Phase-change memory (PCM) is the most promising candidate for next-generation memory devices to replace both dynamic random-access memory and flash memory. Sb2Te3 is a promising phase-change material because of its fast operation speed; however, it has poor thermal stability. The operation mechanism of PCMs is based on the Joule heating process; consequently, sufficient thermal stability is one of the most important factors for scaling PCMs in commercialized devices. Herein, a remarkable increase in the thermal stability of C-incorporated Sb2Te3 is reported. The crystallization and 10-year retention temperatures of C-incorporated Sb2Te3 increased to 66% and 52%, respectively, while a reliable operation speed was maintained as compared to that of Ge2Sb2Te5, an existing commercialized phase-change material for 3D Xpoint memory. Regions with highly incorporated C were observed in the Sb2Te3 crystal grains by transmission electron microscopy. Ellipsometry and X-ray photoelectron spectroscopy revealed increased electron localization caused by interstitial C atoms located between Sb and Te, which effectively hindered grain growth and significantly increased thermal stability. The thermal stability can be further enhanced by adjusting the C content, although some of the device operation characteristics are slightly degraded. This study suggests that Sb2Te3 can be easily and effectively utilized as a suitable material for practical applications involving PCM devices with high thermal stability.
|Number of pages||10|
|Journal||ACS Applied Electronic Materials|
|Publication status||Published - 2021 Aug 24|
Bibliographical noteFunding Information:
This research was supported by the Nano Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (NRF2016M3A7B4910398), the Ministry of Trade, Industry & Energy (MOTIE) in Korea (Project No. 10080625), and the Korea Semiconductor Research Consortium (KSRC) through a project to develop source technologies for future semiconductor devices.
© 2021 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Materials Chemistry