TY - JOUR
T1 - Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO2, TiO2, Al2O3, and HfO2
AU - Arts, Karsten
AU - Utriainen, Mikko
AU - Puurunen, Riikka L.
AU - Kessels, Wilhelmus M.M.
AU - Knoops, Harm C.M.
PY - 2019/11/7
Y1 - 2019/11/7
N2 - Surface recombination of plasma radicals is generally considered to limit film conformality during plasma-assisted atomic layer deposition (ALD). Here, we experimentally studied film penetration into high-aspect-ratio structures and demonstrated that it can give direct information on the recombination probability r of plasma radicals on the growth surface. This is shown for recombination of oxygen (O) atoms on SiO2, TiO2, Al2O3, and HfO2 where a strong material dependence has been observed. Using extended plasma exposures, films of SiO2 and TiO2 penetrated extremely deep up to an aspect ratio (AR) of âˆ900, and similar surface recombination probabilities of r = (6 ± 2) × 10-5 and (7 ± 4) × 10-5 were determined for these processes. Growth of Al2O3 and HfO2 was conformal up to depths corresponding to ARs of âˆ80 and âˆ40, with r estimated at (1-10) × 10-3 and (0.1-10) × 10-2, respectively. Such quantitative insight into surface recombination, as provided by our method, is essential for modeling radical-surface interaction and understanding for which materials and conditions conformal film growth is feasible by plasma-assisted ALD. ©
AB - Surface recombination of plasma radicals is generally considered to limit film conformality during plasma-assisted atomic layer deposition (ALD). Here, we experimentally studied film penetration into high-aspect-ratio structures and demonstrated that it can give direct information on the recombination probability r of plasma radicals on the growth surface. This is shown for recombination of oxygen (O) atoms on SiO2, TiO2, Al2O3, and HfO2 where a strong material dependence has been observed. Using extended plasma exposures, films of SiO2 and TiO2 penetrated extremely deep up to an aspect ratio (AR) of âˆ900, and similar surface recombination probabilities of r = (6 ± 2) × 10-5 and (7 ± 4) × 10-5 were determined for these processes. Growth of Al2O3 and HfO2 was conformal up to depths corresponding to ARs of âˆ80 and âˆ40, with r estimated at (1-10) × 10-3 and (0.1-10) × 10-2, respectively. Such quantitative insight into surface recombination, as provided by our method, is essential for modeling radical-surface interaction and understanding for which materials and conditions conformal film growth is feasible by plasma-assisted ALD. ©
KW - OtaNano
UR - http://www.scopus.com/inward/record.url?scp=85074789607&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.9b08176
DO - 10.1021/acs.jpcc.9b08176
M3 - Article
AN - SCOPUS:85074789607
SN - 1932-7447
VL - 123
SP - 27030
EP - 27035
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 44
ER -