Another simpler method (but not as accurate), weigh substrate prior to deposition, deposit film and reweigh. Subtract substrate mass, thus you now have mass of deposited film. Measure columnar height of structures on film using SEM, calculate the mass of a solid cubic volume using the columnal height as the thickness and using the density of the material calculate the mass of the solid volume. You now have a mass difference between the actual film and the calculated solid volume, you can use this to get a relatively accurate porosity value. My original method is more accurate though.

hello Artoni..

i have no idea any softwares avalible for measuring density.

But Density of the thin film of any material usually less than the bulk material density.

Because whatever the technique you used for deposition there will be porosity present in the film .(except the costly tech. such as ALD, MBE etc)

i understand that from SEM you can get surface morphology,grain size,Thickness of film,composition of the constituent elements by EDAX only possible.

From AFM , you can estimate the surface roughness of the sample.

If you have EDX capability on your SEM, then you can get film composition using the variable spot size technique. Using the % composition and the atomic weights of each element the film density can be easily calculated.

With AFM is possible to measure the film thickness. So, if you know the area you can calculate the film volume. With the mass and with the volume you can calculate the density ….

Artoni,

The best way to determine the mass density of thin films is grazing angle x-ray reflectance.

See my artcles about porous SiO2 and TaOx thin films:

"High-acoustic-impedance tantalum oxide layers for insulating acoustic reflectors".

Jose Capilla, Jimena Olivares, Marta Clement, Jesús Sangrador, Enrique Iborra, Arnaud Devos

IEEE transactions on ultrasonics, ferroelectrics, and frequency control. 03/2012; 59(3):366-72.

"Sputtered SiO2 as low acoustic impedance material for Bragg mirror fabrication in BAW resonators."

Jimena Olivares, Enrique Wegmann, José Capilla, Enrique Iborra, Marta Clement, Lucía Vergara, Robert Aigner

IEEE transactions on ultrasonics, ferroelectrics, and frequency control. 01/2010; 57(1):23-9.

X-ray reflectance is a good technique as suggetsed by Enrique to measure thin film density provided the density of the film is not too close to that of the substrate. Optical measurements can be also used to get the density via Clausius Mossotti relation .

Which method of deposition you are using?

Dr. Ang,

Ask to Prof. [email protected].

The easiest way would be to find calculate the volume and use the mass, density relationship. However, there is another technique called the EELS (electron energy loss spectroscopy) that can determine the density very accurately. But you need access to a TEM in order to carry this out.

I think cheapest and easy method is mentioned by Sumeet Walia

By which technique u deposited thin film?

Khursheed: we deposit thin by thermal evaporation method.

Ok. Is the thickness of film uniform by this method?

If yes you can use ellisometry for yout purpose

The film thickness is uniform. Please send me your contact numbers. At present we are working on new material (Cu-Sn-Sb-S system)

With oblique angle deposition the structure of your films can be very intricate and confusing. So I suggest that you create a step, measure thickness (e.g. with AFM, SEM or a profiler) and weigh your films. The step has to be created with photolitography, mechanical masking will not do for oblique deposition.

Just a quick question, if you are using oblique angle deposition, is this a fixed deposition or are you also rotating your substrate (known as GLAD) ?

Do you just need a software for image processing? You could try with the freeware ImageJ at http://rsbweb.nih.gov/ij/

Use Spectroscopic ellipsometry. Here is a detailed method. PHYSICAL REVIEW B 70, 195406 (2004)

I would also "vote" for spectroscopic ellipsometry! By introducing "pores" to the optical model and obtaining their percentage in the well defined layer type you can get the density of the film. With AFM and SEM - no way!

Thank you for your comments and suggestions! I suddenly realized that my question wasn't very accurate. What I meant was, how do I get the porosity of the film from SEM or AFM images? Would it be possible to do it? We deposited the films using oblique angle deposition with a stationary substrate.

Jan Schröder, I already have Gwyddion and is currently exploring the options available using this software. Thank you for the link.

Tamás Haraszti, yes, I mean "mean surface coverage", I will try working on that as soon as possible. Thank you for your suggestion.

Here is a good paper you may want to have a read through, it gives good ideas on how to calculate various parameters from the angle of incidence, through to the vapour flux rate.

There is a parameter called "Roughness" in the AFM software. This is a good estimate of the porosity of the surface.

Semilab www.semilab.com sell a porosity metrology tool. It is a spectroscopic ellipsometer with an integrated chamber to insert gas into the pores. The change in dielectric costant allows calculation of porosity.

Another simpler method (but not as accurate), weigh substrate prior to deposition, deposit film and reweigh. Subtract substrate mass, thus you now have mass of deposited film. Measure columnar height of structures on film using SEM, calculate the mass of a solid cubic volume using the columnal height as the thickness and using the density of the material calculate the mass of the solid volume. You now have a mass difference between the actual film and the calculated solid volume, you can use this to get a relatively accurate porosity value. My original method is more accurate though.

X-ray reflectivity technique is a good technique for determination of density of thin films and multilayer. By this technique you can also determine the film roughness. Various software are available freely on net for the x-ray reflectivity data analysis. You can easily determine the film density, film thickness, surface roughness, electron density profile in a single measurement. One measurement is typically an issue of 10 minutes.

AFM @ Atomic Force Microscopy is better than SEM. AFM can show 3D character with the best resolution to determine the roughness, porosity, grain size and also with SEM characters. The nanosize particles of the film can easily be seen by AFM. And then we can calculate the density with appropriate formula.

Hi, you can also try to cleave your substrate after deposition and go for cross-sectional SEM imaging and subsequently try the ImageJ analysis as few people pointed out. This may give you both surface and volume porosity information

You can measure the density of thin film by pressureof-flotation method (PFM). A density difference is determined by the PFM while a mass difference is measured by an electric balance for the samples before and after thin-film is prepared on a substrate. Then, the density and thickness of the thin-film on the substrate can be derived. The density and thickness of a any thin-film prepared on a silicon substrate are evaluated by this method.

Pleas also go through the attached papers.....

The weight gain method is usually followed by many researchers, and I don't know about it's accuracy based on my personal experience. Is it provide accurate results if the deposition is very very thin? More over you need a high precision weigh scale. In weight gain method, first weigh the substrate prior to deposition, then take the weight after the deposition of the film. From this you can find.....! If you don't have any other way, then you can follow the weight gain method-really simple. If need some good results, then better go for SEM or AFM, as these techniques provides more accurate results. The thickness and density of metallic thin films can be measured by other X-ray methods like, X-ray reflectivity and total reflection X-ray fluorescence spectrometry (TXRF). The thickness and density can be determined from the incident angle scan data. If you are interested in this method, you can check this paper, which is avaiable free to download from - http://goo.gl/FUjmc

X-ray reflectivity technique (XRR) is a good technique for determination of thickness and density of thin films. Also they gives you an idea if you have a single layer or multilayer. If your film is thick enough, the measurement takes 5 minutes.