靶基距对脉冲激光沉积β-FeSi_2薄膜质量的影响

Effect of Target- Substrate Distance on Crystallinity and Light-Absorbing Performance of β-FeSi_2 Films Fabricated by Pulsed Laser Deposition

常用的分子束外延、粒子束沉积法难以获得均匀、致密性好的单一相β-FeSi2薄膜,利用脉冲激光沉积及热退火处理法在P型Si(100)基片上制备了均匀的单一相β-FeSi2薄膜。利用X射线衍射仪、扫描电镜、原子力显微镜及红外光谱仪研究了靶基距对β-FeSi2薄膜的结构、组分、结晶质量、表面形貌及光吸收特性的影响。结果表明:随着靶基距的增加,薄膜的晶化程度先变差后增强再变差,晶粒尺寸先减小后增大再减小,颗粒分布均匀性先变好后变差;表面粗糙度先减小后增大;靶基距为40 mm时,β-FeSi2薄膜的结晶度较高,颗粒大小均匀、趋于球形化,薄膜致密性较好,粗糙度较低,对红外光的吸收较好。

Uniform single phase β-FeSi2films were prepared on Si( 100) substrates by pulsed laser deposition and annealing process. The effect of target-substrate distance on the structure,composition,crystallinity,surface morphology,and light-absorbing performance of as-prepared β-FeSi2films was analyzed with an X-ray diffractometer,a scanning electron microscope,an atomic force microscope,and an infrared spectrometer. Results indicated that,with increasing target-substrate distance,the crystallinity of β-FeSi2films tended to decline,rise,and decline; and the grain size ofβ-FeSi2films tended to decrease,increase,and decrease therewith. Besides,the distribution uniformity of the grains of β-FeSi2films tended to increase initially and decline later with elevating target-substrate distance,while the surface roughness of the films initially rose and declined later therewith. Particularly,β-FeSi2film obtained at a target-substrate distance of 40 mm exhibited high crystallinity,high compactness,small surface roughness,and good light-absorbing performance,and the size distribution of its spherical grains was narrow.