Technical Seminar For BE Students "MEMS Technology"

1. Micro-Electro-Mechanical Systems -The Future Technology, but Today’s choice Presented by… Vinayak Hegde Guide: Mrs. Priti M

6. MEMS Scaling

11. Microfabrication Process

13. Photolithography

14. Additive Processes Oxidation Thermal Oxidation of Silicon is done in a furnace in wet or dry conditions

16. Additive Processes Physical Vapor Deposition (PVD) 1. Evaporation Deposition is achieved by evaporation or sublimation of heated metal onto substrate. 2. Sputtering Sputtering is achieved by accelerated inert ion by DC drive in plasma through potential gradient to bombard metallic target. Then the targeting material is sputtered away and deposited onto substrate placed on anode.

17. Additive Processes Physical Vapor Deposition (PVD)

20. Subtractive Processes Reaction Mechanism Produce reactive species in gas-phase Reactive species diffuse to the solid Adsorption, and diffuse over the surface Reaction Desorption Diffusion Dry Etching Plasma Etching

21. Subtractive Processes Dry Etching Deep Reactive Ion Etching (DRIE) A very high-aspect-ratio silicon etch method DRIE Etched Pillars

22. Subtractive Processes Wet Etching Isotropic Wet Etching Isotropic etchants etch in all directions at nearly the same rate. Commonly use chemical for Silicon is HNA (HF/HNO 3 /Acetic Acid) This results in a finite amount of undercutting

23. Subtractive Processes Wet Etching Anisotropic Wet Etching Anisotropic etchants etch much faster in one direction than in another. Etchants are generally Alkali Hydroxides (KOH, NaOH, CeOH Reaction : Silicon (s) + Water + Hydroxide Ions -> Silicates + Hydrogen

24. Metal Patterning

25. Surface Micromachining

26. MEMS Packaging

27. Example: An insulin pump fabricated by classic MEMS technology 1. Pumping membrane 2. Pumping chamber 3. Inlet 4. Outlet 5. Large mesa 6. Upper glass plate 7. Bottom glass plate 8. patterned thin layer (for improved fluidics)

30. An implantable blood pressure sensor developed by CardioMEMS Bio MEMS Application

31. MEMS Memory [Nanochip]

37. Thank You