1. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita

2. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Project Description…. 1.Design a die that will use a four point Kelvin bridge resistance measurement for pyrolized SU-8 2.Design and manufacture high temperature die housing that will incorporate the resistance measurement 3.Fabricate die in the INRF 4.Use the Die Housing to perform the resistance measurements

3. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita What is SU-8? Photosensitive Epoxy Originally developed for the electronics industry Used as a Negative Photoresist Has many attributes that make it suitable for MEMS

4. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Pyrolized SU-8… Different properties manifest for different pyrolysis temperatures As pyrolysis temperature increases, ρ decreases, vertical shrinkage increases May achieve very high aspect ratios Exhibits properties similar to glassy and amorphous carbon

5. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Patterning the Die… SU-8 Pattern Before Pyrolysis

6. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Patterning the Die… Aluminum Pads Metallization Mask Final Die

7. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Quarter wafers only 30 minutes at 300 °C Increased 10 °C/min until 900 °C is achieved Held for one hour Cooled for minimum of 8 hours in nitrogen environment Carbonization of the SU-8

8. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita My Job… 1.Design Kelvin-Bridge Acquire Materials Draw Design Determine Tolerances Construct Final Product 2.Use Kelvin-Bridge Acquire Data Determine Accuracy

9. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita How does a Kelvin Bridge work? Ohm’s Law: V = IR Therefore… R = V/I

10. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Finding the Resistivity (ρ)… ρ = Resistivity R = Resistance across strip l = length of strip A = Cross-Sectional Area

11. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Design Requirements… The Kelvin Bridge must make measurements in temperatures between room and 260 °C It should achieve an accuracy within 0.1% of expected values It needs to demonstrate a high level of repeatability and reliability Safety 

12. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Design Process… 1.Incorporate requirements into an initial design 2.Evaluate design and look at options 3.Select materials based on the requirements (Teflon, Bakelite, Aluminum) 4.Draw out plans in AutoCAD 5.Determine tolerances

13. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Housing Components… Aluminum Heating Mass Teflon Block Aluminum Block Copper Contacts

14. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Complete Design…

15. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Type K Thermocouple Two heated dissimilar metals joined at the ends create a continuous current Alumel and Chromel Omega Thermometer Temperature Measurements…

16. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Temperature Measurements…

17. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita The Outcome…

18. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita The Outcome…

19. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita The Outcome…

20. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita The Outcome…

21. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Final Precautions…

22. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Setbacks… Available wire only withstands 200 °C Pyrolysis tube was inoperable for a week Empty forming gas tank Time constraints

23. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Results…

24. The Resistive Properties of Thin Carbon Films from Pyrolized SU-8 Justin Little Department of Mechanical and Aerospace Engineering University of California, Irvine Funded by the National Science Foundation Mentors: Professor Richard Nelson Professor John Larue Support: Allen Kine and Hideo Morita Thanks… National Science Foundation Professor Richard Nelson and Professor John LaRue Allen Kine Hideo Morita and Farzaneh Bakhshi Ted Ediss