Advantage of fingering layout for transistors


FREE IEEE PAPERS

fingering is to optimize the resistance of the gate poly along the width of the transistor. Since the gate poly is driven from one end and gate poly is resistive, there may be reason to have a guideline that states the maximum width of a single finger. Fingering is the only way to meet this guideline for large transistors.

There is an advantage with an even number of fingers: the active capacitance is less, because the drain region is surrounded with gate poly instead of field.



Why it is beneficial to have the transistors divided into an even number of fingers?
Even numbers of fingers are better because it makes the device layout symmetric. You have two sources and one shared diffusion. In the case of a source coupled differential pair, since the sources are common, you can share source diffusions of device A with device B

What is fingers in transistors?
finger means how many gates a transistor has while multiple is how many times a transistor is repeated. in the case of 3 fingers and 2 multiples, you may layout a single transistor with 6 fingers; that is acceptable

What is number of fingers in Mosfet?
When laying out a MOSFET with a particular width and length, in an EDA tool, one has two options with regards to the shape of the gate: 1) Single stripe

IEEE PAPER UNITED STATES