Abstract: An objective lens arrangement that may include a magnetic lens and an electrostatic lens. The magnetic lens may include one or more coils, an upper polepiece and a lower polepiece. The electrostatic lens may include an upper electrode, an internal lower electrode and an external lower electrode. A majority of the internal lower electrode may be surrounded by a majority of the external lower electrode. The upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement. An area of a bottom aperture of the external lower electrode may not exceed an area of a bottom aperture of the internal lower electrode.

Abstract: An objective lens arrangement that may include a magnetic lens and an electrostatic lens. The magnetic lens may include one or more coils, an upper polepiece and a lower polepiece. The electrostatic lens may include an upper electrode, an internal lower electrode and an external lower electrode. A majority of the internal lower electrode may be surrounded by a majority of the external lower electrode. The upper electrode, the internal lower electrode, and the external lower electrode are arranged in a coaxial relationship along an optical axis of the objective lens arrangement.

Abstract: A system and method for determining a cross sectional feature of a measured structural element having a sub-micron cross section, the cross section is defined by an intermediate section that is located between a first and a second traverse sections. The method starts by a first step of scanning, at a first tilt state, a first portion of a reference structural element and at least the first traverse section of the measured structural element, to determine a first relationship between the reference structural element and the first traverse section. The first step is followed by a second step of scanning, at a second tilt state, a second portion of a reference structural element and at least the second traverse section of the measured structural element, to determine a second relationship between the reference structural element and the second traverse section.

Abstract: A method and charged particle beam column are presented for directing a primary charged particle beam onto a sample. The primary charged particle beam, propagating along an initial axis of beam propagation towards a focusing assembly, passes through a beam shaper, that affects the cross section of the primary charged particle beam to compensate for aberrations of focusing caused by astigmatism effect of a focusing field produced by an objective lens arrangement of the focusing assembly, and then passes through a beam axis alignment system, that aligns the axis of the primary charged particle beam with respect to the optical axis of the objective lens arrangement.

Abstract: A system and method for determining a cross sectional feature of a measured structural element having a sub-micron cross section, the cross section is defined by an intermediate section that is located between a first and a second traverse sections. The method starts by a first step of scanning, at a first tilt state, a first portion of a reference structural element and at least the first traverse section of the measured structural element, to determine a first relationship between the reference structural element and the first traverse section. The first step is followed by a second step of scanning, at a second tilt state, a second portion of a reference structural element and at least the second traverse section of the measured structural element, to determine a second relationship between the reference structural element and the second traverse section.

Abstract: A method and system are presented for controlling inspection of a sample with a charged particle beam. A certain given voltage is supplied to an anode of the column to provide a required accelerating voltage for a charged particle beam. A certain negative voltage is supplied to the sample selected so as to provide a desirably high effective voltage of the column at said given voltage of the anode. A certain voltage is supplied an electrode of a lens arrangement located closer to the sample, this voltage being selected to satisfy one of the following conditions: the electrode voltage is either equal to or slightly lower than that of the sample; and the electrode voltage is significantly higher than that of the sample.

Abstract: A method and apparatus for use in monitoring a sample with a charged particle beam are presented. A mechanical displacement between a plane defined by the sample's surface and an optical axis defined by a beam directing arrangement is provided so as to orient the sample at a certain non-right angle ?1 with respect to the optical axis. A primary charged particle beam propagating towards the sample is deflected so as to affect the trajectory of the primary charged particle beam to provide a certain non-zero angle ?2 between the primary beam propagation axis and said optical axis.

Abstract: A method and system are presented for controlling inspection of a sample with a charged particle beam. A certain given voltage is supplied to an anode of the column to provide a required accelerating voltage for a charged particle beam. A certain negative voltage is supplied to the sample selected so as to provide a desirably high effective voltage of the column at said given voltage of the anode. A certain voltage is supplied an electrode of a lens arrangement located closer to the sample, this voltage being selected to satisfy one of the following conditions: the electrode voltage is either equal to or slightly lower than that of the sample; and the electrode voltage is significantly higher than that of the sample.

Abstract: A deflection system is presented for use in a lens arrangement of a charged particle beam column for inspecting a sample. The system comprises a magnetic deflector operable to create a magnetic field, and a pole piece assembly at least partly accommodated within the magnetic field. The pole piece assembly has a portion made of a soft magnetic material and is formed with an opening for a charged particle beam propagation therethrough. The deflection system allows for conducting the magnetic field created by the magnetic deflector through the pole piece assembly towards the opening in the pole piece assembly. This enables to increase the magnetic field value in the vicinity of the sample at the optical axis of the lens arrangement at a given electric current through the excitation coils of the magnetic deflector, without a need to increase a working distance.

Abstract: A method and apparatus for use in monitoring a sample with a charged particle beam are presented. A mechanical displacement between a plane defined by the sample's surface and an optical axis defined by a beam directing arrangement is provided so as to orient the sample at a certain non-right angle &thgr;1 with respect to the optical axis. A primary charged particle beam propagating towards the sample is deflected so as to affect the trajectory of the primary charged particle beam to provide a certain non-zero angle &thgr;2 between the primary beam propagation axis and said optical axis.

Abstract: A deflection system is presented for use in a lens arrangement of a charged particle beam column for inspecting a sample. The system comprises a magnetic deflector operable to create a magnetic field, and a pole piece assembly at least partly accommodated within the magnetic field. The pole piece assembly has a portion made of a soft magnetic material and is formed with an opening for a charged particle beam propagation therethrough. The deflection system allows for conducting the magnetic field created by the magnetic deflector through the pole piece assembly towards the opening in the pole piece assembly. This enables to increase the magnetic field value in the vicinity of the sample at the optical axis of the lens arrangement at a given electric current through the excitation coils of the magnetic deflector, without a need to increase a working distance.

Abstract: A beam directing method and device are presented for spatially separating between a primary charged particle beam and a beam of secondary particles returned from a sample as a result of its interaction with the primary charged particle beam. The primary charged particle beam is directed towards the beam directing device along a first axis passing an opening in a detector, which has charged particle detecting regions outside this opening. The trajectory of the primary charged particle beam is then affected to cause the primary charged particle beam propagation to the sample along a second axis substantially parallel to and spaced-apart from the first axis. This causes the secondary charged particle beam propagation to the detecting region outside the opening in the detector.

Abstract: A method and charged particle beam column are presented for directing a primary charged particle beam onto a sample. The primary charged particle beam, propagating along an initial axis of beam propagation towards a focusing assembly, passes through a beam shaper, that affects the cross section of the primary charged particle beam to compensate for aberrations of focusing caused by astigmatism effect of a focusing field produced by an objective lens arrangement of the focusing assembly, and then passes through a beam axis alignment system, that aligns the axis of the primary charged particle beam with respect to the optical axis of the objective lens arrangement.

Abstract: A beam directing method and device are presented for spatially separating between a primary charged particle beam and a beam of secondary particles returned from a sample as a result of its interaction with the primary charged particle beam. The primary charged particle beam is directed towards the beam directing device along a first axis passing an opening in a detector, which has charged particle detecting regions outside this opening. The trajectory of the primary charged particle beam is then affected to cause the primary charged particle beam propagation to the sample along a second axis substantially parallel to and spaced-apart from the first axis. This causes the secondary charged particle beam propagation to the detecting region outside the opening in the detector.