JPS58500307A - Screen lens array system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 1 screen lens array system Background of the invention This invention relates to charged particle beam lithography systems, and more particularly to collimated charged particle beam lithography systems. This invention relates to a blank screen lens array used in a camera exposure system.

In recent years, the general trend in semiconductor industry technology has been as integrated circuits have become more complex. The focus has been on increasing device integration density. Technical concept of the present invention The goal is to reduce chip or die size as much as possible and increase device integration density. It is intended to be However, the chip size is This is optionally limited by the inherent resolution of the plate graphics process. It cannot be reduced.

Particularly, the wavelength of light becomes an obstacle to fine reproducibility in the 1 μm region.

Many methods have been proposed to solve this resolution problem, but this This is connected to two trends in the physical industry. These solutions have limited resolution Based on lithography technology that employs particles with wavelengths shorter than visible light to overcome It is something that can be developed. In general, short-wavelength particles include light, that is, high-energy photons. It has been proposed to selectively use two classes consisting of electrons (X-rays) and electrons. There is.

Optimized topography systems should become a valuable element in integrated circuit manufacturing is required to have certain attributes. These attributes include resolution coverage, lithograph These are speed, matching ability and stability.

Currently, the minimum reproducible linewidth is 1 μm, but future integrated circuit structures will One would require a desired system resolution of 1/4 μm or less. exposure system can cover standard 3" and 4" wafers currently used in this field. It must also be able to cover larger size wafers. Must be. and significant wafer exposure times ranging from tens of minutes to hours. is unacceptable in the exposure system of an IC manufacturing process. wafer exposure The acceptable throughput condition is several minutes for 3' and 4' wafers. This is the limit.

International Patent Application No. PCT/USB110○488 filed on April 10, 1981 (CP application) describes a parallel charged particle beam system, and these descriptions is quoted here for reference. This system uses conventional lithography The system's throughput capacity is increased by using a multiple charged particle beam exposure system. This significantly enhances the ability to implement a single concentrating circuit putter at multiple locations on the target surface. In the example, an electron beam is generated by an electron source to irradiate the objective aperture. be done. A screen lens consisting of many holes captures the electronic beams emitted from the objective aperture. The system is interrupted to create a multi-bundle beam.

Their focus is aligned so that they are incident parallel to a substrate with a sensitive layer, the so-called photoresist film. let The holes on the lens plate are used for the screen lens array on the wafer. Acts as a small aperture lens when a positive potential is applied.

In a system of the type disclosed in the said international patent application, a screen lens array is incorporated. - system would present significant technical difficulties. Especially this In some cases, selective means for substrate alignment and pattern writing are required. Ru.

Additionally, the amount of heat imparted to the screen lens array by the colliding beams As a result, the individual lenslets expand beyond their tolerance levels, resulting in will result in pattern distortion. Izuku from Screen Lens Array to Sarah. The secondary electrons generated on either plate overlap the sensitive film (resist) on the target surface of the substrate. It is easy to cause damage.

The optimal lens array system is one that has certain strict performance specifications. especially , selectively forming individual lenslet apertures to suppress low-energy secondary electrons, and It is desirable to be able to minimize the thermal beam load on the lens array.

Accordingly, the general object of the present invention is to overcome the technical difficulties mentioned above and to Charged particles with all the desired properties mentioned above to meet the technical requirements Screen lens array system for use in child beam exposure systems It is to provide.

A particular object of the invention is to provide a high resolution screen lens array system. That's true.

Other objects will become apparent in the following detailed description and practice of the invention. Dew.

Summary of the invention The following detailed description of the preferred embodiments or the practice of the invention will become clearer. The above-mentioned or other purposes and benefits which may occur have the characteristics outlined herein. This can be achieved by the configuration of the invention.

That is, the screen lens array of the present invention has the first and second aperture groups. and a bottom plate having similar first and second opening groups at predetermined intervals. The first group of openings in the top and bottom plates are always aligned. provided that the second group of openings in the top and bottom plates are always misaligned; By moving the plates relative to each other, the permanently aligned aperture groups can be made uniform. and bringing the normally misaligned aperture groups into alignment, respectively. It is designed so that it can be done.

Brief description of the drawing To illustrate an exemplary embodiment of the present invention, the following (2) is attached.

FIG. 1 is a plan view of a typical lens plate constructed according to the present invention, and FIG. 2 is a plan view of a typical lens plate constructed according to the present invention. FIG. 3 is a plan view showing a typical mask plate constructed according to A diagram showing the arrangement of the lens plate and mask plate with the mouths aligned, Figure 4 shows the aperture for realignment. A diagram showing another arrangement of aligned lens plates and mask plates, FIG. FIG. 3 is a diagram illustrating a mode in which secondary electrons are suppressed by biasing the electron beam.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a typical lens plate 0 and mask are shown, respectively. A plan view of the (cover) plate (200) is shown. As shown in Figure 1, the porous layer The lens board QOI has a diameter approximately equal to the substrate to be lit, and has a regular The arrangement of small lens holes is accommodated on a Cartesian coordinate system.

In certain applications, each lenslet group may be rectangular or other geometric pattern. can be placed in Each small hole in lens plate 0 (g) is adjacent to the closest one. They are separated with an interval of 2δ.

In addition, two (typically shown) holes are shown on lens plate 0 (g), and these is used for realignment or test pattern writing. These two holes is the distance from the nearest row of lenslets used for lighting the chip pattern. is far away.

Other details of lens plate 0 (g) are as of April 3Q, 1981. International patent application P CT/U S81/Q○595 (the applicant is the same person as the present application) ), which disclosure is incorporated herein by reference. Lens plate 0 (to) consists of a pair of plates aligned with each other. This upper lens plate is typically has an array of apertures with a diameter of 0.05 to 0.075 cm, and the lower lens plate has a typical It typically has an array of apertures 0.15 cm in diameter.

Similarly, as shown in FIG. 2, the porous mask plate (200) is the same as the lens plate Q(X). have the same number of apertures. The opening of the mask plate (200) is typically about 0.15 cm. has a diameter of Differences between the aperture arrangement shown in Figure 2 and that shown in Figure 1 is the closest row of realignment apertures and writing apertures in the mask plate (200). The distance between the lens plate 0 (G) was D, but the distance between δ).

When the mask plate (200) is placed on the top surface of the lens plate O (G), the tip plate All of the writing apertures are aligned with realignment apertures, and the tip writing apertures are aligned with each other. A valid match between the two occurs when the two are misaligned. Therefore, the lens plate 0 (to ) or the mask (cover) plate (200) by applying a linear motion to the mask (cover) plate (200). The chip writing process and realignment process can be carried out independently and sequentially. Ru. However, in order to obtain a good store when moving the lens plate (2) , higher positional accuracy is not required. Ru. In our application, the i-state is determined by the (fixed) lens position. , the positional accuracy of the lens cover is not as critical, so the mask (cover) -) was easier to slide.

Furthermore, several sets of such misaligned apertures can be combined in a large number of sequential operations. can be adopted for the purpose of

Such linear movement may be applied to either the lens plate QOI or the mask plate (200). One technique for providing a The purpose is to use a rotating cam that has a stable position greater than or equal to this point.

The lens plate rotation and aperture plate (200) shown in FIGS. 1 and 2 are roller bearings. and two metal support rings separated by an annular insulating ring. Typically, the relationship is maintained at 0.05 inch.

As a result, a bias potential as described below is applied to the lens cover. lens The thickness of plate 001 and cover plate (200) is typically 0.1α. to the beam Therefore, the applied heat load causes the cover plate (200) to expand and each bit to each small lens. The lens plate is protected from any thermal radiation by the cover plate (200). The lens plate 0 (T) provides substantial protection from thermal loads and prevents thermal expansion. The image formed on the substrate does not move.

As shown in FIGS. 3 and 4, two of the lens plate a [phase] and the mask plate (200) The two proximal positions are for performing the two operations mentioned above. Ru.

As shown in Figure 3, the chip writing apertures are constantly aligned and realigned. The openings are always misaligned. Lens plate 001 and mask plate (200) By relatively moving a certain distance, the tip lines are always aligned as shown in Figure 4. alignment apertures in misaligned positions and permanently misaligned realignment apertures in aligned positions. It is something that brings.

Referring to FIG. 5, one lens (beam focusing) aperture of lens plate 001 and this An electron beam (30 0) is shown in cross-section to allow passage to the substrate (400). this The figure also shows that the −order electron beam (300) is connected to the mask plate (200) and the lens plate. The orbits of electrons caused by the collision are shown. These electrons are sensitive Upon reaching the surface of the membrane-coated substrate (400), the sensitive membrane fogs and forms the desired pattern exposure will be erased. Mask plate (200) and lens plate Q (X I to prevent reaching the typical (400) sensitive layer coating.

Although it is relatively difficult to suppress the secondary electrons generated in lens plate 0 (g), , the aperture diameter of the mask plate (200) is made smaller than that of the lens plate. can be reduced more significantly. Electrically biased mask plate (200 ), all the secondary electrons generated in the root gyrus of the lens would be +10KV It reaches the sensitive film surface of the substrate (400), which has an attraction effect due to the electric potential, and causes fogging. That will happen.

The description given above of the preferred embodiments does not in any way limit the scope of the invention. Rather, the invention is limited only by the scope of the appended claims.

Procedural amendment (formality) Director General of the Patent Office 1. Display of incident PCT/TjS811010492, title of invention screen Lens array system 3 correction person Relationship with matter A1 (Jr. Patent applicant Private name (first name) Bake Innulments Incorporated 4 Agent 〒604 6. Number of inventions increased by amendment Off-season hem anzu part beef

Claims (1)

[Claims] 1. a, a first plate having a first and second aperture group, and b, a first and second aperture group and a second plate having C9 maintaining the first plate and the second plate at a predetermined interval; d. In this case, if the openings of the first group of the first and second plates are always aligned; together, the apertures of the second group are always misaligned, and e. By relatively moving the first and second plates, the first and second plates Misalignment of the normally aligned apertures in the plates also causes the first and second plates to Aperture groups that are always misaligned can now be aligned. A screen lens array system characterized by: 2. The first opening group in the first plate is connected to the first opening group in the second plate. The screen according to claim 1, characterized in that the aperture group has a smaller aperture diameter. lens array system. 3. Claim 2, wherein the first and second plates are maintained at different potentials. The system described. 4. Claim 3, wherein each of the first group of openings is substantially circular. System described in section. 5. a, a first plate having first and second aperture groups, and b, first and second aperture groups and a second plate having C0 maintaining the first plate and the second plate at a predetermined interval; d. In this case, the first group of openings in the first and second plates are always aligned. and maintain the second group of openings in the first and second plates in a misaligned state at all times. and further e. Due to the relative movement of the first and second plates, the The aperture groups that are always aligned are made to be unaligned, and the aperture groups that are always misaligned are made to be in an aligned state. made it possible to Luminous screen lens array used in collimated charged particle beam exposure system system. 6. The first group of openings in the first plate is connected to the first group of openings in the second plate. 6. The system according to claim 5, wherein the opening is smaller than that of the opening. 7. A claim characterized in that the first plate and the second plate are maintained at different potentials. Scope of Requirement The system according to item 6. 8. Claim 7, wherein each of the first group of openings is substantially circular. System described in section. 9. a, first plate having first and second aperture groups, and b, first and second aperture groups and a second plate having C0 maintaining the first plate and the second plate at a predetermined distance from each other; d. In this case, the first aperture groups of the first and second plates are always aligned; and the second aperture groups of the first and second plates are always misaligned. and further e, by moving the first and second plates relative to each other so that the first and second plates are constantly The aligned aperture groups are made unaligned, and the always misaligned aperture groups in the first and second plates are made unaligned. It is now possible to bring it into a consistent state. A dam screen used in a parallel electron beam exposure system characterized by lens array system. 10 The openings in the first group of the first plate are connected to the first group of the second plate. 10. The system of claim 9, wherein the opening is smaller than the opening. 11. The first plate and the second plate are maintained at different potentials. The system according to claim 10. 12. Claim characterized in that each of the first group of openings has a substantially circular shape. The system according to paragraph 11. 13 Each of the first group of openings in the first plate has a diameter of about 0.05 to 0.075. cm, and the openings of the first group in the second plate are approximately 0.15 cm in diameter. 13. System according to claim 12, characterized in that it has a diameter of 1). 14. The electric potential difference between the first plate and the second plate is about 100■. 13. The system according to claim 12. 15. Claim characterized in that the first plate has a thickness of about 0.1 cm. The system according to item 12. 16 Simultaneously direct lighting of integrated circuit patterns at multiple locations on the target surface It is a system for a. a mask plate having a lighting aperture group and a realignment aperture group; b. Also equipped with a lens plate having a lighting aperture group and a realignment aperture group. , C9 maintaining the mask plate and the lens plate at a predetermined distance; d. In this case, the lighting apertures of the mask plate and lens plate are constantly adjusted. At the same time, the realignment openings of the mask plate and lens plate are kept in a misaligned state at all times. And e. moving the mask plate and lens plate relative to each other to remove the mask plate and lens; The normally aligned lighting apertures in the plate are brought into a misaligned state, and the said mass bringing the constantly misaligned realignment openings in the lens plate and the lens plate into alignment; In a parallel electron beam exposure system characterized by being able to Dual screen lens array system used. 17 The writing opening in the mask plate is the same as the writing opening in the lens plate. 17. The system of claim 16, wherein the system is smaller than the opening for . 18. The mask plate and the lens plate are maintained at different potentials. The system according to claim 17. 19. The lighting aperture of each of the plates is approximately circular. The system according to scope item 18. 20 The diameter of the writing opening in the mask plate is approximately 0.05 to 0.07 The diameter of the writing aperture in the lens plate is approximately 5 cm. . 20. The system according to claim 19, wherein the amount is about 15 cIn. 21 The electric potential difference between the mask plate and the lens plate is about 100V. 20. The system of claim 19, characterized in that: 22. The mask plate has a thickness of about 0.1 cm. The system according to scope item 19. 23. Claim characterized in that the lens plate has a thickness of about 0.1 cm. The system according to item 19. Engraving (no changes to the content)