Secondary cracking at grain boundaries in silicon thin films
نویسندگان
چکیده
In this article, we report irregular cleavage front transmission at grain boundaries in free-standing polysilicon thin films. When the orientations of two adjacent grains are correlated, the crack may bypass the boundary via a ‘‘tunneling’’ process. Similar behavior can also be achieved if the crack path curves in the grain-boundary-affected zone. Moreover, the separation of crack flanks can be aided by secondary cracking. These irregular modes of crack front behavior tend to lower the effective boundary toughness. 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
منابع مشابه
Resistance of through-thickness grain boundaries to cleavage cracking in silicon thin films
Through a set of microtensile experiments, it was discovered that the resistance of a free-standing polycrystalline silicon thin film to cleavage cracking is not a material constant. Rather, it is highly dependent on the film thickness. As the film thickness changes from 1 to 10 lm, the fracture resistance increases by 20–60%, which can be attributed to the nonuniform nature of the crack front ...
متن کاملCleavage cracking across triple grain boundary junctions in freestanding silicon thin films
This article is focused on a fractography study of cleavage cracking at triple grain boundary junctions in freestanding silicon thin films. At a triple junction, as the crystallographic orientations of the two grains ahead of the crack are different by only a few degrees, the cleavage front advance becomes quite jerky. The crack first enters the grain of smaller boundary toughness and then turn...
متن کاملSol – Gel Spin Coated Cadmium Sulphide Thin Films on Silicon (1 0 0) Substrates for Optoelectronic Applications
Cadmium chalcogenides with appropriate band gap energy have been attracting a great deal of attention because of their potential applications in optoelectronic devices. In this work CdS thin films were deposited on p – type silicon substrates by sol – gel spin coating method at different substrate temperatures. The CdS deposited wafers were characterized by X‐ray diffracti...
متن کاملCleavage cracking across twin boundaries in free-standing silicon thin films
Cleavage cracking across twin boundaries in freestanding silicon thin films is investigated in a microtensile fracture experiment. If the twist misorientation is relatively small, the crack front transmission can be quite smooth; otherwise the fracture surface may be either planar or broken down into parallel terrains. In all the cases, the local fracture resistance tends to increase. PACS 62.2...
متن کاملOn size effect of cleavage cracking in polycrystalline thin films
A crack trapping model is developed for the fracture resistance of high-angle grain boundaries in free-standing brittle thin films, based on which a new size effect is predicted. In addition to the crystallographic misorientations, the grain boundary toughness is also dependent on the film thickness, primarily due to the geometrically necessary crack front branching. 2007 Elsevier Ltd. All righ...
متن کامل