This document discusses a study on reliability in MEMS (Micro Electro Mechanical Systems). It first provides an introduction to MEMS, describing their size and key fabrication processes like deposition, lithography, and etching. It then discusses two main MEMS fabrication techniques - bulk micromachining and surface micromachining. The document outlines several failure mechanisms in MEMS like mechanical fracture, corrosion, stiction, and wear. It concludes by stating that understanding the underlying physics of MEMS fabrication processes is key to overcoming mechanical and electrical failures.

1. A STUDY ON MEMSA STUDY ON MEMS
RELIABILITYRELIABILITY
PRESENTED BY
ANIL BHARADWAJ.R
8TH SEM
TCE DEPT

2. INSIDE
 INTRODUCTION
 MEMS FABRICATION PROCESS
 DEPOSITION
 LITHOGRAPHY
 ETCHING
 MEMS FABRICATION TECHNIQUES
 BULK MICROMACHINING
 SURFACE MICROMACHINING
 MEMS RELIABILITY
 CONCLUSION

3. MEMS: MICRO ELECTRO MECHANICAL SYSTEM
SIZE OF MEMS DEVICES
RICHARD FEYNMAN
INTRODUCTION

4. CLEAN ROOM AND SILICON WAFER

5. Same as the process steps used for making
conventional electronic circuits
MEMS PROCESS

6. FABRICATION PROCESS

7. DEPOSITION PROCESS
PHYSICAL VAPOR DEPOSITION
CHEMICAL VAPOR DEPOSITION

8. LITHOGRAPHY
 Application of photo resist
 Optical exposure to print an image of the mask onto the resist
 Immersion in an aqueous developer solution to dissolve the exposed resist

9. ETCHING PROCESS
ETCHING IS PROCESS OF REMOVING UNPROTECTED PART
WET ETCH
DRY ETCH

10. ISTROPIC AND ANISOTROPIC
 ISOTROPIC ETCHING GIVES UNIFORM ETCH RATE
 ANISOTROPIC ETCHING GIVES NON UNIFORM ETCH RATE

11. MEMS FABRICATION TECHNIQUES
BULK MICROMACHINING
SURFACE MICROMACHINING

12. MEMS DEVICES

13. FAILURE MECHANISMS
MECHANICAL FRACTURE
CORROSION
STICTION
WEAR
ELECTRIC SHOT AND OPEN
CONTAMINATION

14. MECHANICAL FRACTURE
Mechanical fracture is local separation of an
object or material into two or more pieces

15. CORROSION
Corrosion is disintegration of material into its
constituent atoms due to chemical reactions with its
surroundings

16. STICTION

17. WEAR
Wear is defined as the removal of material from a solid surface as the result
of mechanical action

18. ELECTRICAL SHORT AND OPEN
THESE OCCURS DUE TO VARIOUS REASONS.
IT’S DIFFICULT TO IDENTIFY THESE KINDS OF FAULTS

19. CONTAMINATION
UNINTENTED MATERIAL
SOURCE FOR CONTAMINATION ARE MANY

20. IMPRECISE FABRICATION METHODS
EXPENSIVE AND COMPLEX PACKAGING
CAD DESIGN TOOL INACCURACIES
REASONS FOR FAILURE

21. APPLICATIONS OF MEMS

22. CONCLUSION
 MEMS is an advancement over VLSI through its rugged
and adaptable electro mechanical features.
 Many mechanical and electro mechanical processes
involved in Lithography, Deposition and Etching is reduced
in MEMS over VLSI
 Still the MEMS is fraught with some more mechanical and
electro mechanical failures which can be overcome by
understanding the mechanism and the physics underlying
MEMS process more clearly.

23. REFERENCES
 [1] R. M. Boysel, T. G. McDonald, G. A. Magel, G. C. Smith, and
J. L. Leonard, “Integration of deformable mirror devices with optical
fibers and waveguides,” in Proc. SPIE, 1992, vol. 1793, pp. 34–39.
 [2] W. Kuehnel and S. Sherman, “A surface micromachined silicon accelerometer
with on-chip detection circuitry,” Sens. Actuators A, Phys.,
vol. 45, no. 1, pp. 7–16, Oct. 1994.
 [3] M. Younis, D. Jordy, and J. M. Pitarresi, “Computationally efficient approaches
to characterize the dynamic response of microstructures under
mechanical shock,” J. Mciroelectromech. Syst., vol. 16, no. 3, pp. 628–
638, Jun. 2007.
 [4] ASM Handbook, vol. 13, “Corrosion,” ISBN 0-87170-007-7, ASM Int.,
Novelty, OH, 1987.
 [5] W. van Arsdell and S. B. Brown, “Subcritical crack growth in siliconMEMS,” J. Mciroelectromech.
Syst., vol. 8, no. 3, pp. 319–327,Sep. 1999.

24. THANK YOU