Pop-in events induced by spherical indentation in compound semiconductors

Abstract

Details of the elastic–plastic transitions in crystalline compound semiconductors have been examined using spherical indentation. Two cubic (InP and GaAs) and two hexagonally structured semiconductors (ZnO and GaN) have been studied. A series of indentations have been made in each material at a number of different loads. The resulting load–penetration curves exhibited one or more discontinuities on loading (so called pop-in events). The load at which the initial pop-in event occurred has been measured along with the corresponding indenter extension. The elastic and elastic–plastic response of each material to spherical indentation has been calculated and compared with the experiment. By taking the difference between the elastic and elastic–plastic penetration depths, it has been found that the pop-in extension at each load could be predicted for each material. The detailed deformation behavior of each of the materials during indentation has also been discussed.

Analysis of onset of dislocation nucleation during nanoindentation and nanoscratching of InP

“…Additionally, this investigation suggests that dislocations nucleate first at the surface and then propagate inside the bulk, which can be an explanation for the so-called pop-in effect in InP indentation. [10][11][12]32 Finally, in opposition to the general beliefs (scratching tests create too many damages), we prove in this article that scratching is a suitable method to control dislocation nucleation inside a crystalline material.…”

“…[9][10][11][12] In this work, the first case can be disregarded as the approach velocity is identical for all indentation tests and no dislocations are generated up to a load of 1 mN. The latter case is observed for tests conducted at loads higher than 2 mN since all indents having a pop-in the load-displacement curves were etched indicating that dislocation nucleation had occurred.…”

“…7,8 Most scientists agree that, in III-V semiconductors, the nucleation of dislocations, also called the elastic-plastic transition, is associated with the pop-in in the load-displacement curve in nanoindentation. [9][10][11][12] Some authors 13,14 found that, for InP, pop-in event is statistical and is related to a low density of native defects. The fact that plastic deformation can occur even without pop-in was explained via the difference in doping that dramatically changes the pathway to plastic deformation.…”

Cleavage Fracture of Brittle Semiconductors from the Nanometre to the Centimetre Scale

“…Once the maximal shearing stress at the surface under the tip has reached a critical value, dislocation nucleation may take place which is related to the so-called pop-in in indention force-penetration curves on III±V semiconductors. [21,22] The response of a material during scratching can change drastically when a thin layer is added on the surface. For instance, for a given tip radius and by using the proper load, it is possible to remove selectively an oxide at the surface of a silicon wafer without generating dislocations or phase transformations.…”

Nano-scaled diffusional or dislocation creep analysis of single-crystal ZnO

“…1,2 As being usually fabricated into low-dimensional piezoelectric devices, it is necessary to measure the mechanical properties of singlecrystal ZnO by contact-induced deformation through nanoindentation. [3][4][5][6][7][8][9][10][11][12][13] In this regard, the timedependent (so called creep) behavior is especially important in order to assess its mechanical reliability during devices being on service under long-term stress conditions. However, only few researches have been performed on the topic of nanoscale creep behavior of single-crystal ZnO with vertically (0001) orientation.…”