Methods for maintaining gap spacing between an optical probe of a probe system and an optical device of a device under test, and probe systems that perform the methods

Abstract

Methods for maintaining gap spacing between an optical probe of a probe system and an optical device of a device under test and probe systems that perform the methods. The methods include determining a desired relative orientation between the optical probe and the DUT and optically testing the optical device with the optical probe. The methods also include maintaining the desired relative orientation during the optically testing. The maintaining includes repeatedly and sequentially collecting an existing DUT image of a DUT reference structure of the DUT and an existing probe image of a probe reference structure of the optical probe, determining a probe-DUT offset between an existing relative orientation between the optical probe and the DUT and the desired relative orientation, and adjusting the relative orientation to return the optical probe and the DUT to the desired relative orientation.