Probing the Chemistry of Alumina Atomic Layer Deposition Using Operando Surface-Enhanced Raman Spectroscopy

Sicelo S. Masango; Ryan A. Hackler; Anne Isabelle Henry; Michael O. McAnally; George C. Schatz; Peter C. Stair; Richard P. Van Duyne

doi:10.1021/acs.jpcc.5b11487

Probing the Chemistry of Alumina Atomic Layer Deposition Using Operando Surface-Enhanced Raman Spectroscopy

Sicelo S. Masango, Ryan A. Hackler, Anne Isabelle Henry, Michael O. McAnally, George C. Schatz, Peter C. Stair, Richard P. Van Duyne^*

^*Corresponding author for this work

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

28 Scopus citations

Abstract

This work demonstrates for the first time the capability of measuring surface vibrational spectra for adsorbates during atomic layer deposition (ALD) reactions using operando surface-enhanced Raman spectroscopy (SERS). We use SERS to study alumina ALD growth at 55°C on bare silver film-over nanosphere (AgFON) substrates as well as AgFONs functionalized with thiol self-assembled monolayers (SAMs). On bare AgFONs, we observe the growth of Al-C stretches, symmetric C-H and asymmetric C-H stretches during the trimethylaluminum (TMA) dose half-cycle, and their subsequent decay after dosing with H₂O. Al-C and C-H vibrational modes decay in intensity with time even without H₂O exposure providing evidence that residual H₂O in the ALD chamber reacts with -CH₃ groups on AgFONs. The observed Al-C stretches are attributed to TMA dimeric species on the AgFON surface in agreement with density functional theory (DFT) studies. We observe Al-C stretches and no thiol vibrational frequency shifts after dosing TMA on AgFONs functionalized with toluenethiol and benzenethiol SAMs. Conversely, we observe thiol vibrational frequency shifts and no Al-C stretches for AgFONs functionalized with 4-mercaptobenzoic acid and 4-mercaptophenol SAMs. Lack of observed Al-C stretches for COOH- and OH-terminated SAMs is explained by the spacing of Al-(CH₃)_x groups from the SERS substrate. TMA penetrates through SAMs and reacts directly with Ag for benzenethiol and toluenethiol SAMs and selectively reacts with the -COOH and -OH groups for 4-mercaptobenzoic acid and 4-mercaptophenol SAMs, respectively. The high sensitivity and chemical specificity of SERS provides valuable information about the location of ALD deposits with respect to the enhancing substrate. This information can be used to evaluate the efficacy of SAMs in blocking or allowing ALD deposition on metal surfaces. The ability to probe ALD reactions using SERS under realistic reaction conditions will lead to a better understanding of the mechanisms of ALD reactions.

Original language	English (US)
Pages (from-to)	3822-3833
Number of pages	12
Journal	Journal of Physical Chemistry C
Volume	120
Issue number	7
DOIs	https://doi.org/10.1021/acs.jpcc.5b11487
State	Published - Feb 25 2016

Funding

We acknowledge Dr. Jon Dieringer, Dr. Bogdan Negru, Dr. Neil Schweitzer, Dr. Dragos Seghete, Dr. Nathan Greeneltch, Stephanie Zaleski, and Naihao Chiang for experimental help, data analysis, and valuable discussions. We gratefully acknowledge financial support from the Northwestern University Institute for Catalysis in Energy Processes (ICEP). ICEP is funded through the US Department of Energy, Office of Basic Energy Science (Award No. DE-FG02-03-ER15457). M.O.M. acknowledges support from the National Science Foundation Graduate Fellowship Research Program under Grant No. DGE-0824162. This work made use of the EPIC facility (NUANCE Center-Northwestern University), which has received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center, the International Institute for Nanotechnology (IIN), and the State of Illinois, through the IIN.

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
General Energy
Physical and Theoretical Chemistry
Surfaces, Coatings and Films

Access to Document

10.1021/acs.jpcc.5b11487

Cite this

@article{50bd4d3dee654db9b41f5f1ecbcb63ff,

title = "Probing the Chemistry of Alumina Atomic Layer Deposition Using Operando Surface-Enhanced Raman Spectroscopy",

abstract = "This work demonstrates for the first time the capability of measuring surface vibrational spectra for adsorbates during atomic layer deposition (ALD) reactions using operando surface-enhanced Raman spectroscopy (SERS). We use SERS to study alumina ALD growth at 55°C on bare silver film-over nanosphere (AgFON) substrates as well as AgFONs functionalized with thiol self-assembled monolayers (SAMs). On bare AgFONs, we observe the growth of Al-C stretches, symmetric C-H and asymmetric C-H stretches during the trimethylaluminum (TMA) dose half-cycle, and their subsequent decay after dosing with H2O. Al-C and C-H vibrational modes decay in intensity with time even without H2O exposure providing evidence that residual H2O in the ALD chamber reacts with -CH3 groups on AgFONs. The observed Al-C stretches are attributed to TMA dimeric species on the AgFON surface in agreement with density functional theory (DFT) studies. We observe Al-C stretches and no thiol vibrational frequency shifts after dosing TMA on AgFONs functionalized with toluenethiol and benzenethiol SAMs. Conversely, we observe thiol vibrational frequency shifts and no Al-C stretches for AgFONs functionalized with 4-mercaptobenzoic acid and 4-mercaptophenol SAMs. Lack of observed Al-C stretches for COOH- and OH-terminated SAMs is explained by the spacing of Al-(CH3)x groups from the SERS substrate. TMA penetrates through SAMs and reacts directly with Ag for benzenethiol and toluenethiol SAMs and selectively reacts with the -COOH and -OH groups for 4-mercaptobenzoic acid and 4-mercaptophenol SAMs, respectively. The high sensitivity and chemical specificity of SERS provides valuable information about the location of ALD deposits with respect to the enhancing substrate. This information can be used to evaluate the efficacy of SAMs in blocking or allowing ALD deposition on metal surfaces. The ability to probe ALD reactions using SERS under realistic reaction conditions will lead to a better understanding of the mechanisms of ALD reactions.",

author = "Masango, {Sicelo S.} and Hackler, {Ryan A.} and Henry, {Anne Isabelle} and McAnally, {Michael O.} and Schatz, {George C.} and Stair, {Peter C.} and {Van Duyne}, {Richard P.}",

note = "Publisher Copyright: {\textcopyright} 2016 American Chemical Society.",

year = "2016",

month = feb,

day = "25",

doi = "10.1021/acs.jpcc.5b11487",

language = "English (US)",

volume = "120",

pages = "3822--3833",

journal = "Journal of Physical Chemistry C",

issn = "1932-7447",

publisher = "American Chemical Society",

number = "7",

}

TY - JOUR

T1 - Probing the Chemistry of Alumina Atomic Layer Deposition Using Operando Surface-Enhanced Raman Spectroscopy

AU - Masango, Sicelo S.

AU - Hackler, Ryan A.

AU - Henry, Anne Isabelle

AU - McAnally, Michael O.

AU - Schatz, George C.

AU - Stair, Peter C.

AU - Van Duyne, Richard P.

PY - 2016/2/25

Y1 - 2016/2/25

N2 - This work demonstrates for the first time the capability of measuring surface vibrational spectra for adsorbates during atomic layer deposition (ALD) reactions using operando surface-enhanced Raman spectroscopy (SERS). We use SERS to study alumina ALD growth at 55°C on bare silver film-over nanosphere (AgFON) substrates as well as AgFONs functionalized with thiol self-assembled monolayers (SAMs). On bare AgFONs, we observe the growth of Al-C stretches, symmetric C-H and asymmetric C-H stretches during the trimethylaluminum (TMA) dose half-cycle, and their subsequent decay after dosing with H2O. Al-C and C-H vibrational modes decay in intensity with time even without H2O exposure providing evidence that residual H2O in the ALD chamber reacts with -CH3 groups on AgFONs. The observed Al-C stretches are attributed to TMA dimeric species on the AgFON surface in agreement with density functional theory (DFT) studies. We observe Al-C stretches and no thiol vibrational frequency shifts after dosing TMA on AgFONs functionalized with toluenethiol and benzenethiol SAMs. Conversely, we observe thiol vibrational frequency shifts and no Al-C stretches for AgFONs functionalized with 4-mercaptobenzoic acid and 4-mercaptophenol SAMs. Lack of observed Al-C stretches for COOH- and OH-terminated SAMs is explained by the spacing of Al-(CH3)x groups from the SERS substrate. TMA penetrates through SAMs and reacts directly with Ag for benzenethiol and toluenethiol SAMs and selectively reacts with the -COOH and -OH groups for 4-mercaptobenzoic acid and 4-mercaptophenol SAMs, respectively. The high sensitivity and chemical specificity of SERS provides valuable information about the location of ALD deposits with respect to the enhancing substrate. This information can be used to evaluate the efficacy of SAMs in blocking or allowing ALD deposition on metal surfaces. The ability to probe ALD reactions using SERS under realistic reaction conditions will lead to a better understanding of the mechanisms of ALD reactions.

AB - This work demonstrates for the first time the capability of measuring surface vibrational spectra for adsorbates during atomic layer deposition (ALD) reactions using operando surface-enhanced Raman spectroscopy (SERS). We use SERS to study alumina ALD growth at 55°C on bare silver film-over nanosphere (AgFON) substrates as well as AgFONs functionalized with thiol self-assembled monolayers (SAMs). On bare AgFONs, we observe the growth of Al-C stretches, symmetric C-H and asymmetric C-H stretches during the trimethylaluminum (TMA) dose half-cycle, and their subsequent decay after dosing with H2O. Al-C and C-H vibrational modes decay in intensity with time even without H2O exposure providing evidence that residual H2O in the ALD chamber reacts with -CH3 groups on AgFONs. The observed Al-C stretches are attributed to TMA dimeric species on the AgFON surface in agreement with density functional theory (DFT) studies. We observe Al-C stretches and no thiol vibrational frequency shifts after dosing TMA on AgFONs functionalized with toluenethiol and benzenethiol SAMs. Conversely, we observe thiol vibrational frequency shifts and no Al-C stretches for AgFONs functionalized with 4-mercaptobenzoic acid and 4-mercaptophenol SAMs. Lack of observed Al-C stretches for COOH- and OH-terminated SAMs is explained by the spacing of Al-(CH3)x groups from the SERS substrate. TMA penetrates through SAMs and reacts directly with Ag for benzenethiol and toluenethiol SAMs and selectively reacts with the -COOH and -OH groups for 4-mercaptobenzoic acid and 4-mercaptophenol SAMs, respectively. The high sensitivity and chemical specificity of SERS provides valuable information about the location of ALD deposits with respect to the enhancing substrate. This information can be used to evaluate the efficacy of SAMs in blocking or allowing ALD deposition on metal surfaces. The ability to probe ALD reactions using SERS under realistic reaction conditions will lead to a better understanding of the mechanisms of ALD reactions.

UR - http://www.scopus.com/inward/record.url?scp=84959420333&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84959420333&partnerID=8YFLogxK

U2 - 10.1021/acs.jpcc.5b11487

DO - 10.1021/acs.jpcc.5b11487

M3 - Article

AN - SCOPUS:84959420333

SN - 1932-7447

VL - 120

SP - 3822

EP - 3833

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 7

ER -

Probing the Chemistry of Alumina Atomic Layer Deposition Using Operando Surface-Enhanced Raman Spectroscopy

Abstract

Funding

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this