Abstract:
A charged particle system comprises a particle source for generating a beam of charged particles and a particle-optical projection system. The particle-optical projection system comprises a focusing first magnetic lens (403) comprising an outer pole piece (411) having a radial inner end (411′), and an inner pole piece (412) having a lowermost end (412′) disposed closest to the radial inner end of the outer pole piece, a gap being formed by those; a focusing electrostatic lens (450) having at least a first electrode (451) and a second electrode (450) disposed in a region of the gap; and a controller (C) configured to control a focusing power of the first electrostatic lens based on a signal indicative of a distance of a surface of a substrate from a portion of the first magnetic lens disposed closest to the substrate.
Abstract:
A charged-particle multi-beam exposure apparatus (1) for exposure of a target (41) uses a plurality of beams of electrically charged particles, which propagate along parallel beam paths towards the target (41). For each particle beam an illumination system (10), a pattern definition means (20) and a projection optics system (30) are provided. The illuminating system (10) and/or the projection optics system (30) comprise particle-optical lenses having lens elements (L1, L2, L3, L4, L5) common to more than one particle beam. The pattern definition means (20) defines a multitude of beamlets in the respective particle beam, forming its shape into a desired pattern which is projected onto the target (41), by allowing it to pass only through a plurality of apertures defining the shape of beamlets permeating said apertures, and further comprises a blanking means to switch off the passage of selected beamlets from the respective paths of the beamlets.
Abstract:
Method of synthesizing carbon nano tubes (CNTs) on a catalyst layer formed on a support member, by catalytic deposition of carbon from a gaseous phase, whereby an ion beam is used prior to, during, and/or after formation of the carbon nano tubes for modifying the physical, chemical, and/or conductive properties of the carbon nanotubes.
Abstract:
In a particle-optical imaging lithography system, an illuminating system comprising a particle source and a first electrostatic lens arrangement produces a particle beam which penetrates a mask foil provided with an orifice structure positioned in the particle beam path. This structure is imaged on a substrate plane by a projection system comprising a second electrostatic lens arrangement. The first and second lens arrangements each comprise, on their respective sides facing the mask holding device, at least one pre- and post-mask electrode, respectively. By applying different electrostatic potentials to the pre- and post-mask electrodes and to the mask foil, the mask foil and the pre-mask electrode form a grid lens with negative refracting power, and the mask foil and the post-mask electrode also form a grid lens with negative refracting power.
Abstract:
An arrangement for shadow-casting lithography by focusing electrically charged particles for the purpose of imaging structures of a mask on a substrate disposed immediately to the rear thereof, comprising a particle source (2) and an extraction system (3) which produces a divergent particle beam issuing from a substantially point-shaped virtual source, and comprising a lens (6) for focusing the divergent particle beam which comprises an electrode arrangement (6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h) which includes at least one electrostatic collector lens (6a to 6f in conjunction with an electrostatic diverging lens (6g, 6h) in order to be able to compensate lens errors of the collector lens in a purposeful manner with respect to lens errors of the diverging lens and to render possible a predeterminable change in the imaging scale. The diverging lens is preferably disposed in the beam direction at a distance to the rear of the collector lens in immediate proximity of the mask in order to be able to use the mask as a grating for the diverging lens.
Abstract:
An arrangement for masked beam lithography by means of electrically charged particles for the imaging of structures of a mask on a substrate arranged behind it, with a substantially punctiform particle source (Q) and an extraction system (Ex) for a specific type of charged particles which leave the source (Q) in the form of a divergent particle beam, and with an electrode arrangement (B, B', El.sub.1, El.sub.2, E.sub.3, . . . El.sub.n) for concentrating the divergent particle beam into a particle beam which is at least approximately parallel, by means of which an electrostatic acceleration field (E) is generated, the potential (U) of which in the beam direction has a constant gradient at least in parts and perpendicular to the beam direction is substantially constant at least within the beam cross-section. The electrode arrangement can be formed for example by a plurality of coaxial ring electrodes (El.sub.1, El.sub.2, El.sub.3, . . . El.sub.n) which are disposed at intervals behind one another in the beam direction, by a coaxial hollow cylinder which is aligned in the beam direction or a grating with a predetermined constant electrical resistance per unit of length, or by a plurality of longitudinal bars which are aligned in the beam direction, disposed parallel on surface of an imaginary coaxial cylinder with a predetermined constant electrical resistance per unit of length.
Abstract:
A charged particle, in particular ion projector system, has a mask arranged in the path of the charged particle beam and provided with transparent spots, in particular openings, arranged asymmetrically to the optical axis, which are reproduced on a wafer by means of lenses arranged in the path of the charged particle beam. The charged particle beam has at least one cross-over (crosses the optical axis at least once) between the mask and the wafer. Charged particles with an opposite charge to the charge of the reproduction particles are supplied into the path of the reproduction charged particle beam in a defined area located between the mask and the wafer. The limits that define said area are selected in such a way that the absolute value of the integral effect of the space charge on the particles that reproduce the mask structures is as high upstream of said area (seen in the direction of radiation) as the absolute value of the integral effect of the space charge downstream of said area.
Abstract:
In an ion optical imaging system, especially for lithographic imaging on a wafer, two collecting lenses are provided between the mask and the wafer. At least one of the collecting lenses is a three-electrode grid lens, i.e. a lens in which a grid is disposed perpendicular to the optical axis between a pair of tubular electrodes.
Abstract:
A multipole corrective element with the individual poles being electromagnetically energized individually and selectively to create a variable field around a charged particle beam projected through a mask and a lens system onto a substrate, e.g. an ion-beam or electron-beam microlithography. The corrective element is provided independently of the ion-optical lens system between the latter and the mask, preferably proximal to the mask.
Abstract:
An apparatus and method for the fine alignment of a mask with a substrate in ion-projection lithography, e.g. for the production of integrated circuit chips, utilizes a multipole, an axial magnetic field generator and a scale controlling projection lens in the path of the beam. The mask is provided with markings which are imaged on the substrate and brought into registry with corresponding markings thereon utilizing pairs of detectors associated with each linear marking and responsive to secondary emission of the ion-beam marking projected on the substrate. All of the markings are straight lines.