In this study, we investigate a GeSb binary phase to be used as a high-speed phase-change material (PCM). In particular, by varying the Ge concentration from 10 at.% to 30 at.%, we study the effects of the PCM composition on the physical and electrical properties of sputtered GexSb100−x films. The Ge10Sb90 film assumes a crystal trigonal structure (Sb phase); however, phase separation occurs in the films at higher Ge concentrations (i.e., the Sb phase coexists with the crystalline Ge phase). As the Ge concentration increases, the grain size decreases, and the sheet resistances of both the amorphous and crystalline states increase. An increase in the Ge concentration in these GeSb films results in an increase in the crystallization temperature, activation energy, data retention, and band gap. The current–voltage measurements show that the threshold and RESET currents decrease with increasing Ge concentrations. In addition, we discuss the R–V curve, crystallization speed, and programming window. The results indicate that GeSb films possess favorable physical and electrical characteristics and can be used as PCMs in phase-change memory applications.
Bibliographical noteFunding Information:
This study was supported by grants from the R&D Program for Industrial Core Technology funded by the Ministry of Trade, Industry, and Energy (MOTIE), Republic of Korea (Grant No. 10039200 ) and the Joint Program for Samsung Electronics–Yonsei University by the Samsung Research Funding Center for Future Technology ( SRFC-MA1502-01 ).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry