Design of an Ultra-High Resolution SEM for Enhanced Analysis
The column is equipped with a well-known single-pol e bjective lens [2] that creates a strong magnetic  field around the sample, thus dramatically decreasi ng optical aberrations. Design optimization and combining the magnetic immersion field with the ele ctrostatic field [3] further improves the resolutio n to less than 1.1 nm at 1 kV. For analytical purpose s (EDS or EBSD) or for use with a FIB column however, the immersion magnetic field becomes a com plication due either to curvature of signal electron trajectories or beam splitting of ion-isot opes.
A New SEM Column Combining Ultra-High Resolution and Flexible Scanning
The critical parts of the scanning electron microscope optical system are the technology of the objective lens (that determines the resolving power) and the configuration of the deflecting elements used for scanning. However, requirements for high resolution, high beam deflection and analytical compatibility are usually in conflict with each other because of design limitations. A significant advance towards the optimal design was the introduction of Wide Field Optics technology incorporating two objective lenses located below and above the double-stage scanning deflectors. This configuration provides several display modes which delivers both high resolution imaging and a large field of view using optimization of the scanning pivot-point position and an advanced engine for correction of optical distortion. The technology further allows a mode with controlled depth of focus and a rocking beam mode with the pivot point on the sample [1]. Another technology uses ultra-high resolving power with immersion optics, but the resolution in magnetic-field-free mode is lower [2].
High‐resolution focused ion beam lithography
The resolution and alignment accuracy of FIB lithography is studied for making devices with 0.1 μm dimensions. 0.1‐μm linewidth patterns are successfully fabricated by 260‐keV Be++ FIB for both positive and negative resists. 50‐nm linewidth Novolak based negative resist patterns are fabricated at 1.0×1012 ions/cm2 dose by 260‐keV Be++ FIB. Dot patterns with 0.3 μm diam and high density (108/cm2) are written on a 1×1 cm area in a PMMA resist to demonstrate that FIB lithography can be applied to make practical devices with a large writing area. Moreover, mark detection and overlay accuracy are studied for marks covered with PMMA and CMS resists. Finally, FIB lithography is applied to fabricate 0.1‐μm NMOS gate patterns. The overlay accuracy for hybrid exposure using FIB and an optical stepper is 0.2 μm at 2σ.