An investigation of hardness and adhesion of sputter-deposited aluminum on silicon by utilizing a continuous indentation test

Abstract

The hardness of aluminum films on silicon are measured as functions of depth of the indenter. The films have thicknesses of 0.25,0.5, and 1.0μm. The adhesion between one film and the substrate has been reduced through the prior deposition of a 10 nm layer of carbon. In each case the hardness is found to increase as the indenter approaches the film-substrate interface, but the rate of increase is greater for a film with good adhesion than for one with poor adhesion. It is suggested that this increase results from the constraint on deformation of the film by the substrate. A physical model is proposed whereby the yield stress of the film, σo, and an average effective shear strength τ of the indenter-film and film-substrate interfaces, may be determined from the data.

Relationships between hardness, elastic modulus, and the work of indentation

“…It is now possible to monitor, with high precision and accuracy, both the load and displacement of an indenter during indentation experiments in the respective micro-Newton and nanometer ranges. [2][3][4] Using these instrumented indentation techniques, the hardness and Young's modulus may be obtained from the peak load and the initial slope of the unloading curves by the method of Oliver and Pharr 5 or that of Doerner and Nix. 6 Both methods, however, depend on estimating contact area under load, which is sometimes difficult, especially when ''piling-up'' occurs.…”

Determination of Anodized Aluminum Material Characteristics by Means of Nano-Indentation Measurements

“…With high-resolution testing equipment, this facilitates the determination of properties at the micrometer and nanometre scales [9][10][11]. For this reason the method has become a primary technique for determining the mechanical properties of thin films without removing the film from the substrate and as well as for capturing small structural features [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Nanoindentation technique nowadays is applied for characterisation of thin films prepared from metals, polymers, rubber-like materials [30] and soft materials.…”

Scaling approach to conical indentation in elastic-plastic solids with work hardening

“…With the improvement in indentation instruments, it is now possible to monitor, with high precision and accuracy, both the load and displacement of an indenter during indentation experiments in the respective micro-Newton and nanometer range. [2][3][4] In addition to hardness, basic mechanical properties of materials, such as Young's modulus, yield strength, and workhardening exponent, may be deduced from the indentation load versus displacement curves for loading and unloading. For example, Oliver and Pharr 5 and Doerner and Nix 6 have proposed methods for determining the hardness and Young's modulus from the peak load and the initial slope of the unloading curves.…”