High-throughput specimen-inspection apparatus and methods utilizing multiple parallel charged particle beams and an array of multiple secondary-electron-detectors

US6465783B1 · kind B1 · utility

Assignee

• NIKON CORPORATION · JP

Inventor

• Mamoru Nakasuji · Yokohama, JP

Key dates

• Filing date: Jun 2, 2000
• Grant date: Oct 15, 2002
• Expiry date: Jun 2, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J2237/2813
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Apparatus and methods are disclosed for inspecting semiconductor wafers and other types of specimens using parallel charged particle beams (e.g., electron beams). An emitter array, including multiple charged-particle-beam (CPB) emitters produces multiple beams that propagate along respective beam axes. The beams pass simultaneously through projection lenses and a deflector so as to cause the beams to be focused simultaneously onto respective loci on the surface of the specimen so as to cause each locus to emit secondary electrons. The secondary electrons are detected by a secondary-electron (SE) array including multiple SE-detector units. Each SE detector unit receives and detects secondary electrons emitted from a respective locus. The deflector simultaneously scans the beams over respective regions on the specimen surface. Each SE detector is configured to detect secondary electrons but not backscattered electrons emitted from the respective locus. Alternatively, multiple channels can be provided, each channel corresponding to a respective beam. Each channel includes a respective set of lenses and deflectors for the respective beam. The channel pitch is adjustable to accommodate …