A thick photoresist process for high aspect ratio MEMS applications

Elias Laforge; Ricky Anthony; Paul McCloskey; Cian O'Mathúna

doi:10.1117/12.2247899

A thick photoresist process for high aspect ratio MEMS applications

Elias Laforge
, Ricky Anthony
, Paul McCloskey
, Cian O'Mathúna

Tyndall IPES (Integrated Power)

University College Cork

Research output: Chapter in Book/Report/Conference proceedings › Conference proceeding › peer-review

Abstract

In recent years, increased demand for high aspect ratio MEMS structures has driven the need for thick photoresist fabrication processes. In this work, the optimization of a thick photoresist process using a negative tone resist (THB-151N) is described. A thickness of 85 μm is obtained with an aspect ratio of 17:1 in a single coating process, with a 5 μm pitch. Conventional UV lithography is used and its parameters are optimized in order to achieve straight and near vertical sidewall profiles. The developed patterns are used as a mold to electroplate high aspect ratio copper windings of micro-inductors and micro-transformers. A high aspect ratio yields a copper track with a large cross sectional area resulting in a lower DC resistance. This enables a further reduction in the footprint area allowing for a more efficient manufacturing process and smaller device size. Unlike other high aspect ratio resist such as SU-8, this resist does not need a post exposure bake and can be readily removed after metal electroplating.

Original language	English
Title of host publication	32nd European Mask and Lithography Conference
Editors	Uwe F.W. Behringer, Jo Finders
Publisher	SPIE
ISBN (Electronic)	9781510604872
DOIs	https://doi.org/10.1117/12.2247899
Publication status	Published - 2016
Event	32nd European Mask and Lithography Conference, EMLC 2016 - Dresden, Germany Duration: 21 Jun 2016 → 22 Jun 2016

Publication series

Name	Proceedings of SPIE - The International Society for Optical Engineering
Volume	10032
ISSN (Print)	0277-786X
ISSN (Electronic)	1996-756X

Conference

Conference	32nd European Mask and Lithography Conference, EMLC 2016
Country/Territory	Germany
City	Dresden
Period	21/06/16 → 22/06/16

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 9 Industry, Innovation, and Infrastructure

Keywords

high aspect ratio
MEMS
microinductors
photolithography
THB-151N

Access to Document

10.1117/12.2247899

Cite this

@inproceedings{fb7d49983b614fc8aa1269435fb60498,

title = "A thick photoresist process for high aspect ratio MEMS applications",

abstract = "In recent years, increased demand for high aspect ratio MEMS structures has driven the need for thick photoresist fabrication processes. In this work, the optimization of a thick photoresist process using a negative tone resist (THB-151N) is described. A thickness of 85 μm is obtained with an aspect ratio of 17:1 in a single coating process, with a 5 μm pitch. Conventional UV lithography is used and its parameters are optimized in order to achieve straight and near vertical sidewall profiles. The developed patterns are used as a mold to electroplate high aspect ratio copper windings of micro-inductors and micro-transformers. A high aspect ratio yields a copper track with a large cross sectional area resulting in a lower DC resistance. This enables a further reduction in the footprint area allowing for a more efficient manufacturing process and smaller device size. Unlike other high aspect ratio resist such as SU-8, this resist does not need a post exposure bake and can be readily removed after metal electroplating.",

keywords = "high aspect ratio, MEMS, microinductors, photolithography, THB-151N",

author = "Elias Laforge and Ricky Anthony and Paul McCloskey and Cian O'Math{\'u}na",

note = "Publisher Copyright: {\textcopyright} 2016 SPIE.; 32nd European Mask and Lithography Conference, EMLC 2016 ; Conference date: 21-06-2016 Through 22-06-2016",

year = "2016",

doi = "10.1117/12.2247899",

language = "English",

series = "Proceedings of SPIE - The International Society for Optical Engineering",

publisher = "SPIE",

editor = "Behringer, \{Uwe F.W.\} and Jo Finders",

booktitle = "32nd European Mask and Lithography Conference",

address = "United States",

}

Laforge, E, Anthony, R, McCloskey, P & O'Mathúna, C 2016, A thick photoresist process for high aspect ratio MEMS applications. in UFW Behringer & J Finders (eds), 32nd European Mask and Lithography Conference., 1003203, Proceedings of SPIE - The International Society for Optical Engineering, vol. 10032, SPIE, 32nd European Mask and Lithography Conference, EMLC 2016, Dresden, Germany, 21/06/16. https://doi.org/10.1117/12.2247899

A thick photoresist process for high aspect ratio MEMS applications. / Laforge, Elias; Anthony, Ricky; McCloskey, Paul et al.
32nd European Mask and Lithography Conference. ed. / Uwe F.W. Behringer; Jo Finders. SPIE, 2016. 1003203 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 10032).

Research output: Chapter in Book/Report/Conference proceedings › Conference proceeding › peer-review

TY - GEN

T1 - A thick photoresist process for high aspect ratio MEMS applications

AU - Laforge, Elias

AU - Anthony, Ricky

AU - McCloskey, Paul

AU - O'Mathúna, Cian

PY - 2016

Y1 - 2016

N2 - In recent years, increased demand for high aspect ratio MEMS structures has driven the need for thick photoresist fabrication processes. In this work, the optimization of a thick photoresist process using a negative tone resist (THB-151N) is described. A thickness of 85 μm is obtained with an aspect ratio of 17:1 in a single coating process, with a 5 μm pitch. Conventional UV lithography is used and its parameters are optimized in order to achieve straight and near vertical sidewall profiles. The developed patterns are used as a mold to electroplate high aspect ratio copper windings of micro-inductors and micro-transformers. A high aspect ratio yields a copper track with a large cross sectional area resulting in a lower DC resistance. This enables a further reduction in the footprint area allowing for a more efficient manufacturing process and smaller device size. Unlike other high aspect ratio resist such as SU-8, this resist does not need a post exposure bake and can be readily removed after metal electroplating.

AB - In recent years, increased demand for high aspect ratio MEMS structures has driven the need for thick photoresist fabrication processes. In this work, the optimization of a thick photoresist process using a negative tone resist (THB-151N) is described. A thickness of 85 μm is obtained with an aspect ratio of 17:1 in a single coating process, with a 5 μm pitch. Conventional UV lithography is used and its parameters are optimized in order to achieve straight and near vertical sidewall profiles. The developed patterns are used as a mold to electroplate high aspect ratio copper windings of micro-inductors and micro-transformers. A high aspect ratio yields a copper track with a large cross sectional area resulting in a lower DC resistance. This enables a further reduction in the footprint area allowing for a more efficient manufacturing process and smaller device size. Unlike other high aspect ratio resist such as SU-8, this resist does not need a post exposure bake and can be readily removed after metal electroplating.

KW - high aspect ratio

KW - MEMS

KW - microinductors

KW - photolithography

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DO - 10.1117/12.2247899

M3 - Conference proceeding

AN - SCOPUS:85006320094

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - 32nd European Mask and Lithography Conference

A2 - Behringer, Uwe F.W.

A2 - Finders, Jo

PB - SPIE

T2 - 32nd European Mask and Lithography Conference, EMLC 2016

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ER -

A thick photoresist process for high aspect ratio MEMS applications

Abstract

Publication series

Conference

UN SDGs

Keywords

Access to Document

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