Study of atomic diffusion in crystalline structures by high-resolution X-ray diffraction

The ability of high-resolution X-ray diffraction to provide information on atomic diffusion is analyzed, the focus being on the thin film crystalline structures important to modern microelectronics and optoelectronics. Specia l attention is paid to the Ti diffusion in waveguide layers of LiNbO3 cryst als and to the Hg diffusion in the CdTe/Hg1-xCdxTe heterostructures. The de pth-resolved concentration profiles obtained are compared with those measur ed by secondary ion mass spectrometry. The limitations of the new method, m ainly due to the variable strain influence on the lattice parameters, are d iscussed. (C) 1999 Elsevier Science B.V. All rights reserved.