应用于相变存储器的Cu-Ge_3Sb_2Te_5薄膜的结构及相变特性研究  

Structure and phase change in Cu-Ge_3Sb_2Te_5 films for use in phase change random access memory

作　　者：孙景阳[1] 王东明[1] 吕业刚[1] 王苗[1] 汪伊曼 沈祥[1] 王国祥[1] 戴世勋[1] 

机构地区：[1]宁波大学信息科学与工程学院,浙江315211

出　　处：《物理学报》2015年第1期210-216,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61306147;61377061);宁波市自然科学基金(批准号:2014A610121);宁波大学王宽城幸福基金资助的课题~~

摘　　要：采用磁控溅射法制备了不同Cu含量的Cu-Ge3Sb2Te5薄膜,原位测试了薄膜电阻与温度的关系,并利用X射线衍射仪、透射电镜、透过和拉曼光谱仪分别研究了Cu-Ge3Sb2Te5薄膜的晶体结构、微结构、禁带宽度及成键情况.结果表明,Cu-Ge3Sb2Te5薄膜的结晶温度和结晶活化能随着Cu含量的增加而增大,Cu的加入有效改善Ge3Sb2Te5薄膜的热稳定性和10年数据保持力.随着Cu含量的增加,非晶态Cu-Ge3Sb2Te5薄膜的禁带宽度逐渐减小.同时,拉曼峰从129 cm-1向127 cm-1处移动,这是由于Cu—Te极性键振动增强的缘故.Cu-Ge3Sb2Te5结晶为均匀、相互嵌套的六方Cu2Te和Ge2Sb2Te5相.The Cu-Ge3Sb2Te5 thin films with different Cu contents were prepared by magnetron sputtering method. The de- pendence of film resistance on temperature is measured in situ by using the four-point probe heating platform. The crystal structure, microstructure, optical gap, and bond states of the Cu-Ge3Sb2Te5 films are investigated by X-ray diffraction, transmission electron microscopy, transmission and Raman spectra, respectively. It is shown that the crystallization temperature and activation energy of crystallization increase with increasing Cu content, suggesting the improvement in thermal stability and data retention ability, while optical gap decreases with increasing Cu concentration. It is observed that the Raman peak shifts from 129 cm-1 to 127 cm-1, which may be ascribed to the vibration of polar Cu--Te bonds. The Cu-Ge3Sb2Te5 crystallizes into the embedded Cu2Te and Ge2Sb2Te5 phases with evenly grown grains.

关 键 词：薄膜 相变 结构 

分 类 号：O484.4[理学—固体物理]