On the real structure of monocrystalline silicon near dislocation slip planes

Abstract

The properties of regions swept by a moving dislocation in silicon crystals are experimentally studied. The peculiarities of forming traces of various types behind dislocations observed by electron microscopy and chemical etching are investigated. These traces are found to arise as result of point defect redistribution by moving dislocations and change in their structural state in a volume swept by a dislocation. It is shown that the processes mentioned enable the slip plane to assume properties of a specific two‐dimensional defect responsible for the appearance of the new mechanism of a charge carrier mobility anisotropy in the plastically deformed crystals.

EBIC characterization of strained Si/SiGe heterostructures

“…Indeed, such defects provide the noticeable EBIC contrast even in Si deformed in clean conditions, when the dislocation contrast is below the detectivity limit [13,14]. These defects could be revealed by chemical etching [15]. The dislocation trail contrast increases with a number of dislocations moving in the neighboring slip planes, therefore the dark regions in the EBIC micrographs could be associated with inhomogeneities in a number of moving threading dislocation and therefore their position could coincide with that of misfit dislocation bunches.…”

“…Thus, the dislocation trails could not be revealed at depth smaller than about 0.4−0.5 µm even if they preserve their recombination activity in this region. It should be also mentioned that dislocation trails give negligible diffuse contrast in the transmission electron microscope [15] therefore it is rather difficult to separate them from threading dislocations to check if they really exist in the structures under study.…”

“…However, recent investigations of individual dislo- ¶ E-mail: yakimov@ipmt-hpm.ac.ru cations in clean Si wafers [12][13][14] showed that their EBIC contrast was negligible. In the same time the electrically active defects can be formed behind moving dislocations (dislocation trails), which could produce the rather strong EBIC contrast even in clean crystals [13][14][15]. Therefore, the question about the nature of EBIC contrast observed in Si/SiGe heterostructures seems to be not totally closed.…”

Structure and recombination properties of extended defects in the dislocation slip plane in silicon

“…However, the numerous experimental data show that the electrical as well as optical properties of deformed crystals are mainly determined by point defects located rather far from dislocations [1][2][3]. The most part of such defects is located in the dislocation trails [4][5][6] and their electrical activity can be studied in the Electron Beam Induced Current (EBIC) mode and by the Deep Level Transient Spectroscopy (DLTS) [6]. As preliminary studies, some elements of their morphology and properties were considered in [5].…”

Effect of dislocation trails on gold diffusion in Si

“…1 Introduction As shown in [1,2], the dislocation trails formed in Si behind moving dislocations demonstrate the essential electrical activity and can be easy revealed by chemical etching and in the scanning electron microscope in the Electron Beam Induced Current (EBIC) mode. Moreover, in Si with a low dislocation density deformed at low temperatures the effect of deformation-induced defects on the electrical properties is mainly determined not by dislocations themselves but by the dislocation trails [3,4].…”