Shape Effect of Surface Defects on Nanohardness by Quasicontinuum Method

Abstract

Nanoindentation on a platinum thin film with surface defects in a rectangular shape and triangular shape was simulated using the quasicontinuum method to study the shape effect of surface defects on nanohardness. The results show that the nanohardness of thin film with triangular defects is basically larger than those with rectangular defects, which is closely related to the height of the surface defects at the boundary near to the indenter. Moreover, the triangular defect might have an enhancement effect on nanohardness by a certain size of the defects and the boundary orientation of the defect, where such an enhancement effect increases as the defect grows. Furthermore, the nanohardness decreases when the defect is folded from wide to narrow in the same atom cavity, and particularly expresses a more obvious drop when the height of the defects increases. In addition, larger sizes of the rectangular defect induce more reduction in nanohardness, while the nanohardness of the triangular surface defect is sensitive to the periodic arrangement of atoms changed by the boundary orientation of the defect, which is well explained and demonstrated by the calculation formula theory of necessary load for dislocation emission.

Study on copper-to-copper bonding of three-dimensional integrated circuits using the quasicontinuum method

“…With commercially accessible bonding equipment, Cu-Cu bonding with a temperature gradient in ambient settings can meet the industry requirement for heterogeneous chip integration [4,16]. The quasi-continuous method has diverse applications, including nanoimprinting [17][18][19][20][21][22], nanocutting [23,24], nanomilling [25], grinding [26], nanowelding [27][28][29], bending and punching [30], cyclic loading [31,32], nanoindentation [33][34][35][36][37][38], rough surfaces [39], interface fracture [40], crack growth characteristics [41], and plastic deformation [42,43] processes, enabling the analysis of plastic deformation and internal mechanical responses occurring within a material subjected to the influence of an indenter involves a comprehensive analysis. This analysis delves into the intricate processes occurring within the material as it undergoes deformation, elucidating the internal mechanisms at play.…”