Revealing electromigration on dielectrics and metals through the step-bunching instability

Abstract

Electromigration, due to its technological and scientific significance, has been a subject of extensive studies for many years. We present evidence of electromigration in dielectric materials, namely C-plane sapphire, obtained from direct experimental observation of an atomic step-bunching instability driven by electromigration. We further expand upon our previously reported findings of electromigration induced step-bunching transformation of a metal surface. The only system where electromigration driven step bunching has been observed and comprehensively investigated is the low index surfaces of silicon. In this study we show that electromigration driven SB can be induced on a variety of crystallographic surfaces, including metals and insulating oxides, and may be more prevalent than previously thought. Electric fields were applied at high temperature to W(110) and Al 2 O 3 (0001) crystals whereupon their surface reordered to a morphology closely resembling that of Si(111) with atomic steps bunched by electromigration. This suggests that the mechanism of step bunching on the W(110), Al 2 O 3 (0001), and Si(111) can be fundamentally the same. Annealing W(110) offcut in the [001] direction with an up-step current produced a morphology with the bunch edges composed of zigzag segments meeting at a right angle.

Quantifying the Effect of Step–Step Exclusion on Dynamically Unstable Vicinal Surfaces: Step Bunching without Macrostep Formation

“…In this context, different materials are studied, such as CH 3 NH 3 PbI 3 , GaN, − AlN, AlGaN, SiC, − graphene, , PTCDA/Ag, W, , SrRuO 3 /(001) SrTiO 3 , KDP, − Si, − ferritin, diamond, and Al 2 O 3 . , The phenomenon of destabilization by both step-down (SD) and step-up (SU) direct currents of Si(111) vicinals was first observed by Latyshev et al on sublimating Si(111) surfaces and it was further shown based on the Burton–Cabrera–Frank (BCF) type of modeling that the directional asymmetry (bias) in the diffusion of the partially charged surface adatoms makes the motion of the steps from the vicinal surface unstable. − The phenomenon of SB was investigated actively in the following years by experimental techniques − as well as theoretically − and numerically. − …”

Analyzing the Pattern Formation on Vicinal Surfaces in Diffusion-Limited and Kinetics-Limited Growth Regimes: The Effect of Step–Step Exclusion

“…Step-bunching phenomenon has been extensively studied over the years by experimental techniques − and by means of theoretical analyses − and numerical simulations. − Step-bunching instability has been observed in diverse crystalline materials, such as Si, ,,− SiC, − CH 3 NH 3 PbI 3 GaAs, GaN, ,− AlN, AlGaN, graphene, ,<...…”

Desert Water Saving and Transportation for Enhanced Oil Recovery: Bridging the Gap for Sustainable Oil Recovery

“…Obtaining environmentally friendly "green" materials for superhydrophobic coating plays a significant role and contributes to the improvement of the level and quality of life of the population [7][8][9][10]. Superhydrophobic sand on vicinal surfaces is an intriguing and innovative area of study that merges the principles of materials science and surface chemistry [11][12][13][14].…”