Systematic variation of anisotropic X-ray line broadening in vapour-deposited Pb films of various thicknesses on glass substrates was studied using dislocation model of strain anisotropy incorporated into a modified Williamson-Hall and modified Warren-Averbach procedure. For smaller film thicknesses in the range of 100 to 200nm, the dislocation network was less correlated and contained substantial screw component and twin or growth faults. The films of larger thicknesses (greater than 500nm), on the other hand, consist mostly of edge dislocations with a more regular and correlated dislocation structure. The present study revealed the inadequacy of applicability of conventional Warren-Averbach analysis in regular and correlated dislocation structures.

Evolution of Dislocation Substructure in Vapour-Deposited Lead Films on Glass