Effect of Annealing on Microstructure and Mechanical Properties of Magnetron Sputtered Cu Thin Films

Abstract

Cu thin films were deposited on Si substrates using direct current (DC) magnetron sputtering. Microstructure evolution and mechanical properties of Cu thin films with different annealing temperatures were investigated by atomic force microscopy (AFM), X-ray diffraction (XRD), and nanoindentation. The surface morphology, roughness, and grain size of the Cu films were characterized by AFM. The minimization of energy including surface energy, interface energy, and strain energy (elastic strain energy and plastic strain energy) controlled the microstructural evolution. A classical Hall-Petch relationship was exhibited between the yield stress and grain size. The residual stress depended on crystal orientation. The residual stress as-deposited was of tension and decreased with decreasing of (111) orientation. The ratio of texture coefficient of (111)/(220) can be used as a merit for the state of residual stress.

A comparative study of copper thin films deposited using magnetron sputtering and supercritical fluid deposition techniques

“…Then, the internal stress distribution could be more even which could make the (220) grain with minimization strain energy grown easily and quickly. Du et al [33] noticed a change in preferred orientation after annealing from (111) to (220). They explained this phenomenon by the effect of yield in (220) grain starting before the (111) grains.…”

“…Quantification of the surface roughness (average surface roughness Ra and total height of the roughness profile Rt) for both samples is presented in Table 3. It is well known for sputtering techniques that substrate temperature plays a key role in controlling the film growth process, leading to modification in surface smoothness [33][34][35] and change in film structure, specifically grain growth. Chan et al [36] demonstrated an increase of the root mean square roughness Rq and lateral feature size of films of 500 nm thick films when the substrate temperature varied from 25 to 250 °C.…”

Facile Ultrasound-Assisted Synthesis of Copper Zinc Tin Sulfide Chalcogenide Nanoparticles for Thin Film Solar Cell Applications

“…Due to the increased surface energy during annealing, particles fuse resulting in increased aggregate formation. This fusion process of the particles also causes the growth of a few grains which increases poly-dispersity [25][26][27]. Size analysis of the annealed particles shows the size range between 10 nm and 45 nm.…”

A critical review on the contributions of chemical and physical factors toward the nucleation and growth of large-area graphene

“…2 with the calculated values summarized in Table 1. However, reports have shown that annealing the copper substrate at high temperature changes its crystal structure [38]. It was shown that at a temperature of up to 350°C, Cu (111) is dominant, and upon increasing the temperature to 500°C, the structure begins to change to Cu (100) [39].…”