XR-1541.006 (FOx-12) Recipe
Application
tone | negative |
special | Superior edge roughness |
reference | J. Vac. Sci. Technol. B. 16 (1998) 69 - 76 |
spincoat | 202 - 128 nm @ 1000 - 6000 rpm thinner layers can be obtained at Karl Suss spinner WITH lid closed: |
prebake | 2 minutes on hotplate @ 150 °C 2 minutes on hotplate @ 220 °C
or
30 minutes in vacuum at room termperature |
exposure | about 500 µC/cm2 @ 100 kV |
development | 1 min. in MF322 15 s in MF322 : demi-water = 1 : 9 15 s in demi-water |
Results: Spincurves
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/fox1a.gif)
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/fox1b.gif)
Work done in FOx-12
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqa.gif)
15 nm single pass line in 44nm thick FOx-12, exposed with spot 21nm_740pa_400um_100kv and dose 5460 µC/cm2 @ 100kV
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqb.gif)
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqc.gif)
20nm dense lines and spaces (single pass lines) in 50nm thick FOx-12, exposed with spot 21nm_740pa_400um_100kv and dose 6970 µC/cm2 @ 100kV
Etchrates of FOx-12 resist in different plasmas in comparison with HPR504
GAS 1: SF6/He plasma on Leybold Z401:
SF6 | 12.5 sccm |
He | 10 sscm |
Pressure | 10 µbar |
P | 40 W |
Biaspotential | -60 V |
GAS 2: CHF3/O2 plasma on Leybold Z401S
CHF3 | 50 sccm |
O2 | 2.5 sccm |
Pressure | 7 µbar |
P | 50 W |
Biaspotential | -350 V |
GAS 3: O2 plasma on Leybold Z401S
O2 | 20 sccm |
Pressure | 3 µbar |
P | 20 W |
Biaspotential | -200 V |
Etch rates (nm/min):
Gas 1 | Gas 2 | Gas 3 | |
HPR504 | 51 | 16 | 29 |
FOx-12 | 29 | 36 | 0.6 |
FOx-12/HPR bilayer resist combination
HSQ can also be used in a bilayer combination with hard baked HPR for high aspect ratio nanoscale e-beam lithography.
For this reason a few steps should be added to the processing flowchart:
- After spincoating and baking HMDS and before following the FOx-12 flowchart HPR504 should be spincoated (5000rpm 937nm) and baked on a hotplate at successive 100, 200 and 250 0C, each temperature for 2 minutes.
- After development of the FOx-12 resist the HPR is etched in above mentioned O2 plasma (gas 3).
A few examples of work done in a bilayer resist of FOx-12 and HPR
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqd.gif)
80nm multi pass lines (10 passes) written in 44nm thick FOx-12 on top of 937nm thick HPR, exposed with spot 21nm_740pa_400um_100kv and dose 290 µC/cm2 @ 100kV
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqe.gif)
80nm multi pass lines (10 passes) written in 44nm thick FOx-12 on top of 635nm thick HPR, exposed with spot 21nm_740pa_400um_100kv and dose 990 µC/cm2 @ 100kV
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqf.gif)
26nm semi-dense lines written in 30nm thick FOx-12 on top of 155nm thick HPR, exposed with spot 21nm_740pa_400um_100kv and dose 815 µC/cm2 @ 100kV
![](https://filelist.tudelft.nl/TNW/Afdelingen/Quantum%20Nanoscience/hsqg.gif)
40nm dense lines and spaces (1:1) written in 30nm thick FOx-12 on top of 129nm thick HPR, exposed with spot 21nm_740pa_400um_100kv and dose 1646 µC/cm2 @ 100kV