Electronic – meant by shallow diffusion in silicon fabrication technology

integrated-circuittransistors

I know this is a google before ask type question, but I didn't find the answer
still on google. Then I went to library and refer some books but my changes were
negative. I've searched more than 20 appendixes of books.

There are specific patents and there's no wiki page written on shallow diffusion.

Could you explain in simple what is called shallow diffusion? I mean in
general.

–Thanks In Advance–

Best Answer

In general, diffusion is one of the main ways in which doping changes are made in selected regions on the surface of a wafer. A fluid (gas or liquid) containing the desired dopant is flowed across the surface, which is masked appropriately. The time and the temperature of the wafer determine the depth of the diffusion.

Any particular fabrication "process" will typically involve several diffusion steps, with the deepest ones being done first, and the shallowest ones being done last. Other than that, there really isn't anything special about "shallow" diffusion.