Charged Particle Beam Detection Unit with Multi Type Detection Subunits
AssigneeHermes Microvision, Inc.
InventorsJoe Wang, Xu Zhang, Zhongwei Chen
Life of this patent
Estimating the term…
Abstract
A detection unit of a charged particle imaging system includes a multi type detection subunit in the charged particle imaging system, with the assistance of a Wien filter (also known as an E×B charged particle analyzer). The imaging system is suitable for a low beam current, high resolution mode and a high beam current, high throughput mode. The unit can be applied to a scanning electron inspection system as well as to other systems that use a charged particle beam as an observation tool.
Claims16
A method for imaging a specimen surface by directing signal charged particles to a specified detection area, the method comprising:
- providing a charged particle beam system to irradiate primary charged particles onto the specimen surface;
- providing a detection unit which includes a multi type detection subunit to receive the signal charged particles emanating from the specimen surface, wherein the detection unit has at least two subunits for different detection purposes;
- providing an E×B charge particle analyzer to direct the signal charged particles emanating from the specimen surface to the two subunits set by a control computer, wherein the control computer calculates superimposed magnetic field strength and electrostatic field strength of the E×B charge particle analyzer that diverts the emanating electrons;
- and
- generating images based on detected signal particles received by the detection unit.
A system for inspecting a specimen utilizing a charged particle beam, the system comprising:
- a charged particle imaging system arranged to provide a specimen surface image;
- a detection unit which includes a multi type detection subunit coupled to receive signal charged particles emanating from a surface of the specimen, wherein the detection unit has at least two subunits for different detection purposes;
- an E×B charge particle analyzer constructed to direct the signal charged particles emanating from the specimen surface to the subunits;
- and
- a control computer configured to set and calculate superimposed magnetic field strength and electrostatic field strength of the E×B charge particle analyzer that diverts the emanating electrons.
A detection unit of a charged particle imaging system, comprising:
- a first sub detection unit for handling larger signal currents;
- a second sub detection unit with high gain, wherein the first sub detection unit and the second sub detection unit are configured in or on an objective lens of the charged particle imaging system to receive signal charged particles from a specimen to be detected, and wherein a center hole is configured between the first sub detection unit and the second sub detection unit to allow a primary beam of the charged particle imaging system to pass therethrough to the specimen;
- and
- an E×B charge particle analyzer between the specimen and the first sub detection unit as well as the second sub detection unit, wherein the signal charged particles are controlled by the E×B charged particle analyzer.
Dependencies are inferred from the claim text.