During semicontact measurements jumps in topography appear during the scan process, that correspond to the measured height changes abruptly by about 2 nm and the change of phase is very high too. Do you have any recommendation how to avoid this problem?
Firstly, please, measure a curve Mag(Height) and look if it is straight or if it has a small leap somewhere in the middle. Most probable, it has. This leap appears due to pobe's immersion into a field of repulsive forces. Amplitudes less then position of a leap correspond to the repulsive mode (or to a regyme of mixed types of forces for high oscillations amplitudes). Amplitudes higher than position of a leap correspond to the attractive mode. To avoid this effect you should decrease or increase SetPoint or change the amplitude of the generator. SetPoint should be on a linear part of Mag(Height) curve, not on a leap.