含氟无定形碳膜的PECVD制备及结构和性能研究

【作者】 肖剑荣；

【导师】 刘雄飞；

【作者基本信息】 中南大学 ， 凝聚态物理， 2003， 硕士

【摘要】 含氟无定形碳薄膜（a-C：F：H）是一种新型功能材料，它可以用作电介质膜、抗摩膜、抗反射膜、保护膜、防腐膜以及包装材料薄膜等。本文利用射频等离子体增强化学气相沉积法，以CF₄和CH₄为反应气体，Ar或N₂为工作气体，制备了在不同工艺参量下的a-C：F：H膜，并对薄膜进行了退火处理；利用SEM、AFM、FTIR、XRD、Ellip、UV-VIS、Raman、XPS等测试、分析手段着重研究了射频功率、沉积温度、流量比和退火温度对薄膜的组分、化学键结构和物理性质的影响。通过研究得出：a-C：F：H薄膜生长速率主要决定于沉积温度和射频功率，低温和适当的功率有利于提高薄膜生长速率，气体的流量比对薄膜的生长速率有一定的影响；薄膜的表面形貌主要取决于射频功率、沉积温度和退火温度，低功率、低温度沉积的薄膜表面均匀致密，光洁度好，退火之后，薄膜表面趋于平坦，但变得疏松；射频功率、沉积温度、气体流量比和退火温度均影响薄膜的组分和化学键结构，尤其受温度的影响较为明显；薄膜的光学带隙决定于膜内H、CF、CF₂、CF₃的含量，也可以说与薄膜内的sp²的含量有关，CH_x、CF₂、CF₃基团越少，CF越多，也就是说sp²的含量越多，薄膜的光学带隙越小，在工艺上，薄膜的光学带隙取决于射频功率、流量比和温度；薄膜的介电常数决定膜内F的含量及键合方式，F的含量高，同时膜内CF、CF₃与CF₂之比较大，薄膜的介电常数小，在工艺上，主要与流量比有关，高流量比制备的薄膜介电常数小，射频功率和温度对薄膜的介电常数中南大学顿」_毕业论文也有一定的影响;薄膜的热稳定性和粘附性取决于温度和射频功率，高温度、高功率下沉积的薄膜，热稳定性好;薄膜的形态主要受沉积和退火温度的影响，在较高的温度下沉积的薄膜内有微晶生成，沉积功率对形态也有一定的影响。更多还原

【Abstract】 Materials of Fluorinated amorphous hydrogenated carbon thin films (a-C: F: H) with new functions will be used in the electrical and optical field. They have been under investigation for a few years due to their excellent physical properties such as low dielectric constant, low refractive index, low friction coefficients, good gap fill capability, ease to be processed and so on. These films will be used in industrial applications as low dielectric constant interlays in ultra large-scale integration (ULSI) technology. In this paper, a-C: F: H were deposited using radio frequency plasma enhance chemical vapor deposition (RF-PECVD) reactor with CF4 and CH4 as source gases and they were deal with thermal annealing in a N2 environment. The effects on thin films of construct and physics properties by RF-power, deposition temperature and flux ratio were investigated. After studying and analysis, many important conclusions are found. Growth rate of a-C: F: H thin films was mainly determined by deposition temperature and RF-power; low deposition temperature and RF-power were the qualification to gain even and smooth surface a-C: F: H films; stability and surface of thin films become better after annealing heat treatment. The factors affecting component and chemical bands of thin films were RF-power, deposition temperature and flux ratio of the gases. Optical band gap is connected with the content of F and CF; in other words, it relates to the configuration of sp2 in thin films; the moreF and CF the films contains, the less optical band gap. In the course of deposition, the optical band gap is determined by RP-power and flux ratio and deposition temperature. The dielectric constant of these films join to the content of F and the ratio of [CF+CF3]/CF2. The flux ratio of CF4/[CF4+CH4] is primary factor to influence the dielectric constant when thin films deposited; of course, RF-power and temperature contribute to it too. The thermal stability of a-C: F: H films has been found to be strongly dependent on the substrate temperature during deposition and the annealing temperature. Some crystal has been created in thin films due to the high deposition and annealing temperature; to a certain extent, RP-power affects the configuration of the films.更多还原