The "target and substrate distance" will affect the thin film growing rate and uniformity. Does it have much influence on stoichiometry? How does it happen?
"Ar gas pressure" may affect the growing rate, is there any other influence?
I ever read some paper mentioned the influence by experiments, but not much physical explanation on them.
Target substrate distance affects the thickness as well as uniformity of the thickness for the film. Other than thickness, the target substrate distance also affects the minimum power required to obtain the plasma and hence, the power density at the target. This will also affect the thickness of the film.
In addition to target substrate distance, Ar gas pressure also affect the minimum power required to obtain the plasma. In turn, this will also affect the deposition rate, thickness and grain size of the film.
If your substrate to target distance is very small let us say 2 to 4 cm, there can be excessive bombardment on the substrate, this can affect the stoichiometry. Especially loss of lead in the deposited film.
In case of PZT many a times a large substrate distance of about 8-to 10 cm, helps in thermalizing the ejected specie from the target, and provides much better reactivity between the ejected species, and helps in maintaining the stoichiometry in the deposited layer.
Of course you to optimise substrate temperature to achieve the incipient nucleation in the deposited layer, and preferably a post deposition annealing at high temperatures say, 550 deg C, to make the film crystalline to see good ferroelectric properties.
Pl see my detailed paper in which I have characterised PZT thin films using multielement metal targets using dc magnetron sputtering, and discussed the effect of various deposition paprameters. It was published in the Journal of applied physics. long ago in 1988 or 1989. In case I come across this paper, I will send you a copy.
K. Sreenivas
Please go through this paper of mine, where I had tried to optimize the various deposition parameters while sputtering multilement PZT metal targets to prepare PZT thin films with good stoiciometric control
K. sreenivas
Dr K. Sreenivas, on your paper PZT by metal targets, I notice the diameter of your target is 10 cm, and you are suggesting a distance to substrate between 8-10 cm, there is a scaling law to calculate the optimum distance?, to improve uniformity without losing much dep rate? thanks for your work is very good! By the way, is better DC sputtering for metallic targets or RF sputtering?
Is there anybody help me regarding reflected power. It would be helpful suggestion from the researcher who are using nanomaster nsc3500 system. Target to substrate distance, power, argon pressure are also my concern.
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