采用低成本、高效率的压印技术实现了高密度相变存储器(PCRAM)存储阵列的制备,开发出Si2Sb2Te5(SST)新材料的4Gbit/inch。存储阵列,存储单元面积为0.04μm2;利用SEM观测压印获得的光刻胶图形阵列以及刻蚀后的SST存储阵列,其单元外形均具有高度的一致性,且单元特征尺寸的3倍标准差均小于6nm;利用AFM研究了SST存储单元的Ⅰ-Ⅴ特性,阂值电压为1.56V,高、低电阻态阻值变化超过两个数量级。实验结果表明了SST新材料及压印技术在PCRAM芯片中的应用价值。
High-density phase change material arrays fabricated by a low cost and high efficient method were considered to be able to speed up research and development of the phase change random access memory (PCRAM), which was characteristic of low-voltage, low-power, fast reading/writing. The Si2Sb2Te5 (SST) based PCRAM array with density of 4 Gbit/inch2 was fabricated by UV-imprint lithography (UV-IL), the PCRAM cell was with size of 0.04μm2. Dimension stability of the array cell was analyzed with SEM, in each case, the 3σ values was less than 6 nm. Due to the small size of PCRAM cell, Ⅰ-Ⅴ performance was measured by a conductive nano-tip on an atomic fore microscope and the typical Ⅰ-Ⅴ curve of the cells was with a threshold voltage of 1. 56 V. The resistance contrast of high-resistance state and low-resistance state is more than two orders according to the bV curve. The results show that the SST and UV-IL have potential enormous application in the low-voltage, high-speed PCRAM chip.