基于金属诱导结晶生长多晶Ge薄膜的成核机理与动力学特征  

The nucleation mechanism and kinetics characterization of poly-Ge thin films grown by metal-induced crystallization

作　　者：董少光[1] 庄君活 潘浩贤 曾亚光[1] DONG Shao-guang;ZHUANG Jun-huo;PAN Hao-xian;ZENG Ya-guang(School of Physics and Optoelectronic Engineering, Foshan University, Foshan, 528000, China)

机构地区：[1]佛山科学技术学院物理与光电工程学院,广东佛山528000

出　　处：《佛山科学技术学院学报（自然科学版）》2017年第4期14-22,共9页Journal of Foshan University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(11474053)

摘　　要：研究低温下利用金属Al对非晶Ge薄膜进行层交换结晶生长多晶Ge薄膜的动力学过程。实验观察到Ge原子从非晶Ge层穿过中间很薄的GeO_x界面层后,大量地迁移到金属Al层的表面,并对多晶Ge薄膜中Ge成核区域的面密度进行了测量,对GeO_x界面层进行偏置电压处理以控制Ge成核区域的面密度。根据实验观察的各种结果并运用JMAK的相迁移理论解释了Ge成核区域的二维生长过程以及成核机理。应用Ge成核区域的动力学方程得到Ge岛的成核率随时间呈指数衰减的变化趋势。随着生长时间的增加,Ge成核区域从恒定生长速率的线性生长方式转变为表面扩散限制生长方式。这两种生长机制的转折点取决于Ge岛成核的位置密度和退火温度。掌握低温下层交换结晶的生长动力学理论对生长大颗粒的多晶Ge薄膜是非常重要的。The kinetics characterization of ploy-Ge thin films grown by metal Al layer exchange crystallization of a-Ge at low temperatures is studied in this paper.Ge atoms transport through the thinner GeOx interfacial layer from amorphous Ge layer to the Al thin films surface massively in our experiments,and we have measured the areal density of Ge islands in the nucleation zone of poly-Ge thin films,and bias-voltage was applied to the GeOx interfacial layer to control the areal density of Ge islands in the nucleation zone.According to the results of experimental observations,the JMAK phase transformation theory is used to explain two dimensions growth regime and nucleation mechanism of Ge islands in the nucleation zone.The nucleation rate of Ge islands follows an exponentially decaying with time by using the kinetics equation of Ge islands in the nucleation zone.The growth of Ge islands in the nucleation zone switches from linear growth at a constant velocity to surface diffusion limited growth with increasing growth time.The transition point between these two growth regimes depends on the density of Ge islands nucleation site and the annealing temperature.Knowing the growth kinetics theory of layer exchange crystallization at low temperature is important to grow the poly-Ge thin films with large grains,and these Ge thin films can be applied for the large-area electronics and the solar cell extensively.

关 键 词：金属诱导结晶 多晶Ge 成核密度 退火温度 

分 类 号：TB303[一般工业技术—材料科学与工程]