THE EFFECT OF HYDROGEN EVOLUTION ON THE MECHANICAL-PROPERTIES OF HYDROGENATED AMORPHOUS-CARBON

The nature of hydrogen bonding and its influence on mechanical propert ies and atomic structure were investigated in two types of a-C:H films , prepared in a DC multipolar plasma system from pure methane at diffe rent substrate bias, by performing H evolution and annealing experimen ts. The results clearly indicate that these two types of samples have different H bonding and microstructures in their as-deposited state. T hey behave differently upon annealing up to high annealing temperature s. These results show that a decrease of the hydrogen concentration re duces the internal stress from compressive to slightly tensile values, increases the sp(2) bonded carbon cluster sizes and reduces the magni tude of the stresses. (C) 1998 Elsevier Science S.A.