Showing papers on "Proximity effect (electron beam lithography) published in 1991"

Proximity correction method for e-beam lithography

Abstract: A method of proximity correction in an E-beam lithography system wherein each design shape is contracted by a predetermined bias and the E-beam dose required at any given point of the design is determined such that each of the design shapes is enlarged, on development, by the value of the predetermined bias, the determination of the E-beam dose being made in accordance with a predetermined relationship between an indicator, such as the electron backscatter, and the required E-beam dose, the indicator being defined for a plurality of points arranged on a coarse grid on the design and being indicative of the degree of the proximity effect at the respective point, the determination of the required dose being made by solving, at each of the plurality of points on the design, an integral equation relating the indicator to the E-beam dose distribution.

Pattern fabrication method using a charged particle beam and apparatus for realizing same

Abstract: The present application relates to a method and an apparatus for forming a pattern, in which a plane on which a pattern on a sample is traced is decomposed into predetermined partial regions; the pattern density in each of the partial regions is stored in data storing means as pattern density map data; and the irradiation energy amount of a charged particle beam is corrected on the basis of the pattern density map data to correct shortage and excess in the exposure dose due to roughness and fineness of the the pattern, i.e. the proximity effect. Further, the present application relates to a method and an apparatus for forming a pattern, in which when one or a plurality of layers located under the layer on which the pattern should be formed have patterns, influences of the underlayers on the proximity effect are taken into account.

Partitioning method for e-beam lithography

Abstract: A method of partitioning design shapes, in an E-beam lithography system, into subshapes such that a constant dose may be applied to an E-beam sensitive resist within each subshape. Within each subshape the constant dose corresponds to an approximation to an indicator function, indicative of the degree of the proximity effect, such as the effective exposure of the resist from backscattered electrons or the required dose. The error of the approximation is equal to a predetermined value for each subshape, and can depend upon the position of the subshape within the shape and the influence of errors in the applied dose at that position on the position, on development, of the edge of the shape.

Patterning tungsten films with an electron beam lithography system at 50 keV for x-ray mask applications

Abstract: The application of electron beam lithography for the fabrication of x‐ray masks is essential in the development of x‐ray lithography technology. In this paper we present experimental results on the patterning of submicron (2–0.25 μm) features into a single‐layer negative e‐beam resist and then subsequent transfer of these patterns onto a 0.4 μm‐thick tungsten film by reactive ion etching. To study the dependence of the proximity effect on the substrate material, a comparison of linewidths and sidewall profiles of electron beam resist images on silicon, silicon dioxide on silicon, and tungsten on silicon wafers has been established.

Electron beam lithographic system - performs correction process to eliminate proximity effect distortion

Abstract: The electron beam lithographic system of the type used in the prodn. of semiconductor wafers, has the workpiece (11) located on a carriage (12) that moves relative to a lens system (22) and deflection elements (23) that control the electron beam emission (21). A distortion of the pattern in the form of thickening and thinning can be produced by the scattered electrons reflected back from the surface. This so called proximity effect is subjected to a correction process in which the area is subdivided into small regions, the size of which is smaller than the spread of the scattered electrons and is larger than the smallest figure. ADVANTAGE - Improved correction in reduced period.

Ion beam working method

Abstract: PURPOSE:To obtain a wiring pattern or an X-ray mask which hardly damages a substrate and whose pattern is not widened due to the effect of a proximity effect by using hydrogen ion or helium ion as an irradiating ion beam. CONSTITUTION:When blasting gas for forming film or etching and irradiating the ion beam to obtain a formed film or etching, hydrogen ion or helium ion is used as the irradiating ion beam 20. Namely, a liquid metal ion source is not used but an He or H2 gas ion source is used as an ion source for irradiating a beam. Since the mass of the He or H2 gas ion is smaller than that of the metal ion, the effect on the substrate is a little and the etching effect thereof is little. Furthermore, the mass thereof is larger than an electron by three or more figures, so that the effect of the proximity effect can be neglected. Thus, the wiring pattern or the X-ray mask which hardly damages the substrate and whose pattern is not widened because of the effect of the proximity effect is obtained.

Proximity effect correcting device

Abstract: PURPOSE: To more simply perform a correction of a proximity effect by a high throughput separately from an original lithographic equipment. CONSTITUTION: The proximity effect correcting device comprises a light source 1 having a finite size, a mask 4 formed with many apertures at a smaller pitch than an extending radius of a rearward scattering electrons at the time of exposing with an electron beam, and a condenser lens 3 for converting a light IL from the source 1 into an illumination light of a predetermined extending angle 6 to guide it to the mask 4. A photosensitive plate 5 to be corrected disposed at a position separated at a predetermined distance D from the mask 4 is subjected to correction exposure through the mask 4 at the time of correcting a proximity effect. COPYRIGHT: (C)1993,JPO&Japio

Variable rectangular charged beam exposure and exposing apparatus

Abstract: PURPOSE: To form predetermined line width with high accuracy by compensating for quantity of exposure CONSTITUTION: Charged beam is fixed previously to rectangular form corresponding to a predetermined line width 12, pairs of proximity effect variables corresponding to the predetermined line width are obtained previously and pairs of these proximity effect variables are inputted as a table 14 to a control circuit of an electron beam exposing apparatus The optimum degree of exposure 16 is computed using these pairs of proximity effect variables for the purpose of electron beam exposure COPYRIGHT: (C)1993,JPO&Japio

Charged particle beam lithography

Abstract: PURPOSE:To enable drawing an extra fine pattern by adding a circuit for correcting a proximity effect to a drawing pattern control circuit and by conducting a preliminary processing. CONSTITUTION:Whenever a drawing control circuit exposes one rectangular figure to light, it outputs as its control data the position (X,Y) of the rectangular figure, the longitudinal width and breadth (W, H) of the figure and the time T for applying charged particles. Then, a proximity effect-correcting circuit 14 is newly added to the rear step of a figure-decomposing circuit 6 to conduct the computation processing of a light exposure and the change processing of the application time. That is, while only the drawing control circuit is operated beforehand prior to actual drawing, the cross section of a charged particle line exposed to light at a time is computed by a signal for controlling the shape of the charged particle line and the cross section is added cumulatively for each partial region. Then, the value of each partial region is smoothed by equalization to the value of other partial regions within a range, on which a proximity effect has an influence, etc., so that the macroscopically changing light exposure is corrected. Thus, it is possible to draw an extra fine pattern.

Inspecting method for resist pattern

Abstract: PURPOSE:To prevent a terminal part of a pattern part for size control from deforming and to accurately observe the cross sectional shape by observing the sectional shape of the pattern part for size control by slantingly viewing from the side of a rectangular pattern part. CONSTITUTION:The pattern part 3 for size control over a parting mold test pattern used by the method for inspecting the resist pattern is formed with an electron beam or ion beam, then the rectangular pattern part 14 of the parting mold test pattern is formed with ultraviolet rays or X rays, and the pattern part 13 for size control is observed slantingly through a scanning electrode microscope from the side of the rectangular pattern part 14 to grasp the sectional shape of the same resist pattern 7, which is thus inspected. Thus, the pattern part 13 for size control and the rectangular pattern part 14 are formed in order with different beams, so the deformation of the terminal part of the pattern part 13 for size control which is brought into contact with the rectangular pattern part 14 by proximity effect at the time of integral formation using an electron beam, etc., is eliminated. Consequently, the sectional shape of the resist pattern is accurately grasped.

Correction method for electron-beam drawing

Abstract: PURPOSE:To reduce the computing time of a computer when many of identical figures are arranged repeatedly by a method wherein an electron-beam exposure is corrected by taking a proximity effect into consideration. CONSTITUTION:A repetition region 4 where eight each of aggregates 1 of identical figures are arranged repeatedly side by side longitudinally and transversely is recognized after it is distinguished from a peripheral region 5 where different figures 2 and 3 around it are arranged. Regarding distinguished regions 6 and 7 and the peripheral region 5, the region 7 and the regions 6 and 5 other than it are corrected by taking a proximity effect into consideration separately from each other. As a result, a computing processing process can be saved sharply.

Electron Beam Direct Writing Technologies for 0.3-μm ULSI Devices : Lithography Technology

Abstract: Electron beam direct writing technologies for 0.3-µm devices are studied in this paper. In order to prevent charging effects, TQV, which is a varnish consisting of 7, 7, 8, 8-tetracyano quino dimethane complex salt, has been coated on the top layer of a trilayer resist system. The effectiveness of TQV coating is indicated by the experimental results obtained from test patterns. A proximity effect correction system with several strategies to reduce the correction time and output data volume has been developed. These technologies have been adopted for the fabrication of ULSI circuit patterns with the dimension of about 0.3 µm. The calculation time and the output data volume of a proximity effect correction are reduced considerably by using new methods. It is revealed that 0.3-µm ULSI patterns can be precisely fabricated by these new technologies.