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Title: Chemical and Electrical Passivation of Single-Crystal Silicon(100) Surfaces Through a Two-Step Chlorination/Alkylation Process

Abstract

Single-crystal Si(100) surfaces have been functionalized by using a two-step radical chlorination-Grignard (R= MgCl, R = CH{sub 3}, C{sub 2}H{sub 5}, C{sub 4}H{sub 9}, C{sub 6}H{sub 5}, or CH{sub 2}C{sub 6}H{sub 5}) alkylation method. After alkylation, no chlorine was detectable on the surface by X-ray photoelectron spectroscopy (XPS), and the C 1s region showed a silicon-induced peak shift indicative of a Si-C bond. The relative intensity of this peak decreased, as expected, as the steric bulk of the alkyl increased. Despite the lack of full alkyl termination of the atop sites of the Si(100) surface, functionalization significantly reduced the rate of surface oxidation in air compared to that of the H-terminated Si(100) surface, with alkylated surfaces forming less than half a monolayer of oxide after over one month of exposure to air. Studies of the charge-carrier lifetime with rf photoconductivity decay methods indicated a surface recombination velocity of <30 cm s{sup -1} for methylated surfaces, and <60 cm s-1 for Si surfaces functionalized with the other alkyl groups evaluated. Soft X-ray photoelectron spectroscopic data indicated that the H-Si(100) surfaces were terminated by SiH, SiH{sub 2}, and SiH{sub 3} species, whereas Cl-Si(100) surfaces were predominantly terminated by monochloro (SiCl and SiHCl)more » and dichloro (SiCl{sub 2} and SiHCl{sub 2}) Si species. Methylation produced signals consistent with termination by Si-alkyl bonding arising from SiH(CH{sub 3})-, SiH{sub 2}(CH{sub 3})-, and Si(CH{sub 3}){sub 2}-type species.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
913952
Report Number(s):
BNL-78520-2007-JA
Journal ID: ISSN 1089-5647; JPCBFK; TRN: US0801426
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Phys. Chem. B; Journal Volume: 110
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 43 PARTICLE ACCELERATORS; ALKYLATION; PASSIVATION; X-RAY PHOTOELECTRON SPECTROSCOPY; MONOCRYSTALS; SILICON; CHLORINATION; NSLS; national synchrotron light source

Citation Formats

Nemanick,E., Hurley, P., Webb, L., Knapp, D., Michalak, D., Brunschwig, B., and Lewis, N. Chemical and Electrical Passivation of Single-Crystal Silicon(100) Surfaces Through a Two-Step Chlorination/Alkylation Process. United States: N. p., 2006. Web. doi:10.1021/jp056773x.
Nemanick,E., Hurley, P., Webb, L., Knapp, D., Michalak, D., Brunschwig, B., & Lewis, N. Chemical and Electrical Passivation of Single-Crystal Silicon(100) Surfaces Through a Two-Step Chlorination/Alkylation Process. United States. doi:10.1021/jp056773x.
Nemanick,E., Hurley, P., Webb, L., Knapp, D., Michalak, D., Brunschwig, B., and Lewis, N. Sun . "Chemical and Electrical Passivation of Single-Crystal Silicon(100) Surfaces Through a Two-Step Chlorination/Alkylation Process". United States. doi:10.1021/jp056773x.
@article{osti_913952,
title = {Chemical and Electrical Passivation of Single-Crystal Silicon(100) Surfaces Through a Two-Step Chlorination/Alkylation Process},
author = {Nemanick,E. and Hurley, P. and Webb, L. and Knapp, D. and Michalak, D. and Brunschwig, B. and Lewis, N.},
abstractNote = {Single-crystal Si(100) surfaces have been functionalized by using a two-step radical chlorination-Grignard (R= MgCl, R = CH{sub 3}, C{sub 2}H{sub 5}, C{sub 4}H{sub 9}, C{sub 6}H{sub 5}, or CH{sub 2}C{sub 6}H{sub 5}) alkylation method. After alkylation, no chlorine was detectable on the surface by X-ray photoelectron spectroscopy (XPS), and the C 1s region showed a silicon-induced peak shift indicative of a Si-C bond. The relative intensity of this peak decreased, as expected, as the steric bulk of the alkyl increased. Despite the lack of full alkyl termination of the atop sites of the Si(100) surface, functionalization significantly reduced the rate of surface oxidation in air compared to that of the H-terminated Si(100) surface, with alkylated surfaces forming less than half a monolayer of oxide after over one month of exposure to air. Studies of the charge-carrier lifetime with rf photoconductivity decay methods indicated a surface recombination velocity of <30 cm s{sup -1} for methylated surfaces, and <60 cm s-1 for Si surfaces functionalized with the other alkyl groups evaluated. Soft X-ray photoelectron spectroscopic data indicated that the H-Si(100) surfaces were terminated by SiH, SiH{sub 2}, and SiH{sub 3} species, whereas Cl-Si(100) surfaces were predominantly terminated by monochloro (SiCl and SiHCl) and dichloro (SiCl{sub 2} and SiHCl{sub 2}) Si species. Methylation produced signals consistent with termination by Si-alkyl bonding arising from SiH(CH{sub 3})-, SiH{sub 2}(CH{sub 3})-, and Si(CH{sub 3}){sub 2}-type species.},
doi = {10.1021/jp056773x},
journal = {J. Phys. Chem. B},
number = ,
volume = 110,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}