Swinging retarding immersion type lens electron optics focusing, deflection and signal collection system

Abstract

A swinging objective retarding immersion lens system and method therefore which provide a low voltage electron beam with high beam current, relatively high spatial resolution, a relative large scan field, and high signal collection efficiency. The objective lens includes a magnetic lens for generating a magnetic field in the vicinity of the specimen to focus the particles of the particle beam on the specimen, an electrode having a potential for providing a retarding field to the particle beam near the specimen to reduce the energy of the particle beam when the beam collides with the specimen; a deflection system including a plurality of deflection units situated along the beam axis for deflecting the particle beam to allow scanning on the specimen with large area, at least one of the deflection units located in the retarding field of the beam, the remainder of the deflection units located within the central bore of the magnetic lens; and an annular detection unit with a relatively small aperture, located underneath the primary beam define aperture, to capture secondary electron (SE) and backscattered electrons (BSE).

Description

technical field [0001] The present invention generally relates to a scanning electron microscope, and in particular relates to a focusing and deflection system and method of a rotary deceleration submerged objective lens electron optics. range, and high signal capture efficiency. Background technique [0002] Scanning electron microscopes are used in many applications where the very small structures of objects need to be examined in great detail. Some of these applications include applications such as defect viewing and inspection of samples of very large scale integrated (VLSI) circuits, or chips, or other objects, the determination of detailed critical dimensions in these samples, and the design and processing of samples. Identification. Due to the short wavelength of the spot size generated by the scanning electron microscope, it is generally about 0.2μm or smaller (1μm=10 -6 m) In the submicron scale, the scanning electron microscope is considered to be superior to th...

AI Technical Summary

Problems solved by technology

As a result, detection can only be performed simultaneously on relatively small sample portions without repositioning the sample

Second, the time required to inspect, view and measure a sample is substantially long because of the inherently small deflection range

This not only results in increased IC turnaround time, but also increases the cost of process, test, inspection, troubleshooting and production

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