Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture

Time-dependent dielectric breakdown (TDDB) reliability is increasingly becoming a critical reliability concern with the introduction of lower dielectric constant materials and shrinking of metal spacing in the back-end-of-line technology. Therefore, there is a need to investigate the factors causing...

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Main Author: Tan, Tam Lyn
Other Authors: Hwang Nam
Format: Theses and Dissertations
Language:English
Published: 2008
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Online Access:https://hdl.handle.net/10356/14244
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-142442023-03-04T16:33:21Z Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture Tan, Tam Lyn Hwang Nam Du Anyan Gan Chee Lip School of Materials Science & Engineering A*STAR Institute of Microelectronics Chartered Semiconductor Manufacturing DRNTU::Engineering::Materials::Microelectronics and semiconductor materials::Nanoelectronics and interconnects Time-dependent dielectric breakdown (TDDB) reliability is increasingly becoming a critical reliability concern with the introduction of lower dielectric constant materials and shrinking of metal spacing in the back-end-of-line technology. Therefore, there is a need to investigate the factors causing the leakage and dielectric breakdown in advanced Cu/low-k interconnects and understand the failure mechanisms involved. In this work, specially designed test structures i.e. line end (S1) and corner (S2) interconnect layouts were used to investigate the failure mechanisms. This is due to its electric field enhancement effects and thus enabling more stringent reliability assessments, and also due to its efficacy in failure analysis. Two failure mechanisms were observed and they were delamination at the SiC(N) dielectric cap and SiOCH low-k dielectric interface and Ta migration from the anode sidewall. The delamination resulted in a lower TDDB activation energy (~0.2eV) for S1 and S2 structures due to field enhancement effects while Ta migration increased the interconnect leakage. This implies that the capping layer properties and its adjacent interface adhesion quality as well as the sidewall barrier integrity degrade TDDB reliability. However, the TDDB reliability was found to be improved in stand-alone and self-aligned CoWP-capped interconnect architecture with lower leakage and higher TDDB activation energies (0.66eV – 0.96eV). This is due to its TDDB dependence on the inter-metal dielectric properties alone instead of the additional interface adhesion quality of the dissimilar interface between the dielectric cap and inter-metal dielectric in dielectric-capped interconnects. DOCTOR OF PHILOSOPHY (SME) 2008-11-07T01:11:07Z 2008-11-07T01:11:07Z 2008 2008 Thesis Tan, T. L. (2008). Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/14244 10.32657/10356/14244 en 157 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Materials::Microelectronics and semiconductor materials::Nanoelectronics and interconnects
spellingShingle DRNTU::Engineering::Materials::Microelectronics and semiconductor materials::Nanoelectronics and interconnects
Tan, Tam Lyn
Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
description Time-dependent dielectric breakdown (TDDB) reliability is increasingly becoming a critical reliability concern with the introduction of lower dielectric constant materials and shrinking of metal spacing in the back-end-of-line technology. Therefore, there is a need to investigate the factors causing the leakage and dielectric breakdown in advanced Cu/low-k interconnects and understand the failure mechanisms involved. In this work, specially designed test structures i.e. line end (S1) and corner (S2) interconnect layouts were used to investigate the failure mechanisms. This is due to its electric field enhancement effects and thus enabling more stringent reliability assessments, and also due to its efficacy in failure analysis. Two failure mechanisms were observed and they were delamination at the SiC(N) dielectric cap and SiOCH low-k dielectric interface and Ta migration from the anode sidewall. The delamination resulted in a lower TDDB activation energy (~0.2eV) for S1 and S2 structures due to field enhancement effects while Ta migration increased the interconnect leakage. This implies that the capping layer properties and its adjacent interface adhesion quality as well as the sidewall barrier integrity degrade TDDB reliability. However, the TDDB reliability was found to be improved in stand-alone and self-aligned CoWP-capped interconnect architecture with lower leakage and higher TDDB activation energies (0.66eV – 0.96eV). This is due to its TDDB dependence on the inter-metal dielectric properties alone instead of the additional interface adhesion quality of the dissimilar interface between the dielectric cap and inter-metal dielectric in dielectric-capped interconnects.
author2 Hwang Nam
author_facet Hwang Nam
Tan, Tam Lyn
format Theses and Dissertations
author Tan, Tam Lyn
author_sort Tan, Tam Lyn
title Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
title_short Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
title_full Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
title_fullStr Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
title_full_unstemmed Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture
title_sort dielectric failure mechanisms in advanced cu/low-k interconnect architecture
publishDate 2008
url https://hdl.handle.net/10356/14244
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