基于Si掺杂Sb2Te3薄膜的相变存储器研究

采用磁控三靶(Si，Sb及Te)共溅射法制备了Si掺杂Sb₂Te₃薄膜，作为对比，制备了Ge₂Sb₂Te₅和Sb₂Te₃薄膜，并且采用微加工工艺制备了单元尺寸为10μm×10μm的存储器件原型来研究器件性能.研究表明，Si掺杂提高了Sb₂Te₃薄膜的晶化温度以及薄膜的晶态和非晶态电阻率，使得其非晶态与晶态电阻率之比达到10⁶，提高了器件的电阻开/关比；同Ge₂Sb₂Te₅薄膜相比，16at% Si掺杂Sb₂Te₃薄膜具有较低的熔点和更高的晶态电阻率，这有利于降低器件的RESET电流.研究还表明，采用16at% Si掺杂Sb₂Te₃薄膜作为存储介质的存储器器件原型具有记忆开关特性，可以在脉高3V、脉宽500ns的电脉冲下实现SET操作，在脉高4V、脉宽20ns的电脉冲下实现RESET操作，并能实现反复写/擦，而采用Ge₂Sb₂Te₅薄膜的相同结构的器件不能实现RESET操作. 关键词： 相变存储器 硫系化合物 2Te₃薄膜')" href="#">Si掺杂Sb₂Te₃薄膜 SET/RESET转变

Study of Si-doped Sb2Te3 films for phase change memory

Silicon doped Sb₂Te₃ films were deposited by three target (Si, Sb and Te) co-sputtering. For comparison, Ge₂Sb₂Te₅ and Sb₂Te₃ films were also prepared. Memory cells (pore size=10 μm×10　μm) were fabricated by micro-fabrication to further study their storage performance. Results indicate that silicon doping increases the crystallization temperature. Meanwhile, silicon doping drastically enhances the resistivity ratio (high resistance state/low resistance state) to 10⁶ by increasing both amorphous resistivity and crystal resistivity so as to further increasing the ON/OFF ratio of memory cell. Compared with Ge₂Sb₂Te₅ film, 16at%Si-Sb₂Te₃ film has a higher crystalline resistivity and lower melting temperature, which are helpful to the reduction of RESET current. Memory cell with silicon doped Sb₂Te₃ film poccesses memory storage characteristics, and it can be reversibly switched between the high resistance state (RESET status) and the low resistance state (SET status). The SET status can be triggered by electrical pulse of 3V, 500ns and it comes back to the RESET status when 4V, 20ns pulse is applied, while Ge₂Sb₂Te₅ cells, with the same structure can't be switched back to RESET state.