Highly conformal TiN by atomic layer deposition: growth and characterization

Kestutis Grigoras (Corresponding author), Oili Ylivaara, Feng Gao, Mikko J. Heikkilä, Kenichiro Mizohata, Mika Prunnila, Jyrki Räisänen, Mikko Ritala, Markku Leskelä, Jouni Ahopelto, Riikka Puurunen

    Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

    Abstract

    Electrically conductive conformal thin films are needed in a variety of applications, e.g. in supercapacitors [1]. This abstract reports the first results of highly conformal TiN films grown by thermal atomic layer deposition (ALD) process from TiCl4 and NH3. The TiN films were characterized by several methods: i) the thickness and density by X-ray reflectometry, ii) the composition by time-of-flight elastic recoil detection, iii) the resistivity by four-point probe measurements, iv) the residual stress by wafer curvature measurement and Stoney's equation, and v) the conformality by the "PillarHall" microscopic lateral high-aspectratio (LHAR) structures [2]. The "stop flow" (SF) option available in the Picosun reactor at VTT was used to increase the thin film conformality. The SF was tested on oxidized 150 mm silicon wafers, LHAR test structures and porous silicon samples. The process was investigated in a temperature window of 300 to 500oC and the typical layer thicknesses were from 10 to 20 nm. Density of up to 5.0 g/cm3 was obtained by XRR. According to ToF ERDA, the main impurity was oxygen. Resistivity, measured after chamber conditioning (initial 500 cycles of AlTiCN and additional 6000 cycles of TiN), decreased with increasing ALD temperature, being <200 µOhm cm for films grown at 450oC. Films were all under tensile stress. The residual stress decreased with increasing deposition temperature, from about 2000 MPa at 350oC to about 1000 MPa at 450oC after which the stress saturated (Figure 1a). For a 200 nm gap LHAR sample an aspect ratio of 2500:1 was achieved using the SF option (cycle time was 36 s; Figure 1b).
    Original languageEnglish
    Title of host publicationTechnical Program & Abstracts
    PublisherAmerican Vacuum Society AVS
    Publication statusPublished - 2016
    Event16th International Conference on Atomic Layer Deposition, ALD 2016 - Dublin, Ireland
    Duration: 24 Jul 201627 Jul 2016

    Conference

    Conference16th International Conference on Atomic Layer Deposition, ALD 2016
    Abbreviated titleALD 2016
    CountryIreland
    CityDublin
    Period24/07/1627/07/16

    Fingerprint

    atomic layer epitaxy
    cycles
    residual stress
    wafers
    electrical resistivity
    electrochemical capacitors
    silicon
    conditioning
    thin films
    porous silicon
    tensile stress
    temperature
    aspect ratio
    chambers
    reactors
    curvature
    impurities
    probes
    oxygen
    x rays

    Keywords

    • ALD
    • Atomic Layer Deposition
    • TiN
    • Lateral high-aspect ratio structures
    • LHAR

    Cite this

    Grigoras, K., Ylivaara, O., Gao, F., Heikkilä, M. J., Mizohata, K., Prunnila, M., ... Puurunen, R. (2016). Highly conformal TiN by atomic layer deposition: growth and characterization. In Technical Program & Abstracts American Vacuum Society AVS.
    Grigoras, Kestutis ; Ylivaara, Oili ; Gao, Feng ; Heikkilä, Mikko J. ; Mizohata, Kenichiro ; Prunnila, Mika ; Räisänen, Jyrki ; Ritala, Mikko ; Leskelä, Markku ; Ahopelto, Jouni ; Puurunen, Riikka. / Highly conformal TiN by atomic layer deposition : growth and characterization. Technical Program & Abstracts. American Vacuum Society AVS, 2016.
    @inbook{16d3d0c6057c48b785b7a37ae762df52,
    title = "Highly conformal TiN by atomic layer deposition: growth and characterization",
    abstract = "Electrically conductive conformal thin films are needed in a variety of applications, e.g. in supercapacitors [1]. This abstract reports the first results of highly conformal TiN films grown by thermal atomic layer deposition (ALD) process from TiCl4 and NH3. The TiN films were characterized by several methods: i) the thickness and density by X-ray reflectometry, ii) the composition by time-of-flight elastic recoil detection, iii) the resistivity by four-point probe measurements, iv) the residual stress by wafer curvature measurement and Stoney's equation, and v) the conformality by the {"}PillarHall{"} microscopic lateral high-aspectratio (LHAR) structures [2]. The {"}stop flow{"} (SF) option available in the Picosun reactor at VTT was used to increase the thin film conformality. The SF was tested on oxidized 150 mm silicon wafers, LHAR test structures and porous silicon samples. The process was investigated in a temperature window of 300 to 500oC and the typical layer thicknesses were from 10 to 20 nm. Density of up to 5.0 g/cm3 was obtained by XRR. According to ToF ERDA, the main impurity was oxygen. Resistivity, measured after chamber conditioning (initial 500 cycles of AlTiCN and additional 6000 cycles of TiN), decreased with increasing ALD temperature, being <200 µOhm cm for films grown at 450oC. Films were all under tensile stress. The residual stress decreased with increasing deposition temperature, from about 2000 MPa at 350oC to about 1000 MPa at 450oC after which the stress saturated (Figure 1a). For a 200 nm gap LHAR sample an aspect ratio of 2500:1 was achieved using the SF option (cycle time was 36 s; Figure 1b).",
    keywords = "ALD, Atomic Layer Deposition, TiN, Lateral high-aspect ratio structures, LHAR",
    author = "Kestutis Grigoras and Oili Ylivaara and Feng Gao and Heikkil{\"a}, {Mikko J.} and Kenichiro Mizohata and Mika Prunnila and Jyrki R{\"a}is{\"a}nen and Mikko Ritala and Markku Leskel{\"a} and Jouni Ahopelto and Riikka Puurunen",
    note = "Published abstract of a poster presentation Project 102086 ALDCoE",
    year = "2016",
    language = "English",
    booktitle = "Technical Program & Abstracts",
    publisher = "American Vacuum Society AVS",
    address = "United States",

    }

    Grigoras, K, Ylivaara, O, Gao, F, Heikkilä, MJ, Mizohata, K, Prunnila, M, Räisänen, J, Ritala, M, Leskelä, M, Ahopelto, J & Puurunen, R 2016, Highly conformal TiN by atomic layer deposition: growth and characterization. in Technical Program & Abstracts. American Vacuum Society AVS, 16th International Conference on Atomic Layer Deposition, ALD 2016, Dublin, Ireland, 24/07/16.

    Highly conformal TiN by atomic layer deposition : growth and characterization. / Grigoras, Kestutis (Corresponding author); Ylivaara, Oili; Gao, Feng; Heikkilä, Mikko J.; Mizohata, Kenichiro; Prunnila, Mika; Räisänen, Jyrki; Ritala, Mikko; Leskelä, Markku; Ahopelto, Jouni; Puurunen, Riikka.

    Technical Program & Abstracts. American Vacuum Society AVS, 2016.

    Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

    TY - CHAP

    T1 - Highly conformal TiN by atomic layer deposition

    T2 - growth and characterization

    AU - Grigoras, Kestutis

    AU - Ylivaara, Oili

    AU - Gao, Feng

    AU - Heikkilä, Mikko J.

    AU - Mizohata, Kenichiro

    AU - Prunnila, Mika

    AU - Räisänen, Jyrki

    AU - Ritala, Mikko

    AU - Leskelä, Markku

    AU - Ahopelto, Jouni

    AU - Puurunen, Riikka

    N1 - Published abstract of a poster presentation Project 102086 ALDCoE

    PY - 2016

    Y1 - 2016

    N2 - Electrically conductive conformal thin films are needed in a variety of applications, e.g. in supercapacitors [1]. This abstract reports the first results of highly conformal TiN films grown by thermal atomic layer deposition (ALD) process from TiCl4 and NH3. The TiN films were characterized by several methods: i) the thickness and density by X-ray reflectometry, ii) the composition by time-of-flight elastic recoil detection, iii) the resistivity by four-point probe measurements, iv) the residual stress by wafer curvature measurement and Stoney's equation, and v) the conformality by the "PillarHall" microscopic lateral high-aspectratio (LHAR) structures [2]. The "stop flow" (SF) option available in the Picosun reactor at VTT was used to increase the thin film conformality. The SF was tested on oxidized 150 mm silicon wafers, LHAR test structures and porous silicon samples. The process was investigated in a temperature window of 300 to 500oC and the typical layer thicknesses were from 10 to 20 nm. Density of up to 5.0 g/cm3 was obtained by XRR. According to ToF ERDA, the main impurity was oxygen. Resistivity, measured after chamber conditioning (initial 500 cycles of AlTiCN and additional 6000 cycles of TiN), decreased with increasing ALD temperature, being <200 µOhm cm for films grown at 450oC. Films were all under tensile stress. The residual stress decreased with increasing deposition temperature, from about 2000 MPa at 350oC to about 1000 MPa at 450oC after which the stress saturated (Figure 1a). For a 200 nm gap LHAR sample an aspect ratio of 2500:1 was achieved using the SF option (cycle time was 36 s; Figure 1b).

    AB - Electrically conductive conformal thin films are needed in a variety of applications, e.g. in supercapacitors [1]. This abstract reports the first results of highly conformal TiN films grown by thermal atomic layer deposition (ALD) process from TiCl4 and NH3. The TiN films were characterized by several methods: i) the thickness and density by X-ray reflectometry, ii) the composition by time-of-flight elastic recoil detection, iii) the resistivity by four-point probe measurements, iv) the residual stress by wafer curvature measurement and Stoney's equation, and v) the conformality by the "PillarHall" microscopic lateral high-aspectratio (LHAR) structures [2]. The "stop flow" (SF) option available in the Picosun reactor at VTT was used to increase the thin film conformality. The SF was tested on oxidized 150 mm silicon wafers, LHAR test structures and porous silicon samples. The process was investigated in a temperature window of 300 to 500oC and the typical layer thicknesses were from 10 to 20 nm. Density of up to 5.0 g/cm3 was obtained by XRR. According to ToF ERDA, the main impurity was oxygen. Resistivity, measured after chamber conditioning (initial 500 cycles of AlTiCN and additional 6000 cycles of TiN), decreased with increasing ALD temperature, being <200 µOhm cm for films grown at 450oC. Films were all under tensile stress. The residual stress decreased with increasing deposition temperature, from about 2000 MPa at 350oC to about 1000 MPa at 450oC after which the stress saturated (Figure 1a). For a 200 nm gap LHAR sample an aspect ratio of 2500:1 was achieved using the SF option (cycle time was 36 s; Figure 1b).

    KW - ALD

    KW - Atomic Layer Deposition

    KW - TiN

    KW - Lateral high-aspect ratio structures

    KW - LHAR

    M3 - Conference abstract in proceedings

    BT - Technical Program & Abstracts

    PB - American Vacuum Society AVS

    ER -

    Grigoras K, Ylivaara O, Gao F, Heikkilä MJ, Mizohata K, Prunnila M et al. Highly conformal TiN by atomic layer deposition: growth and characterization. In Technical Program & Abstracts. American Vacuum Society AVS. 2016