There are different arrangements in a typical sputtering system.

downwards, upwards and sideways.

I find the sideways sputtering to be the best arrangement to avoid any kind of dust settling onto the substrate while the film is being grown.

Clean you substrates thoroughly, do not wipe them with any kind of tissue.

Vapor degreasing is the best method to clean the substrates.

Finally if it is possible to apply rf power onto your substrate heater, insitu cleaning of the substrates by light rf power etch say at 25 to 30W  for about 10 minutes first in Argon and then in O2. If you have some substrate temperature say 100 to 200 deg C. it is all the best.

Please note your substrate hold must be absolutely clean.  If it is made of stainless steel, it should be shining. No previous deposit. 

The whole arrangement (Target and substrate) should be sideways, which means they are vertically mounted in parallel to each other, at an appropriate substrate to target distance.

I have greatly benefited with the sideways arrangement in my sputtering system. 

Prof. K. Sreenivas

Dear Prof. K. Sreenivas,

Thanks for your fast replies. My sputtering system is sideways. The substrate will transport horizontally from load chamber to sputtering chamber and last unload chamber. Based from my experience, we already develops best condition for chamber to eliminate or minimize the particle effect while deposition. Every time we want to deposit, we will run this pre-sputter process where argon gas use and target(Cr) powered with 4kW.   

Can I know why you consider O2 gas with argon? Is is insitu cleaning need o2 gas?

cleanliness is the key issue. Make sure your sample is free from dust   i.e. use appropriate cleaning techniques and store samples in a vacuum.

Use sputtering with a target cleaner installed that will help reduce contamination build up on your sample. Use high purity gases as part of the deposition process.

Insitu cleaning of substrates using low rf power of about 50 W, for about 5 minutes, at a sputtering pressure of 15 milli torr, has greatly helped.

Any residual organic contaminants on the substrate surface can be remove very effective with O2 sputter cleaning, they will form Co2, and can be pumped out.

K. Sreenivas 

Dear Prof. K. Sreenivas,

how to eliminate pinhole in deposition process ? Thanks