Elastic-Plastic Mechanical Properties of AlxGa1-xN Thin Films with High Al Composition
高Al组分AlxGa1-xN薄膜的弹性-塑性力学性质

The elastic-plastic mechanical properties of AlxGa1-xN thin films with high Al composition are investigated by the nano-indentation technique.It is found that the Young's modulus E of the films and the shear stress to produce the plastic deformation in AlxGa1-xN films increase with increasing Al composition,while the occurrence of the clear and sudden displacement discontinuity("pop-in")in the plastic deformation(PD)process decreases.With increasing Al composition,it is believed that the increase of the bond strength and the decrease of the stress due to the lesser lattice mismatch between AlxGa1-xN films and AlN/sapphire templates result in more resistance to the formation of dislocations,which is responsible for the "pop-in" behavior in AlxGa1-xN films.