Specific Process Knowledge/Etch/Etching of Silicon Oxide/SiO2 etch using ASE/More test with CF4/H2, CHF3 and C4F8/H2 - SiO2 etch

More test with CF4/H2, CHF3 and C4F8/H2 - SiO2 etch

Tests performed by Maria Farinha @DTU Nanolab

Recipes and results - CF₄ / H₂ tests

Recipe	Recipe parameters	Process time	Date	SEM picture	SEM pic w/ no resist	Redeposition - top view	Profile angles	Etch rate in SiO2	Etch rate in resist (AZ5214E inverse)	Selectivity (SiO2:resist)
CF4ICP 22.5/22.5	CF4= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C	11:00 min	11/09/2023					68 nm/min +/- 8.5%	60,2 nm/min +/- 9%	1.13
CF4ICP 35/10	CF4= 35 sccm H2= 10 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C	08:00 min	March 2023					69 nm/min +/- 11.1%	77,1 nm/min +/- 9.4%	0.9
CF4ICP 45/0	CF4= 45 sccm H2= 0 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C	08:00 min	March 2023					71.4 nm/min +/- 10.3%	96,5 nm/min +/- 6.0%	0.74
CF4ICP 45/10	CF4= 45 sccm H2= 10 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C	08:00 min	March 2023					67.8 nm/min +/- 14.9%	88,86 nm/min +/- 4.8%	0.76
CF4lowCP 22.5/22.5	CF4= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C	20:00 min	Sept 2023					23.8 nm/min +/- 11%	20,6 nm/min +/- 19.4%	1.16
CF4lowCP 35/10	CF4= 35 sccm H2= 10 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C	10:00 min	Feb 2023					22.65 nm/min +/- 10.2%	35.9 nm/min +/- 10.1%	0.63
CF4lowCP 45/0	CF4= 45 sccm H2= 0 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C	10:00 min	Feb 2023					24.9 nm/min +/- 10.1%	52,3 nm/min +/- 7.1%	0.47
CF4lowCP 45/10	CF4= 45 sccm H2= 10 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C	10:00 min	Feb 2023					29,4 nm/min +/- 13.7%	100,6 nm/min +/- 16.5%	0.29

Recipes and results - C₄F₈ / H₂ tests

Recipe	Recipe parameters	Process time	Date	SEM picture	SEM pic w/ no resist	Redeposition - top view	Profile angles	Etch rate in SiO2	Etch rate in resist (AZ5214E inverse)	Selectivity (SiO2:resist)	Etch rate in Si
SiO2_ICP	C4F8= 10 sccm H2= 28 sccm Coil= 1000W Platen= 100W Press= 2.5mTorr Temp= 20°C	04:00 min	04/09/2023					211,9 nm/min +/- 14.6%	153,4 nm/min +/- 16.7%	1.4
SiO2_ICP	C4F8= 10 sccm H2= 28 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C	04:00 min	22/09/2023					134,7 nm/min +/- 20.8%	145,7 nm/min +/- 25.1%	0.92