In situ observation of nanotwins formation through twin terrace growth in pulse electrodeposited Cu films

Abstract

Nanotwinned copper (nt-Cu) shows a broad application prospects as interconnection materials in integrated circuit industry, since it combines the excellent mechanical and electrical properties. However, the formation and growth behavior of twin lamellae in pulse electrodeposited copper films are not fully understood. In this work, a series of electroplated copper films are prepared by verifying the electroplating parameters and the microstructures are analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM). The surface morphology indicates strong evidence of stacked twin terraces and layers, suggesting that nanotwins grow up layer by layer. Combined with in situ characterization by SEM and molecular dynamics (MD) simulation, it is proved that the terraces originate from the triple junction of grain boundaries and grow up by extending along the lateral (111) crystal plane. A twin terrace-growing model for nt-Cu is then deduced, which distinguishes from deformation twins or annealed twins. This growth model would be prospective to help obtain high quality of nt-Cu in industry.

Investigation of electrodeposited copper layer with island twinning structure on Zr substrate

“…The existence of such a structure reduces the possibility of producing a uniform coating, so it does not seem reasonable to evaluate the copper coating with a thickness of greater than 100 µm. In most studies [18,20], the properties of the copper coating with a thickness of less than 100 µm have been investigated. As the thickness of the coating increases, the edge area of the sample increases, so the amount of electron flux in this area increases.…”

“…In other words, twins can improve the metallurgical properties of the copper layer. The importance of this issue is so great that some studies [19][20][21][22] have investigated the effect of twins and how they are formed in the structure of copper. As the speed of copper deposition increases, the deposition rate of copper atoms on the substrate will increase and the possibility of forming a regular atomic structure will decrease.…”

Electron beam irradiation for the formation of thick Ag film on Ag3PO4

“…Over the past years, microscopic techniques provided valuable insights into the compositions and structures of materials at the nano-and angstrom-levels. 1 Among them, in situ transmission electron microscopy (TEM) is a powerful method for the investigation of atomic structures, dynamics, and diffraction patterns, 2 and atomic-level analyses 3 of various processes including phase/shape transformations, 1,4-7 molten nanouidic migration, 8 and electromigration. 9 The electron beam irradiation (EBI) in TEM could be also used to fabricate nanomaterials that cannot be obtained using conventional chemical and physical methods.…”

Low-Temperature Direct Bonding of 3D-IC Packages and Power IC Modules Using Ag Nanotwinned Thin Films

“…Efforts on other nanotwinned structures, such as hexagonal closed-packed (HCP) or body-centred cubic (BCC) metals, alloys, and synthetic materials, continue to be an essential part of exploration. Furthermore, the nanotwinned structures are known to be beneficial alternatives in numerous material areas like mechanical structures (Anderoglu et al, 2008;Yu et al, 2013) and interconnection materials in the integrated circuit industry (Cheng et al, 2017;Zheng et al, 2021). Clearly, many research options for focusing on nanotwinned hierarchical materials are available for the near future.…”