Nanoindentation hardness measurements using atomic force microscopy

An atomic force microscope (AFM), with a specially prepared diamond tip, has been modified to measure indentation hardness with an indentation depth as low as 1 nm. This indentation depth is much smaller than the depth of more than 20 nm that have been reported to date. The AFM indentation technique allows the hardness measurements of surface monolayers and ultrathin films in multilayered structures at very shallow depths and low loads. The nanoindentation hardness of single crystal silicon is measured using this technique. A subtraction technique is also described which allows the actual hardness measurements of rough surfaces such as magnetic thin film rigid disks.