1. WP 15.2 Progress and critical aspects
Cristian Pira
WP 15.2 Progress and critical aspects
CERN (Alban Sublet)
INFN (Cristian Pira)
ARIES WP15 Meeting 20nd October 2017

2. 5 Different cleaning batches
SuBu5
SuBu5
Tumbling EP
EP+SUBU

3. Samples Size and marking
53 x 53 mm
1 mm thick
3 mm hole at one corner (≈ 2,5 mm from edge)
Marked on the back side
CERN Samples: C XX (XX = 01-25)
LNL Samples: L XX (XX = 01-25)
Ø 3 mm
1 mm thick
53 mm
53 mm

4. Sample preparation @ CERN
50 samples 53 mm x 53 mm cut out of the same OFE Cu sheet and engraved C1..C25 for CERN process and L1..L25 for Legnaro process
Process at CERN:
Degreasing: in NGL 1740 bath for about 2 hours, with 3-5' ultra-sonic ON at start and again 3-5' ultra-sonic ON before end.
Activation: sulfamic acid (H3NO3S, 5 g/l) for about 3' in order to increase surface wettability and avoid bubbling formation at the surface
Polishing: 40' "SUBU5", SUBU5 = sulfamic acid (H3NO3S, 5 g/l), hydrogen peroxide (H2O2, 5% vol), n-butanol (5% vol) and ammonium citrate (1 g/l) at 72°C (70-75°C) with bath agitation, 25 samples at once in a 10L beaker.
Pre-rinsing with acid: sulfamic acid (H3NO3S, 5 g/l) for about 1', to remove hydrophobic layer
Rinsing with water: demineralized water for about 30s
Spaying with alcohol: ethyl alcohol to enhance drying
Drying with dry air (N2 better)
Packing in wafer box
Then in plastic bag under N2
Average etched of 35 um (per side)
Sample file updated

5. Sample preparation @ CERN
Sample dispatched in August as following:
8 samples (including 2 spare samples) sent to RTU,    
6 samples (including 3 spare samples) sent to Siegen
6 samples (including 3 spare samples) sent to STFC
5 spare samples left at CERN
25 raw samples sent to Legnaro

6. INFN SuBu batch (L1-3,L19-20) L2 scratched Spare L19  sample
Degreasing in NGL 1740 bath 2 hours, with 3-5' ultra-sonic ON at start and again 3-ultra-sonic ON before end.
Activation: sulfamic acid (H3NO3S, 5 g/l) for about 3 min
Polishing: 30' "SUBU5“
Pre-rinsing with acid: sulfamic acid (H3NO3S, 5 g/l) for about 1 min
Rinsing with water: demineralized water for about 30s.
Spaying with alcohol: ethyl alcohol to enhance drying.
Drying with N2.
Sample Weight.
Polishing: 35' "SUBU5”
Pre-rinsing with acid: sulfamic acid 5 g/l for about 1‘
Packing in wafer box.
Then in plastic bag under N2.
handling 3
L2 scratched Spare
L19  sample 1 4
Thickness etched:
40 ± 2 μm 15

7. INFN SuBu batch (Roughness)
The roughness was measured with a profilometer Veeco Dektat 8
Parameters:
Scan length: 6 mm
applied force 12 mg
3 scan on 2 different direction (a total of 6 scan) in order to take in account the lamination effect
Scanning point near the hole (but not too close because bending effect is present)
Initial roughness (average values on 6 samples)
Ra = 0.25 ± 0.09 µm
After SUBU (average values on 2 samples: L2 and L20)
Ra = 0.11 ± 0.02 µm

8. INFN SuBu batch (SEM L2,L20)
Lamination texture
Pitting
Before SUBU
After SUBU
Lamination texture
Crystal grains

9. INFN SuBu batch (EDS) No visible contamination with EDS Before SUBU
After SUBU

10. INFN EP batch (L10-15, L21-22) Thickness etched: 40 ± 2 μm 3 End of 3
Degreasing in NGL 1740 bath 2 hours, with 3-5' ultra-sonic ON at start and again 3-ultra-sonic ON before end.
Activation: sulfamic acid (H3NO3S, 5 g/l) for about 3 min
Polishing: 120 min Electropolishing in a 8l solution composed by Phosphoric Acid (85%) and Buthanol (99%) in a ratio 3:2, at room temperature, without bath agitation (3V, 3-2A)
Pre-rinsing with acid: sulfamic acid (H3NO3S, 5 g/l) for about 1 min
Rinsing with water: demineralized water for about 30s.
ethyl alcohol and drying with N2.
Sample Weight
Polishing: 190 min Electropolishing
Pre-rinsing with acid: sulfamic acid 5 g/l for about 1‘
Spaying with alcohol: ethyl alcohol to enhance drying.
Drying with N2.
Packing in wafer box.
Then in plastic bag under N2. 3
End of 3 4
Thickness etched:
40 ± 2 μm 13 13

11. INFN EP batch (SEM L21,L22) Lamination texture Crystal grains
Before EP
After EP
Lamination texture
Crystal grains

12. INFN EP batch (Roughness)
The roughness was measured with a profilometer Veeco Dektat 8
Parameters:
Scan length: 6 mm
applied force 12 mg
3 scan on 2 different direction (a total of 6 scan) in order to take in account the lamination effect
Scanning point near the hole (but not too close because bending effect is present)
Initial roughness (average values on 6 samples)
Ra = 0.25 ± 0.09 µm
After EP (average values on 2 samples: L21 and L22)
Ra = 0.48 ± 0.07 µm
Ra = 0.25 ± 0.04 µm (in the texture direction)

13. INFN SuBu batch (EDS) No visible contamination with EDS Before EP
After EP

14. INFN EP+SUBU batch (L16-18, L23)
Degreasing in NGL 1740 bath 2 hours, with 3-5' ultra-sonic ON at start and again 3-ultra-sonic ON before end.
Activation: sulfamic acid (H3NO3S, 5 g/l) for about 3 min
Polishing: 5 h Electropolishing
Pre-rinsing with acid: sulfamic acid (H3NO3S, 5 g/l) for about 1 min
Rinsing with water: demineralized water for about 30s.
ethyl alcohol and drying with N2.
Sample Weight
Polishing: 8 min SUBU
Pre-rinsing with acid: sulfamic acid 5 g/l for about 1‘
Spaying with alcohol: ethyl alcohol to enhance drying.
Drying with N2.
Packing in wafer box.
Then in plastic bag under N2. 3 4
Thickness etched:
45 ± 2 μm 15

15. INFN EP batch (SEM L21,L22) Before EP+SUBU Lamination texture Pitting
After EP+SUBU

16. INFN EP+SUBU batch (Roughness)
The roughness was measured with a profilometer Veeco Dektat 8
Parameters:
Scan length: 6 mm
applied force 12 mg
3 scan on 2 different direction (a total of 6 scan) in order to take in account the lamination effect
Scanning point near the hole (but not too close because bending effect is present)
Initial roughness (average values on 6 samples)
Ra = 0.25 ± 0.09 µm
After EP (average values on 2 samples: L21 and L22)
Ra = 0.3 ± 0.1 µm

17. INFN EP+SuBu batch (EDS)
No visible contamination with EDS
Before EP+SUBU
After EP+SUBU

18. INFN Tumbling batch (L4-9, L24-25)
Degreasing in NGL 1740 bath 2 hours, with 3-5' ultra-sonic ON at start and again 3-ultra-sonic ON before end.
Tumbling
Rinsing with water: demineralized water for about 30s.
Passivation with acid: sulfamic acid 5 g/l for about 1‘
Spaying with alcohol: ethyl alcohol to enhance drying.
Drying with N2.
Packing in wafer box.
Then in plastic bag under N2.
Scheduled for the first half of november

19. INFN samples dispatched
Sample dispatched in the first week of October as following:
6 samples (including 2 spare samples) sent to Siegen (3 samples of SUBU batch and 3 of EP batch)
3 samples (including 1 spare sample) sent to STFC (3 samples of EP batch)
2 samples left at LNL (2 samples of EP+SUBU batch)
6 spare samples left at LNL (2 spare samples of each batch)
8 samples (including 2 spare samples) will be treat in the tumbling batch scheduled in the first half of november

20. Uploading of the sample list files

21. Basic sample handling guidelines
Use new gloves
Put the box in the right position ("release" sign and box number on the top...)
Maintain bottom of the box in one hand and open with the other hand following the "release" arrow (beware: clockwise!)
Remove the "spider" (and remember the way it was put!)
You will see the backside of the sample with its number in one corner
Use alcohol cleaned tweezers to manipulate the sample (beware of the front side! Try to catch it from the corner with the hole)
N2 blow prior to process to remove dust
Put back the processed sample into the box following the same steps and the backside on top and close the box (don't forget the "spider" in the correct position) by turning the cover anti-clockwise.
take a picture of each sample before and after each step and name the pictures with respect to the step
check very well the copper surface before the deposition, and in case of scratches, general oxidation or spot oxidation, substitute the sample with a spare one