1. Phase Transistions in Ni-Si System With Ti Diffusion Boundary Layer Andrew Smith Advisor: Prof. Kvam University of Purdue, REU Summer Program

2. Overview Objectives Approach Observations Findings Future work

3. Objectives To study effects of Ti interlayer on Ni-Si system

4. Approach Anneal samples 350 o C 500 o C 650 o C 800 o C Analyze annealed samples using XRD

5. Observations False peak- Tungsten contamination Similar results for 500 o C and 650 o C Inconclusive findings for 800 o C

6. Findings 350 o C Formation of Ni 2 Si after 90min No conclusive NiSi growth at this temperature 500 o C Formation of NiSi Appearance of Ni 3 Si 2, Ni 3 Si

7. More Findings 650 o C Similar to 500 o C results Check higher temperature 800 o C Uncertain peak with six possibilities Best guess- NiSi 2

8. Interpretation Pathway similar to previous work How is Ti layer affecting the system? Slows down process

9. Future Work Further analysis of 800 o C Control XRD machine variables Different techniques to verify guesses Develop NiSi 2 -Si system Measure electrical properties Compare with current MESFETs

10. Thanks Prof Kvam REU Students REU Program