利用透射电子显微镜 (TEM)在纳米尺度上直接观察由氮化硅分解出的硅蒸气在蒸发 凝聚过程中产生的分形生长这一实验现象 ,结合相对应的有限扩散凝聚 (DLA)模型以及核晶凝聚 (NA)模型 ,对所获得的分形结构进行了描述和讨论 ,并探讨了分形生长的发生机理。同时 ,由实验中所拍摄的一组照片计算其分形维数 ,分别为Dm1≈ 1.0 9,Dm2 ≈ 1.5 2 ,Dm3 ≈ 1.78,其中Dm3 ≈ 1.78与DLA模型的理论预测值以及数值模拟结果较一致 The experimental phenomenon of fractal growth of silicon vapor decomposed by silicon nitride during the process of evaporation and condensation was directly observed on the nanoscale by transmission electron microscopy (TEM). Combined with the corresponding finite diffusion-aggregation (DLA) model and the nucleation Condensation (NA) model, the fractal structure obtained was described and discussed, and discussed the mechanism of fractal growth. At the same time, the fractal dimension was calculated from a set of photographs taken in the experiment, which are respectively Dm1 ≈ 1.09, Dm2 ≈ 1.5 2, Dm3 ≈ 1.78, and Dm3 ≈ 1.78 are consistent with the theoretical predictions and numerical simulations of DLA model