DOI: 10.1063/1.370531. Stress reduction and bond stability during thermal annealing of tetrahedral amorphous carbon

Stress reduction and bond stability during thermal annealing of tetrahedral amorphous carbon

10.1063/1.370531

Crossref journal-article

AIP Publishing

Journal of Applied Physics (317)

Abstract

A comprehensive study of the stress release and structural changes caused by postdeposition thermal annealing of tetrahedral amorphous carbon (ta-C) on Si has been carried out. Complete stress relief occurs at 600–700 °C and is accompanied by minimal structural modifications, as indicated by electron energy loss spectroscopy, Raman spectroscopy, and optical gap measurements. Further annealing in vacuum converts sp3 sites to sp2 with a drastic change occurring after 1100 °C. The field emitting behavior is substantially retained up to the complete stress relief, confirming that ta-C is a robust emitting material.

Bibliography

Ferrari, A. C., Kleinsorge, B., Morrison, N. A., Hart, A., Stolojan, V., & Robertson, J. (1999). Stress reduction and bond stability during thermal annealing of tetrahedral amorphous carbon. Journal of Applied Physics, 85(10), 7191â7197.

Authors 6

A. C. Ferrari (first)
B. Kleinsorge (additional)
N. A. Morrison (additional)
A. Hart (additional)
V. Stolojan (additional)
J. Robertson (additional)

References 55 Referenced 389

10.1016/0257-8972(92)90001-Q / Surf. Coat. Technol. (1992)
10.1016/0925-9635(94)90297-6 / Diamond Relat. Mater. (1994)
{'key': '2024020516145911000_r3', 'first-page': '507', 'volume': '94', 'year': '1997', 'journal-title': 'Surf. Coat. Technol.'} / Surf. Coat. Technol. (1997)
10.1557/PROC-383-423 / Mater. Res. Soc. Symp. Proc. (1995)
10.1016/0038-1098(83)90936-5 / Solid State Commun. (1983)
10.1103/PhysRevLett.72.2753 / Phys. Rev. Lett. (1994)
{'key': '2024020516145911000_r7', 'first-page': '42', 'volume': '52', 'year': '1997', 'journal-title': 'Surf. Coat. Technol.'} / Surf. Coat. Technol. (1997)
10.1063/1.360979 / J. Appl. Phys. (1996)
10.1088/0034-4885/59/12/002 / Rep. Prog. Phys. (1996)
10.1103/PhysRevB.48.4777 / Phys. Rev. B (1993)
10.1063/1.120339 / Appl. Phys. Lett. (1997)
{'key': '2024020516145911000_r12', 'first-page': '186', 'volume': '308', 'year': '1997', 'journal-title': 'Thin Solid Films'} / Thin Solid Films (1997)
10.1063/1.115891 / Appl. Phys. Lett. (1996)
10.1063/1.120515 / Appl. Phys. Lett. (1997)
10.1016/0925-9635(94)90185-6 / Diamond Relat. Mater. (1994)
10.1063/1.116530 / Appl. Phys. Lett. (1996)
10.1080/01418639708241099 / Philos. Mag. B (1997)
10.1016/S0257-8972(97)00386-1 / Surf. Coat. Technol. (1998)
{'key': '2024020516145911000_r19'}
10.1103/PhysRevLett.68.220 / Phys. Rev. Lett. (1992)
{'key': '2024020516145911000_r21', 'first-page': '361', 'volume': '4', 'year': '1993', 'journal-title': 'Diamond Relat. Mater.'} / Diamond Relat. Mater. (1993)
10.1016/0040-6090(93)90201-Y / Thin Solid Films (1993)
10.1063/1.357385 / J. Appl. Phys. (1994)
10.1063/1.97968 / Appl. Phys. Lett. (1987)
10.1016/0257-8972(91)90344-V / Surf. Coat. Technol. (1991)
{'key': '2024020516145911000_r26', 'first-page': '617', 'volume': '86', 'year': '1996', 'journal-title': 'Surf. Coat. Technol.'} / Surf. Coat. Technol. (1996)
10.1007/s11664-997-0239-9 / J. Electron. Mater. (1997)
{'key': '2024020516145911000_r28', 'first-page': '97', 'volume': '498', 'year': '1998', 'journal-title': 'Mater. Res. Soc. Symp. Proc.'} / Mater. Res. Soc. Symp. Proc. (1998)
{'key': '2024020516145911000_r29'}
{'key': '2024020516145911000_r30'}
10.1063/1.119915 / Appl. Phys. Lett. (1997)
{'key': '2024020516145911000_r32'}
{'key': '2024020516145911000_r33', 'first-page': '55', 'volume': '498', 'year': '1998', 'journal-title': 'Mater. Res. Soc. Symp. Proc.'} / Mater. Res. Soc. Symp. Proc. (1998)
10.1103/PhysRevB.35.2946 / Phys. Rev. B (1987)
{'key': '2024020516145911000_r35'}
{'key': '2024020516145911000_r36', 'first-page': '543', 'volume': '35&36', 'year': '1980', 'journal-title': 'J. Non-Cryst. Solids'} / J. Non-Cryst. Solids (1980)
10.1016/0925-9635(96)90031-X / Diamond Relat. Mater. (1996)
10.1063/1.118798 / Appl. Phys. Lett. (1997)
10.1103/PhysRevLett.78.4869 / Phys. Rev. Lett. (1997)
{'key': '2024020516145911000_r40'}
10.1016/0925-9635(95)00363-0 / Diamond Relat. Mater. (1996)
10.1063/1.362745 / J. Appl. Phys. (1996)
10.1016/0079-6786(91)90002-H / Prog. Solid State Chem. (1991)
10.1103/PhysRevB.29.3482 / Phys. Rev. B (1984)
10.1063/1.101228 / Appl. Phys. Lett. (1989)
{'key': '2024020516145911000_r45', 'first-page': '3176', 'volume': '64', 'year': '1998', 'journal-title': 'J. Appl. Phys.'} / J. Appl. Phys. (1998)
10.1103/PhysRevB.25.1151 / Phys. Rev. B (1982)
10.1063/1.113382 / Appl. Phys. Lett. (1995)
10.1103/PhysRevB.49.16415 / Phys. Rev. B (1994)
10.1103/PhysRevB.52.11837 / Phys. Rev. B (1995)
{'key': '2024020516145911000_r50'}
10.1103/PhysRevB.52.850 / Phys. Rev. B (1995)
10.1063/1.366469 / J. Appl. Phys. (1997)
10.1063/1.364000 / J. Appl. Phys. (1997)
10.1063/1.361081 / J. Appl. Phys. (1996)

Dates

Type	When
Created	23 years, 1 month ago (July 26, 2002, 8:39 a.m.)
Deposited	1 year, 7 months ago (Feb. 5, 2024, 11:32 a.m.)
Indexed	1 week, 3 days ago (Aug. 26, 2025, 3:13 a.m.)
Issued	26 years, 3 months ago (May 15, 1999)
Published	26 years, 3 months ago (May 15, 1999)
Published Print	26 years, 3 months ago (May 15, 1999)

Funders 0

None

BibTeX

@article{Ferrari_1999, title={Stress reduction and bond stability during thermal annealing of tetrahedral amorphous carbon}, volume={85}, ISSN={1089-7550}, url={http://dx.doi.org/10.1063/1.370531}, DOI={10.1063/1.370531}, number={10}, journal={Journal of Applied Physics}, publisher={AIP Publishing}, author={Ferrari, A. C. and Kleinsorge, B. and Morrison, N. A. and Hart, A. and Stolojan, V. and Robertson, J.}, year={1999}, month=may, pages={7191–7197} }

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      "volume": "94",
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      "DOI": "10.1557/PROC-383-423",
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      "first-page": "105",
      "DOI": "10.1016/0038-1098(83)90936-5",
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      "year": "1983",
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    {
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      "doi-asserted-by": "crossref",
      "first-page": "2753",
      "DOI": "10.1103/PhysRevLett.72.2753",
      "volume": "72",
      "year": "1994",
      "journal-title": "Phys. Rev. Lett."
    },
    {
      "key": "2024020516145911000_r7",
      "first-page": "42",
      "volume": "52",
      "year": "1997",
      "journal-title": "Surf. Coat. Technol."
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      "doi-asserted-by": "crossref",
      "first-page": "1416",
      "DOI": "10.1063/1.360979",
      "volume": "79",
      "year": "1996",
      "journal-title": "J. Appl. Phys."
    },
    {
      "key": "2024020516145911000_r9",
      "doi-asserted-by": "crossref",
      "first-page": "1611",
      "DOI": "10.1088/0034-4885/59/12/002",
      "volume": "59",
      "year": "1996",
      "journal-title": "Rep. Prog. Phys."
    },
    {
      "key": "2024020516145911000_r10",
      "doi-asserted-by": "crossref",
      "first-page": "4777",
      "DOI": "10.1103/PhysRevB.48.4777",
      "volume": "48",
      "year": "1993",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r11",
      "doi-asserted-by": "crossref",
      "first-page": "3367",
      "DOI": "10.1063/1.120339",
      "volume": "71",
      "year": "1997",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r12",
      "first-page": "186",
      "volume": "308",
      "year": "1997",
      "journal-title": "Thin Solid Films"
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      "DOI": "10.1063/1.115891",
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      "journal-title": "Appl. Phys. Lett."
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    {
      "key": "2024020516145911000_r14",
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      "first-page": "3820",
      "DOI": "10.1063/1.120515",
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      "key": "2024020516145911000_r15",
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      "first-page": "353",
      "DOI": "10.1016/0925-9635(94)90185-6",
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      "year": "1994",
      "journal-title": "Diamond Relat. Mater."
    },
    {
      "key": "2024020516145911000_r16",
      "doi-asserted-by": "crossref",
      "first-page": "779",
      "DOI": "10.1063/1.116530",
      "volume": "68",
      "year": "1996",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r17",
      "doi-asserted-by": "crossref",
      "first-page": "351",
      "DOI": "10.1080/01418639708241099",
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      "year": "1997",
      "journal-title": "Philos. Mag. B"
    },
    {
      "key": "2024020516145911000_r18",
      "doi-asserted-by": "crossref",
      "first-page": "1097",
      "DOI": "10.1016/S0257-8972(97)00386-1",
      "volume": "98",
      "year": "1998",
      "journal-title": "Surf. Coat. Technol."
    },
    {
      "key": "2024020516145911000_r19"
    },
    {
      "key": "2024020516145911000_r20",
      "doi-asserted-by": "crossref",
      "first-page": "220",
      "DOI": "10.1103/PhysRevLett.68.220",
      "volume": "68",
      "year": "1992",
      "journal-title": "Phys. Rev. Lett."
    },
    {
      "key": "2024020516145911000_r21",
      "first-page": "361",
      "volume": "4",
      "year": "1993",
      "journal-title": "Diamond Relat. Mater."
    },
    {
      "key": "2024020516145911000_r22",
      "doi-asserted-by": "crossref",
      "first-page": "30",
      "DOI": "10.1016/0040-6090(93)90201-Y",
      "volume": "226",
      "year": "1993",
      "journal-title": "Thin Solid Films"
    },
    {
      "key": "2024020516145911000_r23",
      "doi-asserted-by": "crossref",
      "first-page": "3823",
      "DOI": "10.1063/1.357385",
      "volume": "76",
      "year": "1994",
      "journal-title": "J. Appl. Phys."
    },
    {
      "key": "2024020516145911000_r24",
      "doi-asserted-by": "crossref",
      "first-page": "1056",
      "DOI": "10.1063/1.97968",
      "volume": "50",
      "year": "1987",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r25",
      "doi-asserted-by": "crossref",
      "first-page": "710",
      "DOI": "10.1016/0257-8972(91)90344-V",
      "volume": "47",
      "year": "1991",
      "journal-title": "Surf. Coat. Technol."
    },
    {
      "key": "2024020516145911000_r26",
      "first-page": "617",
      "volume": "86",
      "year": "1996",
      "journal-title": "Surf. Coat. Technol."
    },
    {
      "key": "2024020516145911000_r27",
      "doi-asserted-by": "crossref",
      "first-page": "1021",
      "DOI": "10.1007/s11664-997-0239-9",
      "volume": "26",
      "year": "1997",
      "journal-title": "J. Electron. Mater."
    },
    {
      "key": "2024020516145911000_r28",
      "first-page": "97",
      "volume": "498",
      "year": "1998",
      "journal-title": "Mater. Res. Soc. Symp. Proc."
    },
    {
      "key": "2024020516145911000_r29"
    },
    {
      "key": "2024020516145911000_r30"
    },
    {
      "key": "2024020516145911000_r31",
      "doi-asserted-by": "crossref",
      "first-page": "1430",
      "DOI": "10.1063/1.119915",
      "volume": "71",
      "year": "1997",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r32"
    },
    {
      "key": "2024020516145911000_r33",
      "first-page": "55",
      "volume": "498",
      "year": "1998",
      "journal-title": "Mater. Res. Soc. Symp. Proc."
    },
    {
      "key": "2024020516145911000_r34",
      "doi-asserted-by": "crossref",
      "first-page": "2946",
      "DOI": "10.1103/PhysRevB.35.2946",
      "volume": "35",
      "year": "1987",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r35"
    },
    {
      "key": "2024020516145911000_r36",
      "first-page": "543",
      "volume": "35&36",
      "year": "1980",
      "journal-title": "J. Non-Cryst. Solids"
    },
    {
      "key": "2024020516145911000_r37",
      "doi-asserted-by": "crossref",
      "first-page": "589",
      "DOI": "10.1016/0925-9635(96)90031-X",
      "volume": "5",
      "year": "1996",
      "journal-title": "Diamond Relat. Mater."
    },
    {
      "key": "2024020516145911000_r38",
      "doi-asserted-by": "crossref",
      "first-page": "1980",
      "DOI": "10.1063/1.118798",
      "volume": "70",
      "year": "1997",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r39",
      "doi-asserted-by": "crossref",
      "first-page": "4869",
      "DOI": "10.1103/PhysRevLett.78.4869",
      "volume": "78",
      "year": "1997",
      "journal-title": "Phys. Rev. Lett."
    },
    {
      "key": "2024020516145911000_r40"
    },
    {
      "key": "2024020516145911000_r41",
      "doi-asserted-by": "crossref",
      "first-page": "433",
      "DOI": "10.1016/0925-9635(95)00363-0",
      "volume": "5",
      "year": "1996",
      "journal-title": "Diamond Relat. Mater."
    },
    {
      "key": "2024020516145911000_r42",
      "doi-asserted-by": "crossref",
      "first-page": "440",
      "DOI": "10.1063/1.362745",
      "volume": "80",
      "year": "1996",
      "journal-title": "J. Appl. Phys."
    },
    {
      "key": "2024020516145911000_r43",
      "doi-asserted-by": "crossref",
      "first-page": "199",
      "DOI": "10.1016/0079-6786(91)90002-H",
      "volume": "21",
      "year": "1991",
      "journal-title": "Prog. Solid State Chem."
    },
    {
      "key": "2024020516145911000_r44",
      "doi-asserted-by": "crossref",
      "first-page": "3482",
      "DOI": "10.1103/PhysRevB.29.3482",
      "volume": "29",
      "year": "1984",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r44a",
      "doi-asserted-by": "crossref",
      "first-page": "123",
      "DOI": "10.1063/1.101228",
      "volume": "54",
      "year": "1989",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r45",
      "first-page": "3176",
      "volume": "64",
      "year": "1998",
      "journal-title": "J. Appl. Phys."
    },
    {
      "key": "2024020516145911000_r46",
      "doi-asserted-by": "crossref",
      "first-page": "1151",
      "DOI": "10.1103/PhysRevB.25.1151",
      "volume": "25",
      "year": "1982",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r47",
      "doi-asserted-by": "crossref",
      "first-page": "3444",
      "DOI": "10.1063/1.113382",
      "volume": "66",
      "year": "1995",
      "journal-title": "Appl. Phys. Lett."
    },
    {
      "key": "2024020516145911000_r48",
      "doi-asserted-by": "crossref",
      "first-page": "16415",
      "DOI": "10.1103/PhysRevB.49.16415",
      "volume": "49",
      "year": "1994",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r49",
      "doi-asserted-by": "crossref",
      "first-page": "11837",
      "DOI": "10.1103/PhysRevB.52.11837",
      "volume": "52",
      "year": "1995",
      "journal-title": "Phys. Rev. B"
    },
    {
      "key": "2024020516145911000_r50"
    },
    {
      "key": "2024020516145911000_r51",
      "doi-asserted-by": "crossref",
      "first-page": "850",
      "DOI": "10.1103/PhysRevB.52.850",
      "volume": "52",
      "year": "1995",
      "journal-title": "Phys. Rev. B"
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