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Title: Real-time X-ray Studies of the Growth of Mo-Seeded Si Nanodots by Low-Energy Ion Bombardment

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
959852
Report Number(s):
BNL-82838-2009-JA
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Instruments and Methods B; Journal Volume: 264
Country of Publication:
United States
Language:
English
Subject:
national synchrotron light source

Citation Formats

Ozaydin,G., Ozcan, A., Wang, Y., Ludwig, Jr., K., Zhou, H., and Headrick, R. Real-time X-ray Studies of the Growth of Mo-Seeded Si Nanodots by Low-Energy Ion Bombardment. United States: N. p., 2007. Web. doi:10.1016/j.nimb.2007.08.010.
Ozaydin,G., Ozcan, A., Wang, Y., Ludwig, Jr., K., Zhou, H., & Headrick, R. Real-time X-ray Studies of the Growth of Mo-Seeded Si Nanodots by Low-Energy Ion Bombardment. United States. doi:10.1016/j.nimb.2007.08.010.
Ozaydin,G., Ozcan, A., Wang, Y., Ludwig, Jr., K., Zhou, H., and Headrick, R. Mon . "Real-time X-ray Studies of the Growth of Mo-Seeded Si Nanodots by Low-Energy Ion Bombardment". United States. doi:10.1016/j.nimb.2007.08.010.
@article{osti_959852,
title = {Real-time X-ray Studies of the Growth of Mo-Seeded Si Nanodots by Low-Energy Ion Bombardment},
author = {Ozaydin,G. and Ozcan, A. and Wang, Y. and Ludwig, Jr., K. and Zhou, H. and Headrick, R.},
abstractNote = {},
doi = {10.1016/j.nimb.2007.08.010},
journal = {Nuclear Instruments and Methods B},
number = ,
volume = 264,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • The formation of self-organized Si nanostructures induced by Mo seeding during normal incidence Ar{sup +} ion bombardment at room temperature is reported. Silicon surfaces without Mo seeding develop only power-law roughness during 1000 eV ion bombardment at normal incidence, in agreement with scaling theory expectations of surface roughening. However, supplying Mo atoms to the surface during ion bombardment seeds the development of highly correlated, nanoscale structures ('dots') that are typically 3 nm high with a spatial wavelength of approximately 30 nm. With time, these saturate and further surface roughening is dominated by the growth of long-wavelength corrugations.
  • The formation of self-organized Si nanostructures induced by Mo seeding during normal incidence Ar{sup +} ion bombardment at room temperature is reported. Silicon surfaces without Mo seeding develop only power-law roughness during 1000 eV ion bombardment at normal incidence, in agreement with scaling theory expectations of surface roughening. However, supplying Mo atoms to the surface during ion bombardment seeds the development of highly correlated, nanoscale structures ('dots') that are typically 3 nm high with a spatial wavelength of approximately 30 nm. With time, these saturate and further surface roughening is dominated by the growth of long-wavelength corrugations.
  • Native and Mo-seeded nanostructuring of the Si(100) surface during Ar+ ion bombardment is investigated by means of real-time grazing-incidence small-angle x-ray scattering and atomic force microscopy. During off-axis bombardment at room temperature, the native early-stage growth kinetics of nanoripples on the surface is found to be in reasonable overall agreement with theoretical predictions, particularly when an ion impact induced lateral mass redistribution term is included. For normal-incidence bombardment at room temperature, a native short wavelength smoothing of the amorphized Si surface is observed, suggesting that ion impact induced lateral mass redistribution dominates the Bradley-Harper instability. During 5% Mo-seeded normal-incidence bombardmentmore » at temperatures up to 450 C, nanodots form with heights decreasing as the substrate temperature increases. This trend is counter to that typically observed for the growth of large cone structures on metals and suggests that the primary effect of thermal energy here is in promoting surface smoothing, rather than increasing diffusion of seed atoms to form protective clusters. During seeded bombardment at 650 C the surface remains crystalline and surface corrugations exhibit dynamic scaling characteristic of surface diffusion-driven instabilities. This is the same behavior as is found in the absence of seeding and its presence suggests that at this concentration seeding does not play a large role during normal-incidence bombardment of the Si surface at high temperatures.« less
  • Effects of seed atoms on the formation of nanodots on silicon surfaces during normal incidence Ar+ ion bombardment at room temperature are studied with real-time grazing-incidence small-angle x-ray scattering (GISAXS), real-time wafer curvature stress measurements and ex situ atomic force microscopy. Although Si surfaces remain smooth during bombardment at room temperature, when a small amount of Mo atoms is supplied to the surface during ion bombardment, the development of correlated structures ('dots') is observed. Stress measurements show that initially a compressive stress develops during bombardment, likely due to amorphization of the surface and insertion of argon. However, seeding causes amore » larger tensile stress to develop with further bombardment, possibly due to the formation of higher density regions around the Mo seed atoms on the surface. Detailed fits of the GISAXS evolution during nanostructure growth show that the instability is larger than predicted by the Bradley-Harper theory of curvature-dependent sputter yield. These results suggest that the tensile stress is playing a dominant role in driving the nanodot formation.« less