磁控溅射功率对β-Ga_(2)O_(3)薄膜特性的影响

Effects of magnetron sputtering power on β-Ga_(2)O_(3) thin films prepared by magnetron sputtering

近年来,第三代宽禁带半导体材料β-Ga_(2)O_(3)受到越来越多的关注,在材料制备、掺杂、刻蚀等方面都有广泛研究.射频磁控溅射是常用的β-Ga_(2)O_(3)薄膜制备方法之一,而磁控溅射法制膜往往需要进行退火处理以提高薄膜质量.本文研究溅射功率对射频磁控溅射在C面蓝宝石基底上制备得到的β-Ga_(2)O_(3)薄膜特性的影响. X射线衍射(XRD)、原子力显微镜(AFM)和扫描电子显微镜(SEM)表征结果表明,随着溅射功率的增大,半峰宽呈现先增大后减小再增大的趋势,晶粒尺寸变化与之相反.此外,通过积分球式分光光度计,研究了溅射功率对β-Ga_(2)O_(3)薄膜光学特性的影响.光学特性方面,薄膜吸光度随着波长的增加,先升高后下降、再升高再下降,最后吸收边在700 nm附近截止,不同溅射功率制备的薄膜吸收光谱都存在两个吸收峰.

In recent years, the third-generation wide-bandgap semiconductor material β-Ga_(2)O_(3) has attracted more attention, and extensive research has been conducted on material preparation, doping, and etching of β-Ga_(2)O_(3). RF magnetron sputtering is one of the commonly used methods for preparing β-Ga_(2)O_(3) thin film, and the magnetron sputtering method often requires post annealing to improve the quality of the film. In this paper, effect of sputtering power on the film characteristics of β-Ga_(2)O_(3) thin film material prepared by RF magnetron sputtering on the C-plane sapphire substrate are investigated. Testing results of X-ray diffraction(XRD), atomic force microscopy(AFM) and scanning electron microscopy(SEM) indicated that, with the increasing sputtering power, the half-peak width shows a trend of first increasing, then decreasing and then increasing, and the change of crystal grain size is opposite. In addition, the effect of sputtering power on the optical properties of β-Ga_(2)O_(3) film was studied by integrating sphere spectrophotometer. In terms of optical properties, as the wavelength increases, the absorbance of the film first increases, then decreases, then increases and then decreases. Finally, the absorption edge is cut off near 700 nm. There are two absorption peaks in the absorption spectra of films prepared with different sputtering powers.