Patent ID: 7603891
Filing Date: 2009-10-20
Classification: B82Y,G01Q

Abstract:
1. A method of operating an atomic force microscope, comprising: exciting a probe tip of a cantilever at or near a resonant frequency of the cantilever which forms a first eigenmode, while keeping the tip sufficiently far from a sample having a surface that said cantilever oscillates at a free amplitude A changing the relative distance in a Z direction between a base of the cantilever and the sample surface to an amount where a detected amplitude A scanning the sample by creating relative movement between the tip of the cantilever and the sample surface, while using a feedback loop to control the distance between the base of the cantilever and the sample surface so that the amplitude A exciting the probe tip of the cantilever at or near a second eigenmode of the cantilever, where said second eigenmode of the cantilever is a different eigenmode than said first eigenmode, said scanning being at an amplitude A adjusting the amplitude A varying the amplitude A measuring the amplitude and phase of the first and second eigenmodes of the cantilever as measured characteristics of the sample.