Physical properties and structure characteristics of titanium-modified antimony-selenium phase change thin film

Abstract

Effects of the titanium dopant on the physical properties and structure of SbSe thin films were systematically investigated by experiments and first-principles calculations. The amorphous-to-polycrystalline transformation induced by heat was examined by in situ electrical resistance measurements. With the incorporation of titanium atoms, both the crystallization temperature and electrical resistance increase, revealing the improvement of the amorphous thermal stability and programing energy consumption. X-ray diffraction, transmission electron microscopy, and density functional theory calculations illustrate that a small amount of titanium dopant can inhibit the grain growth and refine the crystal size. The shift of Raman modes associated Sb upon the crystallization was observed. X-ray reflectivity and atomic force microscopy results prove the smaller volume fluctuation and the smoother surface morphology, meaning the better interfacial property and reliability of titanium-doped SbSe materials. Phase change memory cells based on titanium-doped antimony-selenium were fabricated to evaluate the electrical performance as well. All these results indicate that the suitable incorporation of the titanium element will be an effective method to optimize the physical properties and tune the structure of the SbSe phase change material.

The study of phase change properties of Sb70Se30 thin film with scandium and aluminum doping

“…This scenario is distinct from the Zn-doped Sb-Se system in our previous work where new Zn-related phase emerges in the sample. It is reported that the doped Al and Sc atoms are preferable at Sb atomic site in Sb2Se3 [28,29]. Thus Al/Sc solute solution (i.e.…”

Simultaneously achieving high performance of thermal stability and power consumption via doping yttrium in Sn15Sb85 thin film

“…The presence of Y shifts the peaks of E g and A 1g to longer wavelengths, which can be attributed to the larger interatomic forces in long-range ordered crystals. When grains are subjected to compressive stress, the reduction in bond length would be accompanied by an increase in bond energy, resulting in subtle changes in the bonding properties [23].…”

Performance Improvement of Sb Phase Change Thin Film by Y Doping

“…This process is called the incubation period of the crystalline grains. 28 Lower annealing temperatures have longer incubation times because the films need more time to accumulate energy for the formation of nuclei and the change of grains from small to large at lower temperatures. After the accumulation of the required energy, a large numerical decrease in resistance occurs in a relatively short time, which was attributed to the formation of percolation paths caused by long-range order in grains.…”