Abstract:
When an emission current is changed, a decrease in brightness of an electron beam is prevented. An electron gun includes a cathode that emits thermoelectrons, a Wehnelt electrode that focuses the thermoelectrons, a control electrode that extracts the thermoelectrons from a distal end of said cathode, an anode that accelerates the thermoelectrons and irradiates a powder with the thermoelectrons as an electron beam, and an optimum condition collection controller that changes at least one of a bias voltage to be applied to the Wehnelt electrode and a control electrode voltage to be applied to the control electrode, and decides a combination of the bias voltage and the control electrode voltage at which the brightness of the electron beam reaches a peak.
Abstract:
L'invention s'applique à un procédé de projection d'un faisceau électronique (100) utilisé notamment en lithographie par écriture directe ou indirecte ainsi qu'en microscopie électronique. Notamment pour les dimensions critiques ou résolutions inférieures à 50 nm, les effets de proximité créés par la diffusion vers l'avant (150) et vers l'arrière (160) des électrons du faisceau en interaction avec la cible (110) doivent être corrigés. On utilise traditionnellement pour ce faire la convolution d'une fonction d'étalement de point avec la géométrie de la cible. Dans l'art antérieur, ladite fonction d'étalement de point est centrée sur le faisceau et utilise des lois de distribution gaussiennes ou exponentielle. Selon l'invention, au moins une des composantes de la fonction d'étalement de point n'est pas centrée sur le faisceau, la fonction d'étalement de point comprend donc au moins une fonction dont la valeur maximale n'est pas localisée au centre du faisceau. Préférentiellement, elle est centrée sur le pic de diffusion vers l'arrière. Avantageusement, la fonction d'étalement de point utilise des lois de distribution gamma.
Abstract:
An electron beam device (10) has a cathode (34) that generates a fan-shaped electron beam. A first focusing lens (44, 46, 48, 50) includes first (48) and second (50) plates on opposed sides of a filament. The edges of the plates closest to a positively charged anode (20) are arcuate, so that as individual electrons are accelerated normal to the edge of the charged plates, the beam (60) increases in length with departure from the filament. A second focusing lens includes third (44) and fourth (46) plates on opposed sides of the first focusing lens. Each of the third and fourth plates has an arcuate edge proximate to the positively charged anode. The plates of the first and second focusing lenses provide focusing in a widthwise direction, while defining the increase in the lengthwise direction. The curvature of the plates of the first focusing lens defines a common radius with the plates of the second focusing lens.
Abstract:
A charged particle optical system, e.g. an energy or mass analyser or a lens system, has a plurality of corrector electrodes (20 to 23) spaced apart across a particle beam passing from a monoenergetic source (4) to a focus (6) and dividing the beam into individual portions with central trajectories (30,31,32) the connector electrodes being electrically biassed to deflect the particles of the beam so as to reduce the aberration caused by portions with central trajectories intersecting the optical axis at different distances from the desired focus.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for correcting an electronic proximity effect by using an off-centered scattering function.SOLUTION: The present invention discloses a method of projecting an electron beam, which is used in especially direct or indirect drawing lithography and an electron microscope examination. Especially in the case of limit dimension or resolution below 50 nm, a proximity effect caused by front and back scattering of electrons in a beam interacting a target should be corrected. For the correction, convolution integration of a point spread function with respect to a shape of the target is used conventionally. A conventional technology has the point spread function whose center is at the center of the beam, and uses a Gaussian function or exponential distribution law. In the present invention, at least one component of the point spread function has a maximum value whose position is not at the center of the beam. Preferably the maximum value is positioned at a back scattering peak. Advantageously, a gamma distribution law is used for the point spread function.
Abstract:
PURPOSE: Electron proximity effect correcting method using off-center scattering function is provided to solve a problem of proximity effect modeling deviation by using a model type of PSF without having a peak. CONSTITUTION: A convolution of a point spread function of geometrical shapes of a target is used. A point spread function is concentrated on a beam. The point spread function uses Gaussian or exponential distribution law. One or more elements of the point spread function have a maximum value which is not positioned in the center of the beam. The maximum value is positioned at the rear scattering peak. The point spread function uses gamma distribution law. [Reference numerals] (AA) Absorbed energy(u,a)
Abstract:
PURPOSE: A shaping offset adjusting method and a charged particle writing apparatus are provided to reduce shaping offset adjusting errors by performing fitting using a third polynomial. CONSTITUTION: A control unit (3) includes a deflection controller (32), a detector (36), and a control calculator (31). The deflection controller controls the deflection of a charged particle beam. The detector measures a current value of the charged particle beam and includes a Faraday cup. A control calculator controls the deflection controller and a stage. [Reference numerals] (31a) Data processor; (31b) Setting unit; (31c) Calculation unit; (31d) Determination unit; (32) Deflection controller; (32a) Correction unit; (33) Blanking amplifier; (34,35) DAC amplifier; (36) Detector; (37) Memory; (39) External I/F