shuichi
Newbie level 2
Really need some help with this issue....
There is a minimum distance design rule for the polysilicon gate contact to the gate area, such that the contact cut is on top of the thick FOX instead of directly above the thin gate oxide.
The reason for such a rule may be due to junction spiking of Aluminum diffusing into Silicon/polysilicon with in direct contact. This is valid for older technologies whereby W-plugs or barrier layers are not in use yet.
With the introduction of W-plugs and barrier layers as 'cushions' that prevent direct contact of aluminum with silicon. Are there any potential reliability issues if we violate this rule and have the contact cut DIRECTLY on top of the transistor gate with thin gate oxide below it???
There is a minimum distance design rule for the polysilicon gate contact to the gate area, such that the contact cut is on top of the thick FOX instead of directly above the thin gate oxide.
The reason for such a rule may be due to junction spiking of Aluminum diffusing into Silicon/polysilicon with in direct contact. This is valid for older technologies whereby W-plugs or barrier layers are not in use yet.
With the introduction of W-plugs and barrier layers as 'cushions' that prevent direct contact of aluminum with silicon. Are there any potential reliability issues if we violate this rule and have the contact cut DIRECTLY on top of the transistor gate with thin gate oxide below it???