Specific Process Knowledge/Etch/Etching of Silicon Oxide/SiO2 etch using Plasma Asher
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SiO2 can be etched in the Plasma Asher using CF4
Test work done January 2014 by Lis Nielsen and Berit G. Herstrøm @Danchip
SiO2 can be etched in the Plasma Asher using CF4. This gives an isotropic etch. In test2 the SiO2 layer has been etched through and there is a small over etch in the Silicon subtrate. The masking material is 100nm Al. Uniformity measurements have been done on wafers with no mask.
Plasma Asher parameter settings and results for the tests | ||||||
Test1 | Test2 | |||||
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O2 flow | 0 sccm | 0 sccm | ||||
N2 flow | 0 sccm | 0 sccm | ||||
CF4 flow | 200 sccm | 200 sccm | ||||
Power | 1000 W | 1000 W | ||||
Process Time | 10 min | 50 min | ||||
Average Etch rate on wafer (5 points measured) | 22.6 nm/min | 31.8 nm/min | ||||
Non-uniformity over the wafer (5 points measured) | ±10.8 % | ±11.0 % | ||||
Non-uniformity plot | ||||||
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