Method for operating a charged particle beam device with adjustable landing energies

摘要

A method of operating a charged particle beam device is provided. The charged particle beam device includes a beam separator that defines an optical axis, and includes a magnetic beam separation portion and an electrostatic beam separation portion. The method includes generating a primary charged particle beam, and applying a voltage to a sample, the voltage being set to a first value to determine a first landing energy of the primary charged particle beam. The method further includes creating an electric current in the magnetic beam separation portion, the current being set to a first value to generate a first magnetic field, and applying a voltage to the electrostatic beam separation portion, the voltage being set to a first value to generate a first electric field. The method includes guiding the primary charged particle beam to the beam separator, wherein the primary charged particle beam enters the beam separator at a first angle relative to the optical axis and, under the influence of the first magnetic field and the first electric field, leaves the beam separator at a second angle relative to the optical axis. The method includes generating a secondary charged particle beam by impingement of the primary charged particle beam on the sample to which the voltage with the first value is applied, and separating the secondary charged particle beam from the primary charged particle beam in the beam separator, wherein the secondary charged particle beam enters the beam separator at a third angle relative to the optical axis and, under the influence of the first magnetic field and the first electric field, leaves the beam separator at a fourth angle relative to the optical axis. The first angle and the fourth angle are different. The method further includes applying the voltage to the sample, the voltage being set to a second value to determine a second landing energy of the primary charged particle beam, creating the electric current in the magnetic beam separation portion, the electric current being set to a second value to generate a second magnetic field, applying the voltage to the electrostatic beam separation portion, the voltage being set to a second value to generate a second electric field, guiding the primary charged particle beam to the beam separator, wherein the primary charged particle beam enters the beam separator at the first angle relative to the optical axis and, under the influence of the second magnetic field and the second electric field, leaves the beam separator at the second angle relative to the optical axis, generating the secondary charged particle beam by impingement of the primary charged particle beam on the sample to which the voltage with the second value is applied, and separating the secondary charged particle beam from the primary charged particle beam in the beam separator, wherein the secondary charged particle beam enters the beam separator at the third angle relative to the optical axis and, under the influence of the second magnetic field and the second electric field, leaves the beam separator at the fourth angle relative to the optical axis.

主权项

1. A method of operating a charged particle beam device, the charged particle beam device including a beam separator that defines an optical axis and includes a magnetic beam separation portion and an electrostatic beam separation portion, the method comprising:
generating a primary charged particle beam; applying a voltage to a sample, the voltage being set to a first value to determine a first landing energy of the primary charged particle beam; creating an electric current in the magnetic beam separation portion, the current being set to a first value to generate a first magnetic field; applying a voltage to the electrostatic beam separation portion, the voltage being set to a first value to generate a first electric field; guiding the primary charged particle beam to the beam separator, wherein the primary charged particle beam enters the beam separator at a first angle relative to the optical axis and, under the influence of the first magnetic field and the first electric field, leaves the beam separator at a second angle relative to the optical axis; generating a secondary charged particle beam by impingement of the primary charged particle beam on the sample to which the voltage with the first value is applied; separating the secondary charged particle beam from the primary charged particle beam in the beam separator, wherein the secondary charged particle beam enters the beam separator at a third angle relative to the optical axis and, under the influence of the first magnetic field and the first electric field, leaves the beam separator at a fourth angle relative to the optical axis, wherein the first angle and the fourth angle are different; thereafter applying the voltage to the sample, the voltage being set to a second value to determine a second landing energy of the primary charged particle beam, the second value being different from the first value; calculating a second value for the electric current to generate a second magnetic field; creating the electric current in the magnetic beam separation portion, the electric current being set to the second value to generate the second magnetic field; calculating a second value for the voltage to generate a second electric field; applying the voltage to the electrostatic beam separation portion, the voltage being set to the second value to generate the second electric field, wherein the second value for the second magnetic field and the second value for the second electric field are calculated so that the second angle and the fourth angle remain substantially constant with the change from the first landing energy to the second landing energy; guiding the primary charged particle beam to the beam separator, wherein the primary charged particle beam enters the beam separator at the first angle relative to the optical axis and, under the influence of the second magnetic field and the second electric field, leaves the beam separator at the second angle relative to the optical axis; generating the secondary charged particle beam by impingement of the primary charged particle beam on the sample to which the voltage with the second value is applied; and separating the secondary charged particle beam from the primary charged particle beam in the beam separator, wherein the secondary charged particle beam enters the beam separator at the third angle relative to the optical axis and, under the influence of the second magnetic field and the second electric field, leaves the beam separator at the fourth angle relative to the optical axis.