Why we increase the number of metals and polys for routing?

[p_shinde]

Technology related query

hi,

as its becomes congested to do routing for the few number of metals, we are increasing number of metals, then at the same point why r they increasing number of polys, as we dont use poly for routing?????

thanks in advance,
Prasad

 

[preet]

Re: Technology related query

thru the different poly layer , we can incorporate many elements like capacitor of high value, and double gate MOS too.

 

[p_shinde]

Re: Technology related query

do u mean fingering by 2 polys????????? we can achieve that with single poly too!!!!!!!!!!!

thanks,

Prasad

 

[preet]

Re: Technology related query

both the poly are in different plane not in the same plane,thus it is very helpful as i said in previous post

 

[p_shinde]

Re: Technology related query

while drawing layouts its 2 dimensional, so which plane would u consider?


does that means poly1 in one transistor , and poly2 in its neighbouring transistor?

would be more clear if i see a snapshot of it, if possible.


thanks,
Prasad

 

[arimilli_r]

Re: Technology related query

Hi ,
poly1 and poly2 may be used in multi(High,low) vt cells, may to differenciate the high vt and low vt (certainly the sio2 layer thickness is different in both) it may be poly1 and poly2.

Thanks,

Rajesh

 

[preet]

Re: Technology related query

Hello P_shinde,

Though we are designig the layout in two dimension,but u have to think in three dimension also, Poly1 and poly2 are in different plane, if u see the cross section view of it then u will be able to find the answer.

Regards

 

[arimilli_r]

Re: Technology related query

Yes, incase of flash memories we have to gates for a transistor one floating then 1 may be poly1 and poly2 respectively.

Thanks,

Rajesh