Investigation on the resistive switching mechanisms and fabrication of recoverable RRAM device

• Main Authors: Jheng-Jie Huang, 黃正杰
• Other Authors: Ting-Chang Chang
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/95530858380377695305

博士 === 國立中山大學 === 物理學系研究所 === 101 === With the development of portable electronic products, the requirement of nonvolatile memory is higher than before. In order to increase the capacity of nonvolatile memory in portable electronic products, the nonvolatile memory device must be scaled down. However, traditional nonvolatile floating gate memory is confronting some physical limits as devices continuously scale down. Hence, it is necessary to develop other kinds of nonvolatile memory, and resistive random access memory (RRAM) is considered one of the most potential candidates of the next generation. However, the switching mechanism or some problems about RRAM has not been solved. Hence, this study will investigate the switching mechanism of RRAM and provide a RRAM device with recoverable property. In addition, the I-V cures will be analyzed during the recovering process. In the first part, we proposed gallium oxide based RRAM devices with various oxygen concentration, and investigated the switching mechanism of gallium oxide with different oxygen concentration, because the resistive switching behavior is related to the migration of oxygen ion. In the second part, we proposed a RRAM device with Pt/BiFeO3/TiN structure and investigated the resistive switching characteristics of BiFeO3 film. The resistive switching layer of BiFeO3 film exhibits some interesting properties. The resistive switching of BiFeO3 can be improved by applied DC bias without thermal anneal process. Furthermore, the resistive switching characteristic of BiFeO3 film can be recovered by constant current stress after hard breakdown. In the third part, we design a RRAM device with Pt/InO/SiO2/TiN structure which has fast recoverable characteristic. After hard breakdown process, the RRAM device with Pt/InO/SiO2/TiN exhibits fast recoverable property by constant current stress, and the recovering process is investigated by the analysis of carrier transport. Finally, the indium-gallium-zinc-oxide (a-IGZO) TFTs exhibit transistor and RRAM characteristic after particular forming process, and this additional function can increase the value of a-IGZO TFTs for display industry.