Optical Lithography Resources
KNI Photoresists
Photoresists provided by KNI:
- S1813,1818: standard positive, withstands acid etching.(Manufacturer Spec Sheet) Shipley 1800 series 0.9-1.9μm range available. 0.5-3.2μm available from manufacturer
- AZ5214: positive and image reversal negative, good for liftoff. (Manufacturer Spec Sheet)
- SU-8: thick polymer structures. (Manufacturer Spec Sheet)
Reminder of lamp intensities:
Suss 1 Exposure Settings
- Channel 1 is 365nm wavelength at 15 mW/cm2.
- Channel 2 is 405nm wavelength at 25 mW/cm2.
Suss 2 Exposure Settings
- Channel 1 is 365nm wavelength at 10 mW/cm2.
- Channel 2 is 405nm wavelength at 15 mW/cm2.
Positive Photoresist Recipes
See recipe notes for additional information on wafer cleaning and prep, edge bead removal, and spin curves.
| Resist | Wafer Prep | Spin | Thickness | Prebake | Exposure | Postbake | Flood | Development | Hardbake | Lamp | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S1813 | Dehydrate on hot plate | 3000rpm | 1.5μmm | 115C 1min | X | - | - | X | - | Suss1 Ch1 15mW/cm^2 | Measured 10/19 (Link KNI recipe doc here) |
| AZ5214 | Dehydrate on hot plate | 3500rpm | 1.4μm | 100C 1min | 25s | - | - | MF319 60s | - | Suss1 Ch1 15mW/cm^2 | Measured 10/19 |
Negative Photoresist Recipes
See recipe notes for additional information on wafer cleaning and prep, edge bead removal, and spin curves.
| Resist | Wafer Prep | Spin | Thickness | Prebake | Exposure | Postbake | Flood | Development | Hardbake | Lamp | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| AZ5214 | Dehydrate on hot plate | 2000rpm | 1.8μm | 100C 1min | 12s | 110C 1min | 40s | MF319 60s | - | Suss1 Ch1 15mW/cm^2 | Measured 10/19 |
| Dehydrate on hot plate | 3500rpm | 1.4μm | 100C 1min | 9s | 110C 1min | 30s | MF319 60s | - | Suss1 Ch1 15mW/cm^2 | Measured 10/19 |
SU-8 Recipes
SU-8 is available in thicknesses ranging from 500nm to 500microns. Remember to use Laurel Spinner 1.
Resist thicknesses currently provided by KNI: 2050, 2005, 2001, 2000.5
| Resist | Wafer Prep | Spin | Thickness | Prebake | Exposure | Postbake | Development | Hardbake | Lamp | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| 2050 | Dehydrate on hot plate | 3000rpm | 50μm | 65C 3min 95C 9min | X | 65C 2min 95C 7min | SU-8 Developer X seconds | Optional | Suss1 Ch1 15mW/cm^2 | Measured 10/19 |
Other Photoresists
Non-KNI Photoresist Recipes
| Resist | Wafer Prep | Spin | Thickness | Prebake | Exposure | Postbake | Flood | Development | Hardbake | Lamp | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| nLoF 2070 | Dehydrate on hot plate | 2500rpm | 7um | 110C 90s | 12s | 110C 90s | - | AZ 729 2min | - | Suss1 Ch1 15mW/cm^2 | Measured 10/19 |
KNI Developers
Developers provided by KNI:
- AZ 726 MIF: 2.38% TMAH-based, pre-diluted (ready-to-use) and slightly further diluted only when the application requires it. Contains surfactants to improve development uniformity, so avoid stirring. MIF identifies the developer as 'Metal Ion Free' as it does not contain potassium as in KOH-based developers, it is based on TMAH, an ammonium salt, which prevents metal contamination of semiconductors. 726 is a recommended developer for almost all AZ resists MicroChemicals Development Application Note
- Microposit MF 319: (Metal-Free) TMAH: 2.45%, Polyalkylene glycol <1%, pH: 13. Paired to Shipley/Microposit 1800 series resists, 1805,1813,1818 MSDS
- Microposit CD-26: TMAH <5.0 % , pH 13, Also 1800 series targeted, no additional surfactants.
- AZ 400K: KOH-based. "The recommended dilutions for the AZ® 400 K or AZ® 351 B for most of the processes are developer concentrate : Water = 1: . For very thick resist films, up to a 1:3 ratio can be applied [with lower contrast], with a very fine (sub-µm) structures, a 1:5 or 1:6 ratio can support a high resolution using thin resist films." Ref: MicroChemicals Development Application Note Users can adjust dilution for accuracy and length of time they will tolerate.
- Critical note on KOH use: "Incompatibilities between MIC and MIF Developers Even small traces of TMAH-based metal ion-free developers such as the AZ® 326 MIF, 726 MIF or 826 MIF) can significantly reduce the development rate of metal ion-containing developers (such as the AZ® 400K or 351B). If both types of developers are used, extremely clean work is to be ensured to prevent mutual contamination even in the ppm range, such as in the dispensing system or developer containers." Ref: MicroChemicals Development Application Note
- Microposit 2401: Legacy developer
Surfactants
Surfactants were developed and added in the 1980s to photoresists to combat their hydrophobic surfaces which cause "hot spots" of fast development. They reduce the surface tension and improve wetting (giving homogeneous development). The common drawback of their inclusion is foaming and an oily nature which makes them incompatible with some agitated processes. Surfactacts also change development speed since they coat photoresist surfaces and inhibit the dissolution reaction. As such exposure-development times must be adjusted and while contrast is improved, resolution may be lost. See here for more in depth discussion: The Lithography Tutor: Photoresist Development