Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films

Ville Miikkulainen (Corresponding author), Heta Nieminen, Oili Ylivaara, Kenichiro Mizohata, Riikka L. Puurunen, Mikko Ritala

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

Abstract

Deposited thin films carry residual stress that can be classified into two categories. One is thermal stress that results from differences in thermal expansion coefficients between the substrate and the film, and the other is so called intrinsic stress that is a result of the deposition process itself. Stress can be either compressive or tensile. In extreme case, films under excessive stress can lead to cracking, buckling or delamination of the film. In polycrystalline films, the residual intrinsic stress originates from morphology, such as grain coalescence, crystallization and phase transformation, and from impurities and voids, and development of these parameters during the deposition process. In amorphous films, residual stress also occurs but its sources are more difficult to elucidate. Residual stress of ALD films has been studied for example for Al2O3, TiO2, and the hybrid material alucone.1-4 These studies have focused on effects of deposition temperature, pulsing parameters, film thickness, and post-deposition annealing temperature. In the present paper we report results on how the precursor chemistry affects the residual stress of ALD Al2O3 and TiO2 films deposited at 250 °C to 50 nm thickness onto 150 mm Si wafers. We employed several metal precursors, such as AlMe3, AlCl3, TiCl4 and Ti(OiPr)4 as well as different oxygen sources (H2O, O3, CH3OH) and studied the effect of both the metal precursor and oxygen source on the residual stress of the deposited films. In addition to stress measurements, film characterization was done by X-ray diffraction, scanning electron microscopy and Time-of-Flight Elastic Recoil Detection Analysis for fundamental morphological and compositional properties. Characterization data will be discussed with the residual stress results. Notably large differences in the residual stress were found as a function of precursor chemistry, for both Al2O3 and TiO2.
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

residual stress
chemistry
stress measurement
oxygen
buckling
thermal stresses
metals
coalescing
phase transformations
voids
thermal expansion
film thickness
wafers
crystallization
impurities
scanning electron microscopy
annealing
temperature
coefficients
thin films

Keywords

  • ALD
  • Atomic Layer Deposition
  • Al203
  • TiO2
  • precursors
  • residual stress

Cite this

Miikkulainen, V., Nieminen, H., Ylivaara, O., Mizohata, K., Puurunen, R. L., & Ritala, M. (2016). Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films. In Technical Program & Abstracts American Vacuum Society AVS.
Miikkulainen, Ville ; Nieminen, Heta ; Ylivaara, Oili ; Mizohata, Kenichiro ; Puurunen, Riikka L. ; Ritala, Mikko. / Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films. Technical Program & Abstracts. American Vacuum Society AVS, 2016.
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abstract = "Deposited thin films carry residual stress that can be classified into two categories. One is thermal stress that results from differences in thermal expansion coefficients between the substrate and the film, and the other is so called intrinsic stress that is a result of the deposition process itself. Stress can be either compressive or tensile. In extreme case, films under excessive stress can lead to cracking, buckling or delamination of the film. In polycrystalline films, the residual intrinsic stress originates from morphology, such as grain coalescence, crystallization and phase transformation, and from impurities and voids, and development of these parameters during the deposition process. In amorphous films, residual stress also occurs but its sources are more difficult to elucidate. Residual stress of ALD films has been studied for example for Al2O3, TiO2, and the hybrid material alucone.1-4 These studies have focused on effects of deposition temperature, pulsing parameters, film thickness, and post-deposition annealing temperature. In the present paper we report results on how the precursor chemistry affects the residual stress of ALD Al2O3 and TiO2 films deposited at 250 °C to 50 nm thickness onto 150 mm Si wafers. We employed several metal precursors, such as AlMe3, AlCl3, TiCl4 and Ti(OiPr)4 as well as different oxygen sources (H2O, O3, CH3OH) and studied the effect of both the metal precursor and oxygen source on the residual stress of the deposited films. In addition to stress measurements, film characterization was done by X-ray diffraction, scanning electron microscopy and Time-of-Flight Elastic Recoil Detection Analysis for fundamental morphological and compositional properties. Characterization data will be discussed with the residual stress results. Notably large differences in the residual stress were found as a function of precursor chemistry, for both Al2O3 and TiO2.",
keywords = "ALD, Atomic Layer Deposition, Al203, TiO2, precursors, residual stress",
author = "Ville Miikkulainen and Heta Nieminen and Oili Ylivaara and Kenichiro Mizohata and Puurunen, {Riikka L.} and Mikko Ritala",
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Miikkulainen, V, Nieminen, H, Ylivaara, O, Mizohata, K, Puurunen, RL & Ritala, M 2016, Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films. in Technical Program & Abstracts. American Vacuum Society AVS, 16th International Conference on Atomic Layer Deposition, ALD 2016, Dublin, Ireland, 24/07/16.

Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films. / Miikkulainen, Ville (Corresponding author); Nieminen, Heta; Ylivaara, Oili; Mizohata, Kenichiro; Puurunen, Riikka L.; Ritala, Mikko.

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

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

TY - CHAP

T1 - Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films

AU - Miikkulainen, Ville

AU - Nieminen, Heta

AU - Ylivaara, Oili

AU - Mizohata, Kenichiro

AU - Puurunen, Riikka L.

AU - Ritala, Mikko

N1 - Published abstract of a poster presentation Project 102086 ALDCoE

PY - 2016

Y1 - 2016

N2 - Deposited thin films carry residual stress that can be classified into two categories. One is thermal stress that results from differences in thermal expansion coefficients between the substrate and the film, and the other is so called intrinsic stress that is a result of the deposition process itself. Stress can be either compressive or tensile. In extreme case, films under excessive stress can lead to cracking, buckling or delamination of the film. In polycrystalline films, the residual intrinsic stress originates from morphology, such as grain coalescence, crystallization and phase transformation, and from impurities and voids, and development of these parameters during the deposition process. In amorphous films, residual stress also occurs but its sources are more difficult to elucidate. Residual stress of ALD films has been studied for example for Al2O3, TiO2, and the hybrid material alucone.1-4 These studies have focused on effects of deposition temperature, pulsing parameters, film thickness, and post-deposition annealing temperature. In the present paper we report results on how the precursor chemistry affects the residual stress of ALD Al2O3 and TiO2 films deposited at 250 °C to 50 nm thickness onto 150 mm Si wafers. We employed several metal precursors, such as AlMe3, AlCl3, TiCl4 and Ti(OiPr)4 as well as different oxygen sources (H2O, O3, CH3OH) and studied the effect of both the metal precursor and oxygen source on the residual stress of the deposited films. In addition to stress measurements, film characterization was done by X-ray diffraction, scanning electron microscopy and Time-of-Flight Elastic Recoil Detection Analysis for fundamental morphological and compositional properties. Characterization data will be discussed with the residual stress results. Notably large differences in the residual stress were found as a function of precursor chemistry, for both Al2O3 and TiO2.

AB - Deposited thin films carry residual stress that can be classified into two categories. One is thermal stress that results from differences in thermal expansion coefficients between the substrate and the film, and the other is so called intrinsic stress that is a result of the deposition process itself. Stress can be either compressive or tensile. In extreme case, films under excessive stress can lead to cracking, buckling or delamination of the film. In polycrystalline films, the residual intrinsic stress originates from morphology, such as grain coalescence, crystallization and phase transformation, and from impurities and voids, and development of these parameters during the deposition process. In amorphous films, residual stress also occurs but its sources are more difficult to elucidate. Residual stress of ALD films has been studied for example for Al2O3, TiO2, and the hybrid material alucone.1-4 These studies have focused on effects of deposition temperature, pulsing parameters, film thickness, and post-deposition annealing temperature. In the present paper we report results on how the precursor chemistry affects the residual stress of ALD Al2O3 and TiO2 films deposited at 250 °C to 50 nm thickness onto 150 mm Si wafers. We employed several metal precursors, such as AlMe3, AlCl3, TiCl4 and Ti(OiPr)4 as well as different oxygen sources (H2O, O3, CH3OH) and studied the effect of both the metal precursor and oxygen source on the residual stress of the deposited films. In addition to stress measurements, film characterization was done by X-ray diffraction, scanning electron microscopy and Time-of-Flight Elastic Recoil Detection Analysis for fundamental morphological and compositional properties. Characterization data will be discussed with the residual stress results. Notably large differences in the residual stress were found as a function of precursor chemistry, for both Al2O3 and TiO2.

KW - ALD

KW - Atomic Layer Deposition

KW - Al203

KW - TiO2

KW - precursors

KW - residual stress

M3 - Conference abstract in proceedings

BT - Technical Program & Abstracts

PB - American Vacuum Society AVS

ER -

Miikkulainen V, Nieminen H, Ylivaara O, Mizohata K, Puurunen RL, Ritala M. Effect of precursor chemistry on residual stress of ALD Al2O3 and TiO2 films. In Technical Program & Abstracts. American Vacuum Society AVS. 2016