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: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]] | [[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. Process development tests 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. | ||
Please note that the ashing rate for a full boat is approximately ten times slower, than when processing a single substrate. | Please note that the ashing rate for a full boat is approximately ten times slower, than when processing a single substrate. | ||