导　　师： 陈俊芳

学科专业： 080903

授予学位： 硕士

作　　者： ;

机构地区： 华南师范大学

摘　　要： 本论文主要研究了感应耦合等离子体增强化学气相沉积/(ICPECVD/)技术和反应主要由等离子体参数的分布特性以及Si/_3N/_4粉体材料的制备工艺方法，寻求合适的工艺参数，制备纳米Si/_3N/_4粉体材料，以及利用马沸炉对纳米Si/_3N/_4粉体材料进行煅烧的初步研究，探索提高纳米Si/_3N/_4粉体材料性能的有效途径。 利用朗缪尔探针诊断了反应室内等离子体参数，得到不同位置、不同功率和不同气压下等离子体密度的变化规律，结果表明离子密度为10~8～10~/(10/)cm~/(-3/)，等离子体密度随着功率的增大而增大，随着气压的升高而减小，由于离子鞘层的存在，在一定条件下提供了局部等离子体密度稳定的区域。 通过对探针诊断结果的分析，调整ICP装置系统，得到很好的匹配效果，在射频输出功率为200W以内时，反射功率小于0.6W。在此基础上，采用ICP等离子体化学气相沉积技术，用硅烷和氮气为反应气体合成氮化硅纳米粉体。 对得到氮化硅纳米粉体材料的TEM、IR和XRD分析表明：在射频功率为200W，气压为53Pa时，感应耦合等离子体CVD技术制备的纳米Si/_3N/_4粉体材料属于β-Si/_3N/_4六方晶系结构，其颗粒大小为20nm左右，分布均匀、不团聚、分散性好。而在功率为100W和150W时，所得到的氮化硅样品为非晶结构。 粒径分布和团聚是纳米粉体材料重要的表征手段，采用激光散射技术对纳米氮化硅粉末粒径的分布和团聚进行分析，激光散射技术由于本身的限制和对样品的高要求，测量纳米材料的分布有较大的误差。 氮化硅的煅烧表明：原始氮化硅纳米粉末中的β晶核在氮化中诱发β相生长，形成β-Si/_3N/_4。 This paper mainly study on the technics of preparing nano- Si3N4 and ICPECVD.seeking for the proper parameter and technics, crystallization of nano-Si3N4 powder with Muffle furnace, probe the new effective way of improving the properties of nano- Si3N4 powder The ion density in the reaction chamber was diagnosed by a Langmuir probe. The rules were obtained under different air pressure, different radio frequency power and different position which the ion density changes about from 1010cm-3 to 1010cm -3 decreasing as the pressure increases and increasing as the power decreases . Because of the ion sheath, the area emerged where the ion density is symmetrical. A set of ICPCVD system has been designed and manufactured through the analysis of the probe diagnosed results. When the output power of the RF is within 200W and the reflection power is within 0.6W, a good matching effect can be gained. The SisN4 nanopowder was prepared by means of ICPECVD by decomposing of SiH4 and N2. Analysis by FT-IR, TEM and XRD reveals the characteristic of Si3N4. The results indicated that Si3N4 nanopowder synthesized by ICPECVD is hexagonal cell β -Si3N4 and the particles is spherical with diameter about 20nm, the distribution of those particles is symmetrical when power is 200W and pressure is 53Pa. However, the Si3N4 is non-crystalline when power is 100W or 150W. The agglomeration and the distribution were important parameter of nanopowder , which were analyzed by the laser light scattering particle-size test instrument. But the result appeared great error because of this instrument itself and high requirement to sample. The result of annealing of silicon nitride showed the β crystal nuclear existing in the origin silicon nitride powder led on the grow of hexagonal 3 -Si3N4 and formed the 3 -Si3N4.

关 键 词： 纳米粉末 等离子体密度

领　　域： [电子电信]