Aluminum and it's oxide have wide and various applications in nanotechnology
as thin film (metallic mirror) ,substrate and also ALN which is good semi-conductor with various optical usage,[1,2]. To study the optical characteristics of Al thin film and it's variations with deposition rate pure Aluminum has been coated on white glass substrate by magnetron sputtering methods. To inv-estigate how deposition rate varies with coating parameters for plasma formation
research grade Argon(99.999%).In pressure range of 0.02-0.2 m.bar was used.
Discharge current was varied from 0.2-1.4 A and voltage following these changes also varied between 230-450 volts. To measure and knowing how substrate temperature changes with period of sputtering an exact digital thermocouple was used and was placed next to glass substrate behind it's holder.
Deposition rate and film thickness were measured by employing a vibrating cry- stal thickness monitor as well as using an exact balance (10-4 gr), coating rate changed from 3 to 15 Å/s and showed a linear behavior with electrical power while Argon pressure was kept constant. Lowering gas pressure caused increase of rate as well as better adhesion of Al to substrate.
To study and measure the reflection power of Al thin films with respect to film thickness, and deposition rate a double beam spectrophotometer (shimadsu,mo-del : )with wavelength range of 200—2500 nm was employed. When
Al film thickness was increased while deposition rate is kept constant (11 Å/s),
power of reflection of film also becomes more up to certain thickness , after that
reflection remains constant.
Reflection power of Al thin films for different deposition rates also were investig-
ated for the same wavelength range , when film thickness was fixed ( 100 nm ).
References:
[1]. R.Saha and W.D.Nix , Acta Metall.,Vol.58,(2002)
[2]. A.Kinbara,S.baba and A.Kikuchi,Thin Solid Films,171(1989)
[3]. F.A.Jenkins and H.E.White,Fundamentals of optics,Forth Edition,(1985)
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