Glancing Angle Deposition Method (GLAD)

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Glancing Angle Deposition Glancing Angle Deposition Dhruv Pratap Singh (2008PHZ8058) Under the supervision of Dr. J. P. Singh Department of Physics Indian Institute of Technology Delhi, New Delhi, India-110016 1

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An introductory ppt on GLAD

Transcript of Glancing Angle Deposition Method (GLAD)

Page 1: Glancing Angle Deposition Method (GLAD)

Glancing Angle DepositionGlancing Angle Deposition

Dhruv Pratap Singh(2008PHZ8058)

Under the supervision of Dr. J. P. Singh

Department of Physics Indian Institute of Technology Delhi, New Delhi, India-110016

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Glancing Angle Deposition Glancing Angle Deposition (GLAD)(GLAD)

Schematic of GLAD

It is is a physical vapor deposition process where the

deposition flux is incident onto a substrate making a large angle

(θ) with respect to the surface normal and the substrate is

rotating in its azimuthal plane.

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Vapor source

substrate

θθ tilt in polar plane

Φ rotation in azimuthal plane

Substrate normal

flux

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θθ β

Initial nucleation forms shadowing centers Columnar structures formed due to the shadowing effect

The empirical relation

between vapor incidence (θ)

angle and column tilt (β)angle is

tanβ= ½ tanθ.

Schematic of columnar growth in oblique angle deposition Schematic of columnar growth in oblique angle deposition

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(Brett M J et al , IEEE Transactions on Nanotechnology 2005, 4, 269)

1µm

Vapor flux

For θ = 65°

Interplay of surface diffusion and shadow effect occurs during columnargrowth.

Surface roughness

Flux

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600nmSlanted silver nanorods for θ = 87°

Shadow region increases with

increase in incidence angle (θ)

which results in increase in

inter columnar separation and

hence the porosity of film

Increase in columnar growth with angle θ (Zhao et al, Proceedings of SPIE 2003, 5219, 59 ).

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200nm

(Dhruv P Singh et al, IIT Delhi)

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Production of periodically structured thin film :Production of periodically structured thin film :

By growing artificial seeds (nucleation centers) we can grow the

columnar structures of desired distribution and periodicity.

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Growth of Si slantedposts over patternedsubstrate

1 µm(Ye et al, Nanotechnology 15, 2004, 817 ).

θ

Substrate normal

Vapor flux

seeds

Substrate(Brett M J et al , IEEE Transactions on Nanotechnology 2005, 4, 269)

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Effect of substrate rotation on columnar Effect of substrate rotation on columnar structuresstructures

Chevrons (zig-zag structures).

Vertical Post.

Helices (nanospring).

Multilayered columnar structures.

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Chevrons 7(Brett M J et al , IEEE Transactions on Nanotechnology 2005, 4, 269)

ChevronsChevrons

180° rotation in azimuth plane

Normal to substrate

Columnar structure

substrate

Vapor source

Vapor flux

Zig-zag(chevrons) columns

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θ

Substrate normalVapor flux (F)

Substrate

θ

Substrate

FF

F׀׀

Rotation in azimuth plane

Vertical posts

Substrate rotation

(Zhao et al, Proceedings of SPIE 2003, 5219, 59 ).

Vertical postsVertical posts

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Helices

Slow rotation

Substrate is rotated at very slow speed ( 0.07 to 0.20 rpm). Rotation is decided by deposition rate,

One pitch of helical column must grow in one substrate rotation.

One Pitch

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(Zhao et al, Proceedings of SPIE 2003, 5219, 59 ).

NanospringsNanosprings

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Multilayered nanostructures

By programming the stepping motor for different rotation speed

multilayered structures can be grown .

(Zhao et al, Proceedings of SPIE 2003, 5219, 59 ).

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Nano-structures

Deposition rate (Å/sec)

Oblique Angle

Substrate Rotation

( rpm )

Material –Substrate

Reference

Vertical post

4.0 86° 0.5 ZnO - Soda lime glass

Abraham Wolcott, Advanced functional mat. 2009, 19, 1849.

15 86° 0.22 Co – Si M. J. Brett, J. Vac. Sci. Technol. 1999, 17, 2671.

20 75° 0.64 Fe –Si(100) F. Liu, J. Appl. Phys. 1999, 85, 5486

Helices

3.0 87° 0.07 Si–SiO2 Ambarish Ghosh, Nanoletter 2009, 9, 2243

15.5 86° 0.12 Ti – Si M. J. Brett, J. Vac. Sci. Technol. 1999, 17, 2671.

20 75° 0.16 Fe –Si(100) F. Liu, J. Appl. Phys.1999, 85, 5486

Reported growth parameters for different Reported growth parameters for different nanostructuresnanostructures

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QCM and Electric feed through ( on rear side)

Turbo molecular pump

Pirani gauge

Water cooled feed through

LT power supply

View port

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My deposition chamber (GLAD)

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