Post on 05-Feb-2016
description
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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)…
R lA
ρ = Resistivity
R = Resistance across strip
l = length of strip
A = Cross-Sectional Area
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
Complete Design…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
Temperature Measurements…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
The Outcome…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
The Outcome…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
The Outcome…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
The Outcome…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
Final Precautions…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity of California, Irvine
Funded by the National Science Foundation
Mentors: Professor Richard Nelson
Professor John Larue
Support: Allen Kine and Hideo Morita
Results…
The Resistive Properties of Thin Carbon Films from Pyrolized SU-8
Justin Little
Department of Mechanical and Aerospace EngineeringUniversity 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