Department of Materials Science and Engineering, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan, Republic of China.
Nanotechnology. 2012 Jun 8;23(22):225703. doi: 10.1088/0957-4484/23/22/225703. Epub 2012 May 10.
An extremely large memory window shift of about 30.7 V and high charge storage density =2.3 × 10(13) cm(-2) at ± 23 V gate voltage sweep were achieved in the nonvolatile floating gate memory (NFGM) device containing the AgInSbTe (AIST)-SiO(2) nanocomposite as the charge trap layer and HfO(2)/SiO(2) as the blocking oxide layer. Due to the deep trap sites formed by high-density AIST nanocrystals (NCs) in the nanocomposite matrix and the high-barrier-height feature of the composite blocking oxide layer, a good retention property of the device with a charge loss of about 16.1% at ± 15 V gate voltage stress for 10(4) s at the test temperature of 85 °C was observed. In addition to inhibiting the Hf diffusion into the programming layer, incorporation of the SiO(2) layer prepared by plasma-enhanced chemical vapor deposition in the sample provided a good Coulomb blockade effect and allowed significant charge storage in AIST NCs. Analytical results demonstrated the feasibility of an AIST-SiO(2) nanocomposite layer in memory device fabrication with a simplified processing method and post-annealing at a comparatively low temperature of 400 °C in comparison with previous NC-based NFGM studies.
在包含 AgInSbTe(AIST)-SiO2 纳米复合材料作为电荷俘获层和 HfO2/SiO2 作为阻挡氧化层的非易失性浮栅存储器 (NFGM) 器件中,实现了约 30.7V 的极高存储窗口位移和高电荷存储密度=2.3×10(13)cm(-2),在±23V 栅极电压扫描下。由于纳米复合材料基质中高密度 AIST 纳米晶体 (NCs) 形成的深陷阱位和复合阻挡氧化层的高势垒高度特性,该器件具有良好的保持特性,在测试温度为 85°C 时,在±15V 栅极电压应力下,经过 10(4)s 的测试,电荷损失约为 16.1%。除了抑制 Hf 向编程层的扩散之外,在样品中掺入通过等离子体增强化学气相沉积制备的 SiO2 层提供了良好的库仑阻塞效应,并允许在 AIST NCs 中进行显著的电荷存储。分析结果表明,与以前基于 NC 的 NFGM 研究相比,采用简化的处理方法和在 400°C 相对较低温度下进行后退火,在制造存储器件方面,AIST-SiO2 纳米复合材料层是可行的。