Extension cord for 220 outlet?
Depends what you mean by "make".  

If you mean hokey-doke something together out of random bits, then no.  

But if you have the skill/experience/attention to detail, that is needed for good workpersonship... and go down to a competent electrical supplier and get some #14/3 SJOOW cordage (noting that cordage numbering does count the ground)... and get a NEMA 6-15R socket and 6-15P plug whose strain relief is compatible with the cord size... and assemble them competently according to instructions... and the strain reliefs work properly on the cable sheath... and you check it in-service for heat where none should be... then yeah. Build away. 

It could also be built with 6-20 plug/socket and 12 AWG cordage.  However the plug and socket must match, and a 6-20 plug will not fit a 6-15 (Ms. Nope) socket in the wall.