Hi,
First find out which diode you need for your design.?
There are many types of diodes, Ndiode, PDiode, Nwell Diode, DeepNwell Diode, RF Diodes, native diodes, Schottkey Diode etc. Again in some of this like Normal Ndiode and Pdiode we have lowVT high VT, medium VT diodes. Again in some designs we need overdrive and underdrive capability diodes.
See what type of diodes your Process and technology nodes support from DRM( Design rule Manual) given by the foundry. and then find out what are all the specific layers you need for the specific diode layout from your DRM. There are different layers like VTH_N, VTL_N, VTH_P, VTL_P layers also for different vt devices. Similarly there are NT_N fabrication layers for native diodes.
The Layout of each one of the above diodes differs!!!!.
Please Note : Different Process types: Low Power, general Purpose etc.
If you get back which diode you actually need, we can tell how to draw the layout.
Thanks
vlsi123