Undercut measurement using sem
AssigneeKLA-Tencor Technologies Corporation
InventorsGian Francesco Lorusso, Luca Grella
Life of this patent
Estimating the term…
Abstract
The disclosure relates to measuring an undercut of a feature on a specimen using a scanning electron microscope (SEM). In accordance with one embodiment, a method for measuring the undercut includes illuminating the feature with a primary electron beam at an incident angle, changing the incident angle of the primary electron beam over a set of angles, measuring an intensity of scattered electrons from the feature for each incident angle in the set of angles, and determining a discontinuity in the intensities as a function of the incident angle.
Claims21
A method for measuring an undercut of a feature on a specimen using a scanning electron microscope (SEM), the method comprising:
- illuminating the feature with a primary electron beam at an incident angle;
- changing the incident angle of the primary electron beam over a set of angles;
- measuring an intensity of scattered electrons from the feature for each incident angle in the set of angles;
- and
- determining a discontinuity in the intensities as a function of the incident angle.
A method for measuring an undercut of a feature on a specimen using a scanning electron microscope (SEM), the method comprising:
- illuminating the feature with primary electrons at an incident angle;
- measuring an intensity of scattered electrons from the feature by a plurality of detectors at a set of scattering angles;
- and
- determining a discontinuity in the intensities as a function of the scattering angle.
A scanning electron microscope (SEM) for measuring an undercut of a feature on a specimen, the SEM comprising:
- an electron illumination system for illuminating the feature with a primary electron beam at an incident angle;
- a mechanism for changing the incident angle of the primary electron beam over a set of angles;
- a detector for measuring an intensity of scattered electrons from the feature for each incident angle in the set of angles;
- and
- a processor for determining a discontinuity in the intensities as a function of the incident angle.
An apparatus for measuring an undercut of a feature on a specimen, the apparatus comprising:
- means for illuminating the feature with a primary electron beam at an incident angle;
- means for changing the incident angle of the primary electron beam over a set of angles;
- means for measuring an intensity of scattered electrons from the feature for each incident angle in the set of angles;
- and
- means for determining a discontinuity in the intensities as a function of the incident angle.
Dependencies are inferred from the claim text.