Characterization of room temperature recrystallization kinetics in electroplated copper thin films with concurrent x-ray diffraction and electrical resistivity measurements

Abstract

Concurrent in-situ four-point probe resistivity and high resolution synchrotron x-ray diffraction measurements were used to characterize room temperature recrystallization in electroplated Cu thin films. The x-ray data were used to obtain the variation with time of the integrated intensities and the peak-breadth from the Cu 111 and 200 reflections of the transforming grains. The variation of the integrated intensity and resistivity data with time was analyzed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. For both 111-textured and non-textured electroplated Cu films, four-point probe resistivity measurements yielded shorter transformation times than the values obtained from the integrated intensities of the corresponding Cu 111 reflections. In addition, the JMAK exponents fitted to the resistivity data were significantly smaller. These discrepancies could be explained by considering the different material volumes from which resistivity and diffraction signals originated, and the physical processes which linked these signals to the changes in the evolving microstructure. Based on these issues, calibration of the resistivity analysis with direct structural characterization techniques is recommended. V C 2013 AIP Publishing LLC.

Sidewall Texture and Microstructure of iPVD Copper Seed in Narrow Damascene Trenches

“…This is followed by development of a minor 200 texture, indicating the minimization of strain energy. 5,13 In the patterned samples with wide features (>100 nm), texture development is similar to the blanket samples, with development of a major 111 component surface normal and a minor 200 component. This occurs even though there is a stress difference due to the patterning.…”

Prediction of recrystallization times in electroplated copper thin films

“…2 is approached through imposing tight controls on plating current, time, and chemistry [2][3][4][5][6][7][8][9][10][11][12].…”

“…These effects are usually ascribed to thickness variations. To obtain a better metric of sample repeatability we used real-time synchrotron x-ray diffraction [3,13] to study microstructural changes from electroplated films deposited with a variety of frequently employed, phenomenological plating parameters. These included plating time and film thickness [4,13], seed layer deposition methodology [5,6], seed layer and plated film texture [7,8], diffusion barrier chemistry [9,10], and impurity concentration [11,12].…”

Evolution of strain energy during recrystallization of plated Cu films

“…2 A dependence of recrystallization rates on texture was identified by an analysis of films possessing seed layers with different initial textures produced by different deposition techniques. 3 Historical treatments of microstructural transformation within plated Cu films often employ differences in elastic strain energy among different texture components to predict the evolution of texture. 4-7 A lower strain energy density results during the growth of (100)-oriented grains in most FCC materials than that for (111)-oriented grains, under the application of an in-plane, biaxial strain field.…”