What's the correct way of connecting gates and drain/source in multiple MOS layout?

[bernerdzl]

hey all,

i am confuse with the layout of multiple MOS. for example, i have a MOS with a size of 10 and assume i divided them evenly into 4 MOS with the size 2.5 each. may i know the correct way to connect the gates and drain/source?

should they connect in series or parallel as shown in the attachment and the reason why. please advise.

thank you so much and have a nice day.


best regards

 

[erikl]

Re: Multiple MOS layout

may i know the correct way to connect the gates and drain/source?
should they connect in series or parallel as shown in the attachment and the reason why.

Always in parallel, always to one side (doesn't matter which one).
Why? Minimize parasitic capacitance!
S. the example from the CMOS Transistor Layout KungFu book below.

 

[leozuo]

Multiple MOS layout

it is better not to route metal wire right above transistor..

 

[protonixs]

Re: Multiple MOS layout

In erikl's attachment, the second illustration is better than the third because the gates are not connected with poly. This reduces antenna effect during poly layer etching.

 

[dipak.rf]

Re: Multiple MOS layout

Obviously in parallel, drain and source are interchangable.

it seems you are new to IC layout, Not to worry i would suggest you to first go through the basic IC layout books or tutorial and start doing it.........

 

[bernerdzl]

Re: Multiple MOS layout

thank you so much for the help.

dipak.rf, can you pls suggest any good books or tutorials for beginners like me?

Thank you so much

 

[deepak242003]

Multiple MOS layout

IC layout basics by christoper and JUdy Saint is gud to start wiht... For more deeper understanding your can move on with art of analog layout

 

[sparkyung]

Re: Multiple MOS layout

Of couse you should connect S/D in parallel, respectively.
And connect gate all together.
You'd better to connect gate by metal rather than poly, and put more contacts (two is ok for most layout) if it will not hurt your area.