Thick resist alignment technology for MEMS and advanced packaging

Chad Brubaker; Bernhard Wieder; Paul Lindner

doi:10.1117/12.484736

16 June 2003 Thick resist alignment technology for MEMS and advanced packaging

Chad Brubaker, Bernhard Wieder, Paul Lindner

Proceedings Volume 5037, Emerging Lithographic Technologies VII; (2003) https://doi.org/10.1117/12.484736
Event: Microlithography 2003, 2003, Santa Clara, California, United States

Abstract

The number of lithographic applications that require ultra-thick layers of resist (>50 um) is rapidly increasing. One field in which this requirement is growing is in the field of MEMS (Micro-Electro-Mechanical-Systems) and MOEMS (Micro-Optical-Electro-Mechanical-Systems). A second is in the realm of wafer-level, advanced chip scale packaging1. For both of these fields, ultra-thick, as well as high aspect ratio, photolithography is an absolute requirement for device processing. The process optimization required to obtain high aspect ratio structures in these ultra-thick photoresist films is extremely challenging. Alignment accuracy is a critical factor in this process. Because of the thick films involved, the alignment keys between mask and wafer could be separated by more than a hundred microns. Standard microscope and objectives have limited depth of focus. Once resist thickness and separation gap exceeds the depth of focus, alignment accuracy suffers from image quality between substrate and mask. Various special microscope options have been developed for alignment of very thick resist. However, most of these processes suffered from one failing or another. This paper addresses a new method to perform true large gap alignment for these applications. True large gap alignment systems overcome these limitations by using identical focal planes for mask and wafer alignment key. Both alignment keys are focused clearly with resist thickness and separation gap of up to 500 um. This paper will present detailed experimental results of alignment accuracy obtained at different thicknesses of photoresist in a contact/proximity production aligner system.

Citation Download Citation

Chad Brubaker, Bernhard Wieder, and Paul Lindner "Thick resist alignment technology for MEMS and advanced packaging", Proc. SPIE 5037, Emerging Lithographic Technologies VII, (16 June 2003); https://doi.org/10.1117/12.484736

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Optical alignment

Photomasks

Semiconducting wafers

Microelectromechanical systems

Packaging

Microscopes

Optical lithography

Show All Keywords

Keywords/Phrases

Search In:

Publication Years