Abstract

The ion-induced formation of nanometer-scale ripples on semiconductors, long known as the sputter erosion surface instability, is explained using a coupled atomistic-continuum framework. Molecular dynamics simulations of individual medium energy ion impacts on an amorphous silicon target show that the average effect of an incident ion is to leave an ngström-scale crater-like impression on the surface, complete with a crater rim. The summation of many such impacts on a micron-scale surface, combined with the smoothing effect of surface diffusion, leads to the formation of surface ripples aligned perpendicular to the projected ion beam direction. The same numerical approach can be used to evaluate the standard analytical model for this process, known as the Bradley-Harper model. Both Bradley-Harper surface evolution and the atomistically determined crater function surface evolution are computed over time under conditions similar to those for known experimental data. The results show that the surface mass rearrangement associated with the finite atomistic crater rims explains a key experimental observation, ripple amplitude saturation, which cannot be accurately explained using the Bradley-Harper model or any other known numerical or analytical model for the sputter erosion surface instability.

Original languageEnglish (US)
Article number224018
JournalJournal of Physics Condensed Matter
Volume21
Issue number22
DOIs
StatePublished - Jun 9 2009

Fingerprint

Silicon
craters
Ions
silicon
ions
ripples
rims
erosion
Analytical models
Erosion
ion impact
Surface diffusion
surface diffusion
Amorphous silicon
smoothing
Ion beams
amorphous silicon
Molecular dynamics
Numerical models
ion beams

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

A multiscale crater function model for ion-induced pattern formation in silicon. / Kalyanasundaram, N.; Freund, J. B.; Johnson, H. T.

In: Journal of Physics Condensed Matter, Vol. 21, No. 22, 224018, 09.06.2009.

Research output: Contribution to journalArticle

@article{40a1fafdab6647fab2af024e6cb95e7e,
title = "A multiscale crater function model for ion-induced pattern formation in silicon",
abstract = "The ion-induced formation of nanometer-scale ripples on semiconductors, long known as the sputter erosion surface instability, is explained using a coupled atomistic-continuum framework. Molecular dynamics simulations of individual medium energy ion impacts on an amorphous silicon target show that the average effect of an incident ion is to leave an ngstr{\"o}m-scale crater-like impression on the surface, complete with a crater rim. The summation of many such impacts on a micron-scale surface, combined with the smoothing effect of surface diffusion, leads to the formation of surface ripples aligned perpendicular to the projected ion beam direction. The same numerical approach can be used to evaluate the standard analytical model for this process, known as the Bradley-Harper model. Both Bradley-Harper surface evolution and the atomistically determined crater function surface evolution are computed over time under conditions similar to those for known experimental data. The results show that the surface mass rearrangement associated with the finite atomistic crater rims explains a key experimental observation, ripple amplitude saturation, which cannot be accurately explained using the Bradley-Harper model or any other known numerical or analytical model for the sputter erosion surface instability.",
author = "N. Kalyanasundaram and Freund, {J. B.} and Johnson, {H. T.}",
year = "2009",
month = "6",
day = "9",
doi = "10.1088/0953-8984/21/22/224018",
language = "English (US)",
volume = "21",
journal = "Journal of Physics Condensed Matter",
issn = "0953-8984",
publisher = "IOP Publishing Ltd.",
number = "22",

}

TY - JOUR

T1 - A multiscale crater function model for ion-induced pattern formation in silicon

AU - Kalyanasundaram, N.

AU - Freund, J. B.

AU - Johnson, H. T.

PY - 2009/6/9

Y1 - 2009/6/9

N2 - The ion-induced formation of nanometer-scale ripples on semiconductors, long known as the sputter erosion surface instability, is explained using a coupled atomistic-continuum framework. Molecular dynamics simulations of individual medium energy ion impacts on an amorphous silicon target show that the average effect of an incident ion is to leave an ngström-scale crater-like impression on the surface, complete with a crater rim. The summation of many such impacts on a micron-scale surface, combined with the smoothing effect of surface diffusion, leads to the formation of surface ripples aligned perpendicular to the projected ion beam direction. The same numerical approach can be used to evaluate the standard analytical model for this process, known as the Bradley-Harper model. Both Bradley-Harper surface evolution and the atomistically determined crater function surface evolution are computed over time under conditions similar to those for known experimental data. The results show that the surface mass rearrangement associated with the finite atomistic crater rims explains a key experimental observation, ripple amplitude saturation, which cannot be accurately explained using the Bradley-Harper model or any other known numerical or analytical model for the sputter erosion surface instability.

AB - The ion-induced formation of nanometer-scale ripples on semiconductors, long known as the sputter erosion surface instability, is explained using a coupled atomistic-continuum framework. Molecular dynamics simulations of individual medium energy ion impacts on an amorphous silicon target show that the average effect of an incident ion is to leave an ngström-scale crater-like impression on the surface, complete with a crater rim. The summation of many such impacts on a micron-scale surface, combined with the smoothing effect of surface diffusion, leads to the formation of surface ripples aligned perpendicular to the projected ion beam direction. The same numerical approach can be used to evaluate the standard analytical model for this process, known as the Bradley-Harper model. Both Bradley-Harper surface evolution and the atomistically determined crater function surface evolution are computed over time under conditions similar to those for known experimental data. The results show that the surface mass rearrangement associated with the finite atomistic crater rims explains a key experimental observation, ripple amplitude saturation, which cannot be accurately explained using the Bradley-Harper model or any other known numerical or analytical model for the sputter erosion surface instability.

UR - http://www.scopus.com/inward/record.url?scp=66349094236&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=66349094236&partnerID=8YFLogxK

U2 - 10.1088/0953-8984/21/22/224018

DO - 10.1088/0953-8984/21/22/224018

M3 - Article

C2 - 21715756

AN - SCOPUS:66349094236

VL - 21

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

SN - 0953-8984

IS - 22

M1 - 224018

ER -