二氧化铪栅介质薄膜的制备及物性研究

发布时间：2018-03-30 09:05

本文选题：磁控溅射　切入点：高介电常数材料　出处：《安徽大学》2015年硕士论文

【摘要】：在微电子领域中,集成电路的发展是一直遵循摩尔定律的发展而发展的。随着MOSFET特征尺寸的不断缩小,其等效氧化物层的厚度减小到纳米数量级别,此时作为传统的栅介质材料二氧化硅已经接近物理极限,这时由于量子效应导致MOS的隧穿漏电流急剧增大,从而影响了器件的可靠性和稳定性。因此,寻找应用于下一代的MOSFET的高介电常数材料替代传统的氧化硅成为当前微电子领域研究的热点和重点。钛酸锶,氧化钽,氧化铝,氧化锆和氧化铪等材料由于其独特的物理特性引起了研究者们广泛关注。在这些高介电常数材料中,氧化铪具有较高的介电常数,较大的禁带宽度,适中的价带和导带偏移,以及与硅基底的良好热稳定性。因此,氧化铪可以用来作为取代传统二氧化硅的一种很好的高介电常数材料。本文采用射频磁控溅射法制备了氧化铪薄膜,系统研究了实验参数依赖的氧化铪薄膜的结构和光学性质。借助X-射线衍射技术,我们分析了氧化铪薄膜结构信息,探索了氧化铪薄膜的微结构随实验参数变化的演变规律；借助傅里叶红外变换光谱仪分析了氧化铪薄膜与硅基底的界面结构随外界实验参数的变化函数；使用原子力显微镜和扫描电子显微镜表征了薄膜表面形貌的变化；利用紫外可见分光光度计,研究了氧化铪薄膜光学常数的演变函数,有效获取了薄膜的吸收率和透射率,并根据吸收系数算出了氧化铪薄膜的光学带隙；借助于椭圆偏振仪拟合得出了氧化铪薄膜的厚度,折射率,消光系数和介电常数,并利用消光系数转化为吸收系数,最后得出了氧化铪薄膜的光学带隙值。所有的研究为氧化铪薄膜在未来MOS器件中的应用奠定了实验技术。本文的研究点和创新点如下：1.采用射频磁控溅射法制备了氧化铪薄膜,通过改变不同的磁控溅射功率,有效获取了薄膜的结构和光学性质随溅射功率的变化规律。2.通过改变不同的退火温度系统研究了氧化铪薄膜的结构和光学性质的变化。3.通过改变不同氧氩分压获取了高质量的氧化铪薄膜,系统研究了氧分压依赖的薄膜的结构和光学性质的变化规律。
[Abstract]:In the field of microelectronics, the development of integrated circuits has followed the development of Moore's law.With the decreasing of the characteristic size of MOSFET, the thickness of the equivalent oxide layer decreases to the nanoscale level. As a traditional gate dielectric material, silicon dioxide is close to the physical limit.The tunneling leakage current of MOS increases rapidly due to quantum effect, which affects the reliability and stability of the device.Strontium titanate, tantalum oxide, alumina, zirconia and hafnium oxide have attracted much attention due to their unique physical properties.Among these high dielectric constant materials, hafnium oxide has high dielectric constant, large band gap, moderate valence band and conduction band migration, and good thermal stability with silicon substrate.Hafnium oxide thin films were prepared by RF magnetron sputtering. The structure and optical properties of the experimental parameter-dependent hafnium oxide thin films were systematically studied.The structure information of hafnium oxide thin film is analyzed by means of X-ray diffraction technique, and the evolution law of the microstructure of hafnium oxide film with experimental parameters is explored.The evolution function of the optical constants of hafnium oxide thin films was studied by using UV-Vis spectrophotometer. The absorptivity and transmittance of the films were obtained effectively, and the optical band gap of hafnium oxide thin films was calculated according to the absorption coefficient.The thickness, refractive index, extinction coefficient and dielectric constant of hafnium oxide thin film were obtained by using ellipsometer, and the extinction coefficient was converted into absorption coefficient. Finally, the optical band gap value of hafnium oxide thin film was obtained.All the studies have laid a solid foundation for the application of hafnium oxide thin films in MOS devices in the future.The hafnium oxide thin films were prepared by RF magnetron sputtering. By changing the different magnetron sputtering power, the structure and optical properties of the films varied with the sputtering power.The structure and optical properties of hafnium oxide thin films were studied by changing the annealing temperature.High quality hafnium oxide thin films were obtained by changing the partial pressure of argon oxide. The changes of the structure and optical properties of the films with oxygen partial pressure dependence were systematically studied.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ134.13;TB383.2

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