Specific Process Knowledge/Etch/Etching of Silicon Oxide/SiO2 etch using ASE/tests CHF3+H2
Tests performed with UV resist:
The tests were performed on a 100mm wafer patterned on MLA3, with 2.2um AZ5214E resist.
| Recipe | Recipe parameters | Duration (min) | Date | SEM picture | Redeposition - top view | Profile angles | Etch rate in SiO2 | Etch rate in resist (AZ5214E inverse) |
Selectivity (SiO2:resist) |
|---|---|---|---|---|---|---|---|---|---|
| CHF3_t1 | CHF3= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
12:00 | 04/09/2023 | 
|
|
69.7 nm/min +/- 10.5% |
57.3 nm/min +/- 12.9% |
1.22 | |
| CHF3_t2 | CHF3= 22.5 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C |
25:00 | 04/09/2023 | 
|
|
|
26.7 nm/min +/- 11.9% |
24.2 nm/min +/- 21.1% |
1.1 |
| CHF3 t2 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C |
10:00 | 22/09/2023 | 
|
|
|
9,7 nm/min +/- 34.4% |
1,8 nm/min +/- 46.5% |
5.4 |
| CHF3_t1 | CHF3= 22.5 sccm H2= 10 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 12/09/2023 | 
|
|
|
59,6 nm/min +/- 12.9% |
47,5 nm/min +/- 21.5% |
1.25 |
| CHF3_t1 | CHF3= 22.5 sccm O2= 10 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 11/09/2023 | 
|
|
|
60,6 nm/min +/- 10.1% |
130,8 nm/min +/- 8.8% |
0.46 |
| CHF3 t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 20/09/2023 | 
|
|
|
47,3 nm/min +/- 12% |
26,4 nm/min +/- 17,4% |
1.8 |
| CHF3 t1 | CHF3= 22.5 sccm H2= 35 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 22/09/2023 | 
|
|
|
36,5 nm/min +/- 10.6% |
17,5 nm/min +/- 13.9% |
2.09 |
| CHF3 t1 | CHF3= 35 sccm H2= 35 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 22/09/2023 | 
|
|
|
42 nm/min +/- 15.4% |
23,8 nm/min +/- 22.2% |
1.76 |
| CHF3 t1 | CHF3= 22.5 sccm CF4= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
10:00 | 22/09/2023 | 
|
|
|
75,8 nm/min +/- 13.1% |
74,9 nm/min +/- 10.8% |
1.01 |
| CHF3 t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 15W Press= 25mTorr Temp= 20°C |
10:00 | 22/09/2023 | 
|
|
|
- | - | no etch done, polymer deposited |
| CHF3 t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 0°C |
10:00 | 22/09/2023 | 
|
|
|
48 nm/min +/- 11.2% |
23,3 nm/min +/- 13.7% |
2.06 |
Tests performed with DUV resist:
The resist used was a negative DUV resist (UVN) with 915nm + 88nm BARC layer.
| Recipe | Recipe parameters | Duration (min) | Date | SEM picture | Etch rate in SiO2 | Etch rate in resist (UVN) |
Selectivity (SiO2:resist) |
|---|---|---|---|---|---|---|---|
| CHF3_t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 30W Press= 2.5mTorr Temp= 20°C |
10:00 | 13/11/23 |  
|
47 | 24.6 | 1.9 |
| CHF3_t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 45W Press= 2.5mTorr Temp= 20°C |
10:00 | 13/11/23 |  
|
59 | 30 | 1.9 |
| CHF3_t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 45W Press= 2.5mTorr Temp= 0°C |
10:00 | 07/12/23 | 
|
96 | 56 | 1.7 |
| CHF3_t2 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C |
10:00 | 23/10/23 | 
|
27 | 12,5 | 2.1 |
| CHF3_t2 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 25W Press= 2.5mTorr Temp= 20°C |
20:00 | 23/10/23 | 
|
8.15 | 7.5 | 1.1 |
TEST OF TABLES DESIGN (WORK ON GOING):
SiN tests
| Recipe | Recipe parameters | Time (min) | Date | SEM picture | Redeposition - top view | Etch rate SiN | Etch rate resist | Selectivity (SiN:resist) |
|---|---|---|---|---|---|---|---|---|
| CHF3_t1 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 800W Platen= 15W Press= 2.5mTorr Temp= 20°C |
2:30 | 29/02/2024 |    
|
 
|
nm/min +/- % |
nm/min +/- % |
|
| CHF3_t2 | CHF3= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 45W Press= 2.5mTorr Temp= 20°C |
5:00 | 12/09/2023 |    
|
 
|
nm/min +/- % |
nm/min +/- % |
|
| CF4lowCP | CF4= 22.5 sccm H2= 22.5 sccm Coil= 150W Platen= 45W Press= 2.5mTorr Temp= 20°C |
5:00 | 29/02/2024 | nm/min +/- % |
nm/min +/- % |