Abstract: A field emission source produces a charged particle beam that can be electrostatically aligned with the optical axis. Quadrupole (or higher multipole) centering electrodes approximately centered on the optical axis are placed between the emitter and the extraction electrode. By applying centering potentials of equal amplitude and opposite polarity on opposing elements of the centering electrodes, an electrostatic deflection field is created near the optical axis. The electrostatic deflection field aligns the charged particle beam with the optical axis thereby obviating the need to mechanically align the emitter with the optical axis. A second set of centering electrodes may be used to deflect the charged particle beam back and to ensure that the charged particle beam is parallel with the optical axis. Further, the extraction electrode may be split into a quadrupole arrangement with the extraction and centering potentials superimposed.

Abstract: A photocathode having a gate electrode so that modulation of the resulting electron beam is accomplished independently of the laser beam. The photocathode includes a transparent substrate, a photoemitter, and an electrically separate gate electrode surrounding an emission region of the photoemitter. The electron beam emission from the emission region is modulated by voltages supplied to the gate electrode. In addition, the gate electrode may have multiple segments that are capable of shaping the electron beam in response to voltages supplied individually to each of the multiple segments.

Abstract: An improved compact tandem photon and electron beam lithography system includes a field lens adjacent the photoemission source which is utilized in combination with an objective lens to minimize field aberrations in the usable emission pattern and minimize the interaction between electrons to improve the throughput of the system. If desired, a demagnifying lens can be utilized between the field lens and the objective lens to increase the demagnification ratio of the system.

Abstract: A charged particle beam column efficiently illuminates a blanking aperture array by splitting a charged particle beam into multiple charged particle beams and focusing each charge particle beam on a separate aperture of the blanking aperture array. Where an electron source with a small effective source size is used, for example an electron field emission source or Schottky source, crossovers of the individual beams may occur within the separate apertures of the blanking aperture array. Consequently, no demagnification of the beams passing through the blanking aperture array is necessary to form a small exposure pixel on the writing plane. Thus, for example, electron-electron interactions are minimized, thereby increasing throughput of the system. Further, undesirable scattering of the charged particle off the edge or sidewall of the apertures of the blanking aperture array is avoided.

Abstract: A shaped electron beam column focuses electrons from an electron source to produce a shadow image of a shaped aperture on a writing plane. The shadow image of the shaped aperture is the defocused image of a shape aperture. This defocused shadow image is in the the object plane of the shaped electron beam column. The shadow image in the writing plane is defocused because an electron beam lens produces a focused image of the electron source off the writing plane. The size of the shadow image on the writing plane may be altered by adjusting the electron beam lens to change the distance between the electron source image and the writing plane, i.e., defocus. Thus, a relatively large shaped aperture may be used in comparison to shaped apertures used in conventional electron beam columns. Further, only a small total linear demagnification may be used, which permits the length of the shaped electron beam column to be decreased.