Specific Process Knowledge/Etch/ICP Metal Etcher/silicon oxide/By BGHE: Difference between revisions
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Zhibo Li @ Danchip has also tried with similar setting, see his results in this file: [[:File:Zhibo Li SiO2 ICP etch (dose205).docx]] | Zhibo Li @ Danchip has also tried with similar setting, see his results in this file: [[:File:Zhibo Li SiO2 ICP etch (dose205).docx]] | ||
==C4F8 [[image:Under_construction.png| | ==C4F8 [[image:Under_construction.png|50px]]== | ||
I started out with a recipe developed by Peixiong called pxSiO2try9, look at his results [[Specific Process Knowledge/Etch/ICP Metal Etcher/silicon oxide/By Peixiong| here]] | I started out with a recipe developed by Peixiong called pxSiO2try9, look at his results [[Specific Process Knowledge/Etch/ICP Metal Etcher/silicon oxide/By Peixiong| here]] | ||
Revision as of 17:16, 19 December 2016
I tried with two different gas regimes: CF4 and C4F8. I only made a few tests with CF4 since I got a very bad selectivity to the resist mask and I dicided to go for the C4F8 instead. Zhibo Li @ Danchip has also tried with similar setting, see his results in this file: File:Zhibo Li SiO2 ICP etch (dose205).docx
C4F8 ![Under construction.png](/images/thumb/f/f8/Under_construction.png/50px-Under_construction.png.jpeg)
I started out with a recipe developed by Peixiong called pxSiO2try9, look at his results here
Parameter | Mask material | Barc etch | Coil power | Platen power | Pressure | Flow rate C4F8 | Flow rate H2 | Flow rate Ar | T | Process time | Comment | Results | CD change (mask 55% trench) after s007467 is it <50% after barc etch trench opening as a fraction of pitch |
Profile angles | Etch depth in SiO2 | Etch rate | Etch depth in resist | Selectivity (resist:SiO2) | Etch rate in Si |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
s008684 | 880nm KRF | barc etch CF 50s | 1000W | 200W | 2.5mTorr | 13sccm | 30sccm | 0 | 0 | 1:30min | The layer in this case is 300nm Si3N4 |
35% (1µm pitch) |
83-88 |
>300nm/min (Si3N4) |
240nm |
~1:2 (Si3N4) |
? | ||
s007419 | 750nm KRF | none | 800W | 200W | 2.5mTorr | 8sccm | 30sccm | 0 | 0 | 5min | Increased the platen power. The selectivity and profile looks good but the resist profile has been rounded more on the edge and this will effect the profile for a deeper etch. |
46.6% (1µm pitch) |
86-90 |
270nm (1µm pitch) |
54 nm/min (1µm pitch) |
100nm |
1:4 (2.5µm pitch) |
||
s007410 | 750nm KRF | none | 800W | 75W | 2.5mTorr | 8sccm | 30sccm | 0 | 0 | 7min | Reduced the platen power.Effect: ARDE - less CD increase but more possitive ptappered profile. |
42.3% (2µm pitch) |
80-82 |
0 nm (1µm pitch) |
0 nm/min (1µm pitch) |
100nm |
1:0 (1µm pitch) |
||
s006656 | 750nm KRF | none | 1000W | 150W | 2.5mTorr | 15sccm | 0sccm | 30sccm | 0 | 10min | Tried with C4F8/Ar instead of C4F8/H2 => much lower etch rate and bad selectivity to the resist. |
358 nm |
35.8 nm/min (2µm pitch) |
526nm |
1:0:68 |
||||
s007409 | 750nm KRF | none | 800W | 150W | 2.5mTorr | 8sccm | 30sccm | 0 | 0 | 5min | Repeated Pexiongs recipe without barc etch and only 5 min's runs. It probably takes about 1 min to get through the barc. If you count that in then the etch rate and relectivity to resist is almost the same as for the first run. Effect: CD increase |
47.4% (1µm pitch) |
86-89 |
280 nm (1µm pitch) |
56 nm/min (1µm pitch) |
160nm |
1:1.8 (1µm pitch) |
||
s006106 | 750nm KRF | Barc etch O2 75s | 800W | 150W | 2.5mTorr | 8sccm | 30sccm | 0 | 0 | 10min | From Peixiong |
60% |
79 |
1053 nm (center) |
105 nm/min |
280nm |
1:3:75 (2µm pitch) |
CF4
I stopped trying with CF4 because I got bad selectivty to the resist and decided to focus on the recipe with C4F8 instead.
Parameter/Wafer ID | s006687 | s006701 | s007258 | s007350 | s007352 |
---|---|---|---|---|---|
Mask material | 750nm KRF | 750nm KRF | 750nm KRF | 750 nm KRF | 750nm KRF |
Barc etch | none | none | none | none | none |
Coil power | 800W | 800W | 800w | 800w | 800w |
Platen power | 100W | 100W | 100w | 60W | 30w |
Pressure | 4mTorr | 4mTorr | 4mTorr | 4mTorr | 4mTorr |
Flow rate CF4 | 20sccm | 25sccm | 30sccm | 30sccm | 30sccm |
Flow rate H2 | 20sccm | 15sccm | 10sccm | 10sccm | 10sccm |
T | 0 | 0 | 0 | 0 | 0 |
Process time | 10min | 10min | 2min30 | 2min30 | 3min30 |
Comment | Little resist left, Trenching | A little trenching | very little trenching in large lines - anti trenching in small lines | ||
Results | |||||
Etch depth in SiO2 | 374nm | 505nm | 578nm | 336nm | 235nm |
Etch rate | 37.4nm/min | 50.5nm/min | 231nm/min | 134.4nm/min | 88nm/min |
Etch depth in resist | 345nm | 633nm | 700nm | 405nm | 308nm |
Selectivity (resist:SiO2) | 1:1.1 | 1:0.80 | 1:0.83 | 1:0.83 | 1:0.76 |