Specific Process Knowledge/Wafer cleaning/7-up & Piranha: Difference between revisions

Revision as of 13:43, 20 February 2008

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":

	7-up	Piranha
General description	Cleaning of wafers or masks using the dedicated tanks. There are one tank for masks and pyrexwafers 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!
Possible masking materials	None	None
Etch rate	Cleaning only	Cleaning only
Batch size	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

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 |'''General description'''
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-Cleaning of wafers or masks using the dedicated tanks. There are one tank for masks and pyrexwafers and one for 4-6" Si wafers in cleanroom 4 and one tank in cleanroom 3 for 4" wafers only.
+Cleaning of wafers or masks using the dedicated tanks. There are one tank for masks and pyrexwafers and one for 4-6" Si wafers in cleanroom 4 and one tank in cleanroom 3 for 4" Si wafers only.
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 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.