1. Alloy Thin Films by Multi-Target Sputtering Karla L. Perez MSE/REU Final Presentation Adv. Prof. King and Prof. Dayananda August 5, 2004

2. Overview Introduction Research Project Processing Measuring Film Thickness –Optical Microscope –AFM Alloy Thin Film Deposition –Composition Conclusion

3. Application of Thin Films Antireflection coatings for camera lenses Optical filters for communication Decorative coatings on plastics Silicon chips Metallic coatings To provide insulating layers between conductors

4. Research Project The main goal is to create alloy thin films with uniform composition and thickness Study the compositions of pure metal thin films and their thickness Pure metal components to be used: Ag, Cu, Ta, Mo, Ni, Fe, Ti Design a system which will enable us to manage the composition and geometry of the alloy thin films

5. Processing Sputtering It is a type of Physical Vapor Deposition. It is carried out at high vacuum in a chamber connected to a high voltage DC supply. Argon gas is pumped into the chamber and creates argon plasma. The Argon plasma is directed to the target and its atoms are vaporized. The vaporized material is then deposited on the substrate.

6. Measuring Film Thickness Optical Microscope –Differential Interference Contrast (DIC) Ag 20min 4cm

7. Measuring Film Thickness Optical Microscope Cu 10min 4cmAg 20min 4cm

8. Measuring Film Thickness Optical Microscope Ag 10 min 4cmAg 20min 4cm

9. Measuring Film Thickness Atomic Force Microscope (AFM) –Tapping mode: Measures the topography by tapping the surface with an oscillating tip. This eliminates the shear forces which can damage soft samples and reduce image resolution.

10. Measuring Film Thickness

11. Measuring Film Thickness AFM Ag 20min 2cm

13. Measuring Film Thickness AFM Mo 30min 2cm

15. Measuring Film Thickness AFM Cu 30min 2cm

17. Ag 30min 2cm 14.19 52.40

18. Alloy Thin Film Deposition Deposit alloy thin films using a sputter coater with a Copper-Silver target

19. Composition of Ag-Cu Thin Film 92.7% 7.3% 50.3% Position on slide

20. Composition of Ag-Cu Thin Film 95.6% 4.4% 50.3% Position on slide

21. Conclusion The thickness of the film varies according to their position relative to the target. Films deposited are thicker in the middle. Deposited one alloy thin film The same composition gradients of silver and copper do not occur in the middle of the film.

22. Acknowledgements Prof. King Prof. Dayananda Prof. Kvam NSF Grant

23. Questions??? Thank you!!!