Specific Process Knowledge/Wafer cleaning/7-up & Piranha: Difference between revisions
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==Cleaning of wafers or masks== | ==Cleaning of wafers or masks== | ||
Cleaning of wafers or masks with sulphuric acid can be done either in a dedicated tank "7-up" or in the fumehood in a beaker "Piranha" | Cleaning of wafers or masks with sulphuric acid can be done either in a dedicated tank "7-up" or in the fumehood in a beaker "Piranha" | ||
Both 7-up and Piranha removes heavy organics | Both 7-up and Piranha removes heavy organics. | ||
Always use one of these after KOH to remove alkali ions before further processing. 7-up and Piranha are also used as cleaning solutions after stripping resist. | |||
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|~70 <sup>o</sup>C the chemicals will heat up to working temperature during mixing, '''therefore be carefull!''' | |~70 <sup>o</sup>C the chemicals will heat up to working temperature during mixing, '''therefore be carefull!''' | ||
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|'''Process time''' | |||
|''' | |||
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10 min. | |||
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10 min. | |||
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|'''Batch size''' | |'''Batch size''' | ||
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19 | 1-19/25 4" wafers or 5 masks at a time | ||
| | | | ||
1-5 4" wafer at a time | 1-5 4" wafer at a time | ||
Revision as of 10:12, 21 February 2008
Cleaning of wafers or masks
Cleaning of wafers or masks with sulphuric acid can be done either in a dedicated tank "7-up" or in the fumehood in a beaker "Piranha" Both 7-up and Piranha removes heavy organics. Always use one of these after KOH to remove alkali ions before further processing. 7-up and Piranha are also used as cleaning solutions after stripping resist.
| 7-up | Piranha | |
|---|---|---|
| General description |
Cleaning of wafers or masks using the dedicated tanks. There are one tank for masks and glasswafers and one for 4-6" Si wafers in cleanroom 4 and one tank in cleanroom 3 for 4" Si wafers only. |
Cleaning of wafers using a beaker in the fumehood in cleanroom 2.Used for glass wafers or wafers with metal or other materials that you are not allowed to put in the 7-up for wafers. |
| Chemical solution | 98% Sulfuricacid and Ammoniumsulfat | 98% Sulfuricacid and Hydrogenperoxide 4:1 |
| Process temperature | 80 oC | ~70 oC the chemicals will heat up to working temperature during mixing, therefore be carefull! |
| Process time |
10 min. |
10 min. |
| Batch size |
1-19/25 4" wafers or 5 masks at a time |
1-5 4" wafer at a time |
| Size of substrate |
4-6" wafers |
2-4" wafers |