This document summarizes a seminar on sputtering processes. Sputtering is a thin film deposition technique where atoms are ejected from a target material when bombarded by energetic particles in vacuum. The ejected atoms then deposit onto a substrate to form a thin film. Key aspects of sputtering discussed include sputtering yield, how various parameters like ion mass, energy and pressure affect the process, and applications in microelectronics, decorative coatings, and medical devices.

1. A
SEMINAR ON
SPUTTERING PROCESS
Presented
By
K. GANAPATHI RAO
(13031D6003)
Presence of
Mr. Sumair sir

2. Outline
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Introduction.
Sputtering Process.
Sputtering Yield.
Sputtering Deposition Film Growth.
Application Of Sputtering.
Additional Methods.
Applications Of Thin Film.

3. Solids
2D
Zero Dimension
1D
3D

4. Thin films
• Thin films are thin material layers
ranging from fractions of a
nanometer (monolayer) to several
micrometers in thickness.

5. Synthesis of thin films

6. Sputtering – General
• Sputtering is a term used to describe the mechanism in which
atoms are ejected from the surface of a material when that
surface is stuck by sufficiency energetic particles.
• First discovered in 1852, and developed as a thin film
deposition technique by Langmuir in 1920.
• Metallic films: Al-alloys, Ti, Tantalum, Nickel, Cobalt, Gold, etc.

7. Reasons for sputtering
• Use large-area-targets which gives uniform thickness
over the wafer.
• Control the thickness by Deposition time and other
parameters.
• Even materials with very high melting points are easily
sputtered.
• Sputtered films typically have a better adhesion on the
substrate.
• Sputtering can be performed top-down.

8. Basic Model

9. Requirements
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Vacuum.
Inert gas.
Power supply.
Sputtering gas.

10. Sputtering steps
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Ions are generated and directed at a target.
The ions sputter targets atoms.
The ejected atoms are transported to the substrate.
Atoms condense and form a thin film.

11. Sputtering yield
 Defined as the number of atoms ejected per
incident ion.
 Determines the deposition rate.
 Depends on:
 Mass of bombarding ions.
 Energy of the bombarding ions.
 Direction of incidence of ions (angle).
 Pressure.

12. Mass & size of atoms
Molecule size – need to be about the same size as the sputtered material
– too big cause layer deformation and yield a lot of material
on walls.
– too small cause layer deformation w.r.t not proper
ejecting atoms.
Target deformation = Less uniform deposition.

13. Energy Of The Bombarding Ions
Ion energy Vs. sputter yield:

14. Direction
• There is a probability that atom C will be ejected from the
surface as a result of the surface being stuck by atom A.
• In oblique angle (45º-90º) there is higher probability for
sputtering, which occur closer to the surface.

15. Direction Of Incidence Of Ions
• Sputter yield peaks at <90º.
• Atoms leave the surface with cosine distribution.

16. Pressure
Pressure reduction – allow better deposited atoms/molecules flux
flow towards the substrate. Expressed by “Mean free path” which
is the average distance an atom can move, in one direction
without colliding at another atom.

17. Sputtering deposition film growth
• Sputtered atoms have
velocities of 3-6 E5 cm/sec
and energy of 10-40 eV.
• Many of these atoms
deposited upon the substrate.
• Thus, sputtered atoms will
suffer one or more collision
with the sputter gas.

18. Sputtering deposition film growth
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The sputter atoms have:
 Arrive at surface with reduce energy (1-2 eV).
 Be backscattered to target/chamber.
 The sputtering gas pressure can impact on film deposition
parameters, such as Deposition rate and composition of the
film.

19. Sputtering deposition film growth

20. Application of Sputtering
• Thin film deposition:
– Microelectronics
– Decorative coating
– Protective coating
• Etching of targets:
– Microelectronics patterning
– CMOS, NMOS, PMOS fabrication
• Surface treatment:
– Hardening

21. Sputtering – additional methods
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Reactive & Non reactive sputtering
RF & DC sputtering
Magnetron sputtering
Collimated sputtering
Ion-Beam sputtering

22. Applications Of Thin Film Technology
Microelectronics
CPU processors,
cell phones,
ipod,
watches,
batteries,
Solar Panels

23. Applications Of Thin Film Technology
AR (anti-reflective coatings)
On cars,
jewelry,
mirrors,
night vision goggles
Oxidation resistance
on cutting tools,
chemical factories.
Medical
drug delivery

24. VIDEOS
1
2
3

25. References
• Hand book of thin film deposition process and techniques- By
Krishna Seshan
• Thin Film Phenomena - Kasturi L. Chopra
• http://en.wikipedia.org/wiki/Thin-film_memory
• http://www.uccs.edu/~tchriste/courses/PHYS549/549lectures/
• http://nptel.iitm.ac.in/syllabus/syllabus.php?subjectId=11510201
9
• http://www.azom.com/article.aspx?ArticleID=8796