電機資訊學院: 電子工程學研究所指導教授: 胡振國曾冠豪Tseng, Kuan-HaoKuan-HaoTseng2017-03-062018-07-102017-03-062018-07-102016http://ntur.lib.ntu.edu.tw//handle/246246/276486本篇論文中，我們製備了金屬閘極外圍被超薄金屬環繞的超薄閘極氧化層金氧半穿隧二極體。本研究中，元件圖形的內圈為圓形厚金屬鋁，外圈則是擁有高電阻特性的超薄金屬環形電極。在論文的第三章，外圍有環形超薄金屬電極的金氧半穿隧二極體，其反轉區飽和電流較一般的金氧半穿隧二極體來得小，這是因為在鋁 / 超薄二氧化矽 / p型矽的金氧半結構中，反轉區的飽和電流是由邊緣電場所控制，而此飽和電流值下降的原因在於外圍超薄金屬扮演著類似電阻的角色，抑制了元件周邊的電場使得反轉區的飽和電流下降。此外在電容電壓曲線中也發現，外圍有超薄金屬環繞之金氧半穿隧二極體的累積區電容，其值較傳統金氧半穿隧二極體的小，這說明了超薄金屬的等效面積比實際物理面積來得小。在論文的第四章，對金氧半穿隧二極體施加脈衝偏壓後可發現正負之雙態電流現象，這和傳統動態隨機存取記憶體利用充電放電機制判讀狀態0和狀態1的方式不同。因為外圍超薄金屬的存在，閘極不再處處等電位，此機制使得雙態電流特性較傳統金氧半穿隧二極體的更為被放大。此外，元件的信號維持時間為650毫秒，符合ITRS對於動態隨機存取記憶體維持時間64毫秒的標準。綜合來說，本篇論文中探討的元件具有易於判讀的雙態電流而且製程簡單的優點，相當有應用於記憶體元件的潛力。In this thesis, a Metal-Insulator-Semiconductor (MIS) tunnel diode with an ultrathin oxide and with a metal gate electrode surrounded by ultrathin metal was fabricated. The pattern of the device in this work is a circle with thicker metal encircled by a circular electrode with ultrathin metal, which has a high-resistance property. In chapter 3, the declined saturated gate current under inversion region was demonstrated compared to that of a traditional MIS tunnel diode whose saturated gate inversion current is influenced by the fringing field effect in an Al / ultrathin SiO2 / p-Si MIS structure. The current reduction phenomenon is attributed to the fact that the ultrathin metal structure plays a role like a resistance which suppresses the fringing field effect at the gate edge. Also, the C-V curves show the analogous experimental results that the effective gate area of ultrathin metal is more subtle than practically physical area of gate metal owing to the big difference in accumulation capacitance. In chapter 4, the two-state current phenomenon with opposite read current sign was observed after applying voltage pulses. It is quite different from the traditional DRAM with charged and discharged states which can be represented as “0” state and “1” state. With the help of surrounding ultrathin metal, the potential distribution of gate electrode is no longer equivalent everywhere, and the two state currents are magnified compared to those of a traditional MIS tunnel diode. Further, the retention time constant of the device reaches a value of 650ms, which matches the 64ms requirement of ITRS. In summary, the device discussed in this thesis is the promising candidate to be applied into memory application on account of its advantages of distinguishable two state currents and simple processes for semiconductor industry to fabricate.2857421 bytesapplication/pdf論文公開時間: 2021/7/26論文使用權限: 同意有償授權(權利金給回饋學校)雙態電流金氧半元件超薄閘極金屬揮發性記憶體動態隨機存取記憶體two state currentMIS devicesultrathin gate metalvolatile memoryDRAMthesis10.6342/NTU201601002http://ntur.lib.ntu.edu.tw/bitstream/246246/276486/1/ntu-105-R03943060-1.pdf