of emerging nonvolatole memory
technologies. IEEE, 2004.
[11] Liu, S.Q., N.J. Wu, and A. Ignatiev, Electric-pulse-induced reversible
resistance change effect in magnetoresistive films. Applied Physics
Letters, 2000. 76(19): p. 2749-2751.
[12] Sawa, A., et al., Hysteretic current-voltage characteristics and
87
resistance switching at a rectifying Ti/Pr0.7Ca0.3MnO3 interface.
Applied Physics Letters, 2004. 85(18): p. 4073-4075.
[13] Beck, A., et al., Reproducible switching effect in thin oxide films for
memory applications. Applied Physics Letters, 2000. 77(1): p. 139-141.
[14] Ma, L.P., et al., Organic bistable light-emitting devices (vol 80, pg 362,
2002). Applied Physics Letters, 2002. 80(16): p. 3018-3018.
[15] Ma, L.P., J. Liu, and Y. Yang, Organic electrical bistable devices and
rewritable memory cells. Applied Physics Letters, 2002. 80(16): p.
2997-2999.
[16] Seo, S., et al., Reproducible resistance switching in polycrystalline NiO
films. Applied Physics Letters, 2004. 85(23): p. 5655-5657.
[17] I. G Baek, M.S.L., S. Seo, M. J. Lee, D. H. Seo, D. S. Suh, J. C. Park, H.
104 S. Kim, I. K. Yoo, U. I. Chung, and J. T. Moon, Highly Scalable
Non-volatile Resistive Memory using Simple Binary Oxide Driven by
Asymmetric Unipolar Voltage Pulses. IEDM Tech. Dig., 2004.
[18] Chang, W.Y., et al., Unipolar resistive switching characteristics of ZnO
thin films for nonvolatile memory applications. Applied Physics Letters,
2008. 92(2): p. 3.
[19] Kyung Min Kim, Byung Joon Choi, Yong Cheol Shin, Seol Choi, and Cheol
Seong Hwang, “Anode-interface localized filamentary mechanism in resistive
switching of TiO2 thin films,” Appl. Phys. Lett., vol. 91, p. 012907, Jul. 2007.
[20] 施敏 半導體元件物理.
[21] Akihito Sawa, “Resistive Switching in Transition Metal oxides,” Materialstoday,
Vol. 11, 2008, pp. 28-36.
[22] J. E. Ralph, and J. M. Woodcock, “A new filamentary model for voltage formed
amorphous oxide films,” J. Non-Cryst. Solids, vol. 7, pp. 236-250, Apr. 1972.
[23] I. Emmer, “Conducting filaments and voltage-controlled negative resistance in
88
Al-Al2O3-Au structures with amorphous dielectric,” Thin Solid Films, vol. 20, pp.
43-52, Jan. 1974.
[24] Christina Rohde, Byung Joon Choi, Doo Seok Jeong, Seol Choi, Jin-Shi Zhao,
and Cheol Seong Hwang, “Identification of a determining parameter for resistive
switching TiO2 thin films,” Appl. Phys. Lett., vol. 86, p. 262907, Jun. 2005.
[25] Christina Rohde, Byung Joon Choi, Doo Seok Jeong, Seol Choi, Jin-Shi Zhao,
and Cheol Seong Hwang, “Identification of a determining parameter for
resistive switching TiO2 thin films,” Appl. Phys. Lett., vol. 86, p. 262907, Jun.
2005.
[26] Kyung Min Kim, Byung Joon Choi, and Cheol Seong Hwang, “Localized
switching mechanism in resistive switching of atomic-layer-deposited TiO2 thin
films,” Appl. Phys. Lett., vol. 90, p. 242906, Jun. 2007.
[27] An Chen, Sameer Haddad, Yi-Ching (Jean) Wu, Tzu-Ning Fang, Zhida Lan,
Steven Avanzino, Suzette Pangrle, Matthew Buynoski, Manuj Rathor, Wei
(Daisy) Cai, Nick Tripsas, Colin Bill, Michael VanBuskirk, and Masao Taguchi,
“Non-Volatile Resistive Switching for Advanced Memory Applications,” Tech.
Dig. – Int. Electron Devices Meet. pp 746-749 Dec. 2005.
[28] A. Sawa, T. Fujii, M. Kawasaki, and Y. Tokura, “Hysteretic current-voltage
characteristics and resistance switching at a rectifying Ti/Pr0.7Ca0.3MnO3
interface,” Appl. Phys. Lett., vol. 85, pp. 4073-4075, Nov. 2004.
[29] M. J. Rozenberg, I. H. Inoue, M. J. Sánchez, “Strong electron correlation effects
in nonvolatile electronic memory devices” Appl. Phys. Lett., vol. 88, p. 033510,
Jan. 2006.
[30] M. J. Rozenberg, I. H. Inoue, and M. J. Sa´nchez, “Nonvolatile Memory with
Multilevel Switching: A Basic Model,” Phys. Rev. Lett,” vol. 92, 178302-1,April
2004.
[31] M. J. Sánchez, M. J. Rozenberg, and I. H. Inoue, “A mechanism for unipolar
resistance switching in oxide nonvolatile memory devices,” Appl. Phys. Lett.,
vol. 91, p. 252101, Dec. 2006.
89
[32] L. Courtade, Ch. Turquat, Ch. Muller, J.G. Lisoni, L. Goux, D.J. Wouters, D.
Goguenheim, P. Roussel, L. Ortega, “Oxidation kinetics of Ni metallic films:
Formation of NiO-based resistive switching structures,” Thin Solid Films 516
(2008) 4083– 4092.
[33] Dongsoo Lee, Dong-jun Seong, Hye jung Choi, Inhwa Jo, R. Dong, W. Xiang,
Seokjoon Oh, Myeongbum Pyun, Sun-ok Seo, Seongho Heo, Minseok Jo,
Dae-Kyu Hwang, H. K. Park, M. Chang, M. Hasan, and Hyunsang Hwang,
“Excellent uniformity and reproducible resistance switching characteristics of
doped binary metal oxides for non-volatile resistance memory applications,”
Tech. Dig. – Int. Electron Devices Meet., 2006, pp. 1-4.
[34] Yin-Pin Yang, and Tseung-Yuen Tseng, “Electronic defect and trap-related
current of (Ba0.4Sr0.6)TiO3 thin films,” J. Appl. Phys., vol. 81, pp. 6762-6766,
May. 1997.
[35] Chun-Chieh Lin, Bing-Chung Tu, Chao-Cheng Lin, Chen-His Lin, and
Tseung-Yuen Tseng, “Resistive switching mechanisms of V-doped SrZrO3
memory films,” IEEE Electron Device Lett., vol.27, pp. 725-727, 2006.
[36] Jae-Wan Park, Kyooho Jung, Min Kyu Yang, and Jeon-Kook Lee, Dal-Young
Kim, and Jong-Wan Park, “Resistive switching characteristics and set-voltage
dependence of low-resistance state in sputter-deposited SrZrO3:Cr memory
films,” J. Appl. Phys., vol. 99, p. 124102, Jun. 2006.
[37] Markus Janousch, Gerhard Ingmar Meijer, Urs Staub, Bernard Delley, Siegfried
F. Karg, and Björn Pererik Andreasson, “Role of oxygen vacancies in Cr-doped
SrTiO3 for resistance-change memory,” Adv. Mater., vol. 19, pp. 2232-2235, Sep.
2007.
[38] Kyung Min Kim, Byung Joon Choi, Doo Seok Jeong, Cheol Seong Hwang, and
Seungwu Han, “Influence of carrier injection on resistive switching of TiO2 thin
films with Pt electrodes,” Appl. Phys. Lett., vol. 89, p. 162912, Oct. 2006.
[39] John R. Jameson, Yoshiaki Fukuzumi, Zheng Wang, Peter Griffin, Koji Tsunoda,
G. Ingmar Meijer, and Yoshio Nishi, “Field-programmable rectification in rutile
TiO2 crystals,” Appl. Phys. Lett., vol. 91, p. 112101, Sep. 2007.
[40] Chih-Yang Lin, Chen-Yu Wu, Chung-Yi Wu, Chenming Hu, and Tseung-Yuen
90
Tseng, “Bistable Resistive Switching in Al2O3 Memory Thin Films,” Journal of
The Electrochemical Society, 154 9 G189-G192 2007.
[41] Heng Yuan Lee, Pang Shiu Chen, Tai Yuan Wu, Ching Chiun Wang, Pei Jer
Tzeng, Cha Hsin Lin, Frederick Chen, Ming-Jinn Tsai, and Chenhsin Lien,
“Electrical evidence of unstable anodic interface in Ru/HfOx /TiN unipolar
resistive memory,” Appl. Phys. Lett., vol. 92, p. 142911, Apr. 2008.
[42] Masayuki Fujimoto, Hiroshi Koyama, Masashi Konagai, Yasunari Hosoi,
Kazuya Ishihara, Shigeo Ohnishi, and Nobuyoshi Awaya, “TiO2 anatase
nanolayer on TiN thin film exhibiting high-speed bipolar resistive switching,”
Appl. Phys. Lett., vol. 89, p. 223509, Nov. 2006.
[43] L. F. Liu, H. Tang, Y. Wang, D. Y. Tian, X. Y. Liu, X. Zhang, R. Q. Han, and J.
F.Kang, “Reversible resistive switching of Gd-doped TiO2 thin films for
nonvolatile memory applications,” Inf. Conf. Solid-State and Integrated Circuit
Technology, 2006, pp. 833-835.
[44] Kyng Min Kim, Byung Joon Choi, Bon Wook Koo, Seol Choi, Doo Seok Jeong,
and Cheol Seong Hwang, “Resistive switching in Pt/Al2O3/TiO2/Ru
stackedstructures,” Electrochem. Solid-State Lett., vol. 9, pp. G343-G346, Sep. 2006.
[45] Kyung Min Kim, Byung Joon Choi, and Cheol Seong Hwang, “Localized
switching mechanism in resistive switching of atomic-layer-deposited TiO2 thin
films,” Appl. Phys. Lett., vol. 90, p. 242906, Jun. 2007.
[46] Kyng Min Kim, Byung Joon Choi, Bon Wook Koo, Seol Choi, Doo Seok Jeong,
and Cheol Seong Hwang, “Resistive switching in Pt/Al2O3/TiO2/Ru
stackedstructures,” Electrochem. Solid-State Lett., vol. 9, pp. G343-G346, Sep. 2006.
[47] Kyung Min Kim, Byung Joon Choi, and Cheol Seong Hwang, “Localized
switching mechanism in resistive switching of atomic-layer-deposited TiO2 thin
films,” Appl. Phys. Lett., vol. 90, p. 242906, Jun. 2007.
[48] Markus Janousch, Gerhard Ingmar Meijer, Urs Staub, Bernard Delley, Siegfried
F. Karg, and Björn Pererik Andreasson, “Role of oxygen vacancies in Cr-doped SrTiO3 for resistance-change memory,” Adv. Mater., vol. 19, pp. 2232-2235, Sep.2007.91[49] http://en.wikipedia.org/wiki.
[50] 黃志文, 利用熱氧化法製備氧化銅薄膜於電阻式轉態記憶體之研究. 交通大學, 碩士論文, 2008.
[51] 王韋婷, 應用在RRAM 記憶體之氧化鋅薄膜及其電極材料開發. 清華大學,碩士論文, 2009.