Specific Process Knowledge/Wafer cleaning/IMEC: Difference between revisions

← Older edit

VisualWikitext

@@ Line 1: / Line 1: @@
-===IMEC process for cleaning of wafers before fusion bonding:===
+{{cc-nanolab}}
+'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Wafer_cleaning/IMEC click here]'''
+'''Please note: This elaborate cleaning method is only used very rarely. It has turned out that at DTU Nanolab an '[http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Wafer_cleaning/RCA RCA clean]' prior to bonding (and do the cleaning and bonding very early in the morning with few people and thus lower particle level in the cleanroom) gives the best results. If you for some reason still prefer to do the IMEC clean described below, please contact DTU Nanolab to make arrangements. We do not have dedicated IMEC equipment which is immediately ready for use.
+<br>
+<br>
+===The IMEC process: Cleaning of wafers prior to fusion bonding===
+The IMEC cleaning process is used in circumstances where extraordinary clean wafers are required. It is primarily intended for cleaning wafers prior to fusion bonding. This procedure is based on the IMEC cleaning process with slight modifications by Karen Birkelund.: ''M. Meuris et al. "The IMEC clean: A new concept for particle and metal removal on Si surfaces.", Solid state Technology, Vol. 38, Issue 7, pp 109-113, 1995.''
+'''Information about equipment relevant to this procedure can be found in LabManager:'''<br>
+<!-- remember to remove the type of documents that are not present -->
+Info page for '[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=368 Fume hood 01: Acids/bases]'<br>
+Info page for '[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=369 Fume hood 02: Acids/bases]'<br>
+Info page for '[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=411 Wet bench 03: Wafer and mask cleaning]'<br>
+Info page for '[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=413 Wet bench 05: Al etch]'<br>
+Info page for '[http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=383 Wafer Cleaning]'<br>
-Based on the IMEC clean process: ''M. Meuris et al. "The IMEC clean: A new concept for particle and metal removal on Si surfaces.", Solid state Technology, Vol. 38, Issue 7, pp 109-113, 1995.'' <br \>
-Has been modified by Karen Birkelund @DTU Nanotek.
 {| border="1" cellspacing="0" cellpadding="5" align="center"
@@ Line 13: / Line 29: @@
 | 1
 | Pre-bond cleaning of Si wafers prior to fusion bonding.
+|.
 |
-|
+*Takes approximately 1,5 hours
-*Takes 1½ hours
 *Orient flat to minimize handling
-*Preferable done just before bonding!
+*Preferably do the cleaning just before bonding to maintain cleanliness!
 |Get CLEAN box for wafers!!!
 |-
 |2
 |Piranha
-|Mixture: H<math>_2</math>SO<math>_4</math>:H<math>_2</math>O<math>_2</math> (4:1)
+|Mixture: H<sub>2</sub>SO<sub>4</sub>:H<sub>2</sub>O<sub>2</sub> (4:1)<br>
-Temp: 80 <sup>o</sup>C
+Temp: 80<sup>o</sup>C<br>
 Time: 5 min
-(a yellow and a black spot)
+|You can use the 'Mask Clean' bath in Wet Bench 04 (in cleanroom D-3). <b>However, this requires planning at least a couple of days in advance, since the bath is primarily used for other purposes!</b> Alternatively use a very clean glass beaker. The recommended procedure is:
-|Clean tank (cleanroom 4, 7-up bath for wafers) and make your own or make in dedicated glass.
+*Pour H<sub>2</sub>SO<sub>4</sub> into bath/beaker
-Pour up H<math>_2</math>SO<math>_4</math> first, put wafers in carrier (USE this in steps4.1-4.6), add H2O2, wait 30 sec, dip wafers.
+*Place wafers in clean carrier (USE this in steps 2-7)
+*Add H<sub>2</sub>O<sub>2</sub> to the beaker that already contains H<sub>2</sub>SO<sub>4</sub>
+*Wait 30 sec to ensure mixing of chemicals, then dip wafers.
 |Maybe clean the tank the day before!
 |-
@@ Line 33: / Line 51: @@
 |Rinse
 |2 min. rinse
-|
+|Rinse you wafers with DI-water.
 |Put into dedicated wet box for IMEC
 |-
 |4
 |IMEC
-|DI water:5% HF:isopropanol (100:10:1)
+|Mixture: DI water:5% HF:Isopropanol (100:10:1)<br>
-Temp: 25 <sup>o</sup>C
+Temp: 25<sup>o</sup>C<br>
 Time: 100 sec
-(two black spots)
+|<b>Make an appointment some days in advance with a Nanolab employee to help you with this step!</b>
-|Clean tank (cleanroom 4, tank for buffer with wetting solution) and make your own. Mix in dedicated bottle (IMEC) in fume hood and add to tank using BHF pump from RCA fumehood!
+*Clean tank (Cleanroom D-3, the 'Optional Bath' inside Wet Bench 05: Al etch)
+*Mix your IMEC solution in dedicated bottle (IMEC) inside a fume hood
+*Ask a Nanolab employee to help you filling the solution into the 'Optional Bath' tank!
 |
 .
@@ Line 56: / Line 76: @@
 |Piranha
 |Not nitride wafers!
-Mixture: H<math>_2</math>SO<math>_4</math>:H<math>_2</math>O<math>_2</math> (4:1)
+Mixture: H<sub>2</sub>SO<sub>4</sub>:H<sub>2</sub>O<sub>2</sub> (4:1)
-Temp: 80 <sup>o</sup>C
+Temp: 80<sup>o</sup>C<br>
-Time: 20 min
+Time: 20 min<br>
-|Re-use previous piranha
+|Re-use piranha previously made in step 2
 Makes wafers hydrophilic