| 초록 |
For thin films the tensile residual stress can lead to cracks in thin films whereas compressive residual stress may cause films delamination from substrate. These phenomena inevitably contribute to the reduction of reliability of thin films. The intrinsic stress behavior of thin films was observed during deposition using the measurement of substrate curvature. When the deposition of thin films was interrupted, the stress was eased(relaxed) to a certain level depending on the time. Understanding the phenomenon of the stress recovery may help to produce thin films with excellent reliability with controlled residual stress in thin films. The control of the stress and grain size of thin metallic films is a major issue in the field of thin films. The stress relaxation phenomenon and change of grain size in thin copper films using aluminum, aluminum oxide, chromium interlayers deposited onto (111)-silicon wafer was studied by using the wafer curvature method. It is known that the stress relaxation of metallic films such as Al, Cu, Ag occurs by chemical potential difference in the presence of growth flux and the consequent exchange of adatoms between the surface and the grain boundaries. We have studied that deposition of Al2O3, Al, Cr interlayers between the copper thin films and silicon substrates can lead to the reduction of grain size. Thin interlayer films can make rough interface. The roughing of the interface by increasing shadowing effects, plays a leading part in preventing lateral growth a copper grains. |
