FINITE-ELEMENT MODELING OF NANOINDENTATION FOR DETERMINING THE MECHANICAL-PROPERTIES OF IMPLANTED LAYERS AND THIN-FILMS

The mechanical properties of implanted layers and thin films on dissim ilar substrates are difficult to determine accurately. Nanoindentation of the layer provides information, but detailed numerical modeling is required in order to separate the properties of the layer from those of the substrate. We describe here the procedures we have developed to accomplish this modeling with the commercially available finite-eleme nt code ABAQUS. Using these techniques, we are able to extract from na noindentation testing the yield stress, Young's modulus, and hardness of the layer material, with an absolute accuracy of at least 20%. The procedure is applicable to layers as thin as 50 nm on essentially any substrate, hard or soft. We have used it for materials ranging from io n-implanted layers to thin films of metals and dielectrics formed usin g plasma-deposition methods. An example is given of O-implanted Al, a thin, hard layer on a soft substrate.