本文關(guān)鍵詞：SONOS存儲(chǔ)器保持特性模型及存儲(chǔ)層退火工藝研究　出處：《華中科技大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： SONOS存儲(chǔ)器 退火 保持特性 陷阱分布 存儲(chǔ)層

【摘要】：隨著對(duì)存儲(chǔ)要求的增加，非揮發(fā)性存儲(chǔ)器的市場(chǎng)增長(zhǎng)速度非常快，，尤其是閃存存儲(chǔ)器，因此閃存存儲(chǔ)器的發(fā)展越來(lái)越受大家的關(guān)注。SONOS存儲(chǔ)器可避免懸浮柵存儲(chǔ)器的缺點(diǎn)如耦合率顯著降低、浮柵干擾嚴(yán)重、工作電壓偏高和漏電嚴(yán)重等，且具有工藝簡(jiǎn)單、操作速度快、保持時(shí)間長(zhǎng)、存儲(chǔ)密度高等特點(diǎn)，是未來(lái)存儲(chǔ)器發(fā)展的方向。因此改善其性能參數(shù)成為目前研究的熱點(diǎn)之一。本文是以SONOS存儲(chǔ)器為研究對(duì)象，通過(guò)采用高k存儲(chǔ)層材料和不同淀積后退火工藝來(lái)研究存儲(chǔ)器的特性，并建立電荷保持特性模型，分析存儲(chǔ)層陷阱空間分布。 本文采用了反應(yīng)濺射法制備了LaTiON和HfLaON作為存儲(chǔ)層的MONOS電容存儲(chǔ)器，研究了不同退火工藝對(duì)存儲(chǔ)特性的影響。實(shí)驗(yàn)結(jié)果表明LaTiON樣品中，Ti-NH3樣品具有較好的電荷保持特性和編程/擦除速度，但疲勞特性較差；HfLaON樣品中，Hf-NH3樣品具有更好的存儲(chǔ)特性；二者比較發(fā)現(xiàn)Hf-NH3樣品具有最好的存儲(chǔ)特性，NH3退火HfLaON是最具潛力的存儲(chǔ)層材料。 本文首先分析了隧穿層厚度、陷阱深度和溫度對(duì)最主要兩種電荷泄漏機(jī)制(陷阱-襯底導(dǎo)帶隧穿和熱發(fā)射)的影響，得出常溫下陷阱-襯底導(dǎo)帶隧穿是最主要的電荷泄漏機(jī)制；建立了考慮陷阱分布對(duì)電荷保持特性影響的電荷保持特性模型；分析了陷阱空間和能量分布對(duì)電荷保持特性的影響。結(jié)果表明陷阱空間分布為局域分布有助于改善電荷保持特性；當(dāng)隧穿層厚度較薄時(shí)，陷阱能量分布為局域分布利于改善電荷保持特性；當(dāng)隧穿層厚度較厚時(shí)，陷阱能量分布為三角形分布有助于改善電荷保持特性。 利用模型分析實(shí)驗(yàn)中兩組樣品的存儲(chǔ)層陷阱空間分布發(fā)現(xiàn)LaTiON樣品的存儲(chǔ)層陷阱空間分布為均勻分布；Hf-no樣品和Hf-NH3樣品的存儲(chǔ)層陷阱空間分布為局域分布，而Hf-N2樣品的存儲(chǔ)層陷阱空間分布為均勻分布。該結(jié)論進(jìn)一步說(shuō)明N2退火調(diào)整了HfLaON樣品的陷阱分布。根據(jù)修正因子，推斷出NH3退火LaTiON樣品的陷阱深度最深。HfLaON樣品的陷阱深度比LaTiON樣品淺。
[Abstract]:With the increasing demand for storage, the market of non-volatile memory is growing very fast, especially flash memory. Therefore, the development of flash memory has attracted more and more attention. SONOS memory can avoid the disadvantages of suspended gate memory, such as significantly reduced coupling rate, serious floating gate interference, high working voltage and serious leakage. The utility model has the advantages of simple process, fast operation speed, long retention time and high storage density. It is the direction of memory development in the future. Therefore, improving its performance parameters has become one of the research hotspots. This paper takes SONOS memory as the research object. The characteristics of the memory are studied by using high-k storage layer materials and different post-deposition annealing processes, and the charge-retention characteristic model is established to analyze the spatial distribution of storage layer traps. In this paper, MONOS capacitive memory with LaTiON and HfLaON as storage layer was fabricated by reactive sputtering method. The effects of different annealing processes on the storage characteristics were studied. The experimental results showed that the Ti-NH3 samples in LaTiON samples had better charge retention characteristics and programming / erasure rate, but the fatigue characteristics were poor. The Hf-NH _ 3 sample of HfLaON has better storage characteristics. It is found that Hf-NH3 samples have the best storage properties and NH3 annealed HfLaON is the most promising storage layer material. In this paper, the effects of tunneling layer thickness, trap depth and temperature on the two main charge leakage mechanisms (trap-substrate conduction tunneling and thermal emission) are analyzed. It is concluded that the main mechanism of charge leakage is trap-substrate conduction tunneling at room temperature. A charge-retention model considering the effect of trap distribution on charge-retention characteristics is established. The effects of trap space and energy distribution on charge retention characteristics are analyzed. When the thickness of tunneling layer is thin, the local distribution of trap energy is helpful to improve the charge retention characteristics. When the tunneling layer thickness is thicker, the trap energy distribution is triangular, which is helpful to improve the charge retention characteristics. The spatial distribution of storage layer traps of LaTiON samples was found to be uniform by using the model analysis of the two groups of samples. The storage layer trap spatial distribution of Hf-no and Hf-NH3 samples is localized. However, the storage layer trap spatial distribution of Hf-N2 samples is uniform. This conclusion further indicates that N2 annealing adjusts the trap distribution of HfLaON samples. It is inferred that the trap depth of LaTiON sample annealed by NH3 is the deepest. The trap depth of HF Laon sample is lower than that of LaTiON sample.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TP333

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相關(guān)期刊論文 前2條

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