Specific Process Knowledge/Etch/DRIE-Pegasus/Pegasus-4/SiO2 Etch
SiO2 Etch using resist as masking material
Unless otherwise stated, all content in this section was done by Berit Herstrøm, DTU Nanolab
I have do some development of a SiO2 etch with resist as masking material. I have found this fairly good recipe. For now it is the standard SiO2 etch recipes but I might change the "Standard recipe" a a later time if I find a better one. If you need to etch deeper than 1 micrometer then I advise you to split the etch in several runs with O2 cleans in between (3min TDESC Clean) or else it seems like the the etch rate is going down over time.
- Recipe name: SiO2_res_10, Recipe no. 10: C06445_02 coil_2500W, platen:300W, He/C4F8= 17.5, C4F8/H2=1, Pressure:8.8mTorr, C4F8:25.6sccm, He:448.7sccm, H2:25.6sccm, 3:56 min
0.4µ/0.2µ
Bad lithography
0.5/0.25µ
Etch depth: 652 nm
Resist left: 456 nm
1µ/0.5µ:
Etch depth: 855 nm
Resist left: 487 nm
2µ/1µ:
Etch depth: 952 nm
Resist left: 487 nm
4µ/2µ:
Etch depth: 1106 nm
Resist left: 487 nm
0.8µ/0.2µ
Etch depth: 867 nm
Resist left: 426 nm
1.0µ/0.25µ:
Etch depth: 893 nm
Resist left: 460 nm
4µ/1µ:
Etch depth: 1033 nm
Resist left: 473 nm
SiO2 Etch using aSi as masking material
Unless otherwise stated, all content in this section was done by Berit Herstrøm, DTU Nanolab
I am now starting up development of SiO2 etch using aSi as masking material.
The samples I use are:
- 6" Si afters with oxide (2µm),
- aSi (~300nm),
- Neg. DUV reist (~60nm barc, ~350 nm resist)
- Reticle: Danchip/Triple-D
- Dose 230 J/m2
First I need to make sure that the resist work for pattering the aSi layer is good. If the resist is not good the final etch will also not be good.
DUV optimization
Dose test with the doses (J/m2): 200, 210, 220, 230, 240, 250, 270, 280 The aim was to get good line for 400nm pitch/200nm lines
- 400nm pitch 200 nm lines
200 J/m2 400nm/268nm
210 J/m2 400nm/239nm
220 J/m2 400nm/208nm
230 J/m2 400nm/209nm
240 J/m2 400nm/215nm
250 J/m2 400nm/207nm
260 J/m2 400nm/188nm
270 J/m2 400nm/155nm
280 J/m2 400nm/0nm
- 1000nm pitch 500 nm lines
210 J/m2 1000nm/581nm
230 J/m2 1000nm/517nm
240 J/m2 1000nm/518nm
250 J/m2 1000nm/510nm
260 J/m2 1000nm/493nm
270 J/m2 1000nm/494nm
