Hydrogen as origin of compressive intrinsic stress in hydrogenated amorphous silicon: the contribution of clustered forms

The role of hydrogen in hydrogenated amorphous silicon (a-Si:H) has been studied from the viewpoint of its specific contribution to mechanical stress in the material. Hydrogen ion implantation has been used to increase the hydrogen concentration. In order to distinguish the effect of the changed hydrogen concentration/bonding configuration from the accompanying implantation-induced defects, a-Si:H samples with corresponding number of displacements have been studied, created using proper doses of silicon ion implantation. The experimental results have shown that it is the silicon-bonded hydrogen that essentially affects the stress, as the major contribution has its clustered bonding configuration.