Drain to bulk breakdown voltage

Hi everyone!
I need to know the Drain to bulk breakdown voltage of CMOS 0.18um technology, but I couldn't find it in the pdk, there is nothing even about junction breakdown of diodes! does anyone know the VBD of drain to bulk or some estimation of it?
it is always said that the drain voltage can be twice the vdd, but there is nothing about the actual limit. what if I need to increase it to 4 or 5 times of vdd (assume I have been careful of the gate drain and gate source VBD)?

thanks a lot!

check this maybe it will help you.

https://www.edaboard.com/showthread.php?t=201308