how standard cell height is dependent on transistor width

[sudhachocky]

Hi,
Transistor width can be increased by using double-height cells or by increasing the finger.
So, how cell height is dependent on transistor width?

Thanks & Regards,
Sudha

 

[artmalik]

the standard cells are designed to have a certain pmos/nmos width depending on the p/n ratio for optimal performance. Actually double hieght cells are done for complex cells as they require routing resources. But even in double height cells the pmos/nmos widths for a single finger is controlled by the height of single height cells.

so making the cell taller will give one more resources but the impact is the low drive cells with sub-finger widths there is a waste in area. Basically the height is very strong parameter of routing the devices and whether you can design a flop without using higher metal layers. it was prefered that all the metal routing within the cell is Metal 1 but now Metal2 is used in the designs.

Hi,
Transistor width can be increased by using double-height cells or by increasing the finger.
So, how cell height is dependent on transistor width?

Thanks & Regards,
Sudha