鐵電與反鐵電Hf1-xZrxO2多階操作及暫態負電容於低功耗記憶體內運算之應用
dc.contributor | 李敏鴻 | zh_TW |
dc.contributor | Lee, Min-Hung | en_US |
dc.contributor.author | 謝馥竹 | zh_TW |
dc.contributor.author | Hsieh, Fu-Jhu | en_US |
dc.date.accessioned | 2022-06-08T02:28:54Z | |
dc.date.available | 9999-12-31 | |
dc.date.available | 2022-06-08T02:28:54Z | |
dc.date.issued | 2021 | |
dc.description.abstract | 在過去的十年中,鐵電材料被作為熱門的研究題目之一,當鐵電應用在電晶體時,具有電壓放大、能降低次臨界斜率(SS)突破60mV/dec的極限和負電容特性 (Negative Capacitance, NC),所以負電容也是FeFET應用中的重要課題。為了理解NC效應的頻率響應,我們在Hafnium–zirconium oxide (HZO)中配置了不同的Zr濃度,不同的電容器連接模式(並聯或串聯)以及不同的電容器面積,以提高負電容效應。兩種方法分別顯示了不同頻率測量下NC的影響,得到了以下兩個結論,第一個並聯使用兩個HZO電容器以增加HZO電容器的總電容; 第二個將高電容的HZO電容器與介電電容器串聯使用,以通過不同頻率C-V測量的NC效應獲得電容放大。我們研究了HZO基材料中三種Zr濃度([Zr]=50%,75%,90%),以證明帶有FE和AFE電容器的NC的頻率響應。最後總結來說,並聯連接的HZO-Zr50%+ HZO-Zr75%可以在<30 kHZ的頻率下獲得更高的電容,這表明存在NC效應。 在記憶體的應用,基於鐵電HfO2閘極堆疊的鐵電場效電晶體(FeFET),具有穩定遲滯現象(Hysteresis)和非破壞性讀取的特性,可用於多級單元(MLC)操作的非揮發性記憶體(NVM)。矯頑電場(EC)和殘餘極化(Pr)都是鐵電薄膜改變FeFET閾值電壓(VT)的決定性參數。在這項工作中,採用HZO不同厚度和濃度的調控來實現每一個記憶單元下可存入2~3位元的NVM。 在成功做出記憶體之後,未來可能面臨的問題不外乎為記憶體可靠度的提升。我們知道當HZO中的Zr濃度為50%時,會形成典型的FE。從FE的遲滯曲線可以看出,極化可以在沒有外部電壓的情況下存儲,並且正向和反向掃描將有兩個閾值電壓(VT),可以將其定義為“ 0”和“ 1”以用於非揮發性記憶體。當Zr為75%時,它將變為AFE。在沒有電場的作用下,AFE的遲滯曲線在兩階之間顯示出很小的差異,因此不適合用於非揮發性記憶體。實驗的目的是使用高濃度Zr(75%)Hf0.25Zr0.75O2分別在上下電極使用不同功函數材料。由功函數差異產生的內建電場將AFE的遲滯曲線移位,因此完成不施加偏壓的即可產生非揮發性記憶體的特性,使AFE與FE有相同的記憶特性。進而我們可以使用較小範圍的電壓來操作記憶體,從而可以降低功耗並延長記憶體的使用壽命。 | zh_TW |
dc.description.abstract | During the past decades, ferroelectric materials are one of the most promising research topics for advanced CMOS. As ferroelectric technology is applied for transistors, the voltage amplification, with subthreshold slope (SS) improvement for negative capacitance (NC) characteristics. In order to understand the frequency bandwidth of NC effect, the various Zr concentrations in HZO and capacitor connection modes (parallel or series) with ratio of area. The HZO-Zr50% + HZO-Zr75% in parallel connection has higher capacitance at the frequency< 30 kHZ and this indicating the NC effect. Ferroelectric field effect transistor (FeFET) has also been studied due to non-destructive readout characteristics. The modulation of HZO thickness and Zr concentration is employed in this thesis to achieve Multi-Level Cell (MLC) non-volatile memory (NVM) of 2~3-bits each memory cell. The one of challenges for FeFET would be the reliability and power consumptions. The AFE may pave the solution due to a small range of acess voltage to operate memoryand excellent reliability. However , the small or close to zero Pr at zero electric field, maybe the issue to using AFE in NVM application.. The last experiment part in my thesis is to use high-concentration Zr (75%) Hf0.25Zr0.75O2 capacitors with high and low work function materials electrodes to make built-in bias. | en_US |
dc.description.sponsorship | 光電工程研究所 | zh_TW |
dc.identifier | 60877025H-39737 | |
dc.identifier.uri | https://etds.lib.ntnu.edu.tw/thesis/detail/01a865a22f3cfc5cf69a56294fc634be/ | |
dc.identifier.uri | http://rportal.lib.ntnu.edu.tw/handle/20.500.12235/116533 | |
dc.language | 英文 | |
dc.subject | 鐵電材料 | zh_TW |
dc.subject | 氧化鉿鋯 | zh_TW |
dc.subject | 鐵電記憶體 | zh_TW |
dc.subject | 功函數調控 | zh_TW |
dc.subject | Ferroelectric field effect transistor | en_US |
dc.subject | Hafnium-Zirconium-Oxide | en_US |
dc.subject | modulation the flat band voltage | en_US |
dc.title | 鐵電與反鐵電Hf1-xZrxO2多階操作及暫態負電容於低功耗記憶體內運算之應用 | zh_TW |
dc.title | Ferroelectric and Antiferroelectric Hf1-xZrxO2 of Multibit Cell and Transient Negative Capacitance for Low Power Computing-in-Memory Application | en_US |
dc.type | 學術論文 |