Atomic layer deposited tungsten nitride thin film as a contact barrier layer for sub-80 nm dynamic random access memory

Soo Hyun Kim, Jun Ki Kim, Nohjung Kwak, Hyunchul Sohn, Jinwoong Kim, Sung Hoon Jung, Mi Ran Hong, Sang Hyeob Lee, Josh Collins

Research output: Contribution to journalConference article

Abstract

Tungsten nitride thin films were grown by atomic layer deposition (ALD) using alternating exposures of B 2 H 6 , WF 6 , and NH 3 at 300 °C. The film thickness linearly increased with the number of the reaction cycles and determined growth rate was ∼ 0.28 nm/cycle with B 2 H 6 , WF 6 and NH 3 pulse time of 5, 0.25, and 2 s, respectively. The film had a resisitivity of ∼ 350 μΩ-cm with metallic W-N bond and density of ∼15 g/cm 3 at 10 nm thickness. X-ray diffractometry analysis showed that the film had nanocrystalline grains with β-W 2 N and δ-WN phase. Step coverage was approximately 100% even on the 0.14 μm diameter contact hole with 16:1 aspect ratio. ALD-WN x film was evaluated as a barrier layer for W-plug deposition at the contact with an ultrahigh aspect ratio of about 17 for sub-80 nm dynamic random access memory. The results showed that while TiN control group has failed or has a higher contact resistance, ALD-WN x control group showed a low contact resistance. The plan-view scanning electron microscopy images after focused ion beam milling showed that a new contact integration scheme with ALD-WN x showed better plug filling capability due to its excellent step coverage. We also demonstrated that ALD-WN x was successfully integrated at plate contact of polycrystalline Si or TiN and at via contact.

Original languageEnglish
Pages (from-to)213-219
Number of pages7
JournalAdvanced Metallization Conference (AMC)
Publication statusPublished - 2006 Mar 23
Event22nd Annual Advanced Metallization Conference, AMC 2005 - Colorado, Springs, CO, United States
Duration: 2005 Sep 272005 Sep 29

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Tungsten
Atomic layer deposition
Nitrides
Data storage equipment
Thin films
Contact resistance
Aspect ratio
Focused ion beams
X ray diffraction analysis
Film thickness
Scanning electron microscopy

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)

Cite this

Kim, Soo Hyun ; Kim, Jun Ki ; Kwak, Nohjung ; Sohn, Hyunchul ; Kim, Jinwoong ; Jung, Sung Hoon ; Hong, Mi Ran ; Lee, Sang Hyeob ; Collins, Josh. / Atomic layer deposited tungsten nitride thin film as a contact barrier layer for sub-80 nm dynamic random access memory. In: Advanced Metallization Conference (AMC). 2006 ; pp. 213-219.
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title = "Atomic layer deposited tungsten nitride thin film as a contact barrier layer for sub-80 nm dynamic random access memory",
abstract = "Tungsten nitride thin films were grown by atomic layer deposition (ALD) using alternating exposures of B 2 H 6 , WF 6 , and NH 3 at 300 °C. The film thickness linearly increased with the number of the reaction cycles and determined growth rate was ∼ 0.28 nm/cycle with B 2 H 6 , WF 6 and NH 3 pulse time of 5, 0.25, and 2 s, respectively. The film had a resisitivity of ∼ 350 μΩ-cm with metallic W-N bond and density of ∼15 g/cm 3 at 10 nm thickness. X-ray diffractometry analysis showed that the film had nanocrystalline grains with β-W 2 N and δ-WN phase. Step coverage was approximately 100{\%} even on the 0.14 μm diameter contact hole with 16:1 aspect ratio. ALD-WN x film was evaluated as a barrier layer for W-plug deposition at the contact with an ultrahigh aspect ratio of about 17 for sub-80 nm dynamic random access memory. The results showed that while TiN control group has failed or has a higher contact resistance, ALD-WN x control group showed a low contact resistance. The plan-view scanning electron microscopy images after focused ion beam milling showed that a new contact integration scheme with ALD-WN x showed better plug filling capability due to its excellent step coverage. We also demonstrated that ALD-WN x was successfully integrated at plate contact of polycrystalline Si or TiN and at via contact.",
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Atomic layer deposited tungsten nitride thin film as a contact barrier layer for sub-80 nm dynamic random access memory. / Kim, Soo Hyun; Kim, Jun Ki; Kwak, Nohjung; Sohn, Hyunchul; Kim, Jinwoong; Jung, Sung Hoon; Hong, Mi Ran; Lee, Sang Hyeob; Collins, Josh.

In: Advanced Metallization Conference (AMC), 23.03.2006, p. 213-219.

Research output: Contribution to journalConference article

TY - JOUR

T1 - Atomic layer deposited tungsten nitride thin film as a contact barrier layer for sub-80 nm dynamic random access memory

AU - Kim, Soo Hyun

AU - Kim, Jun Ki

AU - Kwak, Nohjung

AU - Sohn, Hyunchul

AU - Kim, Jinwoong

AU - Jung, Sung Hoon

AU - Hong, Mi Ran

AU - Lee, Sang Hyeob

AU - Collins, Josh

PY - 2006/3/23

Y1 - 2006/3/23

N2 - Tungsten nitride thin films were grown by atomic layer deposition (ALD) using alternating exposures of B 2 H 6 , WF 6 , and NH 3 at 300 °C. The film thickness linearly increased with the number of the reaction cycles and determined growth rate was ∼ 0.28 nm/cycle with B 2 H 6 , WF 6 and NH 3 pulse time of 5, 0.25, and 2 s, respectively. The film had a resisitivity of ∼ 350 μΩ-cm with metallic W-N bond and density of ∼15 g/cm 3 at 10 nm thickness. X-ray diffractometry analysis showed that the film had nanocrystalline grains with β-W 2 N and δ-WN phase. Step coverage was approximately 100% even on the 0.14 μm diameter contact hole with 16:1 aspect ratio. ALD-WN x film was evaluated as a barrier layer for W-plug deposition at the contact with an ultrahigh aspect ratio of about 17 for sub-80 nm dynamic random access memory. The results showed that while TiN control group has failed or has a higher contact resistance, ALD-WN x control group showed a low contact resistance. The plan-view scanning electron microscopy images after focused ion beam milling showed that a new contact integration scheme with ALD-WN x showed better plug filling capability due to its excellent step coverage. We also demonstrated that ALD-WN x was successfully integrated at plate contact of polycrystalline Si or TiN and at via contact.

AB - Tungsten nitride thin films were grown by atomic layer deposition (ALD) using alternating exposures of B 2 H 6 , WF 6 , and NH 3 at 300 °C. The film thickness linearly increased with the number of the reaction cycles and determined growth rate was ∼ 0.28 nm/cycle with B 2 H 6 , WF 6 and NH 3 pulse time of 5, 0.25, and 2 s, respectively. The film had a resisitivity of ∼ 350 μΩ-cm with metallic W-N bond and density of ∼15 g/cm 3 at 10 nm thickness. X-ray diffractometry analysis showed that the film had nanocrystalline grains with β-W 2 N and δ-WN phase. Step coverage was approximately 100% even on the 0.14 μm diameter contact hole with 16:1 aspect ratio. ALD-WN x film was evaluated as a barrier layer for W-plug deposition at the contact with an ultrahigh aspect ratio of about 17 for sub-80 nm dynamic random access memory. The results showed that while TiN control group has failed or has a higher contact resistance, ALD-WN x control group showed a low contact resistance. The plan-view scanning electron microscopy images after focused ion beam milling showed that a new contact integration scheme with ALD-WN x showed better plug filling capability due to its excellent step coverage. We also demonstrated that ALD-WN x was successfully integrated at plate contact of polycrystalline Si or TiN and at via contact.

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