Abstract:
Ion sources and methods of operating an electromagnet of an ion source for generating an ion beam with a controllable ion current density distribution. The ion source (10) includes a discharge chamber (16) and an electromagnet (42; 42a-d) adapted to generate a magnetic field (75) for changing a plasma density distribution inside the discharge chamber (16). The methods may include generating plasma (17) in the discharge space (24), generating and shaping a magnetic field (75) in the discharge space (24) by applying a current to an electromagnet (42; 42a-d) that is effective to define the plasma density distribution, extracting an ion beam (15) from the plasma (17), measuring a distribution profile for the ion beam density, and comparing the actual distribution profile with a desired distribution profile for the ion beam density. Based upon the comparison, the current applied to the electromagnet (42; 42a-d) may be adjusted to modify magnetic field (75) the magnetic field in the discharge space and, thereby, alter the plasma density distribution.
Abstract:
An electron beam lithographic apparatus has an electron gun providing a beam of accelerated electrons, a mask stage adapted to hold a mask in a path of the beam of accelerated electrons, and a workpiece stage adapted to hold a workpiece in a path of electrons that have traversed the mask. The electron gun has a cathode having an electron emission surface, an anode adapted to be connected to a high-voltage power supply to provide an electric field between the cathode and the anode to accelerate electrons emitted from the cathode toward the anode, and a current-density-profile control grid disposed between the anode and the cathode. The current-density-profile control grid is configured to provide an electron gun that produces an electron beam having a non-uniform current density profile. A method of producing a micro-device includes generating a beam of charged particles having a non-uniform charged-particle current density, illuminating a mask with the beam of charged particles, and exposing a workpiece with charged particles from the beam of charged particles.
Abstract:
PROBLEM TO BE SOLVED: To provide a charged particle beam apparatus which can emit a stable electron beam, having high brightness and a narrow energy width.SOLUTION: A charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10Pa or less. The apparatus is so constituted as to use electron beams having an electron-beam-center radiation angle of 1×10str or less among the emitted electron beams, and to use the electric current thereof, the second order derivative of which with respect to the time of the electric current of the electron beam is negative or zero and which decreases at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam. The field emission electron source is repeatedly heated to keep the electric current of the electron beam to be emitted, at a predetermined value or higher.