| 학회 | 한국재료학회 |
| 학술대회 | 2017년 가을 (11/15 ~ 11/17, 경주 현대호텔) |
| 권호 | 23권 2호 |
| 발표분야 | A. 전자/반도체 재료 분과 |
| 제목 | Enhancement of the TMR ratio for Double MgO based Perpendicular Magnetic-tunnel-junction Spin-valve by reducing Synthetic-anti-ferromagnetic Multi-layers |
| 초록 | Recently, conventional memories such as dynamic random access memory (DRAM) have faced their limitation like scaling down. Alternatively, new memories have been researched to replace conventional memories. Among them, perpendicular-spin-transfer torque magnetic random access memory (p-STT MRAM) has received attention for the candidate of alternative memory. STT-MRAM has low power consumption, read and write speed according to DRAM and non-volatility. For the commercialization of STT-MRAM, however, some critical parameters have to be improved. One of them is the tunneling magnetoresistance (TMR) ratio that means difference of high resistance and low resistance. STT-MRAM consists of 1 transistor and 1 resistor called magnetic tunnel junction (MTJ). In our study, we investigated to enhance the TMR ratio on CoFeB/MgO based p-MTJ by reducing synthetic-anti-ferromagnetic (SyAF) multi-layers. The dependence of the TMR ratio on the thickness of W bridge layer was estimated by using current-in-plane tunneling (CIPT) at room temperature. The TMR ratio of p-MTJ spin-valve having conventional SyAF multi-layers slightly increases up to 0.25 nm thickness of W bridge layer and abruptly decreases beyond 0.34 nm. On the other hand, The TMR ratio of p-MTJ spin-valve having reduced SyAF multi-layers slightly increases up to 0.3 nm and abruptly decreases beyond 0.37 nm. The maximum TMR ratio of conventional p-MTJ is 156 % while that of reduced p-MTJ is 180 %. In our presentation, we will demonstrate improvement of TMR ratio by reducing SyAF layers and explain how TMR ratio can be improved by examining crystallinity, magnetization behavior and TMR raio characteristics. Acknowledgment * This work was supported by a Basic Science Research Program grant from the National Research Foundation of Korea (NRF) funded by the Korean government (MSIP) (No. 2017R1A2A1A05001285) and the Brain Korea 21 PLUS Program in 2014. |
| 저자 | 이동기, 최진영, Kondo Kei, 백종웅, 박재근 |
| 소속 | 한양대 |
| 키워드 | <P>TMR ratio; p-MTJ; SyAF multi-layers; Crystallinity; Magnetic tunneling</P> |
