Charged particle beam apparatus

摘要

The present invention provides apparatuses to inspect small particles on the surface of a sample such as wafer and mask. The apparatuses provide both high detection efficiency and high throughput by forming Dark-field BSE images. The apparatuses can additionally inspect physical and electrical defects on the sample surface by form SE images and Bright-field BSE images simultaneously. The apparatuses can be designed to do single-beam or even multiple single-beam inspection for achieving a high throughput.

主权项

1. A single-beam apparatus, comprising:
an electron source emitting primary electrons along an optical axis of said single-beam apparatus and said primary electrons form a primary electron beam; a gun aperture plate below said electron source and having at least one first opening, wherein one of said first openings is aligned with said optical axis and limits a current of said primary electron beam to a first current value; a condenser lens below said gun aperture plate and aligned with said optical axis; a beam-limit aperture plate below said condenser lens and having at least one second opening, wherein one of said second openings is aligned with said optical axis and limits said current of said primary electron beam to a second current value; a magnetic objective lens below said beam-limit aperture plate and aligned with said optical axis; a first scanning deflector inside a bore of said magnetic objective lens; a first detector below said magnetic objective lens and having a through hole, wherein said through hole is on an electron detection plane of said first detector and aligned with said optical axis so that said primary electron can pass through; an attraction electrode beside said first detector; and a sample stage below said first detector and said attraction electrode and for supporting a sample and making a being-inspected surface thereof upturned,
wherein an illumination angle formed between said optical axis and a normal of said being-inspected surface is larger than 0°,wherein said condenser lens and said magnetic objective lens together focus said primary electron beam onto said being-inspected surface, thereby forming illumination thereon,wherein said electron detection plane of said first detector faces aslant said being-inspected surface so as to collect backscattered electrons which are generated therefrom by said primary electron beam and travel towards an incidence side thereof, wherein said backscattered electrons are Dark-field BSEs,wherein said attraction electrode attracts secondary electrons generated from said being-inspected surface by said primary electron beam so as not to hit said first detector,wherein said first scanning deflector deflects said primary electron beam so as to scan said being-inspected surface, thereby obtaining a Dark-field BSEs image by said first detector.