磁控溅射制备铬薄膜的结构和光电学性质

用直流磁控溅射技术在石英基片上制备不同厚度(5 nm~114 nm之间)的铬膜.使用X射线衍射仪和分光光度计分别检测薄膜的结构和光学性质,利用德鲁特模型和薄膜的透射、反射光谱计算铬膜的厚度和光学常量,并采用Van der Pauw方法测量薄膜电学性质.结果表明:制备的铬薄膜为体心立方的多晶态,随着膜厚的增加,薄膜的结晶性能提高,晶粒尺寸增大;在可见光区域,当膜厚小于32 nm时,随着膜厚的增加,折射率快速减小,消光系数快速增大,当膜厚大于32 nm时,折射率和消光系数均缓慢减小并逐渐趋于稳定;薄膜电阻率随膜厚的增加为一次指数衰减.

Structural,Optical and Electrical Properties of Chromium Thin Films Prepared by Magnetron Sputtering

Chromium (Cr) thin films with thickness ranging from 5 nm to 114 nm were deposited on quartz substrates by the direct current magnetron sputtering. X-ray diffraction and optical spectrophotometer were employed to characterize the crystal structure and optical properties, respectively. Based on the Drude optical dielectric model, optical constants and thicknesses of the films were calculated from the transmittance and reflectance data. The sheet resistance was measured by Van der Pauw method. The results show that the films have a body-centered cubic crystalline structure. The grain size of the film increases gradually and the crystalline performance enhances as film thickness increases. When film thickness is less than 32 nm, transmittance decreases sharply, reflectance and extinction coefficient increase rapidly as the increase of thickness. When thickness is larger than 32 nm, both refractive index and extinction coefficient decrease gradually until they become stable as the thickness increases. Resistivity is the first order exponential decay when thickness increases from 5 nm to 114 nm.