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

Revision as of 13:41, 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 one for 4-6" wafers in cleanroom 4 and one tank in cleanroom 3 for 4" 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

@@ Line 9: / Line 9: @@
 |'''General description'''
 |
-Cleaning of wafers or masks using the dedicated tanks.
+Cleaning of wafers or masks using the dedicated tanks. There are one tank for masks and one for 4-6" wafers in cleanroom 4 and one tank in cleanroom 3 for 4" wafers only.
 |
-Cleaning of wafers or masks using a beaker in the fumehood.
+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'''
@@ Line 20: / Line 20: @@
 |80 <sup>o</sup>C
-|~70 <sup>o</sup>C
+|~70 <sup>o</sup>C the chemicals will heat up to working temperature during mixing, '''therefore be carefull!'''
 |-
@@ Line 38: / Line 37: @@
 |'''Batch size'''
 |
-  4" wafers or 5 masks at a time
+-25  4" wafers or 5 masks at a time
 |
 -5 4" wafer at a time