摘要:
A method and device for correcting errors and setting the focus of an electron optical condenser of a microprojector which condenser produces a bundle of axially parallel electron rays for illuminating a large surface transmission mask to create an image which is projected by means of an electron optical lens system on a surface of a wafer characterized by placing an annular field stop or diaphragm which passes a bundle of rays having a ring-shaped or annular cross section and recording the image in a plane preferably adjacent the surface of the wafer. The recording can be accomplished by utilizing a photographic plate or by utilizing a detector arrangement. When the image on the recording unit is the same size and shape as the annular field stop, then the electron optical condenser has the correct focal length and the source is disposed on the front focal plane.
摘要:
In an exemplary system, a two stage deflection system responds to a first control signal of low frequency such that extra-axial chromatic errors due to electrostatic and magnetic deflection are made equal and opposite. The magnetic and electrostatic deflection systems may be arranged in either order along the beam path just so the low frequency electrostatic deflection is one-half the magnetic deflection and is in an opposite direction at the target. A second higher frequency control signal controls only the electrostatic deflection system. Preferably the deflection velocities at the target produced by the two control signals are equal, with the higher frequency being an integral multiple of the lower frequency and with the control signals being poled to provide opposite deflections. When the two deflection velocities are superimposed, the resultant is then a step type deflection as a function of time.
摘要:
A method and a device used for determining the focal length of a long focal length electron optical lens particularly used with a microprojector characterized by projecting a bundle of parallel rays along the axis of the long focal length lens, said bundle of rays having a ring-shaped cross section with a radius R, providing a pinhole diaphragm having a diameter which corresponds approximately to the diameter of the circle of least confusion of the lens for a ring-shaped bundle of parallel rays, either positioning the diaphragm axially relative to the lens or holding the diaphragm fixed and changing the excitement of the lens to obtain the least influence of the diaphragm on the bundle of rays passing through the pinhole diaphragm, detecting the image of the rays passing through the diaphragm on a plane at a distance z.sub.2 from the diaphragm, measuring the radius r of the image of the ring-shaped bundle of rays on the plane and then determining the focal length f from the magnitude of R, r, z.sub.2 according to the formula f=(R/r).multidot.z.sub.2. The device includes an annular field stop for producing the bundle of rays having a ring-shaped cross section, means for positioning the field stop in that path of the rays prior to their reaching the lens, a diaphragm having an aperture of the circle of least confusion for the lenses of the ring-shaped bundle of parallel rays and means for recording the image passing through the diaphragm.
摘要:
A method for irradiating a specimen by corpuscular-beam radiation in which an irradiated surface pattern including isolated areas unexposed to the corpuscular beam surrounded at least almost completely by areas exposed to the beam is generated on a specimen by first imaging a mask which is supported by a support grid comprising a plurality of parallel strips and having a pattern corresponding to the surface pattern to be generated, on the specimen by shadow projection by means of a corpuscular beam consisting of a plurality of parallel rays. The image of the supporting grid is then removed by tilting the corpuscular beam in a direction perpendicular to the longitudinal axis of the strips forming the support grid through an angle which is at least equal in radians to the ratio of the width of the strips to the distance between the mask and the specimen.
摘要:
A particle beam device is provided with an arrangement for eliminating deflection errors having a deflection system and a stigmator. The deflection system has at least two pairs of deflection means disposed in a single plane at right angles to each other. The two deflection means of each of the pairs are disposed diametrically opposite each other and are centered with respect to the beam axis. The stigmator has at least four pairs of field generating means grouped into two systems of two pairs each and the two field generating means of each of the pairs are likewise disposed diametrically opposite each other and centered with respect to the beam axis. The two systems are disposed in the single plane at right angles to each other and are arranged so that each of the systems forms an angle of 45.degree. with the two pairs of deflection means.
摘要:
An electron-optical system with a variable-shaped beam for generating and measuring microstructures, such as circuits on a semiconductor substrate, generates the variable-shaped electron beam by the use of electron-optical shadow projection imaging and has a remote focus multipole Wehnelt electrode for adjusting, focusing, and controlling the intensity of the electron beam. The system also has a ferrite polecylinder in the beam projections lens with field attenuation or may have a beam projection lens with an external air gap. The length of the electron beam is approximately 60 centimeters.
摘要:
A high current electron source with a narrow energy band of the type employed in an electron beam printer has a beam generating system consisting of a cathode and focusing electrodes and an anode with at least one electrode functioning to astigmatically focus at least one electron crossover in the low velocity range. For varying the position and shape of the crossover in a simple manner for adaptation to particular use conditions of the high current electron source, the Wehnelt electrode of the electron source consists of one or more cylinder lenses or of an electrostatic multipole element, or an electromagnetic multipole element is disposed in the plane of a conventional non-ferromagnetic Wehnelt electrode with a circular aperture for the electron beam. By pole reversal of the Wehnelt voltage or of the coil current and by changing the size of the current, the shape and azimuth position of the first crossover in the cathode space can be varied to any configuration. By so doing, an energy spread of the electrons is prevented and an optimum illumination of surfaces to be imaged is achieved.
摘要:
A charged-particle beam optical apparatus for the reduction imaging of a mask on a specimen to be examined. The apparatus comprises a beam source for illuminating the mask, a condenser lens system comprising a plurality of lenses generating a ray bundle which strikes the mask as a probe, a beam deflection system located ahead of the last of the condenser lenses in the direction of the beam path, and a projection lens system including a long focal length intermediate lens and a short focal length imaging lens. The intermediate and imaging lenses are spaced apart by a distance which is equal to the sum of their focal lengths, and the mask is located in the front focal plane of the intermediate lens. The improvement of the invention comprises the provision of means for generating a probe in the form of a ray bundle comprising a plurality of rays which are at least approximately parallel to each other and which simultaneously illuminate a partial two-dimensional surface area of the mask.