TY - JOUR
T1 - Nucleation and conformality of iridium and iridium oxide thin films grown by atomic layer deposition
AU - Mattinen, Miika
AU - Hämäläinen, Jani
AU - Gao, Feng
AU - Jalkanen, Pasi
AU - Mizohata, Kenichiro
AU - Räisänen, Jyrki
AU - Puurunen, Riikka
AU - Ritala, Mikko
AU - Leskelä, Markku
N1 - Project code: 102086
PY - 2016/10/18
Y1 - 2016/10/18
N2 - Nucleation and conformality are important issues, when
depositing thin films for demanding applications. In this
study, iridium and iridium dioxide (IrO2) films were
deposited by atomic layer deposition (ALD), using five
different processes. Different reactants, namely, O2,
air, consecutive O2 and H2 (O2 + H2), and consecutive O3
and H2 (O3 + H2) pulses were used with iridium
acetylacetonate [Ir(acac)3] to deposit Ir, while IrO2 was
deposited using Ir(acac)3 and O3. Nucleation was studied
using a combination of methods for film thickness and
morphology evaluation. In conformality studies,
microscopic lateral high-aspect-ratio (LHAR) test
structures, specifically designed for accurate and
versatile conformality testing of ALD films, were used.
The order of nucleation, from the fastest to the slowest,
was O2 + H2 > air ~ O2 > O3 > O3 + H2, whereas the order
of conformality, from the best to the worst, was O3 + H2
> O2 + H2 > O2 > O3. In the O3 process, a change in film
composition from IrO2 to metallic Ir was seen inside the
LHAR structures. Compared to the previous reports on ALD
of platinum-group metals, most of the studied processes
showed good to excellent results.
AB - Nucleation and conformality are important issues, when
depositing thin films for demanding applications. In this
study, iridium and iridium dioxide (IrO2) films were
deposited by atomic layer deposition (ALD), using five
different processes. Different reactants, namely, O2,
air, consecutive O2 and H2 (O2 + H2), and consecutive O3
and H2 (O3 + H2) pulses were used with iridium
acetylacetonate [Ir(acac)3] to deposit Ir, while IrO2 was
deposited using Ir(acac)3 and O3. Nucleation was studied
using a combination of methods for film thickness and
morphology evaluation. In conformality studies,
microscopic lateral high-aspect-ratio (LHAR) test
structures, specifically designed for accurate and
versatile conformality testing of ALD films, were used.
The order of nucleation, from the fastest to the slowest,
was O2 + H2 > air ~ O2 > O3 > O3 + H2, whereas the order
of conformality, from the best to the worst, was O3 + H2
> O2 + H2 > O2 > O3. In the O3 process, a change in film
composition from IrO2 to metallic Ir was seen inside the
LHAR structures. Compared to the previous reports on ALD
of platinum-group metals, most of the studied processes
showed good to excellent results.
UR - http://www.scopus.com/inward/record.url?scp=84991772112&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.6b03007
DO - 10.1021/acs.langmuir.6b03007
M3 - Article
VL - 32
SP - 10559
EP - 10569
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 41
ER -