The Glide-Shuffle Controversy in Silicon

Dislocations in Silicon have been a subject to intense studies in the last several decades. It is not only an interesting subject by itself, but is also important for understanding generic dislocation behaviors in a wider class of materials. In the 1970s, researchers had concluded that glide sets can move more easily than shuffle sets via experiments and theoretical calculations. It became widely accepted then that plastic deformation occurs by the motion of partial dislocations in the glide planes of diamond or zinc blende structures. TEM images confirmed this solidarity by showing the motion of dislocations under stress. In 1998, some researchers working on InP found that at very low temperatures (77 K) and high hydrostatic pressure, non-dissociated dislocations move in shuffle planes. It was also subsequently shown that a shuffle-set dislocation has a lower Peierls stress than glide-set partial dislocation. Other calculations debunked older models such as the Peierls-Nabarro model and showed that shuffle set-dislocations always move faster than glide sets. It has since broiled into a highly debated issue with a number of papers supporting either side. This paper attempts to give an overview of most of the seminal papers written on this topic and some newer work.

Inhaltsverzeichnis (Table of Contents)

• Abstract
• Introduction
• Early Observations on Dislocation Networks
• Weak-Beam Technique
• Lattice Images of Ge and Si Cores
• Axial Beam Imaging Techniques
• Theoretical Work
• The Kink Pair Mechanism
• Atomistic Simulation
• Conclusion

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This paper provides an overview of the glide-shuffle controversy in silicon, a topic of intense debate within the field of materials science. It examines the historical development of understanding dislocations in silicon, explores the various experimental and theoretical approaches to the problem, and analyzes the evidence supporting both the glide and shuffle models.

• The nature of dislocations in silicon
• The mechanisms of dislocation motion
• The role of experimental and theoretical approaches in understanding dislocation behavior
• The influence of temperature, stress, and other factors on dislocation movement
• The ongoing debate surrounding the glide and shuffle models

Zusammenfassung der Kapitel (Chapter Summaries)

• The paper begins by outlining the historical background of the glide-shuffle controversy, explaining the initial assumption that dislocations in silicon were of the shuffle type. It then details how early observations using weak-beam techniques challenged this assumption, suggesting that dislocations were extended (glide type).
• The paper continues by exploring the use of lattice imaging techniques to observe the dislocation core. These studies yielded conflicting results, with some suggesting a narrow, unextended core, while others supported the presence of extended dislocations.
• The paper then reviews the development of axial beam imaging techniques, which allowed for more direct and accurate lattice images. These observations confirmed the presence of extended dislocations, supporting the glide model. However, more detailed theoretical work using the Peierls-Nabarro model initially favored the shuffle model.
• The paper then dives into the kink pair mechanism, proposed by Duesbery as a possible explanation for the discrepancy between experimental and theoretical results. The kink mechanism suggests that dislocations might not move by rigid translation, but rather through the nucleation and propagation of kink pairs.
• The paper concludes by summarizing the findings of atomistic simulations, which provide further support for the shuffle model. These simulations indicate that shuffle-set dislocations always move faster than glide-set dislocations under all temperature and stress conditions.

Schlüsselwörter (Keywords)

The paper focuses on the key concepts of dislocations, glide and shuffle models, weak-beam techniques, lattice images, Peierls stress, kink pair mechanism, and atomistic simulations in the context of silicon.

Details

• College: University of California, Santa Barbara
• Grade: A
• Author: Anchal Agarwal (Author)
• Publication Year: 2017
• Pages: 9
• Catalog Number: V387313
• ISBN (eBook): 9783668630062
• ISBN (Book): 9783668630079
• Language: English
• Tags: glide-shuffle controversy silicon