layout question -- diff. b/w material of n-well and n-diff

[vikram789]

hi, i would like to know the diff. b/w the materials for nwell and n-diff bcoz while making bulk/substrate connection for pmos we use :

metal + contact + n-diff + nseltap (this is just to mark active region for tapping connection) + nwell .

my question is why we are using extra layer of n-diff here.

 

[Fady Atef]

Re: layout question -- diff. b/w material of n-well and n-di

hi vikram789

The Nwell layer is lightly doped region, so we need the N+diff to create highly doped region for the contacts