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.
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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",
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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