X射线反射法测量α:CH薄膜的密度和厚度

 利用低压等离子体化学气相沉积法制备厚度不同的非晶碳氢薄膜，采用X射线反射法测量了非晶碳氢薄膜的密度和厚度。实验中分别采用曲线拟合法和周期估算法计算薄膜的厚度，两种方法测得的厚度平均差别为5.5%，一致性较好。利用X射线反射谱的临界角计算所得的7个样品的密度差别较小，在8%之内。

X-ray reflectivity characterization of thickness and mass density of α:CH films

Grazing-angle X-ray reflectivity(XRR) is described as an efficient, nondestructive means to measure the mass density of various amorphous carbon films down to the nanometer thickness range. Amorphous hydrogenated carbon films(α:CH films) are fabricated by low pressure plasma chemical vapor deposition method. The thickness of α:CH films is derived from XRR by the method of line fitting(according to the theory of modified Bragg equation) and by the period width(fringe space) of XRR. The mass density of the films is also derived from the critical angle of XRR based on the refractive theory. The results show that the thicknesses of films obtained by the two methods agree well, the average difference among them is only 5.5%. The mass density of the films’ error obtained from the critical ang