Team:EPF Lausanne/Microfluidics/Making/PartI
From 2014.igem.org
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- | + | <!--<p class="lead">The following processes will explain the making of a mask and a positive/negative resist wafer. A wafer is used as a mold to make the microfluidic layer. | |
+ | A photoresist is a light-sensitive material used in several industrial processes, such as photolithography and photoengraving to form a patterned coating on a surface | ||
+ | -A negative resist is a type of photoresist in which the portion of the photoresist that is exposed to light crosslinks and thus becomes insoluble to the photoresist developer. The unexposed portion of the photoresist is dissolved by the photoresist developer. | ||
+ | - A positive resist is a type of photoresist in which the portion of the photoresist that is exposed to light becomes soluble to the photoresist developer. The portion of the photoresist that is unexposed remains insoluble to the photoresist developer.</p>--> | ||
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Revision as of 16:07, 10 October 2014
Mask process and outline
Step | Process description | Machines | Cross-section after process |
---|---|---|---|
01 | ![]() Cross section of a photolithography mask |
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02 | Laser exposure | ![]() Heidelberg DWL200, Laser lithography system |
![]() The laser beams on the surface of the photoresist. By doing so, it imprints the pattern of the design on the PR. |
03 | Developing of the mask | ![]() DV10 Mask and Thick positive resist developer |
![]() A chemical treatment is used to remove the PR that was exposed by the laser in the previous step, creating the ‘holes’ on the photoresist |
04 | Etching of the chrome | ![]() Coillard Gravure |
![]() The chrome is removed at the sites where the resist layer is missing, using an acid bath. |
05 | Removal of Resist | ![]() Coillard Photolithographie |
![]() Once the chrome is removed at the precise sites (previous step), the rest of the resist is removed from the whole surface. |
06 | Use of mask | ![]() The mask can now be used to expose its pattern on the wafer using UV light |
Control Layer Process outline
Step | Process description | Machines | Cross-section after process |
---|---|---|---|
01 | Substrate: Wafer Clean | ![]() Tepla 300 |
![]() Clean the wafer using plasma treatment |
02 | Photolith: Resist deposition Photo Resist : Su8 GM1070 – 30μm | ![]() Sawatec |
![]() A layer of negative photoresist is added on the wafer by spincoating |
03 | Relaxation time + Softbake | ![]() Sawatec |
![]() Softbake wafer using Sawatec hotplate, to solidify the photo resist |
04 | Photolith:UV exposure | ![]() Mask Aligner |
![]() The UV lights are exposed through the Mask on the surface of the wafer. By doing so, it imprints the pattern of the design on the PR. |
05 | Post exposure bake | ![]() Sawatec |
![]() Bake wafer using Sawatec hotplate |
06 | Relaxation delay | Wait 1 hour – overnight | |
07 | Photolith: Develop | ![]() Wetbench plane solvent |
![]() This removes the unexposed photoresist from the wafer using chemical treatment on a wet bench |
08 | Hard bake | ![]() DataPlate |
![]() Bake 135°C 2 hours, using an oven |
Flow layer process outline
Step | Process description | Machines | Cross-section after process |
---|---|---|---|
01 | Substrate: Si test Priming | ![]() YES III |
![]() Dehydrate and prime with HMDS, using the oven to create hydrophobic surface on the wafer, to prepare the wafer for coating |
02 | Photolith: Resist deposition Photo Resist : AZ9260 – 14μm | ![]() EVG 150 |
![]() A layer of positive photoresist is added on the wafer by spincoating |
03 | Rehydratation time | Wait minimum 1 hour, maximum 3 days | |
04 | Photolith:UV exposure | ![]() Mask Aligner |
![]() The UV lights are exposed through the Mask on the surface of the wafer. By doing so, it imprints the pattern of the design on the PR. |
05 | Develop immediately | Wait maximum 1 hour before develop | |
06 | Photolith: Develop | ![]() EVG 150 |
![]() This removes the exposed photoresist from the wafer using chemical treatment with the EVG 150 |
07 | Rinse with Deionized water | ![]() Coillard Wetbench |
Rinse wafers in Quick Dump Rinse then in Ultra Clean bath, using wetbench |
08 | Bake to round edges | ![]() DataPlate |
![]() Bake in horizontal position, 160°C 2 hours |