Abstract: A multi-beam e-beam system employs a set of independently controllable (for blanking and deflection) subsystems placed in a solenoid field, each system having a demagnifying lens comprising at least one passive pole piece, so that the final image demagnifies imperfections in the upstream electron beam. Upper and lower sections of the system employ the focusing effect of the solenoid field to form an image at a shaping aperture and a demagnified image of the beam at the shaping aperture on the workpiece. Small focus corrections due to magnetic lens field non-uniformity and/or target height variations, are accomplished with an electrostatic unipotental lens built into the pole pieces and target voltage variations.

Abstract: A multi-beam e-beam system employs a set of independently controllable (for blanking and deflection) subsystems placed in a solenoid field, each system having a demagnifying lens comprising at least one passive pole piece, so that the final image demagnifies imperfections in the upstream electron beam. Upper and lower sections of the system employ the focusing effect of the solenoid field to form an image at a shaping aperture and a demagnified image of the beam at the shaping aperture on the workpiece. Small focus corrections due to magnetic lens field non-uniformity and/or target height variations, are accomplished with an electrostatic unipotental lens built into the pole pieces and target voltage variations.

Abstract: A magnetic lens employs a solenoid field containing a passive pole piece that shapes the solenoid field to create a demagnifying lens that has very low geometrical aberrations by adjusting the field upstream and downstream of the gap between the pole pieces to create a negative term in the formula for spherical aberrations, subtracting a significant amount from the contribution to the aberrations that comes from the field in the gap.

Abstract: A method for improving image fidelity on a resist. The method adjusts the intensity distribution of the electron beam such that the feature size at the edges and the center of a subfield have a same width “w”. This is accomplished by intentionally increasing the incident intensity where the images are small (more pronounced blurring), and intentionally decreasing the incident intensity where the images are large (less pronounced blurring). This can be achieved, for example, by maintaining a cathode temperature profile which increases or decreases radially by an appropriate amount.

Abstract: A method of optimizing locations of correction elements of a charged particle beam system determines respective corrector element currents to achieve optimum correction as a function of individual corrector location. Substantially complete dynamic correction of FSD and SFD can be obtained consistent with efficiency of operation and minimization of deflection distortion. In particular, FSD and SFD corrections can be sufficiently separated for substantially complete correction of SFD and FSD simultaneously with two stigmators. Both of these types of correction can be provided in complex charged particle beam systems employing curvilinear axis (CVA) particle trajectories and or large area reduction projection optics (LARPO) which cause complex hybrid aberrations in order to achieve high throughput consistent with extremely high resolution supporting one-tenth micron minimum feature size lithography regimes and smaller.

Abstract: A magnetic lens having a lens bore for the passage of a particle beam includes a dynamic focus coil that is positioned outside the lens bore and within the pole piece that shapes the lens field, so that the magnetic flux lines from the dynamic focus coil all end on the pole pieces of the lens and the shape of the lens field between the pole pieces has its magnitude changed by the current passing through the dynamic focus coil, but the field shape is not changed, thus changing the focal plane of the beam without moving the beam transversely with respect to the system axis.

Abstract: Numerous largely unpredictable criticalities of operating parameters arise in electron beam projection lithography systems to maintain throughput comparable to optical projection lithography systems as minimum feature size is reduced below one-half micron and resolution requirements are increased. Using an electron beam projection lithography system having a high emittance electron source, variable axis lenses, curvilinear beam trajectory and constant reticle and/or target motion in a dual scanning mode wherein the target and/or wafer is constantly moved orthogonally to the direction of beam scan, high throughput is obtained consistent with 0.1 .mu.m feature size ground rules utilizing a column length of greater than 400 mm, a beam current of between about 4 and 35 .mu.A, a beam energy of between about 75 and 175 kV, a sub-field size between about 0.1 and 0.

Abstract: An electron beam system for direct writing applications employs an electron gun having a large emitting surface compared to the prior art and a brightness approximately two orders of magnitude less than prior art systems to illuminate an initial aperture uniformly with a slightly diverging beam that passes efficiently through the aperture, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel proce

Abstract: An electron beam system for direct writing applications combining the parallel throughput of a projection system and the stitching capability of a probe-forming system employs an electron gun to illuminate an initial aperture uniformly, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel processing of the order of 10.sup.

Abstract: An electron beam system for direct writing applications combining the parallel throughput of a projection system and the stitching capability of a probe-forming system employs an electron gun to illuminate an initial aperture uniformly, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel processing of the order of 10.sup.

Abstract: A three-stage E-beam deflection system employs breaking the entire field to be scanned into clusters and sub-fields. The scanning provided by the first stage of deflection which scans within the entire field is rectilinear and discontinuous with the scan stopping in the center of each of the clusters where an exposure is to be made, and scanning is the same within each cluster from sub-field to sub-field. The scanning within a cluster by the second stage stops in the center of each sub-field where exposure is to be made. The third stage uses high speed electrostatic deflection to provide scanning with a vector scanning mode within the sub-field being scanned.

Abstract: A two staqge, electron beam projection system includes a target, a source of an electron beam and means for projecting an electron beam towards the target with its upper surface defining a target plane. A magnetic projection lens has a principal plane and a back focal plane located between said means for projecting and the target. The means for projecting provides an electron beam directed towards the target. First stage means provides deflection of the beam from area to area within a field. Second stage means provides for deflection of the beam for providing deflection of the beam within an area within a field. The beam crossing the back focal plane produces a telecentric condition of the beam in the image plane with the beam substantially normal to the target plane from the principal plane to the target plane.

Abstract: An electron beam system and method for testing three dimensional networks of conductors embedded in an insulating material specimen without physical contact to detect open and short circuit conditions. Top to top surface wiring is tested by irradiating the specimen with an electron beam at a first beam potential to charge the specimen while negatively biasing a grid placed above the specimen surface, and then irradiating selected portions of the specimen with an electron beam at a second beam potential to read the charge on selected conductors while applying a zero or a positive bias to the grid. In one embodiment the charge beam is a focused scanning beam and the first beam potential is preferably greater than the second beam potential.

Abstract: This system employs writing of lithographic patterns with a shaped electron beam exposure system which minimizes the time wasted by workpiece positional requirements. The writing field contains an array of sub-fields written in a raster sequence. The large width of the writing field provided by the VAIL system reduces the number of mechanical scans required to write the pattern on the workpiece which further reduces the time required for workpiece positioning. When patterns are being superimposed over previously written patterns, registration is employed. This system includes a registration field confined to local areas on the workpiece, which is larger than the writing field, without requiring change in focus and without requiring the mechanical system comprising the X-Y work table to change speed during the registration and reregistration of the various fields on a semiconductor wafer or mask.

Abstract: A variable axis immersion lens electron beam projection system shifts the electron beam while eliminating rapidly changing fields, eddy currents and stray magnetic fields in the target area. The electron beam projection system includes an electron beam source and a deflection means. A variable axes immersion lens for focusing the electron beam includes an upper pole piece, and a lower pole piece having a non-zero bore section, a zero bore section and an opening therebetween for inserting the target into the lens. The variable axis immersion lens provides an axial magnetic projection field which has zero first derivative in the vicinity of the target area. A magnetic compensation yoke, positioned within the bore of the upper pole piece produces a magnetic compensation field which is proportional to the first derivative of the axial magnetic projection field.

Abstract: An electron beam, which is applied along an axis from a source to a target, is aligned along the axis by deflecting the beam off the axis to a reference location. At the reference location, the source image of the electron beam is centered on a sensing plate through shifting the beam by an alignment yoke until the sensed current is a maximum through correction signals that are supplied to the alignment yoke. These correction signals are continuously applied to the alignment yoke when the electron beam is returned from the reference location to the position in which it is applied to the target.

Abstract: An electron beam system for non contact testing of three dimensional networks of conductors embedded in dielectric material, specifically detection of open and short circuit conditions. Top to bottom and top to top surface wiring is tested electrically without making physical electrical contact. The system comprises two flood beams and a focus probe beam wih one flood beam located at either side of the specimen. Proper choice of acceleration potentials, beam currents and dwell times of the beams allow alteration of the secondary electron emission from the specimen in such a way that electrical properties of the conductor networks can be measured directly. The difference in secondary electron emission resulting from different surface potentials is detected as a strong signal which allows clear discrimination between uninterrupted and interrupted as well as shorted pairs of conductors.

Abstract: A system of testing the continuity of electrical conductors extending through an insulating layer without contact. A flood gun irradiates one side of the body to charge the exposed conductors to a given potential. A steerable electron beam scans the front side to generate secondary electron emission from those conductors. The secondary emission is enhanced from conductors with conductivity between front side and back side as a result of the surface potential established by the rear flood beam. The secondary emission varies depending on the state of continuity in the three dimensional network of conductors and produces signals at the detector which allow clear discrimination between uninterrupted and interrupted conductors. The system is applicable for unfired ceramics where contact destroys the specimen.

Abstract: An electron beam projection system having a projection lens arranged so that upon pre-deflection of the electron beam the electron optical axis of the lens shifts to be coincident with the deflected beam. The projection system includes means for producing an electron beam, means for deflecting the beam, a magnetic projection lens having rotational symmetry for focusing the deflected beam and a pair of magnetic compensation yokes positioned within the bore of the projection lens means. The pair of correction yokes has coil dimensions such that, in combination, they produce a magnetic compensation field proportional to the first derivative of the axial magnetic field strength distribution curve of the projection lens. Upon application of current to the pair of compensation yokes the electron optical axis of the projection lens shifts to the position of the deflected beam so that the electron beam remains coincident with the shifted electron optical axis and lands perpendicular to a target.

Abstract: A toroidal magnetic deflection coil for an electron beam lithography system which is compensated for deflection placement errors that normally result from eddy currents generated within the coil windings by deflection current inputs to the coil. The compensation is achieved through addition of passive conductive material along the outer periphery of the coil. The conductive material or layer is arranged close to the outer arms of the toroidal coil windings, and thereby compensates the eddy currents within the deflection coils generated by the deflection currents in the inner arms. The compensating material can be utilized to compensate for beam drag which results from the driving circuit settling time and the inductive or capacitive coupling as well, by adding more material of appropriate dimensions.