Photoresist
Photoresist is a photoactive polymer suspended in a solvent used in Lithography processing. We have positive novolak based resists for use with our mask aligners and stepper, negative epoxy based resists ..... and e-beam resists for use with the JOEL.
LNF Supported Photoresists
Name | LNF stock | Positive/Negative | Reversible | Min Thickness (um) | Max Thickness (um) | Exposure type | RIE | Wet Etching | Plating | Lift-off | Comments |
---|---|---|---|---|---|---|---|---|---|---|---|
[SPR 955 (0.9)] | Y | Pos | Y | 0.97 | 0.97 | UV | Good | OK | Good | OK | Considered a high resolution resist. The material underneath the resist has a significant impact on the required dose |
[SPR 220 (3.0)] | Y | Pos | Y | 2 | 5 | UV | Good | OK | Good | OK | Not recommended for long wet etches (specially after exposure to plasma) |
SPR 220 7.0 | N | Pos | Y | 6 | 12 | UV | Good | OK | Bad | OK | |
AZ 12XT | N | Pos | N | 10 | 25 | UV | Good | Good | OK | OK | This is a chemically enhanced PR. |
AZ 5214E | N | Pos | Y | 1 | 2 | UV | OK | OK | Bad | Good | Image Reversal Resist for High Resolution and intended for lift-off |
Shipley 1813 | Y | Pos | Y | 1 | 1.3 | UV | OK | Good | Bad | Good | It must be hard baked for wet etches. It is thin and not good for long wet etches. |
PMGI SF 6 | N | N/A | N/A | 0.28 | 0.68 | N/A | Bad | Bad | Bad | Good | This is an LOR resist. The thickness should be at least 1.5x the thickness or metal. Other LOR versions are available for different thicknesses. |
LOR 10B | N | N/A | N/A | 0.9 | 1.8 | N/A | Bad | Bad | Bad | Good | LOR thickness should be at least 1.5x the thickness or metal. Other LOR versions are available for different thicknesses. |
KMPR 1010 | N | Neg | N | 10 | 20 | UV | Good | Good | OK | Bad | Resist can swell during metal coating. |
[KMPR 1025] | N | Neg | N | 20 | 70 | UV | Good | Good | OK | Bad | Resist can swell during metal coating. |
SU-8 2005 | N | Neg | N | 4 | 7 | UV | Good | Good | OK | Bad | This resist is considered a thick chemically and thermally stable epoxy. Coating only allow in Wet Chemistry. Extremely hard to remove. |
SU-8 2010 | N | Neg | N | 10 | 20 | UV | Good | Good | OK | Bad | This resist is considered a thick chemically and thermally stable epoxy. Coating only allow in Wet Chemistry. Extremely hard to remove. |
SU-8 2050 | N | Neg | N | 40 | 170 | UV | Good | Good | OK | Bad | This resist is considered a thick chemically and thermally stable epoxy. Coating only allow in Wet Chemistry. Extremely hard to remove. |
PMMA 950 A2 | Y | Pos | N | 0.05 | 0.10 | E-beam | OK | OK | Good | Good | It is use for direct writing on the e-beam |
[PMMA 950 A4] | Y | Pos | N | 0.20 | 0.40 | E-beam | OK | OK | Good | Good | It is use for direct writing on the e-beam |
[PMMA 950 A9] | Y | Pos | N | 1.5 | 2.8 | E-beam | OK | OK | Good | Good | It is use for direct writing on the e-beam |
[PMMA 495 A2] | Y | Pos | N | 0.05 | 0.10 | E-beam | Bad | OK | Good | Good | It is use for direct writing on the e-beam |
[PMMA 495 A4] | Y | Pos | N | 0.18 | 0.30 | E-beam | Bad | OK | Good | Good | It is use for direct writing on the e-beam |
ZEP 520A | N | Pos | N | E-beam | Good | Bad | It is use for direct writing on the e-beam |
LNF stock: This parameter indicates if the resist is supplied by LNF.
Positive/Negative: Positive resist develop the exposed areas, negative resists develope unexposed areas.
Reversible: Some photoresist allowed to have the polarity reverse.
Applications
Etch
- RIE - Photoresist used in RIE needs to be thermally stable and resistant to the etch chemistry.
- Wet Etch - A photoresists adhesion is very important as any adhesion failure greatly increases undercut.
Deposition
- Liftoff - Need a photoresist profile that prevents sidewall deposition. Often this is done by using a bi-layer stack and undercutting the bottom layer.
- Plating
- Molding
Below you can find a list of public and private approved photoresists for the LNF. If you would like to bring a new photoresist into the robin lab or clean room, then please create a help desk ticket or email info@lnf.umich.edu. All photoresists must be handled using the green polychloroprene gloves.