Reactively sputtered tantalum pentoxide thin films for integrated capacitors

Tommi Riekkinen (Corresponding Author), Jyrki Molarius

Research output: Contribution to journalArticleScientificpeer-review

13 Citations (Scopus)

Abstract

The aim of this work was to develop a deposition process for a high-dielectric constant tantalum pentoxide for integrated capacitors. Thin films were deposited reactively on glass wafers using a radio-frequency magnetron sputtering cluster tool at various O2/Ar flow ratios. By using 2 MeV 4He+ backscattering spectroscopy and X-ray diffraction, the films obtained showed a stoichiometric orthorhombic β-Ta2O5 phase at 20% O2 in the sputtering gas flow. With low-frequency measurements (f=100 kHz), a 200×200-μm2 square metal–insulator–metal (MIM) capacitor with copper electrodes and a 340-nm thick dielectric gave a capacitance density of 0.066 μF/cm2, with a quality factor (Q) of 650. The value of the relative permittivity (εr) was approximately 25 determined from MIM capacitors of various sizes. The surface roughness of the 376-nm thick oxide film was found to be small: 0.255 nm. The largest measured capacitor (200×200 μm2) gave reasonable results at low frequencies. When the frequency was increased (100 kHz–20 GHz) only for the smaller capacitors (30×30 μm2) the capacitance remained constant. However, the Q values decreased of the smaller capacitors as a function of frequency. Processed tantalum pentoxide MIM capacitors possessed reasonable electrical properties below 2 GHz and good potential for further improvement.
Original languageEnglish
Pages (from-to)392-397
Number of pages6
JournalMicroelectronic Engineering
Volume70
Issue number2-4
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed
EventMaterials for Advanced Metallization 2003 - La Londe Les Maures, France
Duration: 9 Mar 200312 Mar 2003

Fingerprint

Tantalum
tantalum
capacitors
Capacitors
Thin films
thin films
Permittivity
Capacitance
capacitance
permittivity
low frequencies
frequency measurement
Backscattering
tantalum oxide
Thick films
Magnetron sputtering
Oxide films
gas flow
Sputtering
Flow of gases

Keywords

  • reactive sputtering
  • thin film capacitor
  • thin films
  • tantalum pentoxide
  • tantalum

Cite this

Riekkinen, Tommi ; Molarius, Jyrki. / Reactively sputtered tantalum pentoxide thin films for integrated capacitors. In: Microelectronic Engineering. 2003 ; Vol. 70, No. 2-4. pp. 392-397.
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Reactively sputtered tantalum pentoxide thin films for integrated capacitors. / Riekkinen, Tommi (Corresponding Author); Molarius, Jyrki.

In: Microelectronic Engineering, Vol. 70, No. 2-4, 2003, p. 392-397.

Research output: Contribution to journalArticleScientificpeer-review

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