热处理升温快慢对非晶硅中形成的纳米硅粒尺寸的影响

含氢非晶硅薄膜经过快速热退火处理后,我们用拉曼散射和X-射线衍射技术对样品进行分析.我们的实验结果表明:在非晶硅薄膜中形成的纳米硅晶粒的大小随着热退火过程中升温快慢而变化.在升温过程中,当单位时间内温度变化量较大时（～100℃/s）,则所形成纳米硅粒较小（～1.6～15nm）;若单位时间内温度变化量较低（～1℃/s）,则纳米硅粒较大（～23～46nm）。根据分形生长理论和计算机模拟,我们讨论了升温快慢与所形成的纳米硅颗粒大小的关系.

Effect of Temperature-rising-rate on the Sizes of Nanoscale Silicon Particles Formed in Thermally Annealed a-Si:H Films

In this report, we have studied the effect of temperature-rising-rate on the sizes of nanoscale siliconparticles formed in thermally annealed hydrogenated amorphous silicon (a-Si:H) films. The a-Si:H films wereprepared with electron-beam evaporation in a high-vacuum chamber, then the films were thermally annealedin a furnace at the equilibrium temperature of 620℃ for about 10 seconds but with a high (～100 ℃/min) anda low (～1 ℃/min) temperature-rising-rate in the first stage of their thermal annealing processes, respectively.Using the micro-Raman scattering and the X-ray diffraction techniques, we have found that sizes of the formedsilicon particles change with the temperature-rising-rate in the process of thermal annealing the a-Si:H films.When the a-Si:H films have been annealed with high temperature-rising-rate (～100 ℃/s), the sizes of nanoscalesilicon particles are small in the range of 1.6～15 nm. In the meanwhile, if the a-Si:H films are annealed witha low temperature-rising-rate (～1℃/second), the sizes of nanoscale silicon particles are large in the range of23～46 nm. Using the method of diffusion limited aggregation, we have simulated the growth of nanoscale siliconparticles in a-Si:H films and discussed the effect of temperature-rising-rate on the sizes of the formed siliconparticles.