Parallel atomic force microscopy with optical interferometric detection

We have developed an atomic force microscope that uses interferometry for p arallel readout of a cantilever array. Each cantilever contains a phase sen sitive diffraction grating consisting of a reference and movable set of int erdigitated fingers. As a force is applied to the tip, the movable set is d isplaced and the intensity of the diffracted orders is altered. The order i ntensity from each cantilever is measured with a custom array of silicon ph otodiodes with integrated complementary metal-oxide-semiconductor amplifier s. We present images from five cantilevers acquired in the constant height mode that reveal surface features 2 nm in height. The interdigital method f or cantilever array readout is scalable, provides angstrom resolution, and is potentially simpler to implement than other methods. (C) 2001 American I nstitute of Physics.