Apparatus and Method for Measuring Deformation of a Cantilever Using Interferometry

An apparatus for measuring deformation of a cantilever, comprising:

• a projection system for projecting a radiation beam onto a cantilever;
• and
• a measurement system for detecting radiation transmitted through or reflected from said cantilever, wherein
• said projection system is arranged such that the radiation transmitted through or reflected from said cantilever forms an interference pattern;
• said measurement system is configured to measure the spatial variation in intensity within at least a portion of said interference pattern;
• and
• said apparatus further comprises a deformation calculating system for calculating a deformation of said cantilever from the spatial variation in intensity measured by said measurement system, wherein the deformation calculated from said spatial variation in intensity consists of a change in shape of the portion of the cantilever through or from which the radiation forming said interference pattern is transmitted or reflected.

A method of measuring deformation of a cantilever, comprising:

• projecting a radiation beam onto a cantilever;
• and
• detecting radiation transmitted through or reflected from said cantilever, wherein:
• said radiation beam is projected onto said cantilever in such a way as to form an interference pattern in said transmitted or reflected radiation;
• and
• said method further comprises:
• measuring the spatial variation in intensity within at least a portion of said interference pattern;
• and
• calculating a deformation of said cantilever from the measured spatial variation in intensity, wherein the deformation calculated from said spatial variation in intensity consists of a change in shape of the portion of the cantilever through or from which the radiation forming said interference pattern is transmitted or reflected.