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:
For compensation of a magnetic field in an operating region a number of magnetic field sensors (S1, S2) and an arrangement of compensation coils (Hh) surrounding said operating region is used. The magnetic field is measured by at least two sensors (S1, S2) located at different positions outside the operating region, preferably at opposing positions with respect to a symmetry axis of the operating region, generating respective sensor signals (s1, s2), the sensor signals of said sensors are superposed to a feedback signal (ms, fs), which is converted by a controlling means to a driving signal (d1), and the driving signal is used to steer at least one compensation coil (Hh). To further enhance the compensation, the driving signal is also used to derive an additional input signal (cs) for the superposing step to generate the feedback signal (fs).
Abstract:
In a charged-particle beam exposure device, an electrostatic lens (ML) comprises several (at least three) electrodes with rotational symmetry (EFR, EM, EFN) surrounding a particle beam path; the electrodes are arranged coaxially on a common optical axis representing the center of said particle beam path and are fed different electrostatic potentials through electric supplies. At least a subset of the electrodes (EM) form an electrode column realized as a series of electrodes of substantially equal shape arranged in consecutive order along the optical axis, wherein outer portions of said electrodes (EM) of the electrode column have outer portions (OR) of corresponding opposing surfaces (f1, f2) facing toward the next and previous electrodes, respectively. Preferably, the length of the electrode column is at least 4.1 times (3 times) the inner radius (ri1) of said surfaces (f1, f2).
Abstract:
Apparatus and method for projection ion beam lithography are described which allow formation of low distortion, large field, reduced images of a mask pattern at a wafer plane using an optical column of practical size. The column shown is comprised of an accelerating Einzel lens followed by a gap lens, with numerous cooperating features. By coordinated selection of the parameters of the optical column, lens distortion and chromatic blurring are simultaneously minimized. Real time measurement of the position of the image field with respect to the existing pattern on the wafer is employed before and during the time of exposure of the new field and means are provided to match the new field to the existing pattern even when the latter has been distorted by processing. A metrology system enables convenient calibration and adjustment of the apparatus.
Abstract:
An ion projection lithography system provides an immersion lens between the mask and the substrate, a mask between the immersion lens and the ion source and ExB fiter between the mask and the source but cooperating with a diaphragm located close to the crossing point or focal point of the immersion lens so that ions of undesired mass are rejected from the beam by impingement upon the diaphragm while utilizing low magnetic and electrical field strengths of the ExB filter.
Abstract:
The mask of our invention can be used in image forming units, for example in ion projection microlithography. The mask comprises a mask foil clamped into a retaining frame. The mask foil has a larger thermal expansion coefficient than the retaining frame. To make this mask the mask foil and retaining frame are heatead to a higher temperature than room temperature and clamped in position at this temperature.
Abstract:
Our invention is a process for stabilizing a projection mask which is put in operation at an elevated temperature. The frame containing the mask foil is heated to a temperature which is higher than the temperature of the mask foil. The mask foil is thus kept under tension by controlling the temperature of the frame it is held in and distortions like the distortions which would otherwise occur in long time operation and as conditioned by the mask foil hanging through it are avoided. The effect of the expansion of the mask foil can be compensated in the image forming unit by correction of the image formation scale.
Abstract:
In a particle projection lithography system, an alignment system is used to determine alignment parameters to measure the position and shape of an optical image of a pattern of structures formed in a mask and imaged onto a target by means of a broad particle beam, by means of an apparatus with a plurality of alignment marks adapted to produce secondary radiation upon irradiation with radiation of said particle beam. In order to allow for a variation of the alignment parameters along the optical axis, the alignment marks are positioned outside the aperture of the alignment system for the part of the beam that generates said optical image, arranged at positions to coincide with particle reference beams projected through reference beam forming structures provided on the mask while said optical image is projected onto the target, and situated on at least two different levels over the target as seen along the directions of the respective reference beams.
Abstract:
An electrostatic lens system consisting of several electrodes and a novel method of making same. The invention relates to a lithography apparatus that includes a field composable lens where at least one lens electrode has a novel structure, said structure comprising an outer support structure, an insulating intermediate part and a conductive inner part composed of a number of segment-like subelectrodes that can be individually powered, if necessary, slightly differently to produce desired individual electrostatic subfields to be superimposed to the lens field. With the field composable lens design, it has been successfully demonstrated that a number of shape and alignment errors of lens components can be corrected by supplying slightly different voltages to individual subelectrodes, thus optimizing the overall lens performance (in view of its optical properties). The lens components may be manufactured on less expensive and readily available conventional precision machinery rather than expensive and rarely available high precision equipment.
Abstract:
In a pattern-lock system of particle-beam apparatus wherein the imaging of the pattern is done by means of at least two consecutive projector stages of the projecting system, reference marks are imaged upon registering means to determine the position of the particle-beam, at the location of an intermediary image of the reference marks produced by a non-final projector stage, with the registering means being positioned at locations of nominal positions of an intermediary imaging plane. Furthermore, to produce a scanning movement over the registering means the reference beamlets are shifted laterally by means of deflector means provided in the pattern defining means in dependence of a time-dependent electric voltage.