NEW INFORMATIONS WILL BE ADDED AS SOON AS I HAVE (WRITTEN) THEM.
Since several years, I have been working with SU8 photoresists. I also worked in the swiss company SOTEC Microsystems, which has stopped its activities AND HAS NOT BEEN REPLACED. I believe that the informations of this page are useful for the users of SU8 and that is the reason why I publish them right here.
This page is copyrighted by Dr Louis J. Guerin. It is based on my knowledge and my experience with the SU8.
An epoxy resin is defined as a molecule containing one or more 1,2-epoxy groups.
Such molecules are capable of being converted to a thermoset form or three-dimensional network structure. This process is called curing or crosslinking.
Epoxy resin curing agents can be divided into three categories:
- Active hydrogen compound, which cure by polyaddition reactions.
- Ionic initiators, which are subdivided into anionic and cationic.
- Crosslinkers, which couple through the hydroxyl functionality higher molecular-weight epoxy resins.
Cationic polymerization is induced by Lewis acids. The general mechanism is represented at figure 3.1. The Lewis acid is generated during UV illumination. The polymerization is done by the ring-opening of the 1,2-epoxy.
It has been originally developed, and patented (US Patent No. 4882245 (1989) and others) by IBM-Watson Rechearch Center (Yorktown Height-USA). In 1996 the material has been adapted for MEMS applications during a collaboration between EPFL-Institute of Microsystems and IBM-Zurich (CH).
The SU8 photoresist is an epoxy based photoresist. The main part is the EPON SU8 epoxy from Shell Chemicals. It is a highly functionalized molecule with 8 epoxy groups (see figure 4.1). The polymerisation is done by a cationinc photopolymerization mechanism (see above)
Figure 4.1 : The basic SU8 molecule, note the 8 epoxy groups.
60% SU8-40% solvent : 1.5 Pa.s
70% SU8-30% solvent : 15 Pa.s
1.7 at 1.6 THz
40 /cm at 1.6 THZ
The results and the processes described here have been developed by the author. I believe that the results are reliable, but I don't guarantee that the used process-parameters are optimised for other cleanrooms.
Adhesion promoter :
Several people have try to use the classical promoter HMDS (Hexamethyldisilazane), that is used for thin-film photoresists in the microelectronic fabrication.
Another choice is to use an epoxy molecule such as the one shown on figure 6.1.b. This molecule has on one side methyl groups that stick on glass or silicon and on the other side it has a epoxy group that reacts with SU8.
Figure 6.1 : Adhesion promoter for SU8.
Deshydratation : see above
Deposition (spin-coating): 2 ml ; 5000rpm for 30 seconds
Curing : 5 minutes at 120 degres C.
Deposition :
For very thick layers, the softbake time is very long. It can be reduced by an order of 2 to 5, by first evaporating the solvent under a vaccum.
Exposure:
Never illuminate the SU8 for to long periods. Energies of 200 mJ/cm2, heat the SU8 at the interface with the photolithographic mask. This heating is responsible for a hard skin formation at the surface of the SU8. Therefore for thick layers and for high exposure doses, the illumination should be done stepwise ( expose for 10 to 15 seconds, leave the system cool down for 60 seconds, illuminate again, etc ...).
It is important to note that the optimal exposure energy depends on the nature of the substrate.
90 mJ/cm2 for layer thickness of 200 micron
However temperature of 50 deg.C are acceptable if the PEB time is increased (at 50 deg.C PEB time is about 1 hour). The main advantage of using lower PEB temperature is the final internal thermal stress is much less important than after a PEB with a temperature of 95 deg. C.
The PEB can be done on a hotplate or in an oven. Again it is important that the surface is flat and horizontal. After the PEB, the substrate should be cooled down slowly. Apply no thermal shock.
Development :
Hardbake :
But it is possible to get ride of the material by different techniques:
- The SU8 can be destroyed by mechanical methods, such as for example high pressure water jets.
- Remove the SU8 by high temperature ashing. At high temperature the epoxy is burnt. Above 600 °C, almost all SU8 is gone. It is important to notice that the ashing has to be done under a inert (nitrogen) atmosphere, in order to prevent the oxidation of metal part (as for example electroplated copper and nickel) of the structures.
-Chemical etching: there are different ways to etch the SU8 in this manner. You can for example use fuming nitric acid. This works fine as long as you are using an inert atmosphere. Metals such as i.e. Al, Au. Cu, Ni are not attacted in this case, but only the SU8 is removed. Another chemical product is the K-10 process salt (Kolene Corp.), which is a mixture of sodium nitrate and potassium hydroxide (T: 300-350 °C). It completely oxidizes crosslinked materials and has very little effect on Ni parts ( for more informations, see ref. 41). A last chemical mixture has been developped by the author of this page and consists of a mixture of Dimethyl-sulfoxide, picoline and fuming acid. This solution attacts the SU8, but depending on the ratio of the different components, also some metals. It is however possible to optimize it so that the metal etching is not detectable. I ahd taken a patent application on this solution, and I have decided to put it in the public domain. If you want to know how to prepare it, please contact me.
- Plasma etching: SU8 can be removed in this way. A good description of this method is given in ref. 35 and 42.
Capacitors
Dielectric material
Fast Prototyping
µTAS
Micropumps
MCM 3D
CSP
Microconnectics
Microrelays
Microoptics
Microwaves
There are different ways to acheive this.
The first one, which we consider to be the less interesting one, is to add metal (i.e. silver) nanoparticles with the SU8 monomer. It is less interesting in our eyes, because, as the silver particles are not transparent to the UV light, much of the resolution of the resist is lost. Typical resolution are about 35 microns by using standard processing steps. Using more complicated procedures, resolutions of 5 microns may be acheived, but only for relatively thin layers ( less then 10 microns). The method allows to get conductivities of 10E1 to 10E7 Sm, depending on the filling proportion of the nanoparticles in the SU8. However the polymerized SU8 is unstable and not well polymerised and by this fact it is rather useless. If nevertheless you want to prepare these solutions, please contact me for informations
A second way to render the SU8 conductive is to use conductive polymers and more precisely polyaniline (this method is patented by the author). Polyaniline is a very interesting material and it can be used for many applications. Polyaniline can be found in an isolating form, that in presence of a protonating acid is transformed into a conductive form. The change or doping can be done in-situ and in a very selective manner.
Some substances, such as the triarylium salts (TSS) are photosensitve. With an ultraviolet illumination, TSS are decomposed (see figure 3.1a) and change into weak acids (Lewis acids). Those acids can be used as in-situ dopants of the polyaniline. Knowing now that there is a great difference in the solubility of the doped and undoped form of polyaniline in certain solvents (undoped polyaniline: high solubility; doped polyaniline: no solubity) it becomes possible, by using photolithographical methods, to pattern polyaniline and to realise conductive polymer interconnection lines. This has been shown by researchers from IBM (see ref.)
But it is now important to remember that the TSS are also used for the SU8 photresist. In fact, in the chemical formulation, the TSS are used to render the base epoxy photosensitive and to make the polymerisation (see figure 3.1b). We could show that the mixing of SU8, polyaniline and TSS gives a very interesting substance. The TSS is now used as a curing agent for the epoxy and as doping agent for the polyaniline. The result is a conductive thick-film photoresist.
The big advantage of this method is that the thickness of the layer is not restricted and it is possible to get the same conductivity for thin and for thick layers (larger than 200 microns). Typical conductivities are around 10E2 to 10E6 Sm. They are perhaps smaller than those obtained with metal nanoparticles, but are enough for many useful applications (and the polymerised SU8 is stable!)
ref:
M. Angelopolous, Conducting polymers in microelectronics, IBM J. Res. & Dev., 45, 1, (2001)
M. Angelopolous et al, J. Vac. Sci. Tech. B, 9, 6 (1991)
Silicon and glass: When very small and high accuracy channels are required, the "classical" materials such as silicon or glass are usually preferred. Their advantages are high quality and well known standard technologies that can be combined to fabricate other components such as sensors, electrodes or membrane pumps. Glass is also a material which is widely accepted for handling chemical fluids. Silicon and glass can be combined by bonding to form the channels. These technologies are for instance used in analytical chips that use capillary electrophoresis. Material and processing cost of silicon and glass are limiting factors for disposable devices.
Polymer technologies: Very low cost channels can be manufactured by modern high precision polymer replication techniques. This is well suited for single layers of channels. Polymer replication techniques are used in a number of industrial developments of microfluidic devices for high (and mega) throughput drug screening as well as for DNA chips. The various processes (injection molding, hot embossing or UV molding) can be applied to many materials. The mold master can be fabricated with conventional precision tools or by microtechnology techniques. Complementing the above techniques, a new technique based on ultra-high precision replica molding has recently been applied for making sub-micrometer size channels in plastics.
SU8 Microfluidic device fabrication
A set of processes to fabricated embedded (multilevel) microchannels is described below. They are all based on a polymer material that is patterned by UV light exposure which has been recently developed for high aspect ratio UV-LIGA: the SU8. This is an epoxy polymer which has excellent mechanical and chemical properties. This can sometimes be a drawback when this material is used as a photoresist for UV-LIGA process: it creates high stress levels and is very difficult to removewhen it is needed. Its good mechanical strength and chemical resistance make the SU8 photopolymer a perfect candidate for not using it as constitutive material for polymer microstructures. Moreover, this material is sufficiently cheap to be considered in low cost (or even disposable) devices. For making embedded microchannels in the photopolymer, one should find a way of defining cavity in the bulk of the material. The following ideas have been considered:
a) The cavities are developed and filled with a non-photosensitive material which is subsequently dissolved (fill-process).
b) The cavities are defined by unexposed masked areas that are developed after the last layer(mask-process).
c) The liquid photopolymer is replaced by a flim that can be laminated over cavities(lamination-process).
Fill-process
In the fill-process, the structure is developed. The resulting channel is filled with a material, that can easily be dissolved. A third layer is deposited and processed. In a last step, the SU-8 is developed, the filling material is dissolved, and the structure with the micro-channel is released from the substrate.
Mask-process
For the mask-process, the second SU-8 layer is not developed after step b), but a metal that will act as a shadow mask is deposited over the structure and is patterned in order to stay just on the top of the channel. A third SU-8 layer is spun on the surface and illuminated. The metal mask prevents the photosensitive SU-8 inside the channel to be exposed and cross-linked during this process-step. Finally the polymer is developed outside the structure and inside the micro-channel. The last step is the liberation of the structure from the substrate.
With both technologies, channels of cross-sections as small as 25x50 micron^2 and lengths of more than 10 mm have been realized. The mask-process is more complicated and therefore more expensive than the fill-process because of the additional metallization step. But unlike the latter it allows the realization multilevel channels.
Lamination-process
The first 2 steps of the lamination-process are the same as before and as for the fill-process the structure is developed. It is now possible to realize thin films, between 10 and 200 microns, of photopolymer. Such a film can then be laminated over the whole structure and is finally processed in the standard way.
The laminated process offers some advantages over the 2 other techniques. First of all the fabrication time is much shorter as the channel is formed before the deposition of the last photoplastic layer. Secondly this technique allows the realization of completely closed cavities which is not possible with the mask- or fill-process.
I also want to apologize as the papers are not listed in a good order. This wil be changed very soon)
REMARK: All the papers listed here below use or mention the SU8 photoresist in one way or the other. But not all of them are focused on this material.
2. LaBianca N. et al, High aspect ratio optical resist chemistry for MEMS applications, 4th Int. Symp. on Magnetic Materials, Processes, and Devices, The Electrochem. Soc., 95-18 (1995), pp.386-396
3. Lee K. et al, Micromachining applications for a high resolution ultra-thick photoresist, J. Vac. Scien. Technol. B, 13(1995), pp. 3012-3016
4. Shaw J. M. et al, Negative photoresists for optical lithography, IBM Journal of Research and Development, 41(1997), pp. 81-94
5. Despont M. et al, High aspect ratio ultrathick, negative-tone near-UV photoresist for MEMS applications, MEMS'97, IEEE, Nagoya, (1997), pp. 518-522
6. Shaw J.M. et al, Negative photoresists for optical lithography, IBM Journal of Research and Development, 41, (1997), pp. 81-94
7. Lorenz H. et al, EPON SU8 : A low-cost negative resist for MEMS, MicroMechanics Europ MME 96, Spain, (1996), pp. 32-35
8. Lorenz H. et al, Mechanical charaterization of a new high-aspect-ratio near UV-Photoresist, MNE'97, Athens, Greece, (1997)
9. Guerin L. , C.W. Newquist, P. Renaud, SU8 photoepoxy : A new material for FPD and PDP applications, DISPLAY WORKS'98, San Jose, (1998)
10. Guerin L. , A. Torosdagi, P. Eichenberger, P. Renaud,High aspect ratio planar coils embedded in SU8 photoepoxy for MEMS applications, EUROSENSORS XII, Southampton, (1998)
11. Renaud P. , H van Lintel, M. Heuschkel, L. Guerin, Photo-polymer microchannel technologies and applications, µTAS'98, Banff, Alberta, 1998, pp. 17-22
12. Guerin L. , A. Torosdagi, M. Heuschkel, P. Renaud, Microfluidic systems fabrication by lamination of photoplastic (SU8) films, NANOTECH'98, Montreux, Switzerland, (1998)
13. Thorpe J.R. et al, High frequency transmission line using micromachined polymer dielectric, Electronics Letters, Vol. 34, No. 12, pp. 1237-1238
14. Arscott S. et al, Terahertz time-domain spectroscopy of films fabricated from SU-8, Electronics Letters, Vol. 35, No. 3, pp. 243-244
15. Duffy D.C. et al, Rapid prototyping of microfluidic systems in Poly(dimethylsiloxane), Anal. Chem., Vol. 70, (1998), pp. 4974-4984
16. Flack W.W. et al, The optimization of ultra-thick photoresist films, SPIE 1998 #3333-67
17. Dutoit B.M. , P.A. Besse, H. Blanchard, L. Guerin, R.S. Popovic, High performance micromachined Sm2Co17 bonded magnets, Sensors and Actuators A (1999)
18. Agarwal V. et al, Improvements and recent advances in nanocomposite capacitors using a colloidal technique, 1998 Electronic Components and Technology Canference, Denver, (1998), pp. 165-170
19. Ayliffe H. E. et al, Electric Impedence spectroscopy using microchannels with integrated metal electrodes, IEEE Journal of Microelectromechanical systems, Vol. 8, No. 1, March 1999, pp. 50-57
20. T. Kawabata et al,, The micromachined accelerometer fabrication using thick resist, Technical digest of the 16th Sensor Symposium, Japan, (1998), pp. 199-202
21. Strike D.J. et al, Miniaturized detectors fabricated using Si and Epon SU8, TRANSDUCERS'99, Sendai-Japan, (1999)
22. Guerin L. , M. Bossel, M. Demierre, S. Calmes, and P. Renaud, Simple and low cost fabrication of embedded microchannels by using a new thick-film photoplastic, Transducers 1997, Chicago, (1997), pp. 1419-1422
23. Dellmann L. et al.,Fabrication process of high-aspect ratio elastic structures for piezoelectric motor applications, Transducers'97, Chicago, (1997)
24. Bertsch A. et al, 3D microfabrication by combining microstereolithography and thick resist UV lithography, Sensors and Actuators A, 73, (1999), pp. 14-23
25. Eyre B. et al., Taguchi Optimization for processing EPON SU8 resist, Proceedings MEMS'98, Heidelberg, (1998), pp. 218-222
26. Heuschkel M. et al., Buried microchannels in polymer for delivering of solutions to neurons in a network, Sensors and Actuators : B, 48/1-3, (1998), pp. 356-361
27. Dumschat C. et al, Encapsulation of Chemically Sensitive Field-effect Transistors with Photocurable Epoxy Resin , Sensors and Actuators B, 2, (1990), pp. 271-276
28. Chang H.-K. et al, UV-LIGA Process for High Aspect Ratio Structures Using Stress Barriers and C-shaped Etch Holes, Transducers'99, Sendai-Japan, (1999)
29. Seidemann V. et al, A novel fabrication process for the 3D meander shaped micro coils in SU8 dielectric and their application to linear micromotors, Proc SPIE Conf. in Microelectronics and MEMS Technolgies, SPIE 4407, pp. 304-309, (2001)
30. Zhang J. et al, Polymerization optimization of SU-8 photoresist and its applications in Microfluidic systems and MEMS, J. Micromech Microeng. 11, pp 20-26, (2001)
31. Lin C.-H. et al, A new fabrication process for ultrathick microfluidic microstructures utilizing SU-8 photoresist, J. Micromech. Microeng. 12, pp 590-597, (2002)
32. Seidemann V. et al, SU8-micromechical structures with in situ fabricated movable parts, Microsystem Technologies 8, pp 348-350 (2002)
33. Conradie E.H. et al, SU8 thick photoresist processing as a functional material for MEMS applications, J. Micromech. Microeng. 12, pp 368-374, (2002)
34. Ho et C.-H. al, Ultrathick SU-8 mold fabrication and removal, and its application of LIGA-like micromotors with embedded roots, Sensors and Actuators A, 102, pp 130-138, (2002)
35. Hong G. et al, SU8 resist plasma etching and its optimisation, DTIP 2003, Mandelieu-La Napoule, France, 5-7 May 2003
36. Bogdanov A.L. et al, Use of SU-8 photoresist for very high aspect ratio x-ray lithography, Proceedings of Micro- and Nano-engineering '99, Rome (1999)
37. Bogdanov A.L. , Use of SU-8 negative photoresist for optical mask Manufacturing,
38. Curtis P.D. et al, SU-8 as a material for integrated all-optical microwave filters, Microwave Engineering (2001)
39. Choi Y. et al, Continously-varying, three-dimensional SU-8 structures: Fabrication of inclined magnetic actuators, MEMS2002 (2002)
40. Tseng F.G. et al, A novel fabrication method of embedded microchannels employing simple UV dosage control and antireflection coatings, MEMS2002 (2002)
41. Dentinger P.M. , Removal of SU-8 photoresist for thick-film applications I: Wet techniques, Micro and Nano Engineering Conference, Grenoble, (2001)
42. Dentinger P.M. , Removal of SU-8 photoresist for thick-film applications II: Dry techniques, Micro and Nano Engineering Conference, Grenoble, (2001)
43. Watt F. , Focused high energy proton beam micromachining: a perspective view, Nuclear Instruments and Methods in Physics Research B 158 (1999)
44. Jackmann R. et al, Microfluidic systems with on-line UV detection fabricated in photodefinable epoxy, J. Micromech. Microeng, 11 (2001)
45. Calleja M. et al, Polymeric cantilever arrays for biosensing applications, Sensor Letters, 1, 1-5, (2003)
46. Seidemann V. et al, Application and investigation of in-plane compliant SU8 structures for MEMS, Transducers'01 EuroSensor XV, (2001)
47. Kukharenka E. et al, Electroplating moulds using dry film thick negative photoresist, J. Micromech Microeng, 13, (2003)
48. Feng R. et al, Influence of processing conditions on the thermal and mechnical properties of SU8 negative photoresist coatings, J. Micromech Microeng, 13, (2003)
49. Evans M. et al, An encoded particle array tool for multiplex bioarrays, ASSAY and Drug Development Technolgogies, 1, (2003)
50. Stumbo D., Ion exposure characterzation of a chemically amplified epoxy resist, J. Vac. Scien. Technol. B11 (1993)
51. Lorenz H. et al, SU8: a low-cost negative resist for MEMS, J. Micromech. Microeng. 7 (1997)
52. Bertsch A. et al, Combining microstereolithographpy and thick resist UV lithography for 3D microfabrication, MEMS'98 (1998)
53. Lorenz H. et al, High aspect ratio ultrathick negative-tone near-UV photoresist and its application to MEMS, Sensor and Actuators (1998)
54. Lorenz H. et al, Fabrication of photplastic high-aspect ratio microparts and micromolds using SU8 UV resist, Microsyst. Technol. 4 (1998)
55. Dellmann L. et al, Two step micromolding and photopolyme high-aspect ratio structuring for applications in piezoelectric motor components, Microsyst. Technol. 4 (1998)
56. Malek C. Mask prototyping for ultra-deep X-ray lithography: preliminary studies for mask blanks and high-aspect ratio absorber patterns, roc SPIE vol. 3512 (1998)
57. Cheng Y. et al, Wall profile of thick photoresist generated via contact printing, IEEE Jour. MEMS 8 (1999)
58. Flack W.W. et al, Process characterization of 100 micron thick photoresist films, Proc SPIE 3678 (1999)
59. Campbell M. et al, Fabrication of photonic crystals for the visible spectrum by holographic lithography, Nature 404 (2000)
60. Ling Z.-E. et al, Improved patterning quality of SU8 microstructures by optimizing the exposure parameters, Proc SPIE 3999 (2000)
61. Vestergaard R.K. et al, Electroplated compliant metal microactuators with small feature sizes using a removable SU8 mold, Microsyst. Technol. 6 (2000)
62. van Kan J.A. et al, Proton micromachining: a new technique fro the productin of three-dimensional microstructures, Microsyst. Technol. 6 (2000)
63. L'Hostis E. et al, Microreactor and electrochemical detectors fabricated using Si and EPON SU-8, Sensors and Actuators B: Chemical 64 (2000)
64. Osipowicz T. et al, The use of proton microbeams for the production of microcomponents, Nuclear Instruments & Methods in Physcs Research B 83 (2000)
65. Bogdanov et al, Use of SU8 photoresist for very high aspect ratio x-ray lithography, Microelectr. Eng. 53 (2000)
66. Watt F. et al, Three-dimensional microfabrication using maskless irradiation with MeV ion beams: proton-beam micromachining, MRS Bulletin 25 (2000)
67. Ghantassala M. K., Patterning electroplating and removal of SU-8 moulds by excimer micromachining, J. of Micromech. and Microeng. 11 (2001)
68. Lucyszn S., Comment: Terahertz time-domain spectroscopy of films fabricated from SU8, Electro. Lett. 35 (2001)
69. Akiyama T. et al, Lithographically defined polymers tips for quartz tuning fork based scanning force microscopes, Microelect. Eng. 57-58 (2001)
70. Zhang J. et al, Characterization of the polymerization of SU8 photoresist and its applications in micro-electro-mechanical systems (MEMS), Polymer Testing 20 (2001)
71. Tay F.E.H. et al, A novel micromachining method for the fabrication of thick-film SU8 embedded micro-channels, J. Micromech. and Microeng. 11 (2001)
72. Tseng F.G. et al, Reduction of diffraction effects of UV exposure on SU-8 negative thick PR by air gap elimination, HARMST (2001)
73. Oh S.H. et al, Micro-heat flux sensor using copper elecroplating in SU8 microstructures, J. Micromech. and Microeng. 11 (2001)
74. Cremer C. et al, SU-8 as resist material for deep X-ray lithography, Microsyst. Technol. 7 (2001)
75. Liu W.Y. et al, Micro-heat-pipe for InP/InGaAs microwave integrated circuits, IEEE EDMO 2002 (2002)
76. Lin C.-H. et al, A new fabrication process for ultra-thin microfluidic microstructures utilizing SU8 photoresist, J. Micromech. and Microeng. 12 (2002)
77. Chuang Y.-J. et al, Reduction of diffraction effect of UV exposure on SU8 negative thick photoresist by air gap elimination, Microsystem. Techn. 8 (2002)
78. Dentinger P.M. et al, High aspect ratio patterning with a proximity ultraviolet source, Microelect. Eng. 61-62 (2002)
79. Dentinger P.M. et al, Removal of SU-8 photoresist for thick film applications, Microelect. Eng. 61-62 (2002)
80. Ouchi T. et al, Direct coupling of VCSELs to plastic optical fibers using guide holes patterned in a thick photoresist, IEEE Photonics Tech. Lett. 14 (2002)
81. Kim G.M. et al, Surface modification with self assembled monolayers for nanoscale replication photoplastic MEMS, J. Microelectromechanical Systems 11 (2002)
82. Malek C., SU8 resist for low cost X-ray patterning of high-resolution, high-aspect-ratio MEMS, Microelectronic Journal 33 (2002)
83. Luo C. et al, A new method to release SU8 structures using polystyrene for MEMS applications, Proc. Eurosensors (2002)
84. Bettiol A.A. et al, Proton beam micromachining electron emission from SU8 resist during ion beam irradiation, Nuclear Instruments and Methods in Physics Research B 190 (2002)
85. van Kan J.A. et al, Nickel and copper electroplating of proton beam micromachined SU8 resist, Microsystem. Technol. 8 (2002)
86. Lin C.-L. et al, A high sensitive fabry-perot shear stress sensor employing flexible membranes and double SU8 structures, Proc Sensors 2002 (2002)
87. Chuang Y.-J. et al, A novel fabrication method of embedded micro-channels by using SU8 thick-film photoresists, Sensors and Actuators A: Physical (2003)
88. Lee G.-B. et al, Micro flow cytometers with bureid SU8/SOG optical waveguides, Sensors and Actuators A: Physical (2002)
89. Ansel Y. et al, Optical waveguide device realised using two SU8 layers, Proc Optical MEMS 2002 (2002)
90. Pan C.-T. et al, A low temperature wafer bonding technique using patternable materials, J. Micromech. and Microeng. 12 (2002)
91.Siedemann V. et al, Fabrication and investigation of in-plane compliant SU8 structures for MEMS and their application to micro valves and grippers, Sensors and Actuators A: Physical (2002)
92. Kudryashov V. et al, Grey scale structures formation in SU8 with e-beam and UV, Microelect. Eng. (2003)
93. Gadre A. et al, An integrated BioMEMS Fabrication Technology, ISDRC (2001)
94. Shaw M. et al, Improving the process capabilty of SU-8, reference unknown (for the moment)
95. Johnson D. W et al, Improving the process capability of SU-8, Part II, reference unknown (for the moment)
96. Houlet L. et al, Magnetic actuator for optical switch, MEMS 2001 (?)
97. Wang K. et al, Micro-optical components for a MEMS integrated display, reference unknown (for the moment)
98. Lo Y.C., Development of a systematic set for the processing SU8-5 photoresist, Proceedings SPIE 4592 (2001)
99. Report: ATIP03.023: Power generating MEMS devices in Asia, (2003)
100. Denoual M. et al, Neural bio-electrical interfacing, MEMS 2001 (?)
101. Francis L.A., A SU8 liquid cell for surface acousitc waves biosensors, Proceedings of SPIE 5455 (2004)
102. Ford S.M., Rapid fabrication of embossing tools for the production of polymeric microfluidic devices for bioanalytical applications, Proc. SPIE 4560 (2001)
103. Martinoia S. et al, Development of ISFET array-based microsystems for bioelectronchemical measurements of cell populations, Biosensors&Bioelectronics 16 (2001)
104. Yoon Y.-K. et al, RF MEMS based on epoxy-core conductors, reference unknown (for the moment)
105. Chung C.K. et al, Novel monolithic micro droplet generator, Proc. 2004 NSTI Nanotechnology Conference (2004)
106. Todd B et al, Thick photoresist imaging using a three wavelength exposure stepper, SPIE MEMS 1999 #3874-40
107. Flack W.W. et al, Process characterization of an ultra-thick strippable photoresist using a broadband stepper, SPIE 2000 #3999-47
108. Chaing Y.M. et al, SU-8 processing on a variety of substrates, Materials Sciences of Microelectromechanical Systems (MEMS) Devices II, Ed deBoer M.P. et al, Materials Research Society Symposium Proceedings, vol 605 (1999)
109. McAleavey A. et al, Mechanical Properties of SU-8, Materials Science of Microelectromechanical Systems-Devices, Vol. 546, (1999)
110. Reyes D.R. et al, Micro Total Analysis Systems. 1. Introduction, Theory and Technologies, Anal. Chem. 74 (2002)
111. Schafer H. et al, A new technology for an application specific Lab-on-Microchip, Nano-Micro-interface Conference 2003 (2003)
112. Singelton L. et al, Consideration for the deep X-ray lithography with the SU-8 resist, Journal of Polymer Science and Technology, Vol 14 Number 4 (2001)
113. Kim C.J., Fabrication of microchannels in MEMS, WTC MEMS Workshop Tutorial (2000)
114. Calleja M. et al, Polymeric mechanical sensors with integrated readout in a microfluidic systems, SPIE 5116 (2003)
115. Miklyaev Y.V. et al, Three-dimensional face-centered-cubic photonic crystal templates by laser holographiy: fabrication, optical characterization, and band-structure calculations, Applied Physics Letters Vol 82 No.8 (2003)
116. Conklin et al, Alternative fabrication methods for capillary electrophoretic device manufacturing, reference unknown (for the moment)
117. Mooriani S. et al, Lithographically patterned channels spatially segregate kinesin motor activity and effectively guide microtubule movements, Nanoletters 3 (2003)
118. Jia L. et al, Microscale transport and sorting by kinesin molecular motors, Biomed. Micro. 6 (2003)
119. Hwang D.-H. et al, Development of a systematic recipe set for processing SU8-5 photoresist, SPIE 4592 (2001) (papers seems to be identical with ref 98!; I have to check in more details...)
120. Houlet L. et al, Copper microcoil array for the actuation of optical matrix microswitches, SPIE 4592 (2001)
121. Keatch R.P. et al, Applications of photosensitive resins to microengineering target components, references unknown (for the moment)
122. O'Sullivan E.J. et al, Integrated variable-reluctance magnetic minimotor, IBM J. Res. Develop. 42 5 (1998)
123. Jiang K. et al., SU-8 Ka-Band Filter and Microfabrication, Journal of Micromechanics and Microengineering, Vol, 15, pp. 1522-1526, (2005)
124. Jin P. et al, Ultra-thick SU-8 fabrication for Reciprocating Engines, Journal of Microlithography, Microfabrication and Microsystems, Vol 3, No. 4, 2004
to be continued...
MCC has many distributors and representatives all over the world.
See the Microchem Corp page for more informations.
micro resist technology
(Very competent people, they sell also other photoresists (just as Microchem Corp) that are great. Have a look at their wonderful pictures...)
THERE IS NO OTHER PROVIDER OF SU8!
(at least in my eyes)
EPFL - groupe of Prof. Ph. Renaud: That's where it really started, first MEMS applications with SU8 ...
IBM: The inventors... and their swiss research labs...,
University of Neuchatel: Another great place with innovative SU8 structures...
Sporian Microsystems: A good place to go if you have questions about SU8
Center of Ion Beam Applications (Singapore): Interesting page on many aspects of SU8
University of Hertfordshire: Microfluidic devices in SU8
3D Molecular Sciences: Nice biotechnological application of SU8, see their paper (ref 49)
Sandia National Lab: Many LIGA material, but also information about SU8
Lund University: Wonderful SU8 pictures
Lionix: MEMS manufacturer from the Netherlands with SU8 capabilities
Purdue University- the Center for Nanoscale Devices: Microfluidics with SU8 and glass
Forschungszentrum Karlsruhe GmbH: Microsystem center working with SU8 (and other technologies)
Pennsylvania State University, Center of Nanoscale Science, Nanotechnologies, Biotechnologies and SU8 microfluidics (Prof William Hancock)
University of Dundee (Dr Robert P. Keatch): Biotechnologies with SU8
University of Washington - Prof. Marty Afromowitz: grayscale lithography with SU8, really great application :-)
Royal Melbourne Institute of Technology
University of Birmingham : Very nice and impressive SU-8 devices (height: over 1 mm. aspect ratio 40:1 (!!) with UV lithography.
(more links will come...)
