论文部分内容阅读
采用磁控溅射技术在Si衬底上以350?C沉积14 nm的非晶Ge薄膜,通过退火改变系统生长热能,实现了低维Ge/Si点的生长.利用原子力显微镜(AFM)和拉曼(Raman)光谱所获得的形貌和声子振动信息,对Ge点的形成机理和演变规律进行了研究.实验结果表明:在675?C退火30 min后,非晶Ge薄膜转变为密度高达8.5×109cm-2的Ge点.通过Ostwald熟化理论、表面扩散模型和对激活能的计算,很好地解释了退火过程中,Ge原子在Si表面迁移、最终形成纳米点的行为.研究结果表明用高速沉积磁控溅射配合热退火制备Ge/Si纳米点的方法,可为自组织量子点生长实验提供一定的理论支撑.
The amorphous Ge film was deposited by magnetron sputtering at 1450 ◦ C on Si substrate, and the growth of low-dimensional Ge / Si dots was achieved by changing the thermal energy of the system by annealing.Using atomic force microscopy (AFM) and pull The morphologies and phonon vibration information obtained from Raman spectroscopy were used to study the formation mechanism and evolution of Ge dots.The experimental results show that after annealing at 675 ° C for 30 min, 8.5 × 109cm-2 Ge. The Ostwald ripening theory, the surface diffusion model and the calculation of the activation energy are very good explanations of the behavior of Ge atoms migrating on Si surface and finally forming nano-dots during the annealing process. The preparation of Ge / Si nanodots by high-speed deposition magnetron sputtering combined with thermal annealing can provide theoretical support for self-organized quantum dot growth experiments.