How to make a 100pH inductor with a line ?

Hi people,

I want to make a 100pH unductor in tsmc 180nm. The minimum tech inductor is 200pH so i have to make it myself by designing a line. Do you have any tutorial or can you give me some hints ?

15 Q is enough or minimum 10 is ok.

Tnx :)

Serpentine Line will give you low valued inductance.Their Q factors are quite high..

I meant layout. I am making it on-chip.

basically you make the line as thin a width as possible--giving you the highest impedance possible. Then you take the impedance of a 100 pH inductor at the frequency you want to operate at, and make the series transmission line match that impedance. This will only actually match at narrowband, like 10% bandwidth max.

I meant too.I realized a very small inductor in serpentine form using with 0.25 GaAs proccess.
If you don't have sufficient area, consider a single/double turn inductor.There are many literature on calculation of planar inductors.
The task will be cut-and-try method but it will converge at last.I recommend you to use ADS/Sonnet EM simulator because they are VLSI substrate compatible.