| 摘要 |
Two dimensional profiling of samples, such as integrated circuits containing trenches or lines, is accomplished using contact force atomic force microscopy by controlling the tip position responsive to the real-time measured local slope of the surface in contact with the tip. The tip is brought so close to the surface of the sample to be investigated that the forces occurring between the atoms at the apex of the tip and those at the surface cause a spring-like cantilever to deflect. The deflection of the cantile ver provides a variation of a tunnel current, and that variation is used to generate a correction signal which can be employed to control the distance between the tip and the surface of the sam ple, in order, for example, to maintain the force between the tip and sample constant as the tip is scanned across the surface of the sample by means of an xyz-drive. The tip (10) which is coupled to the cantilever (12) of an atomic force microscope is disposed within a trench (14) located in the sample substrate (20), the sidewalls (16, 18) of which are to be profiled. Preferably the tip (10) has a "boot" shaped cross-section in order to enable sensing of a bottom corner of a trench or line. <IMAGE> |
