Depth Profiling Biaxial Stresses in Sputter Deposited Molybdenum Films; Use of the Cos~2 PHI Method

摘要

Depth profiles of intrinsic in-plane, biaxial stresses were obtained as a function of tau, the 1/e penetration depth, in a 1.0 mu m thick planar d. c. magentron sputter deposited molybdenum film using asymmetric grazing incidence x-ray diffraction (GIXD), tau was varied between 20 and 276 A. The stresses sigma_(11) and sigma_(22) were characterized in the directions parallel and perpendicular to the long axis of the cathode respectively using a cos~2 PHI method. The results show that starting from tau=17A, sigma_(11) and sigma_(22) are compressive and become rapidly more compressive with a minimum at tau approx 20 - 40A thereafter increasing gradually toward tensile values. The reasons for the shape of the stress gradient are not well understood but may be related to the relaxation of the stresses at the tops of the columnar Zone T-type microstructure and to the oxygen gradient in the film.