Han Jeong Hwa, Jeong Hun, Park Hanjin, Kwon Hoedon, Kim Dasol, Lim Donghyeok, Baik Seung Jae, Kwon Young-Kyun, Cho Mann-Ho
Department of Physics, Yonsei University Seoul 03722 Republic of Korea
Department of Physics, Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea
RSC Adv. 2021 Jun 25;11(36):22479-22488. doi: 10.1039/d1ra02210e. eCollection 2021 Jun 21.
In this study, we investigated the effect of phase-change characteristics on the device performance of carbon-incorporated GeSbTe (CGST) to understand the origin of the enhanced reliability and stabilization of the device. Macroscopic and microscopic measurements confirmed that the structural stability significantly increased with the incorporation of as much as 10% carbon. After the completion of bond formation between C and Ge, the excess C (>5 atomic%) engages in bonding with Sb in localized regions because of the difference in formation energy. These bonds of C with Ge and Sb induce non-uniform local charge density of the short-range order. Finally, because the strong bonds between Ge and C shorten the short Ge-Te bonds, the high thermal stability of CGST relative to that of GST can be attributed to intensified Peierls distortion. The formation of strong bonds successfully underpins the local structures and reduces the stochastic effect. Moreover, extension of the C bonding to Sb enhances the structural reliability, resulting in highly stable CGST in the amorphous phase. Finally, the device stability of CGST in the reset state of the amorphous structure during the device switching process was significantly improved.
在本研究中，我们研究了相变特性对掺碳锗锑碲（CGST）器件性能的影响，以了解该器件增强的可靠性和稳定性的来源。宏观和微观测量证实，随着高达10%的碳的掺入，结构稳定性显著提高。在C与Ge之间形成键之后，由于形成能的差异，过量的C（>5原子%）在局部区域与Sb形成键。C与Ge和Sb的这些键导致短程有序的非均匀局部电荷密度。最后，由于Ge和C之间的强键缩短了短的Ge-Te键，CGST相对于GST的高热稳定性可归因于增强的派尔斯畸变。强键的形成成功地支撑了局部结构并降低了随机效应。此外，C键向Sb的扩展增强了结构可靠性，从而使CGST在非晶相中具有高度稳定性。最后，在器件切换过程中，CGST在非晶结构复位状态下的器件稳定性得到了显著改善。
