Does anybody know why is N2 or Ar (gas) used as an ambient inside of a RTA or normal furnace when dopant diffusion on silicon is done?. why not just vacuum? Many thanks
The manner in which I used RTA required both rapid heating and rapid cooling. In my system, cooling was accomplished primarily though the gas. N2 and Ar are used because they are inert. I sometimes used He to improve thermal dissipation.
I also agree with opinions suggested by Jameas and Tillmann. When you use a normal furnace with an ambient of inert gas temperature uniformity of the silicon substrate would be better than the case of using vacuum system due to convection effect. In the case of RTA James and Tillmann already answered your question. Moreover why do you want to use expensive/cumbersome vacuum system for activation annealing?
Actually, I have just access to a sputtering chamber equiped with a rotating substrate heating system to make my tests, but this heating system doesn´t work at atmosphere pressure, (security reasons!!!?? I thought).
That is why I asked about the ambient gas, if these gases (N2, Ar) doesn´t help in the diffusion process and are used just to transfer heat, heating could be done on vacuum and maybe cooling down on N2 or Ar partial, or atmospheric pressure.
Thanks a lot for your feedback
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