Result: Study of crack formation in high-aspect ratio SU-8 structures on silicon

Title:
Study of crack formation in high-aspect ratio SU-8 structures on silicon
Authors:
BYSTROVA, S, LUTTGE, R, VAN DEN BERG, A
Source:
Proceedings of the 32nd International Conference on Micro- and Nano-Engineering, Barcelona, 17-20 September 2006Microelectronic engineering. 84(5-8):1113-1116
Publisher Information:
Amsterdam: Elsevier Science, 2007.
Publication Year:
2007
Physical Description:
print, 5 ref
Original Material:
INIST-CNRS
Subject Terms:
Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Circuits intégrés, Integrated circuits, Conception. Technologies. Analyse fonctionnement. Essais, Design. Technologies. Operation analysis. Testing, Fabrication microélectronique (technologie des matériaux et des surfaces), Microelectronic fabrication (materials and surfaces technology), Circuit intégré, Integrated circuit, Circuito integrado, Circuit à la demande, Custom circuit, Circuito integrato personalizado, Cuisson au four, Baking, Cocimiento al horno, Désadaptation, Mismatching, Desadaptación, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Figure attaque, Etch pit, Figura ataque, Fissure, Crack, Fisura, Microstructure, Microestructura, Optimisation, Optimization, Optimización, Pastille électronique, Wafer, Pastilla electrónica, Photolithographie, Photolithography, Fotolitografía, Photorésist, Photoresist, Fotorresistencia, Rapport aspect, Aspect ratio, Relación dimensional, Revêtement centrifugation, Spin-on coatings, Résist, Resist, Resistencia, Solidification, Solidificación, Crack formation, Micromolding, Post Exposure Bake control, SU-8
Document Type:
Conference Conference Paper
File Description:
text
Language:
English
Author Affiliations:
BIOS Lab-on-a-chip Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
ISSN:
0167-9317
Access URL:
http://pascal-francis.inist.fr/vibad/index.php?action=search&terms=18807388
Rights:
Copyright 2007 INIST-CNRS
CC BY 4.0
Sauf mention contraire ci-dessus, le contenu de cette notice bibliographique peut être utilisé dans le cadre d’une licence CC BY 4.0 Inist-CNRS / Unless otherwise stated above, the content of this bibliographic record may be used under a CC BY 4.0 licence by Inist-CNRS / A menos que se haya señalado antes, el contenido de este registro bibliográfico puede ser utilizado al amparo de una licencia CC BY 4.0 Inist-CNRS
Notes:
Electronics
Accession Number:
edscal.18807388
Database:
PASCAL Archive

Further Information

The high-aspect ratio capability of SU-8 photoresist led to the successful use of this epoxy based material in a diversity of microfabricated devices as a construction material as well as for micromolding purposes. Throughout the literature it was noticed that the thermal mismatch of SU-8 and the substrate material silicon generates high film stress in the spin-coated SU-8 causing crack formation in the microstructures. Using baking parameters this crack formation can be minimized but will remain a critical aspect of design. In this study the process was first optimised on non-patterned wafers. Secondly, we transferred this optimised process to a pre-patterned wafer containing deep silicon etch pits to account for a specific application in micromolding. We discuss the behaviour of film stress, number of cracks and crack length. The number of cracks as well as the length of cracks in concave corner designs can be significantly decreased, while round holes resulted even in crack-free microstructures. In the case of pre-patterned wafers no cracks appear around the features, however we observed unsatisfied development within the resist features caused by insufficient solidification in the deep etch pits during Soft Bake. Increased Soft Bake time can overcome these problems but will require more systematic investigations.