Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi-aqueous fluoride solutions

N. Venkataraman; S. Raghavan

doi:10.1016/j.mee.2009.10.008

Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi-aqueous fluoride solutions

N. Venkataraman, S. Raghavan

Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

11 Scopus citations

Abstract

The selective dissolution of thin copper oxide films grown on copper in semi-aqueous formulations containing dimethyl sulfoxide (DMSO), ammonium fluoride (NH₄F) and water was studied. Optimization of the formulations was carried out by systematic evaluation of the effect of solvent content and pH on the removal rates of copper oxide films and selectivity towards copper and carbon doped oxide (CDO) low k dielectric film. Copper oxide removal rate of ∼180 /min with a selectivity of ∼130:1 towards copper and ∼20:1 selectivity towards CDO was obtained in a formulation containing 29% DMSO, 1% NH₄F and 70% H₂O at pH 4. Electrochemical impedance spectroscopy studies were performed on this system and the data were analyzed to characterize the copper oxide/electrolyte interface with the ultimate objective of developing an end point detection technique for copper oxide removal.

Original language	English (US)
Pages (from-to)	1689-1695
Number of pages	7
Journal	Microelectronic Engineering
Volume	87
Issue number	9
DOIs	https://doi.org/10.1016/j.mee.2009.10.008
State	Published - Nov 2010

Keywords

BEOL cleaning
Copper oxide removal
Electrochemical impedance spectroscopy
SAF chemical system

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Atomic and Molecular Physics, and Optics
Condensed Matter Physics
Surfaces, Coatings and Films
Electrical and Electronic Engineering

Access to Document

10.1016/j.mee.2009.10.008

Cite this

@article{f81cfde43de446c3a26ee8ef33917d21,

title = "Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi-aqueous fluoride solutions",

abstract = "The selective dissolution of thin copper oxide films grown on copper in semi-aqueous formulations containing dimethyl sulfoxide (DMSO), ammonium fluoride (NH4F) and water was studied. Optimization of the formulations was carried out by systematic evaluation of the effect of solvent content and pH on the removal rates of copper oxide films and selectivity towards copper and carbon doped oxide (CDO) low k dielectric film. Copper oxide removal rate of ∼180 /min with a selectivity of ∼130:1 towards copper and ∼20:1 selectivity towards CDO was obtained in a formulation containing 29% DMSO, 1% NH4F and 70% H2O at pH 4. Electrochemical impedance spectroscopy studies were performed on this system and the data were analyzed to characterize the copper oxide/electrolyte interface with the ultimate objective of developing an end point detection technique for copper oxide removal.",

keywords = "BEOL cleaning, Copper oxide removal, Electrochemical impedance spectroscopy, SAF chemical system",

author = "N. Venkataraman and S. Raghavan",

note = "Funding Information: The authors would like to acknowledge the financial support from NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing at The University of Arizona. The authors would also like to acknowledge the assistance of Dr. Kenneth Nebesny, Laboratory for Electron Spectroscopy and Surface Analysis, The University of Arizona in performing XPS analysis.",

year = "2010",

month = nov,

doi = "10.1016/j.mee.2009.10.008",

language = "English (US)",

volume = "87",

pages = "1689--1695",

journal = "Microelectronic Engineering",

issn = "0167-9317",

publisher = "Elsevier",

number = "9",

}

TY - JOUR

T1 - Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi-aqueous fluoride solutions

AU - Venkataraman, N.

AU - Raghavan, S.

N1 - Funding Information: The authors would like to acknowledge the financial support from NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing at The University of Arizona. The authors would also like to acknowledge the assistance of Dr. Kenneth Nebesny, Laboratory for Electron Spectroscopy and Surface Analysis, The University of Arizona in performing XPS analysis.

PY - 2010/11

Y1 - 2010/11

N2 - The selective dissolution of thin copper oxide films grown on copper in semi-aqueous formulations containing dimethyl sulfoxide (DMSO), ammonium fluoride (NH4F) and water was studied. Optimization of the formulations was carried out by systematic evaluation of the effect of solvent content and pH on the removal rates of copper oxide films and selectivity towards copper and carbon doped oxide (CDO) low k dielectric film. Copper oxide removal rate of ∼180 /min with a selectivity of ∼130:1 towards copper and ∼20:1 selectivity towards CDO was obtained in a formulation containing 29% DMSO, 1% NH4F and 70% H2O at pH 4. Electrochemical impedance spectroscopy studies were performed on this system and the data were analyzed to characterize the copper oxide/electrolyte interface with the ultimate objective of developing an end point detection technique for copper oxide removal.

AB - The selective dissolution of thin copper oxide films grown on copper in semi-aqueous formulations containing dimethyl sulfoxide (DMSO), ammonium fluoride (NH4F) and water was studied. Optimization of the formulations was carried out by systematic evaluation of the effect of solvent content and pH on the removal rates of copper oxide films and selectivity towards copper and carbon doped oxide (CDO) low k dielectric film. Copper oxide removal rate of ∼180 /min with a selectivity of ∼130:1 towards copper and ∼20:1 selectivity towards CDO was obtained in a formulation containing 29% DMSO, 1% NH4F and 70% H2O at pH 4. Electrochemical impedance spectroscopy studies were performed on this system and the data were analyzed to characterize the copper oxide/electrolyte interface with the ultimate objective of developing an end point detection technique for copper oxide removal.

KW - BEOL cleaning

KW - Copper oxide removal

KW - Electrochemical impedance spectroscopy

KW - SAF chemical system

UR - http://www.scopus.com/inward/record.url?scp=77955229725&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77955229725&partnerID=8YFLogxK

U2 - 10.1016/j.mee.2009.10.008

DO - 10.1016/j.mee.2009.10.008

M3 - Article

AN - SCOPUS:77955229725

SN - 0167-9317

VL - 87

SP - 1689

EP - 1695

JO - Microelectronic Engineering

JF - Microelectronic Engineering

IS - 9

ER -

Dissolution and electrochemical impedance spectroscopy studies of thin copper oxide films on copper in semi-aqueous fluoride solutions

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this