| 摘要 |
Improved scanning methods for use in a scanning particle beam microscope reduce the effects of surface charge accumulation, increasing linearity and precision. More particularly, signal distortion is reduced by scanning across an object (71) along a line in a first direction to produce a first signal, scanning across an object (71) along the identical line in an opposite, anti-parallel direction to produce a second signal, and combining the first and second signals. This technique is referred to as scan reversal. Baseline drift is substantially canceled out of the resulting signal. According to another technique imaging of a general circular high-aspect-ratio structure is enhanced by identifying approximately the center of the structure, electrostatically scanning a particle beam (14) along a multiplicity of radii (R1...Rn) of the structure (73), detecting particles emitted from the surface of the structure being examined to generate a detection signal, and using the detection signal to form an enhanced image of the generally circular high-aspect-ratio structure (73). This technique is referred to as radial scanning. |
