Evolution of stress and structure in Cu thin films

Abstract

Evolution of stresses developing in Cu thin films during and after deposition by thermal evaporation in UHV system is studied. Thin films were deposited on 100 µm thick Si substrate at room temperature. Deposition rates for the films were changed between 0.2 Å/s and 2.0 Å/s, while the total thickness was changed from 7.7 nm to 155 nm. Deformation analysis of crystalline lattice and microstructure was performed by x-ray diffraction measurements (θ-2θ scans, "sin 2 ψ" method). The surface morphology of film was studied by atomic force microscopy. The average stress in the films was determined by measuring the radius of curvature of samples. For thin films three stages of stress evolution (compressive, tensile and compressive) were we distinguished. This behavior is characteristic for materials with a Volmer-Weber mode. A three-dimensional molecular dynamics technique was applied for simulating the stress calculation during thin film growth. The results obtained from the simulation are consistent with the experimental results.

Nonvolatile and tunable switching of lateral photo-voltage triggered by laser and electric pulse in metal dusted metal-oxide-semiconductor structures

“…Figure 1 shows the AFM images of one sample, which indicates that the super thin Cu films are discontinuous, actually nanoparticles in light of the first stage are of Volmer-Weber growth mode. More direct visualized SEM and AFM images of this discontinuity and the growth mode can be found in other previous reports 28 29 . Therefore, the deposited Cu thickness in our samples is only a nominal thickness.…”

A Laser and Electric Pulse Modulated Nonvolatile Photoelectric Response in Nanoscale Copper Dusted Metal‐Oxide‐Semiconductor Structures

“…The Cu films we used in our experiment were deposited with various thicknesses from 0.4 to 40 nm, and the atomic force microscope (AFM) images of these samples' surfaces are shown in Figure . We can see that super‐thin Cu films (average thickness less than 3 nm) are always discontinuous, which can be viewed in the first stage of the Volmer–Weber growth mode as an array of nanoparticles.…”

“…[13,14] The performance of a given MOS device is largely determined by its Schottky barrier, which until now is regarded as fixed and unchangeable because of the Fermi-level pinning effect. It is of great interest www.advelectronicmat.de less than 3 nm) are always discontinuous, [20,21] which can be viewed in the first stage of the Volmer-Weber growth mode as an array of nanoparticles. It is of great interest www.advelectronicmat.de less than 3 nm) are always discontinuous, [20,21] which can be viewed in the first stage of the Volmer-Weber growth mode as an array of nanoparticles.…”

Molecular dynamics simulation of stress and grain evolution

“…Such an evolution of the biaxial stress is often associated with changes in the grain structure of thin films [16].…”