TY - JOUR
T1 - Surface-selective chemical vapor deposition of copper films through the use of a molecular inhibitor
AU - Babar, Shaista
AU - Mohimi, Elham
AU - Trinh, Brian
AU - Girolami, Gregory S.
AU - Abelson, John R.
N1 - Publisher Copyright:
© 2015 The Electrochemical Society.
PY - 2015
Y1 - 2015
N2 - We report a simple process for the selective deposition of copper films on RuO2, while no Cu nucleation occurs on thermal SiO2 or porous carbon doped oxide (CDO). Using the precursor Cu(hfac)VTMS, selectivity is attained by adding a co-flow of excess VTMS to act as a growth inhibitor. With precursor alone, 52 nm of Cu grows on RuO2; on CDO or on thermal SiO2, nucleation is delayed such that 41 or 1.3 nm are deposited, respectively. Repeating the experiment with the co-flow of VTMS affords a 12 nm thick Cu film on RuO2 with roughness of 1.8 nm. But on CDO or thermal SiO2, the Cu deposition is only 0.10 or ∼0.04 nm, respectively. AFM scans of the CDO and SiO2 surfaces are identical to the bare substrates. The small quantity of Cu that is deposited must be finely distributed, presumably on defect sites; it can be etched to below the RBS detection limit using a co-flow of Hhfac and VTMS for few minutes at the end of the growth. The process window is wide: selective growth occurs for a range of VTMS pressures (0.5. 2.0 mTorr), growth times (up to 90 min), and growth temperatures (up to 180.C).
AB - We report a simple process for the selective deposition of copper films on RuO2, while no Cu nucleation occurs on thermal SiO2 or porous carbon doped oxide (CDO). Using the precursor Cu(hfac)VTMS, selectivity is attained by adding a co-flow of excess VTMS to act as a growth inhibitor. With precursor alone, 52 nm of Cu grows on RuO2; on CDO or on thermal SiO2, nucleation is delayed such that 41 or 1.3 nm are deposited, respectively. Repeating the experiment with the co-flow of VTMS affords a 12 nm thick Cu film on RuO2 with roughness of 1.8 nm. But on CDO or thermal SiO2, the Cu deposition is only 0.10 or ∼0.04 nm, respectively. AFM scans of the CDO and SiO2 surfaces are identical to the bare substrates. The small quantity of Cu that is deposited must be finely distributed, presumably on defect sites; it can be etched to below the RBS detection limit using a co-flow of Hhfac and VTMS for few minutes at the end of the growth. The process window is wide: selective growth occurs for a range of VTMS pressures (0.5. 2.0 mTorr), growth times (up to 90 min), and growth temperatures (up to 180.C).
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U2 - 10.1149/2.0061507jss
DO - 10.1149/2.0061507jss
M3 - Article
AN - SCOPUS:84930172604
SN - 2162-8769
VL - 4
SP - N60-N63
JO - ECS Journal of Solid State Science and Technology
JF - ECS Journal of Solid State Science and Technology
IS - 7
ER -