Imaging of suspended silicon nanonwires (SiNW) by SEM reveals that some of the SiNW are buckled. Buckling can impact device performance and it is therefore important to characterize this phenomenon. Measuring the buckling of suspended silicon nanowires (SiNW) poses significant challenges: Small dimensions - SiNW are made with diameters ranging from about 3 to 10 nm and the buckling is of a similar scale. Accurate height measurements - buckling is a three dimensional phenomena. To meet these challenges a new height map reconstruction technique was introduced, using the CDSEM side detectors signal. Measuring pixel by pixel position in X, Y and Z (height) dimensions, we can obtain the buckling vector gradient along the wire in three dimensions. In this paper we present: A description of the height map reconstruction technique used. Three dimensional characterization of SiNW: SiNW buckling measurements Characterization of buckling as a function of the SiNW length and width. © 2013 SPIE.