Etch behavior of ALD Al2O3 on HfSiO and HfSiON stacks in acidic and basic etchants

Jisook Oh, Jihyun Myoung, Jin Sung Bae, Sangwoo Lim

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

For the integration of advance gate stacks, selective wet etching of an Al2O3 capping layer on top of high-k dielectrics was studied. From the fundamental etch study on the single-layer Al 2O3, HfSiO and HfSiON thin films were prepared by atomic layer deposition (ALD). Using the etch rate information of each single layer, several optimized etch conditions in acidic and basic etchants including H 3PO4, NH4OH, and TMAH resulted in wet etch selectivities of Al2O3 to high-k materials higher than 50:1. As a result, the Al2O3 capping layer on Si/SiO 2/high-k multi-layer gate stack could be completely removed without thinning of the underlying high-k thin films. Finally, the etch mechanisms of Al2O3 in acidic and basic etchants were studied and the etch rates of Al2O3 were determined as functions of H and OH-.

Original languageEnglish
JournalJournal of the Electrochemical Society
Volume158
Issue number4
DOIs
Publication statusPublished - 2011 Apr 29

Fingerprint

etchants
Atomic layer deposition
atomic layer epitaxy
Thin films
Wet etching
thin films
selectivity
etching
hydroxide ion
High-k dielectric

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Electrochemistry

Cite this

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title = "Etch behavior of ALD Al2O3 on HfSiO and HfSiON stacks in acidic and basic etchants",
abstract = "For the integration of advance gate stacks, selective wet etching of an Al2O3 capping layer on top of high-k dielectrics was studied. From the fundamental etch study on the single-layer Al 2O3, HfSiO and HfSiON thin films were prepared by atomic layer deposition (ALD). Using the etch rate information of each single layer, several optimized etch conditions in acidic and basic etchants including H 3PO4, NH4OH, and TMAH resulted in wet etch selectivities of Al2O3 to high-k materials higher than 50:1. As a result, the Al2O3 capping layer on Si/SiO 2/high-k multi-layer gate stack could be completely removed without thinning of the underlying high-k thin films. Finally, the etch mechanisms of Al2O3 in acidic and basic etchants were studied and the etch rates of Al2O3 were determined as functions of H and OH-.",
author = "Jisook Oh and Jihyun Myoung and Bae, {Jin Sung} and Sangwoo Lim",
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Etch behavior of ALD Al2O3 on HfSiO and HfSiON stacks in acidic and basic etchants. / Oh, Jisook; Myoung, Jihyun; Bae, Jin Sung; Lim, Sangwoo.

In: Journal of the Electrochemical Society, Vol. 158, No. 4, 29.04.2011.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Etch behavior of ALD Al2O3 on HfSiO and HfSiON stacks in acidic and basic etchants

AU - Oh, Jisook

AU - Myoung, Jihyun

AU - Bae, Jin Sung

AU - Lim, Sangwoo

PY - 2011/4/29

Y1 - 2011/4/29

N2 - For the integration of advance gate stacks, selective wet etching of an Al2O3 capping layer on top of high-k dielectrics was studied. From the fundamental etch study on the single-layer Al 2O3, HfSiO and HfSiON thin films were prepared by atomic layer deposition (ALD). Using the etch rate information of each single layer, several optimized etch conditions in acidic and basic etchants including H 3PO4, NH4OH, and TMAH resulted in wet etch selectivities of Al2O3 to high-k materials higher than 50:1. As a result, the Al2O3 capping layer on Si/SiO 2/high-k multi-layer gate stack could be completely removed without thinning of the underlying high-k thin films. Finally, the etch mechanisms of Al2O3 in acidic and basic etchants were studied and the etch rates of Al2O3 were determined as functions of H and OH-.

AB - For the integration of advance gate stacks, selective wet etching of an Al2O3 capping layer on top of high-k dielectrics was studied. From the fundamental etch study on the single-layer Al 2O3, HfSiO and HfSiON thin films were prepared by atomic layer deposition (ALD). Using the etch rate information of each single layer, several optimized etch conditions in acidic and basic etchants including H 3PO4, NH4OH, and TMAH resulted in wet etch selectivities of Al2O3 to high-k materials higher than 50:1. As a result, the Al2O3 capping layer on Si/SiO 2/high-k multi-layer gate stack could be completely removed without thinning of the underlying high-k thin films. Finally, the etch mechanisms of Al2O3 in acidic and basic etchants were studied and the etch rates of Al2O3 were determined as functions of H and OH-.

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