THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee [email protected] Advisor:...
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Transcript of THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee [email protected] Advisor:...
![Page 1: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/1.jpg)
THIN FILM CERAMIC GAS/TEMPERATURE MICRO-
SENSORS
Paul JooYoung [email protected]: Prof. Rishi Raj
Department of Mechanical EngineeringUniversity of Colorado at Boulder
Acknowledgement: U.S. Department of Energy
![Page 2: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/2.jpg)
Project Outline
• Developing thin film ceramic gas-temperature sensor
– A ceramic micro-sensor to detect gas and temperature
– Fabrication of thin conducting SiCN micro-patterns on insulating substrates
– Establish electrical properties of the SiCN thin film sensor at high temperatures (1000 deg. C)
![Page 3: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/3.jpg)
Polymer Derived SiCN Conducting Ceramic
• Made from monomer liquid precursor, CerasetTM plus photo-initiator mixture
• Silicon CarboNitride amorphous ceramic • Excellent oxidation resistance• Electrically semi-conducting
– Resistance of the film changes with the surrounding temperature and gas environment
![Page 4: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/4.jpg)
Ceramic Micro-sensor?
Micro-electronics/MEMS Fabrication Technology
Many identical chips on one wafer/substrate
Polymer Derived Ceramics(PDC)Technology
Conducting Ceramic - SiCN
+
Conducting ceramic micro-
sensors on substrate
(Batch processing capability leads to cheap production)
![Page 5: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/5.jpg)
Fabrication
Photo-sensitive precursor and
insulating, refractory substrate
Array of polymer micro-patterns on
the substrate
Spin-coat precursor
onto substrate and pattern using UV
lithography
Non-conducting ceramic patterns on the substrate
Microelectronics Technology
Heat treat the whole substrate(polymer ceramic)
Many conducting ceramic devices on
one substrate
Annealing heat
treatment to conducting
ceramic
Polymer Derived Ceramics
![Page 6: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/6.jpg)
Electrical Properties
• Ceramic refractory, oxidation resistant
Working temperature = 1000 deg. C
Cyclic Resistance Response of SiCN Thin Film in Air and Hydrogen Flow (300°C)
0
5
10
15
20
25
30
35
40
0 20 40 60
Time (min)
Res
ista
nce
(kΩ
)
Air H 2 H 2 H 2AirAir
CYCLE I CYCLE II CYCLE III
• Establish the relationship, conductivity vs temperature/gas type gas/temperature sensor
![Page 7: THIN FILM CERAMIC GAS/TEMPERATURE MICRO- SENSORS Paul JooYoung Lee Joo.Y.Lee@colorado.edu Advisor: Prof. Rishi Raj Department of Mechanical Engineering.](https://reader031.fdocuments.us/reader031/viewer/2022012919/56649ed55503460f94be60dc/html5/thumbnails/7.jpg)
Methodology
• Increase sensitivity Reduce resistivity of the thin film– Doping with boron or other dopants– Annealing condition changes
• Electrical property measurement– Four point probe test – resistivity measurement of thin films
(Commercially available = 300 deg. C max)– Build Four point probe testing unit for high temperature
environment– Sealed testing unit can readily change the gas environment– Measure the resistance response vs temperature and
surrounding gas type