Silicon Carbide Temperature Sensor for Harsh Environments

1. Silicon Carbide Temperature Sensor for Harsh Environments

2. Team Members ADVISOR Chris Rice Jason Wallace Dr. Stephen Saddow “a hot project…a cool advisor” Michael Jackson Jovan Bjelobrk

3. Team Responsibilities Chris Rice • Sensor Fabrication • Sensor Testing Jason Wallace • Documentation • Device Controller • PIC Coding • Software Interface • Device Controller • PIC Coding Michael Jackson • Sensor Fabrication • Sensor Testing Jovan Bjelobrk

4. Overview • No reliable way to detect temperature changes in extreme environments using typical semiconductor material (Si) • Space travel involves extreme temperatures • SiC has the ability to operate in and withstand extreme temperatures (>500 °C)

5. Key Specifications • Increased Sensing Range • 25 ° C to 500 ° C • Tolerance • Temperature reading accuracy of 0.5 °C at 25 °C • Cost • Cost of working unit will be less than $300

6. Timeline

7. System Components Temp. Sensor Circuit Software

8. Fabrication Process • Epitaxial Growth • Photolithography • Metalization • Lift-Off / Etching • Re-Fab • Packaging

9. Epitaxial Growth n+ n- p+ p+ layer ~ 1019 cm-3 n- layer ~ 5*1015 cm-3 n+ layer ~ 1017 cm-3

10. Photolithography n+ n- p+

11. Metalization n+ n- p+

12. Lift – Off / Etching n- p+ Top View Side View

13. Packaging

14. Design Equations • R =  (L/A) •  = 1/(qnn) • Ni = sqrt(Nc*Nv)*exp(-Eg/2kT) • n = (2.5*107)*T-2 • A = W*t

15. L (mm) =100 50 20 10 Resistance vs. Temperature Test Spec of 25 to 500 degrees C

16. Controller Board

17. User Interface

18. Cost Analysis • ~ $2000 per substrate (2 inch diameter wafer) • ~ $600 for whole-wafer EPI Growth • ~ $400 for Fabrication Run • Producing 24 cells per wafer, and assuming overall yield of process of 72%, produces 120 usable devices at approximately $25 each • Control board components: $26.61 • Total cost for working unit: $51.61

19. Silicon Carbide Temperature Sensor for Harsh Environments

20. Demonstration Temperature Center_beta3