I am preparing thin films of metals using thermal deposition and using glass as substrate but quality of film is very poor so is it due to the smooth surface of glass or amorphous surface of glass or should i take a crystalline substrate?
Quality of film depends on substrate surface or not?
There are many factors which decides quality of thin films including substrate properties. Major factors are generally deposition parameters (Type of material, purity, temp and vacuum). What kind of properties you are looking for? (conductivity, hardness, reflectance) Metal coating on smooth surface glass would be generally good. Here also glass cleaning is critical . Type of cleaning (plasma, ultra-sonication, alkaline-acidic solution based etc)also will have vital effect on adhesion Your films are poor in what aspect of quality?
What is your Coating material? At what chamber pressure you are doing thermal deposition?
to begin with you can simple use glass slides, which have been thoroughly cleaned with Acetone and IPA. Vapro degreasing methd is the best, rather than wiping with tissue and a little bit of acetone.
K. Sreenivas
Many parameters will dictate the quality of the thin film you are trying to fabricate.
It is in your best interest to give as much detail as possible about your materials, process, and parameters for that process before anyone can give you an actual answer.
Many parameters will transcribe the quality of the thin film you are to fabricate.
It is to give much detail about type of your materials, process, and parameters for that process
Dear Binay,
Better cleaning of glass plates will help. Degassing of glass plates in the deposition chamber at higher temperature for an hour will also help.For good cleaning you keep glass plates in chromic acid for at least one day. Use deionized water with some detergent to clean them in ultrasonic cleaner. Finally vapour cleaning in isopropyle alcohol vapours should be done. Deposit films at higher vacuum. I hope you will get good films.
Dear, if good quality means good adherence the
Clean the substrate chemical ly and then by plasma
Ionization. Smoothness will not mtattert
Smooth substrates should be fine. Glass an crystal. Rough will lead to non uniform thickness, but adhesion in my opinion should be also OK. As already suggested, try different cleaning of the substrates and check the vacuum. Check if your substrates are heated significantly during the process (different thermal expansion/shrinking of substrate vs film).
Are you evaporating alloy or pure metal? Do you start deposition on the substrate at steady rate (do you have moving plate between source and substrate and if deposit some on the moving plate or all is deposited on the substrate. Sorry forgot the word for this moving plate/cover)? Are your films moisture sensitive?
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