ナノスケール銅積層膜の熱処理による表面形状と内部応力の変化挙動

The specimen prepared in this study was multi-layer aluminum nitride and copper films deposited on thermal oxidation silicon by dc sputtering. Thermal stresses in the copper layers were investigated by ultra high X-rays of synchrotron radiation in the heating and cooling process. It found from the sin2Ψ diagrams of the multi-layered film that the copper layers consisted of crystal grains which had two different orientations. One was randomly orientation, and the other was {111} orientation. The FWHM of the diffraction from the {111}-oriented crystal grains was constant regardless of heating temperature. On the other hand, the FWHM of the diffraction from the randomly-oriented crystal grains was decreased with increasing heating temperature at 1st heating cycle and it became constant regardless of heating temperature after 1st heating cycle. The 2θ-sin2θ diagrams of the multi-layered film for the stress measurement showed non-linear. We could obtain thermal stresses in two different orientation crystal grains from the non-linear 2θ-sin2θ diagram at same time. For both crystal grains, the thermal stress differences between the 1st heating and the 1st cooling cycles were shown as a hysteresis loop. In the case of the 2nd thermal cycles, the thermal stresses changed linearly for both crystal grains. For the 1st heating cycle, the compressive thermal stress in the {111}-oriented crystal grains was larger than that in the randomly-oriented one.