动力学研究AlN/α-Al2O3(0001)薄膜生长初期的吸附与扩散  

Dynamics study of the adsorption and diffusion in early growth stage of AlN/α-Al_2O_3(0001) films

作　　者：杨春[1,2] 冯玉芳[1] 余毅[3] 

机构地区：[1]可视化计算与虚拟实现四川省重点实验室 四川师范大学,成都610068 [2]电子薄膜与集成器件国家重点实验室 电子科技大学,成都610054 [3]四川师范大学学报编辑部自然科学版,成都610068

出　　处：《物理学报》2009年第5期3553-3559,共7页Acta Physica Sinica

基　　金：国家国防“973”基金(批准号:61363);四川省青年科技基金(批准号:07ZQ026-021)资助的课题~~

摘　　要：采用基于第一性原理的从头计算分子动力学方法,计算了300—800℃下AlN吸附过程与系统能量、动力学轨迹以及扩散系数.研究表明,吸附过程由物理吸附、化学吸附和表面稳定态三个阶段组成,在吸附成键过程中,温度越高,粒子平均表面扩散能力增强.N原子的扩散系数大于Al原子的扩散系数,尤其是在物理吸附阶段.在较高温度条件下(大于700℃),N的解吸附作用明显增强,不利于AlN的稳定吸附生长,500—700℃之间的温度有利于AlN在α-Al2O3(0001)表面的稳定吸附生长.The research of temperature effect on the surface adsorption and diffusion is an important problem for the initial growth mechanism of AIN/α-Al2O3 （0001） thin films. Using the ab initio molecular dynamics method based on the first principles, the adsorption process, system energy, dynamic track and the diffusion coefficient are calculated at temperatures from 300℃ to 800℃. The results indicate that the adsorption process can be divided into three stages, the physical adsorption, the chemical adsorption and the stable surface growth state. With the temperature increasing, the average diffusivity of the particles at α-Al2O3 （0001） surface is enhanced in the bonding process. The diffusion coefficient of N atom is higher than that of the Al atom, especially in the physical adsorption stage. At higher temperatures （ over 700℃ ）, the role of desorption of the N atom is markedly strengthened, so it is unfavorable to the stable absorption of AlN. The temperature between 500℃ and 700℃ is beneficial to the stable adsorption and the growth of the AlN on α-Al2O3 （0001） surface.

关 键 词：α-Al2O3(0001)表面 扩散 吸附生长 从头计算分子动力学 

分 类 号：O484.1[理学—固体物理] V211[理学—物理]