on wafer sol calibration

I'm measuring a DUT on probe station, so I need to move the reference plane to the probe tip using open-short-load calibration.

I searched on google and all I can get are about 2-port SOLT calibration, but my DUT only has 2 pads so I guess those are not for my application...

Any suggestions? Is it possible to make my own sol calibration kit by some standard, or I have to buy a kit?

Thanks!