Specific Process Knowledge/Lithography/Strip: Difference between revisions
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==Process gas ratio for plasma asher 4 & 5== | ==Process gas ratio for plasma asher 4 & 5== | ||
[[File: | [[File:PA_gas_mix_v3.png|320px|thumb|Ashing rate as function of gas mix ratio when processing a single 100 mm wafer and when processing a full boat with 25 wafers.|right]] | ||
The ashing rate is related to the gas mix, usually expressed as percentage of nitrogen of the total amount of gas. | The ashing rate is related to the gas mix, usually expressed as percentage of nitrogen of the total amount of gas. | ||
Testing found that a gas mix of 50% nitrogen gives the highest ashing rate for both processing single substrates and when processing a full boat with 25 substrates. | |||
'''Single substrate:'''<br> | |||
Test using a single 100 mm wafer in the center of the process chamber shows that 30-80% nitrogen gives the highest ashing rate. | Test using a single 100 mm wafer in the center of the process chamber shows that 30-80% nitrogen gives the highest ashing rate. | ||
Total gas flow rate: 500 sccm<br> | Total gas flow rate: 500 sccm<br> | ||
Gas mix ratio: tested parameter<br> | Gas mix ratio: tested parameter<br> | ||
Chamber pressure: 1.25 mbar<br> | |||
Chamber pressure: 1. | |||
Power: 1000 W<br> | Power: 1000 W<br> | ||
Processing time: 2 minutes<br> | Processing time: 2 minutes<br> | ||
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'''Full boat:'''<br> | |||
Test using a boat of 25 100 mm wafers in the center of the process chamber shows that | Test using a boat of 25 100 mm wafers in the center of the process chamber shows that 50-70% nitrogen gives the highest ashing rate. | ||
Total gas flow rate: 200 sccm<br> | Total gas flow rate: 200 sccm<br> | ||
Gas mix ratio: tested parameter<br> | Gas mix ratio: tested parameter<br> | ||
Chamber pressure: 1.3 mbar<br> | Chamber pressure: 1.3 mbar<br> | ||
Power: 1000 W<br> | Power: 1000 W<br> | ||