Intrinsic stresses of carbon films deposited by direct current (DC) magnetron sputtering were investigated. The bombardments of energetic particles during the growth of films were considered to be the main reason for compressive intrinsic stresses.The values of intrinsic stresses were determined by measuring the radius of curvature of substrates before and after film deposition.By varying argon pressure and target-substrate distance,energies of neutral carbon atoms impinging on the growing films were optimized to control the intrinsic stresses level.The stress evolution in carbon films as a function of film thickness was investigated and a void-related stress relief mechanism was proposed to interpret this evolution.
Influence of interface roughness on the reflectivity of Tungsten/boron-carbide (W/B4C) multilayers varying with bi-layer number,N,is investigated.For W/B4C multilayers with the same design period thickness of 2.5 nm,a real-structure model is used to calculate the variation of reflectivities with N=50,100,150,and 200,respectively.Then,these multilayers are fabricated by a direct current (DC) magnetron sputtering system.Their reflectivity and scattering intensity are measured by an X-ray diffractometer (XRD) working at Cu Kα line.The X-ray reflectivity measurement indicates that the reflectivity is a function of its bi-layer number.The X-ray scattering measured results show that the interface roughness of W/B4C multilayers increases slightly from layer to layer during multilayer growing.The variation of the reflectivity and interface roughness with bi-layer number is accurately explained by the presented realstructure model.
