Abstract
The conformality of a film grown by atomic layer deposition (ALD) is strongly affected by the reactivities of the precursor and coreactant, which can be expressed in terms of their sticking probabilities toward the surface. We show that the leading front of the thickness profile in high-aspect-ratio structures gives direct information on the sticking probabilities of the reactants under most conditions. The slope of the front has been used to determine the sticking probabilities of Al(CH3)3 and H2O during ALD of Al2O3 . The determined values are (0.5-2) × 10-3 for Al(CH3)3 and (0.8-2) × 10-4 for H2O at a set-point temperature of 275 °C, corresponding to an estimated substrate temperature of ∼220 °C. Additionally, the thickness profiles reveal soft-saturation behavior during the H2O step, most dominantly at reduced temperatures, which can limit the conformality of Al2O3 grown by ALD. This work thus provides insights regarding quantitative information on sticking probabilities and conformality during ALD, which is valuable for gaining a deeper understanding of ALD kinetics.
| Original language | English |
|---|---|
| Article number | 030908 |
| Journal | Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films |
| Volume | 37 |
| Issue number | 3 |
| DOIs | |
| Publication status | E-pub ahead of print - 24 Apr 2019 |
| MoE publication type | A1 Journal article-refereed |
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Sticking probabilities of H2O and Al(CH3)3 during atomic layer deposition of Al2 O3 extracted from their impact on film conformality. / Arts, Karsten (Corresponding Author); Vandalon, Vincent; Puurunen, Riikka L.; Utriainen, Mikko; Gao, Feng; Erwin Kessels, Wilhelmus M.M.; Knoops, Harm C.M. (Corresponding Author).
In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 37, No. 3, 030908, 24.04.2019.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Sticking probabilities of H2O and Al(CH3)3 during atomic layer deposition of Al2 O3 extracted from their impact on film conformality
AU - Arts, Karsten
AU - Vandalon, Vincent
AU - Puurunen, Riikka L.
AU - Utriainen, Mikko
AU - Gao, Feng
AU - Erwin Kessels, Wilhelmus M.M.
AU - Knoops, Harm C.M.
PY - 2019/4/24
Y1 - 2019/4/24
N2 - The conformality of a film grown by atomic layer deposition (ALD) is strongly affected by the reactivities of the precursor and coreactant, which can be expressed in terms of their sticking probabilities toward the surface. We show that the leading front of the thickness profile in high-aspect-ratio structures gives direct information on the sticking probabilities of the reactants under most conditions. The slope of the front has been used to determine the sticking probabilities of Al(CH3)3 and H2O during ALD of Al2O3 . The determined values are (0.5-2) × 10-3 for Al(CH3)3 and (0.8-2) × 10-4 for H2O at a set-point temperature of 275 °C, corresponding to an estimated substrate temperature of ∼220 °C. Additionally, the thickness profiles reveal soft-saturation behavior during the H2O step, most dominantly at reduced temperatures, which can limit the conformality of Al2O3 grown by ALD. This work thus provides insights regarding quantitative information on sticking probabilities and conformality during ALD, which is valuable for gaining a deeper understanding of ALD kinetics.
AB - The conformality of a film grown by atomic layer deposition (ALD) is strongly affected by the reactivities of the precursor and coreactant, which can be expressed in terms of their sticking probabilities toward the surface. We show that the leading front of the thickness profile in high-aspect-ratio structures gives direct information on the sticking probabilities of the reactants under most conditions. The slope of the front has been used to determine the sticking probabilities of Al(CH3)3 and H2O during ALD of Al2O3 . The determined values are (0.5-2) × 10-3 for Al(CH3)3 and (0.8-2) × 10-4 for H2O at a set-point temperature of 275 °C, corresponding to an estimated substrate temperature of ∼220 °C. Additionally, the thickness profiles reveal soft-saturation behavior during the H2O step, most dominantly at reduced temperatures, which can limit the conformality of Al2O3 grown by ALD. This work thus provides insights regarding quantitative information on sticking probabilities and conformality during ALD, which is valuable for gaining a deeper understanding of ALD kinetics.
UR - http://www.scopus.com/inward/record.url?scp=85065212730&partnerID=8YFLogxK
U2 - 10.1116/1.5093620
DO - 10.1116/1.5093620
M3 - Article
VL - 37
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
SN - 0734-2101
IS - 3
M1 - 030908
ER -