Abstract: A charge particle optical column capable of being used in a high throughput, mutli-column, multi-beam electron beam lithography system is disclosed herein. The column has the following properties: purely electrostatic components; small column footprint (20 mm square); multiple, individually focused charge particle beams; telecentric scanning of all beams simultaneously on a wafer for increased depth of field; and conjugate blanking of the charged particle beams for reduced beam blur. An electron gun is disclosed that uses microfabricated field emission sources and a microfabricated aperture-deflector assembly. The aperture-deflector assembly acts as a perfect lens in focusing, steering and blanking a multipicity of electron beams through the back focal plane of an immersion lens located at the bottom of the column. Beam blanking can be performed using a gating signal to decrease beam blur during writing on the wafer.

Abstract: An electron optics assembly for a multi-column electron beam inspection tool comprises a single accelerator structure and a single focus electrode mounting plate for all columns; the electron optical components are one per column and are independently alignable. The accelerator structure comprises first and final accelerator electrodes with a set of accelerator plates in between; the first and final accelerator plates have an aperture for each column and the accelerator plates have a single aperture such that the electron optical axes for all columns pass through the single aperture. Independently alignable focus electrodes are attached to the focus electrode mounting plate, allowing each electrode to be aligned to the electron optical axis of its corresponding column. There is one electron gun per column, mounted on the top of the single accelerator structure. In other embodiments, the electron guns are mounted to a single gun mounting plate positioned above the accelerator structure.

Abstract: An image processing system for use in semiconductor wafer inspection comprises a multiplicity of self-contained image processors for independently performing image cross-correlation and defect detection. The system may also comprise an image normalization engine for performing image brightness and contrast normalization. The self-contained image processors and image normalization engine access image data from a memory array; the array is fed data from a multiplicity of imaging modules operating in parallel. The memory array is configured to allow simultaneous access for data input, normalization, and cross-correlation and defect detection. Multiple image processing systems can be configured in parallel as a single image processing computer, all sending defect data to a common display module.

Abstract: An electron beam column incorporating an asymmetrical detector optics assembly provides improved secondary electron collection. The electron beam column comprises an electron gun, an accelerating region, scanning deflectors, focusing lenses, secondary electron detectors and an asymmetrical detector optics assembly. The detector optics assembly comprises a field-free tube, asymmetrical with respect to the electron optical axis; the asymmetry can be introduced by offsetting the field-free tube from the electron optical axis or by chamfering the end of the tube. In other embodiments the detector optics assembly comprises a field-free tube and a voltage contrast plate, either or both of which are asymmetrical with respect to the electron optical axis.

Abstract: A system for precisely positioning and moving a platform, with at least four and preferably six degrees of freedom, relative to a frame is disclosed herein. The platform is particularly suitable for carrying wafers. Charged particle optics can be attached to the frame, in which case any point on the wafer can be positioned to within at least one micron relative to the charged particle optics. The charged particle optics may comprise multiple columns, each column generating at least one charged particle beam. The platform positioning system comprises a base; a frame attached to the base; a stage, comprising a platform and stage actuators, coupled to the base and the frame; stage sensors, for sensing the position of the stage relative to the frame, rigidly coupled to the frame; and a current control system coupled to the stage sensors and the stage actuators.

Abstract: A multi-column electron beam inspection system is disclosed herein. The system is designed for electron beam inspection of semiconductor wafers with throughput high enough for in-line use. The system includes field emission electron sources, electrostatic electron optical columns, a wafer stage with six degrees of freedom of movement, and image storage and processing systems capable of handling multiple simultaneous image data streams. Each electron optical column is enhanced with an electron gun with redundant field emission sources, a voltage contrast plate to allow voltage contrast imaging of wafers, and an electron optical design for high efficiency secondary electron collection.

Abstract: A proximity effect correction method for electron beam lithography suitable for use in a raster scan system. The exposure pattern consists of shapes; these shapes are subdivided into edge pixels and interior pixels; the pattern is then modified by uniformly removing a fraction of the interior pixels. The method reduces the backscattered electron background dose, improving the contrast for shapes with fine features, particularly when they are in close proximity to large or densely packed shapes.

Abstract: An electron source including a non-orthogonal row-column matrix of two dimensional arrays of electron emitters positioned in groups of arrays, common control electrodes mounted adjacent associated groups, and electrical connections to the arrays in each group connecting the emitters in each array in parallel and connecting each array in each group to a similar array in each other group so as to form rows of groups equal in number to the number of arrays in each group. The groups are positioned along a first axial direction and arranged with the arrays in each group spaced apart in a second direction, at an angle to the first direction, so that the arrays are evenly spaced in the first direction. In one embodiment dummy control electrodes are used at each end of the structure and in another embodiment a field compensating electrode is provided on opposite sides of each control electrode and a surrounding electrode extends between adjacent field compensating electrodes.

Abstract: Plasma deposition or etching apparatus is provided which comprises a plasma source located above and in axial relationship to a substrate process chamber. The plasma source may include a sapphire or alumina source tube for use with plasmas containing fluorine. Surrounding the plasma source are an inner magnetic coil and an outer magnetic coil arranged in the same plane perpendicular to the axis of the plasma source and the substrate process chamber. Preferably a first current is provided through the inner coil and a second current in a direction opposite to the direction of the first current is provided through the outer coil. The inner and outer coils are wrapped with a thin sheet of conducting material to shield the coils from RF signal generated by the plasma source.

Abstract: Plasma deposition or etching apparatus is provided which comprises a plasma source located above and in axial relationship to a substrate process chamber. Surrounding the plasma source are an inner magnetic coil and an outer magnetic coil arranged in the same plane perpendicular to the axis of the plasma source and the substrate process chamber. Preferably, a first current is provided through the inner coil and a second current in a direction opposite to the direction of the first current is provided through the outer coil. The result is to advantageously shape the magnetic field in the process chamber to achieve extremely uniform processing, particularly when a unique diamond shaped pattern of gas feed lines is used wherein the diamond is arranged to be approximately tangent at four places to the outer circumference of the workpiece being processed in the apparatus.