Investigation of Cu–Sn–Se material for high-speed phase-change memory applications

摘要：

The second part described about how to examine properties and structure of SnSe and CuSnSe films. The transition from amorphous to crystalline was researched by in  situ temperature dependent conductivity and resistance measurement. The sample temperature was measured by a Pt-100 thermocouple located at a heating stage controlled by a TP 94 temperature controller (Linkam Scientific Instruments Ltd, Surrey, UK). The purity of SnSe and Cu targets were 99.999% and thin films thickness was set to 50 nm by the means of controlling the deposition time. The optical band gap was measured by NIR spectrophotometer. The phase structures of the films which were annealed at various temperatures were investigated by XRD analyses using Cu Ka radiation in the 2θ range from 20° to 60°, with a scanning step of 0.01°. Roughness on the surface of the material could be examined by atomic force microscopy (AFM, FM-Nanoview 1000). The grain states of phase change materials before and after the crystallization were observed by scanning electron microscopy (SEM, Hitachi S-4700). A picosecond laser pump–probe system was used for real-time reflectivity measurement. The light source used for irradiating the samples was a frequency-doubled model-locked neodymium yttriym aluminum garnet laser operating at 532 nm wave-length a pulse duration of 30 ps. The chemical compositions of Sn, Se and Cu element in SnSe and CuSnSe thin films, determined by the energy dispersive X-ray analysis (Oxford INCA Energy), were around 46, 54 and 28, 33, 39 at.%, respectively.

作者：

Haipeng You, Yifeng Hu, Xiaoqin Zhu,Hua Zou, Sannian Song & Zhitang Song

 
期刊：