Vertical Pillars for Biological Force Sensing

1
Vertical Pillars for Biological Force Sensing

• Class update July 20th

Sarah Coulthard, Nahid Harjee, Nathan Klejwa,
Ronald Kwon
2
Device Overview
3
Training

• Completed
• MERL clean shop All
• wafersaw Ron
• amtetcher Nahid
• wbgeneral Nathan
• innotec Nahid and Nathan
• Laser ablator Ron
• To be completed
• Critical point dryer

4
Thick SU-8 Characterization

• Trying to obtain gt300um layer of SU-8
• SU-8 2100 gives huge indentations
• Reason Expired, SU-8 2100 formulation
• Tried SU-8 100 using recipe from last year
• Second attempt 450um /- 25um
• 7 hours to process
• Set up oven in MERL

5
Release Experiments
6
Strain Gage Resistance

• 1000 A of Au on 100 A of Cr
• Desired resistance 100 O
• Measured resistance 103.5 O
• Measurement system resistance 10 O
• Trace resistance 6 O

7
Runsheet
Process Target Recipe Tool
1 Clean Piranha wbnonmetal
2 Lithography 1 um Shipley 3612 1 Align/Spacer karlsuss/karlsuss2
3 Oxide Etch 2500 A 61 BOE wbnonmetal
4 Resist strip Piranha wbnonmetal
5 Evaporate Cr 100 A innotec
6 Evaporate Au 1000 A innotec
7 Singe MERL hot plate
8 Spin SU-8 5 um SU-8 2005 MERL spinner
9 Pre-bake MERL hot plate
10 Expose 2 Cantilever karlsuss/karlsuss2
11 PEB MERL hot plate
12 Develop 5 um SU-8 Developer MERL fumehood
13 Rinse and Dry IPA and N2 MERL fumehood
14 Hard bake MERL hot plate
15 Evaporate Cr 100 A innotec
16 Evaporate Au 1000 A innotec
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Runsheet (contd)
17 Lithography 3 um SPR 220 3 Metal karlsuss/karlsuss2
18 Au etch 1000 A Au etchant wbgeneral
19 Cr etch 100-200 A CR-7/CR-14 wbgeneral
20 Resist strip PRX-127 wbgeneral
21 Singe MERL hot plate
22 Spin SU-8 450 um SU-8 100 MERL spinner
23 Pre-bake MERL hot plate
24 Expose 4 Pillar karlsuss/karlsuss2
25 PEB MERL hot plate
26 Spin SU-8 35 um SU-8 2035 MERL spinner
27 Pre-bake MERL hot plate
28 Expose 1 Align/Spacer karlsuss/karlsuss2
29 PEB MERL hot plate
30 Develop 335 um SU-8 Developer MERL fumehood
31 Rinse and Dry IPA and N2 MERL fumehood
32 Hard bake MERL hot plate
33 Release 50 um HF vapor wbgeneral
34 Dice ablator
35 Wire bond
9
Next Steps

• Further investigation of HF vapor
• Cr/SU-8 mask
• SU-8 only mask
• Exposure time for thick SU-8 layer
• Characterize 35 um SU-8 layer
• Test laser ablator
• Wire bonding (wafer submitted to Pauline)

10
Innotec

• Reservation tomorrow 8 am 12 pm
• Current plan
• 100 A Cr
• 1000 A Au
• 100 A Cr

11
Congratulations!!!

• Nahids birthday
• Sarah got hitched