A Second-Order Aberration Compensation Method for High-Resolution Large-Scan Field System

Abstract

The invention discloses a second-order aberration compensation method for a high-resolution large-scanning field system. When there is a deflection system, the field function is expanded to analyze the electronic optical characteristics of the system along the vicinity of the optical axis at this time. Second-order aberrations due to deflection. Using the electrostatic octopole deflector, by applying voltage signal excitation to the arc electrodes, the deflector can generate the required quadrupole field, which is superimposed on the electrostatic deflector. Calculate the optical characteristics of the entire imaging system or detection system, and control and adjust the azimuth angle and excitation intensity of the added quadrupole field according to the calculated results after superimposing the quadrupole field, so as to achieve the compensation of the second-order aberration caused by the deflection of the system.

Description

technical field [0001] The invention relates to the fields of electron beam imaging and electron beam defect detection, in particular to a second-order aberration compensation method for a high-resolution large scanning field system. Background technique [0002] With the development of semiconductor technology and the advancement of process technology, the size of devices continues to shrink, and those defects and particles that were not important at previous nodes may have a fatal impact on device performance. At the same time, due to the introduction of new materials, the development of new processes and the use of a new generation of photolithography technology, many new defects have been brought about. In order to meet the needs of physical research and the production of semiconductor devices and integrated circuits, electron beam imaging systems and detection equipment are required to have higher resolution and larger scanning fields. [0003] What was pursued before ...

AI Technical Summary

Problems solved by technology

[0004] In the current electron beam imaging system and detection equipment, a stigmatizer device is often added separately to the system, which is only used to eliminate the astigmatism problem on the axis of the system, without considering the deflection aberration caused by deflection. Moreover, due to the flaws in the analysis of the existing methods, there is no effective consideration and analysis of the second-order aberration, and there is no implementation method for correcting it.

Images