The present invention provides a charged particle beam apparatus that covers a wide range of detection angles of charged particles emitted from a sample. Accordingly, the present invention proposes a charged particle beam apparatus that is provided with an objective lens for converging charged particle beams emitted from a charged particle source, and a detector for detecting charged particles emitted from a sample, wherein: the objective lens includes an inner magnetic path and an outer magnetic path which are formed so as to enclose a coil; the inner magnetic path comprises a first inner magnetic path disposed at a position opposite to an optical axis of the charged particle beams and a second inner magnetic path which is formed at a slant with respect to the optical axis of the charged particle beams and which includes a leading end of the magnetic path; and a detection surface of the detector is disposed at the outer side from a virtual straight line that passes through the leading end of the magnetic path and that is parallel to the optical axis of the charged particle beams.

This invention provides a charged particle source, which comprises an emitter and means of generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.

A magnetic lens is disclosed, which includes: a magnetic yoke, an exciting coil and a power supply controlling system. The magnetic yoke is at outside of the exciting coil and surrounds the coil; the exciting coil is made up of litz wires; the power supply controlling system is arranged to supply power to the exciting coil and control the flow directions and magnitudes of the currents in the exciting coil. A method for controlling the magnetic lens is also disclosed.

A charged particle microscope and a method of operating a charged particle microscope are disclosed. The microscope employs a source for producing charged particles, and a source lens below the source to form a charged particle beam which is directed onto a specimen by a condenser system. A detector collects radiation emanating from the specimen in response to irradiation of the specimen by the beam. The source lens is a compound lens, focusing the beam within a vacuum enclosure using both a magnetic lens having permanent magnets outside the enclosure to produce a magnetic field at the beam, and a variable electrostatic lens within the enclosure.

Systems, methods, and components of charged particle microscopes affording improved contrast in dose sensitive samples are described. A pole piece for an electron microscope can include a body, being substantially concentric with a central axis. The body can define an upper surface, substantially normal to the central axis, a lower surface, substantially normal to the central axis, a central aperture formed in the body from the upper surface to the lower surface. The central aperture can be substantially rotationally symmetrical about the central axis. The body can define a lateral surface, inclined relative to the central axis and tapering toward the upper surface and a plurality of lateral apertures formed in the body from the lateral surface to the central aperture. The plurality of lateral apertures can be arrayed substantially symmetrically about the central axis.

This invention provides a charged particle source, which comprises an emitter and means fo generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.

In order to demagnetize the magnetic lens, an alternating attenuation current is applied as an excitation current, the alternating attenuation current oscillating such that a current value alternately becomes a first-polarity current I.sub.1(n) and a second-polarity current I.sub.2(n) in which n represents the number of times of amplitude variation. The first-polarity current I.sub.1(n) and the second-polarity current I.sub.2(n) are expressed as I.sub.1(n)=A??.sub.1(n), I.sub.2(n)=?A????.sub.2(n), in which oscillation of the alternating attenuation current is started from a first polarity, A represents an amplitude of the first-polarity current, ? represents an asymmetric coefficient, ?.sub.1(n) represents an attenuation function of the first-polarity current, and ?.sub.2(n) represents an attenuation function of the second-polarity current. The amplitude A of the first-polarity current is smaller than that of a saturation current of the magnetic lens, ?.sub.1(1)=?.sub.2(1)=1, and 0<?<1.

A charged particle microscope and a method of operating a charged particle microscope are disclosed. The microscope employs a source for producing charged particles, and a source lens below the source to form a charged particle beam which is directed onto a specimen by a condenser system. A detector collects radiation emanating from the specimen in response to irradiation of the specimen by the beam. The source lens is a compound lens, focusing the beam within a vacuum enclosure using both a magnetic lens having permanent magnets outside the enclosure to produce a magnetic field at the beam, and a variable electrostatic lens within the enclosure.

A magnetic gun lens and an electrostatic gun lens can be used in an electron beam apparatus and can help provide high resolutions for all usable electron beam currents in scanning electron microscope, review, and/or inspection uses. An extracted beam can be directed at a wafer through a beam limiting aperture using the magnetic gun lens. The electron beam also can pass through an electrostatic gun lens after the electron beam passes through the beam limiting aperture.

An electron beam microscope comprises an electron beam source, a beam tube, a magnetic objective lens, an object holder, a scintillator arrangement, a detector arrangement and a potential supply system. The power supply system supplies: i) the object holder with a potential U1; ii) the beam tube with a potential U2; iii) a pole end of the objective lens with a potential U3; iv) a scintillator body of the scintillator arrangement with a potential; and v) a light detector of the detector arrangement with a potential U5, such that:

[00001]$\left(U2-U5\right)?5000V;$$\left(U4-U1\right)?0.1*\left(U2-U1\right)$$.Math.U4-U5.Math.?0.1*\left(U2-U1\right),\mathrm{and}$