TWI546614B - Method and system for reducing manufacturing variation using charged particle beam lithography - Google Patents

Description

Method and system for reducing manufacturing variations using charged particle beam development Related application

This application is based on: 1) U.S. Provisional Patent Application No. 61/392,477, entitled "Using a Curved Pattern for the Manufacturing of Integrated Circuits and Preparation of Mask Data", on October 13, 2010, claims priority And 2) US Patent Application No. 13/168,953, entitled "Method and System for Patterning by Charged Particle Beam Microscopy", fujimura, June 25, 2011. Both cases are incorporated herein by reference for all purposes.

Reveal background

This disclosure relates to lithography, and more particularly to the use of charged particle beam lithography to design and fabricate a technique that may be the surface of a reticle, wafer or any other surface.

In the production and manufacture of semiconductor devices such as integrated circuits, semiconductor devices can be fabricated using optical lithography. Optical lithography is a printing process in which a lithographic mask or reticle fabricated from a reticle is used to transfer a pattern to a substrate such as a semiconductor or germanium wafer to produce an integrated circuit (IC). Other substrates may include flat panel displays, full-image masks, or even other reticle. Although optical lithography uses a light source having a wavelength of 193 nm, extreme ultraviolet (EUV) or X-ray lithography is also considered to be a type of optical lithography. The reticle or multiple reticle may contain a circuit pattern corresponding to one of the layers of the integrated circuit, and the pattern may be imaged to a radiation sensitive material that has been coated with a layer called a photoresist or a resist. On a specific area on the substrate. Once the patterned layer is transferred, the layer can undergo various other processes such as etching, ion implantation (doping), metallization, oxidation, and polishing. These processes are employed to repair a separate layer in the substrate. If several layers are required, the entire process or its variation will be repeated for each new layer. Finally, a combination of multiple devices or integrated circuits will appear on the substrate. These integrated circuits can then be separated from one another by dicing or sawing and can then be mounted into individual packages. In a more general case, a pattern on a substrate can be used to define an article such as a display pixel, an hologram, or a magnetic recording head.

In the production or manufacture of semiconductor devices such as integrated circuits, a pattern on a lithographic mask can be transferred to a substrate such as a germanium wafer using a non-optical method. Nanoimprint lithography (NIL) is an example of a non-optical lithography process. In nanoimprint lithography, a lithographic mask pattern is transferred to a surface via contact of the lithography mask with the surface.

In the production or manufacture of a semiconductor device such as an integrated circuit, it is also possible to directly write using a maskless to fabricate a semiconductor element. Direct maskless writing is a printing process that uses charged particle beam lithography to transfer a pattern to a substrate such as a semiconductor or germanium wafer to create an integrated circuit. Other substrate systems may include flat panel displays, embossed masks for nanoimprinting, or even reticle. The desired pattern of one layer is written directly onto the surface of the substrate, also in this example. Once the patterned layer is transferred, the layer can undergo various other processes such as etching, ion implantation (doping), metallization, oxidation, and polishing.

These processes are used to repair a separate layer in the substrate. If several layers are required, the entire process or its variation will be repeated for each new layer. Some of the layers can be written using optical lithography, while other layers can be written directly using the maskless screen used to make the same substrate. Also, a portion of the pattern of a given layer can be written using optical lithography, while other patterns are written using a maskless direct write. Finally, a combination of multiple devices or integrated circuits will appear on the substrate. These integrated circuits are then separated from each other by dicing or sawing and then mounted into individual packages. In more general cases, patterns on the surface can be used to define articles such as display pixels, holograms, or magnetic recording heads.

Two common types of charged particle beam lithography are the variable shaped beam (VSB) and the character projection (CP). These are all areas of shaped beam charged particle beam lithography in which a precision electron beam is shaped and directed to expose a resist coated surface, such as the surface of a wafer or the surface of a reticle. In VSB, these shapes are simple shapes, typically limited to rectangles with specific minimum and minimum dimensions and sides parallel to a Cartesian coordinate plane (ie, having a "manhattan" orientation). And a 45 degree right triangle with a specific minimum and maximum size (ie, three internal angles are 45, 45 and 90 degrees). At predetermined locations, the dose of electrons is shot into the resist in these simple shapes. The total write time for this type of system increases with the number of shots. In character projection (CP), the system has a template containing a plurality of different apertures or characters, which may be complex shapes such as linear, arbitrarily angular, circular, close Circular, annular, nearly annular, ovate, nearly ovoid, partially rounded, partially oblong, partially annular, partially oblong, partially obovate, or arbitrarily curved. It may be a complex shape of a connected group or a complex shape of a connected group of a group of detached groups. An electron beam can be fired through a character on the stencil to efficiently produce a more complex pattern on the reticle. In theory, this system is faster than the VSB system because it can shoot more complex shapes with time-consuming shots. Thus, an E-shaped pattern shot consumes four shots by a VSB system, but the same E-pattern can be fired with a single shot projection system. Please note that the VSB system can be thought of as a special (simple) case of character projection, where the characters are simply characters, usually rectangular or 45-45-90 degrees triangles. It is also possible to partially expose a character. This effect can be achieved, for example, by blocking a portion of the particle beam. For example, the E-shaped pattern may be partially exposed as an F-shaped pattern or an I-shaped pattern in which different portions of the bundle are cut by an opening. This is the same mechanism that can use VSB to shoot rectangles of different sizes. Partial projections in this disclosure represent both character casting and VSB projection.

As described, in optical lithography, the lithographic mask or reticle contains geometric patterns corresponding to the circuit components to be stacked on a substrate. The pattern used to make the reticle can be created using a computer-aided design (CAD) software or program. When designing a pattern, the CAD program can generate a reticle by following a predetermined set of design rules. These rules are set by processing, design, and end-use restrictions. An example of a terminal usage limitation is to define the geometry of a transistor in a manner that does not adequately operate at the required supply voltage. In particular, design rules can define spatial tolerances between circuit devices or interconnects. Design rules are used, for example, to ensure that circuit devices or wires do not interact with one another in a bad manner. For example, design rules are used to make lines not too close to each other in a way that could cause a short circuit. Design rule constraints reflect the smallest dimensions that can be reliably produced, and other items. When referring to these small dimensions, it is usually the concept of introducing a dimension of the neighbourhood. It is for example defined as the minimum width of a line or the minimum space between two lines, which are subject to fine control.

One of the goals in the fabrication of integrated circuits using optical lithography is to reproduce the original circuit design on the substrate using reticle. Integral circuit makers always try to make efficient use of the semiconductor wafer floor structure. Engineers continue to shrink the circuit size to allow the integrated circuit to contain more circuit components and use less power. As the critical dimension of an integrated circuit decreases and its circuit density increases, the critical dimension of the circuit pattern or physical design approaches the resolution limit of optical exposure tools used in optical lithography. As the critical dimension of the circuit pattern becomes smaller and approaches the resolution value of the exposure tool, the physical design becomes difficult to accurately transcribe to the actual circuit pattern developed on the resist layer. In order to further use optical lithography to transfer patterns having a feature configuration that is smaller than the wavelength of light used in the optical lithography process, a process known as optical proximity correction (OPC) has been developed. The OPC system changes the physical design to compensate for distortions caused by effects such as optical diffraction and optical interaction of feature construction and adjacent feature construction. The OPC system includes all resolution enhancement techniques performed with a reticle.

The OPC can add a sub-resolution lithography feature to the mask pattern to reduce the difference between the original design pattern, ie, the design, and the resulting transferred circuit pattern on the substrate. The sub-resolution lithography features the original pattern in the physical design and interacts with each other and compensates for the proximity effect to improve the resulting transferred circuit pattern. A feature structure used to improve pattern transfer is the Sub-resolution Auxiliary Feature Construction (SRAF). Another feature structure added to improve pattern transfer is called "serifs." A serif is a small feature configuration that can be positioned on a corner of a pattern to sharpen the corner in the final transferred image. The precision required for the SRAF surface fabrication process is often less than what is commonly referred to as the primary feature configuration for a pattern that is intended to be printed on a substrate. The serif is part of a main feature structure. As the extreme extension of optical lithography extends far beyond the sub-wavelength scheme, OPC feature construction must be made more complex to compensate for the more subtle interactions and effects. As the imaging system is pushed closer to its limits, the ability to produce reticle with sufficiently fine OPC feature construction becomes important. While it is advantageous to add serifs or other OPC features to a mask pattern, it also significantly increases the total number of feature configurations in the mask pattern. For example, using a technique to add a serif to each corner of a square adds an additional eight rectangles to a mask or reticle pattern. Adding an OPC feature structure is a laborious task that requires high computational time and results in more expensive reticle. Not only is the OPC pattern presently complex, but because the optical proximity effect is long range compared to the minimum and spatial dimensions, the correct OPC pattern in a given location is significantly dependent on which other geometry is nearby. Thus, for example, a line end will have a different size serif depending on which one is on the reticle. This is true even if the purpose is likely to produce exactly the same shape on the wafer. These slight but critical variations are important and have prevented others from forming reticle patterns. It is customary to construct the feature structure of the design and the OPC feature structure before the OPC decoration, where the OPC feature structure may include serifs, jogs, and SRAF to discuss the writing to one. The OPC decorative pattern on the reticle. In order to quantify the representativeness of the slight variation, a typical slight variation in OPC decoration relative to one of the nearby ones may have a 5% to 80% of the size of a main feature. Please note that for the sake of clarity, the variation in the OPC design is the variation referred to. Manufacturing variations such as line edge thickness and corner rounding will also occur in the actual surface pattern. When these OPC variations produce substantially the same pattern on the wafer, it indicates that the geometrical target on the wafer is rendered the same within a specified error, depending on the functional details that the geometry is designed to perform, such as a transistor or a wire. However, typical specifications are in the range of 2% to 50% of a range of main feature configurations. There are many manufacturing factors that can cause variations, but the overall error OPC component is often in the range listed. OPC shapes, such as sub-resolution assisted feature construction, accept a variety of different design rules, such as a rule based on the size of the smallest feature that can be transferred using the optical lithography number. Other design rules may come from the mask manufacturing process, or if a one-character projected charged particle beam writing system is used to form a pattern on a reticle, from the reticle manufacturing process. It should also be noted that the accuracy requirements of the SRAF feature construction on the mask may be lower than the accuracy requirements for the main feature configuration on the mask. As the process nodes continue to shrink, the size of the smallest SRAF on the mask is also reduced. For example, at a 20nm logic process node, 40nm to 60nm SRAF is required for the highest precision layer on the mask.

Inverse lithography (ILT) is a type of OPC technology. ILT is a process for directly computing a pattern to be formed on a reticle from a pattern to be formed on a substrate such as a germanium wafer. This can include using the desired pattern on the substrate as an input and simulating the optical lithography process in the opposite direction. The ILT operational reticle pattern may be purely curved - that is, completely non-linear and may include circular, nearly circular, annular, nearly annular, oval, and/or near-oval patterns. Since the curved pattern will be difficult to form on a reticle and expensive using conventional techniques, a linear approximation of the curved pattern can be used. In this disclosure, ILT, OPC, source mask optimization (SMO), and computational lithography are interchangeable terms.

EUV optical lithography has a much higher resolution than the optical lithography. The high resolution of EUV significantly reduces the need for OPC processing, resulting in lower mask complexity for EUV than 193 nm optical lithography. However, due to the high resolution of the EUV, flaws in a reticle, such as excessive line edge thickness (LER), will be transferred to the wafer. Therefore, the accuracy requirements for the EUV mask are higher than those of the optical lithography. In addition, even though the EUV mask shape is not complicated by the addition of complex SRAF or serifs required for 193 nm lithography, the EUV mask shape is complicated by the complexity inherent in adding EUV manufacturing. For EUV lithography to write patterns onto the mask, a particularly coherent system is mid-range scattering of charged particles such as electrons, which may affect a radius of about 2 [mu]m. This medium-range scattering introduces a new consideration in the preparation of mask data because the effects from adjacent patterns have a significant impact on the shape of a particular pattern that will be thrown onto the surface of the mask for the first time. Previously, when using the mask of 193nm lithography for exposure, short-range scattering is only affected by the written pattern, and the long-range scattering has a large enough range that the size of a pattern rather than its detailed shape is affected. Only use dose modulation for correction. In addition, since EUV processing of wafers is expensive, it is desirable to reduce or eliminate multiple patterning. Multiple patterning is used in conventional optical lithography to allow for exposure of small feature configurations in which a pattern of a layer for wafer processing is exposed using multiple masks each containing a portion of the pattern. Reducing or eliminating multiple exposure systems requires a single mask to contain a finer pattern. For example, a series of collinear line segments can be double patterned by first drawing a long line and then using a second mask in the lithography process to cut the line into line segments. For example, for EUV lithography, the same layer written with a single mask would require a mask containing many smaller line segments. Due to the need to write a larger number of finer patterns on a single mask, the patterns need to be more precise, so the need for EUV mask precision is increased.

There are several techniques for forming a pattern on a reticle, including the use of optical lithography or charged particle beam lithography. The most commonly used system is a variable shaped beam (VSB) in which the surface of a resist coated reticle is exposed as described above with a dose of electrons having a simple shape such as a Manhattan rectangle and a 45 degree right triangle. . In the conventional mask writing, the electronic dose or shooting system is customarily designed to avoid overlap as much as possible, thereby greatly simplifying the calculation of how the resist on the reticle will align the pattern. Similarly, the firing set is designed to completely cover the area of the pattern to be formed on the reticle.

The reticle writing for the most advanced technology nodes generally involves multiple passes of charged particle beam writing, a process known as multi-pass exposure, in which a given shape on the reticle is written and overwritten. . In general, two to four pass lines are used to write a reticle to average the precision errors in the charged particle beam writer, allowing for a more accurate reticle. And in general, the shots of this list - including dose - are the same for each pass. In a variation of multi-pass exposure, the shots of the list may change between exposures, but the combination of shots in any exposure covers the same area. Multi-pass writing reduces the overheating of the resist applied to the surface. Multi-pass writing also averages the random errors of the charged particle beam writer. Multi-pass writes that use different shot lists for different exposures also reduce the effects of specific systemic errors in the write process.

Today's optical lithography writing implements typically reduce the reticle pattern by a factor of four during the optical lithography process. Therefore, the pattern formed on a reticle or mask must be four times larger than the desired pattern on the substrate or wafer.

Today's technology charged particle beam writers using the technology of the prior art can resolve features as small as 100 nm. However, for feature configurations of less than 100 nm, conventional write techniques may not be able to accurately resolve feature configurations. In addition, manufacturing variations may result in unacceptable LER and critical dimension (CD) variations. For optical lithography where OPC may produce SRAF with a mask dimension of less than 100 nm, and for EUV where the main mask pattern may be less than 100 nm and the mask size may be more rigorous than that used in optical lithography This may be a problem with lithography.

Reveal summary

A method and system for rupture or mask data preparation for charged particle beam lithography is disclosed, wherein a partial overlap shot is utilized to enhance a pattern formed on a surface by firing a set of charged particle beams Accuracy and / or dose margin value. In some embodiments, the doses of the shots may change relative to each other prior to the correction of the proximity effect. Particle beam simulation can be used to calculate the pattern and dose margin values. The enhanced dose margin value improves the critical dimension (CD) variation and line edge thickness (LER) of the pattern produced on the surface.

Simple illustration

Figure 1 shows an example of a character projected charged particle beam system; Figure 2A shows an example of a cross-sectional dose pattern depicting the aligned pattern width for each of the two resist thresholds; Figure 2B shows a An example of a cross-sectional dose pattern that is similar to Figure 2A but with a higher dose edge slope than Figure 2A; Figure 3A shows a desired 100 nm line end pattern to be formed on one of the reticle An example; FIG. 3B shows an example of a simulated pattern formed by a shot generated by breaking a pattern of FIG. 3A using a technique; FIG. 4A shows a desired 80 nm to be formed on one of the reticle sheets. An example of a line end pattern; FIG. 4B shows an example of a simulated pattern formed by a shot generated by breaking a pattern of FIG. 4A using a conventional technique; and FIG. 5A shows one of the lines to be formed on a reticle An example of a desired 60 nm line end pattern; FIG. 5B shows an example of a simulated pattern formed by shots generated by breaking the pattern of FIG. 5A using a conventional technique; and FIG. 6 shows an example of forming an 80 nm line end pattern. Different examples of shooting of the group; Figure 7 shows the simulated pattern formed by the different shooting groups of Figure 6; Figure 8A shows one of the rectangular patterns to be formed in a group on a surface Example; Figure 8B shows an example of how the pattern of Figure 8A, which is formed on a surface by a non-overlapping VSB shot, can be used in the presence of medium-range scattering; Figure 9A shows the pattern that can be used to form Figure 8A. An example of a set of overlapping VSB shots on a surface; Figure 9B shows an example of a pattern that can be formed on a surface from a shot of Figure 9A; Figure 10 shows how to prepare a surface, such as a standard A conceptual flow diagram of a wire for use in optical lithography to fabricate a substrate such as an integrated circuit on a wafer; Figure 11A shows a model based on the same design and a fracture Conceptual flow chart of the method; Figure 11B shows a conceptual flow diagram of another method of combining model-based and occlusion fractures in the same design.

Detailed description of the embodiment

The present disclosure describes a method of utilizing overlapping shots to enhance the accuracy of charged particle beam exposure. The present invention is an enhanced charged particle beam system that accurately produces a pattern of less than 100 nm on a reticle that has acceptable CD variation and LER- in view of manufacturing variations. Moreover, the present invention expands the process window under which manufacturing variations of these precise patterns can be produced.

Please refer to the drawings now, in which similar codes refer to similar items. 1 shows an embodiment of a conventional lithography system 100, such as a charged particle beam writer system, in this example an electron beam writer system that employs word projection to create a surface 130. . The electron beam writer system 100 has an electron beam source 112 that projects an electron beam 114 toward an aperture plate 116. An opening 118 through which the electron beam 114 is allowed to pass is formed in the plate 116. Once the electron beam 114 passes through the aperture 118, it is directed or biased by a system lens (not shown) into the electron beam 120 toward the other rectangular aperture plate or stencil mask 122. A number of openings or openings 124 have been formed in the template 122 that define different types of characters 126 that may be complex characters. Each of the characters 126 formed in the template 122 can be used to form a pattern 148 on a surface 130 of a substrate 132, such as a wafer, reticle or other substrate. In partial exposure, partial projection, partial character projection, or variable character projection, the electron beam 120 can be positioned to only strike or illuminate a portion of one of the characters 126, thereby forming a body once One of the set of characters 126 is patterned 148. For each character 126 that is smaller than the size of the electron beam 120 defined by the opening 118, a blackout region 136 that is free of apertures is designed to be adjacent to the character 126 to prevent the electron beam 120 from illuminating a bad character. On the template 122. An electron beam 134 appears from one of the characters 126 and passes through an electromagnetic or electrostatic reduction lens 138 for reducing the size of the pattern from the character 126. In commonly available charged particle beam writer systems, the reduction factor is between 10 and 60. The reduced electron beam 140 emerges from the reduced lens 138 and is directed onto the surface 130 by a series of deflectors 142 to form a pattern 148 that is depicted as a letter "H" shape corresponding to the character 126A. Because the lens 138 is reduced, the pattern 148 is reduced in size compared to the character 126A. Pattern 148 is drawn using a shot of electron beam system 100. This reduces the overall write time of the completed pattern 148 compared to using a variable shaped beam (VSB) projection system or method. Although an opening 118 is shown formed in the plate 116, there may be more than one opening in the plate 116. Although two plates 116 and 122 are shown in this example, there may be only one or more than two plates, and each plate includes one or more openings.

In the charged particle beam writer system, the reduced lens 138 is calibrated to provide a fixed reduction factor. The reduced lens 138 and/or deflector 142 also focuses the beam on the plane of the surface 130. The size of the surface 130 can be significantly greater than the maximum beam deflection capability of the deflecting plate 142. Therefore, the pattern is normally written on the surface in a series of stripes. Each stripe has a plurality of subfields, one of which is located within the beam deflection capability of the deflector 142. The electron beam writer system 100 includes a positioning mechanism 150 to permit positioning of the substrate 132 for each of the fringes and the subfield. In a variation of the charged particle beam writer system, the substrate 132 remains static when the field is exposed, after which the positioning mechanism 150 moves the substrate 132 to the next subfield position. In another variation of the charged particle beam writer system, substrate 132 is continuously moved during the writing process. In this variation involving continuous motion, in addition to the deflecting plate 142, another set of deflecting plates (not shown) may be used to move the beam at the same speed and direction as the substrate 132 moves.

The minimum size pattern that can be projected onto a surface 130 with reasonable accuracy is limited to being associated with the electron beam writer system 100 and with a surface 130 that is normally a resist coating on the substrate 132. A variety of different short-range physical effects. These effects include forward scatter, Coulomb effect, and resist diffusion. Beam blur is a term used to include all of these short-range effects. The most modern electron beam writer system achieves an effective beam blur radius or β _f in the range of 20 nm to 30 nm. Forward scatter can constitute one-quarter to one-half of the total beam blur. Modern electron beam writer systems contain a variety of mechanisms for minimizing the component of the beam blur. Partial electron beam writer systems may allow beam blur to change during the writing process, from a minimum value that can be taken on an electron beam writing system to one or more larger values.

The firing dose of a charged particle beam writer, such as an electron beam writer system, is a function of the intensity of the beam source 112 and the exposure time of each shot. In general, the beam intensity remains fixed and the exposure time is varied to obtain a variable firing dose. In a process called Proximity Effect Correction (PEC), the exposure time can be varied to compensate for various long-range effects such as backscattering and fogging. An electron beam writer system typically allows an overall dose called a substrate dose to affect all shots in an exposure pass. Partial electron beam writer systems perform dose compensation calculations within the electron beam writer system and do not allow individual shot doses to be individually assigned as part of the input shot list, so the input shot has an unassigned shot dose . In such electron beam writer systems, all shots have a substrate dose prior to proximity effect correction. Other electron beam writer systems do allow dose assignments with a shot-by-shot basis. In an electron beam writer system that allows for one shot dose assignment, the number of available dose levels may be 64 to 4096 or greater, or may have relatively few available dose levels, such as 3 to 8 Level. Some embodiments of the present invention are directed to the use of a charged particle beam writing system that allows for the assignment of a dose level.

The mechanism within the electron beam writer has a relatively coarse resolution for calculating. Therefore, today's electron beam writers are unable to accurately calculate the mid-range corrections that may be required for EUV masks, such as in the 2 μm range.

In the case of the case, the shooting system is designed to completely cover an input pattern with a rectangular shot while avoiding overlapping shots as much as possible. Also, all shots are designed to have a normal dose, which is a dose that allows a relatively large rectangular shot to produce a pattern on a surface that has the same size as the shot size without the long-range effect.

For example, when charged particle beam lithography is used to expose a repetitive pattern on a surface, the dimensions of each pattern as measured on the final finished surface will be slightly different due to manufacturing variations. The amount of dimensional variation is an important criterion for manufacturing optimization. In today's mask masks, it may be desirable to have a root mean square (RMS) variation of no more than 1 nm (1 sigma) in the pattern size. Larger size variations mean larger variations in circuit performance, resulting in higher design margins, making it difficult to design faster, lower power integrated circuits. This variation is called the critical dimension (CD) variation. A low CD variant is ideal and indicates that manufacturing variations will result in relatively small size variations on the final fabricated surface. On a smaller scale, the effect of a high CD variation can be observed by line edge thickness (LER). The LER is caused by portions that are made slightly different from one of the line edges, resulting in a portion of the wavy in a line that is intended to have a linear edge. The CD variant is inversely related to the slope of the dose curve at the threshold of the resist, known as the edge slope, and has other effects. Thus, the edge slope, or dose margin value, is one of the critical optimization factors for the particle beam write to the surface. In this disclosure, the edge slope and dose margin values are interchangeable terms.

By ignoring breaks without shot overlap, gap or dose modulation, the dose margin value of the written shape is considered to be immutable: that is, it is not possible to modify the dose margin by selecting the break option. In modern practice, the technique of avoiding extremely narrow shots called slicing is an example of a practical rule-based approach that helps to optimize the shot list for dose marginal values.

In a fracture environment in which overlapping shots and dose-modulated shots can be produced, there is a need and opportunity to optimize the dose margin value. By utilizing the extra elasticity of the combination of shots allowed by shot overlap and dose modulation, it is possible to create a number of fracture solutions that produce a target mask shape on the surface, but only under perfect manufacturing conditions. Therefore, the use of overlapping shots and dose-modulated shots has generated the issue of addressing the issue of dose margins and its improvement.

Figures 2A through B show how the critical dimension can be reduced by exposing the pattern on the resist, thereby producing a relatively high edge slope in the exposure or dose curve. Figure 2A shows a cross-sectional dose curve 202 in which the x-axis shows the cross-sectional distance through an exposed pattern - such as the distance orthogonal to the edges of the pattern - and the y-axis shows the dose received by the resist. A pattern is aligned by the resist, wherein the received dose is above a threshold. Figure 2A shows two thresholds depicting the effect of a variation in resistivity sensitivity. A higher threshold value 204 causes a pattern of width 214 to be aligned by the resist. More A low threshold value 206 causes a pattern of widths 216 to be aligned by the resist, wherein the width 216 is greater than the width 214. Figure 2B shows another cross-sectional dose curve 222. Two thresholds are displayed, with the threshold 224 being the same as the threshold 204 of the 2A diagram, and the threshold 226 being the same as the threshold 206 of the 2A diagram. The slope of the dose curve 222 is higher than the slope of the dose curve 202 near the two thresholds. For dose curve 222, a higher threshold 224 causes a pattern of width 234 to be aligned by the resist. The lower threshold 226 causes a pattern of width 236 to be aligned by the resist. As can be seen, since the dose curve 222 is higher than the edge slope of the dose curve 202, the difference between the width 236 and the width 234 is less than the difference between the width 216 and the width 214. If the resist coated surface is a reticle, the lower sensitivity of the curve 222 to the variation of the resist threshold will result in a pattern width closer to the reticle from the reticle. The target pattern width, whereby the yield of the usable integrated circuit is improved when the mask is used to transfer a pattern to a substrate such as a germanium wafer. For dose curves with higher edge slopes, improvements in tolerances similar to the dose variations for each shot were observed. A relatively high edge slope is therefore desired to be achieved, such as in dose curve 222.

Figure 3A shows an example of a design pattern 302. Pattern 302 is designed to have a constant width 306 that is 100 nm. Pattern 302 includes a line end 304. Figure 3B shows an example of a simulated pattern 312 that can be formed on a surface using a conventional VSB shot, wherein the VSB shot is a 100 nm wide rectangle with a normal dose. As can be seen in Figure 3B, the line end portion 314 of the pattern 312 has rounded corners due to beam blurring caused by the physical limitations of the charged particle beam writer. In addition, the exposed pattern has a poor edge slope in segments 316 and 318 around the pattern. This can be done, for example, by particle beam simulation to determine this edge slope. Portions 316 and 318 of pattern 312 can cause significant variations in size due to manufacturing variations. However, the wire end 314 is of a desired length in its central section, i.e., has the same y coordinate as the design wire end 304.

Figure 4A shows an example of a design pattern 402. Pattern 402 is designed to have a constant width 406 of 80 nm. Pattern 402 includes a line end 404 with the y coordinate of line end 404 being shown with reference line 408. Figure 4B shows an example of a simulated pattern 412 that can be formed on a surface using a conventional VSB shot, wherein the VSB shot is 80 nm wide and has a normal dose. Like the pattern 312, the line end portion 414 of the pattern 412 has rounded corners due to beam simulation. Also, portions 416 and 418 of the periphery of pattern 412 have poor edge slope. As can be seen, portions 416 and 418 around the pattern 412 having a poor edge slope are larger than portions 316 and 318 having a pattern 312 of poor edge slope. This is because the pattern 402 has a narrow width of 80 nm compared to the 100 nm width of the pattern 302. In addition, the y coordinate of the formed line end 414 is greater than the y coordinate of the reference line 408, indicating that the pattern 412 has a line end shortening that affects the performance of an integrated circuit fabricated using a mask containing the pattern 412 and/or Or function.

Figure 5A shows an example of a design pattern 502. Pattern 502 is designed to have a constant width 508 of 60 nm. Pattern 502 includes a line end 504 with the y coordinate of line end 504 being shown with reference line 506. Figure 5B shows an example of a pattern 512 that can be formed on a surface using a conventional VSB shot wherein the VSB shot is 60 nm wide and has a normal dose. As can be seen, the line end portion 514 of the pattern 512 is very rounded. There is also a line end shortening - the minimum value y coordinate of the pattern 512 is greater than the y coordinate of the reference line 506. Moreover, the peripheral region 518 of the pattern 512 has a poor edge slope that affects the overall line end 514.

The patterns of Figures 3B, 4B, and 5B show how the pattern formation having a width of 80 nm and below can have a line end shortening when formed by conventional VSB shots, and can also have rounded corners including a bad edge slope.

Figure 6 shows a different method for breaking a pattern to enhance the quality of a pattern formed on a surface such as a reticle. Shape 602 shows a designed line end pattern with pattern 602 having a width of 80 nm. Pattern 602 includes a line end 606. Dashed line 608 represents the y coordinate of line end 606. The pattern 612 of FIG. 6 shows a prior art method for breaking the pattern 602 to improve the quality of the pattern formed on a surface as compared to the pattern 412 of FIG. Pattern 612 shows a single VSB shot in which the shot size has been enlarged in the negative y dimension, so the minimum y coordinate of the shot is 7 nm smaller than the reference y coordinate 608. The dose of shot 612 is a normal dose. Pattern 712 of Figure 7 shows a shot shape of shot 612. The line ends of pattern 712 have rounded corners and also have perimeter regions 714 and 716 in which the pattern includes a too low edge slope.

Figure 6 also shows three groups of VSB shots: group 622, group 632, and group 642, which may form a pattern 602. Shooting group 632 and shooting group 642 demonstrate an embodiment of the present invention, while shooting group 622 represents a prior art method. Shooting group 622 is comprised of shot 624 and shot 626 that do not overlap each other. Shot 624 was fired at 1.2 times the normal dose before the long-range PEC, while shot 626 was fired at a normal dose. The width 628 of the shot 624 is less than 604 and is calculated to produce a pattern of width 604 greater than the normal dose on the surface. As can be seen, the shot 626 extends in the negative and positive x-directions beyond the dimension of the shot 624 and also exceeds the dimensions of the pattern 602. The pattern 722 of Figure 7 shows the simulated pattern produced by the shooting group 622. The line end corner 724 of the pattern 722 has a higher edge slope than the pattern 712, wherein no portion of the corner has a too small edge slope. Moreover, although not shown, the shot 624 above the normal dose improves the edge slope on the left and right sides of the pattern 722 compared to the pattern 712. A method for determining the firing of the firing group 622 is via a model-based fracture that is determined by simulations such as charged particle beam simulation to form a desired pattern on a resist coated surface. A set of shots is determined by a simulation of a pattern formed on a surface from a given set of shots, wherein some or all of the shots may have an abnormal dose. Alternatively, the shooting of the shooting group 622 can be determined via a rule-based approach. Model-based fractures—although relatively more computationally intensive than rule-based fractures—can be determined to produce a more precise pattern than one of the shot lists determined by the rule-based approach. A list of shots on the surface.

Figure 6 Shooting Group 632 shows an exemplary method for breaking pattern 602 in accordance with one embodiment of the present invention. Shooting group 632 is comprised of shot 634, shot 636, and shot 638. Shots 636 and 638 are shaded for improved clarity. Shot 634 is fired at a higher than normal dose, such as 1.2 times the normal dose, and the width of shot 634 is calculated to produce a pattern having a width 604 on a surface. Both shot 636 and shot 638 overlap with shot 634 and extend below reference y coordinate 608. For example, the overlap between shots 634 and 636 is a partial overlap, and the intersection area between shot 634 and shot 636 is different from either of the two shots. Shot 636 and shot 638 are fired at this dose in this example. The pattern 732 of Figure 7 shows an analog pattern from one of the groups 632. Pattern 732 exhibits a smaller corner rounding than pattern 722, but also has a poor edge shape at the corners with an edge slope that is less than the minimum acceptable value in perimeter regions 734 and 736. Shooting group 632 shows how the use of overlapping shots and abnormal doses can allow for a higher fidelity to form a pattern than would be the case with a normal dose of non-overlapping shots.

Figure 6 Shooting Group 642 shows another example of a fracture pattern 602 that utilizes partial overlap shots in accordance with the present invention. The shooting group 642 is composed of shots 644, 646, 648, and 650. Shots 646, 648 and 650 are shaded for improved clarity. As with shots 624 and 634, shoot 644 uses a higher than normal dose, such as a 1.2x normal value. Shots 646, 648 and 650 use a normal dose in this example. Shot 650 is overlaid on shot 644. Shots 646 and 648 extend beyond reference y coordinate 608. The pattern 742 of Figure 7 shows a simulated pattern from the firing group 642. The corner 744 of the line end of the pattern 742 is less rounded than the corner of the pattern 722. In addition, the edge slope in the corner zone is above the minimum in all locations. Like the shooting group 632, the shooting group 642 shows how the use of overlapping shots incorporating an abnormal dose can allow for a pattern to be formed with a higher fidelity than the method shown by the method such as shooting 612 or prior art. .

The solution described above and shown in Figure 6 for firing groups 632 and 642 can be implemented even with a charged particle beam system that does not allow for dose assignment for individual shots. In one embodiment of the invention, a small number of doses can be selected, such as two doses such as 1.0x normal and 1.2x normal, and the firing system for each of the two doses can be separated in two separate exposure passes and Exposure, wherein the base dose for one exposure pass was 1.0 x normal and the base dose for another exposure pass was 1.2 x normal. For example, in shot group 632 of Figure 6, shot 636 and shot 638 can be assigned to a first exposure pass using a 1.0x normal dose of base dose, and shot 634 can be assigned to a base using a 1.2x normal dose. The second exposure of the dose is passed. In this embodiment, the combination of shots for any exposure pass will be different from the combination of shots for the combined exposure pass.

In other embodiments of the invention, overlapping shots may be utilized to reduce the sensitivity of the type of manufacturing variation that is not a dose variation. Beam blurring is an example of another type of manufacturing variation. Moreover, the method of the present invention can also be practiced using complex character projection (CP) shots, or a combination of complex CP and VSB shots.

Figure 8A shows an example of a rectangular pattern 800 to be formed on a group on a surface. The pattern 800 of the group includes six complete rectangles including a rectangle 802, a rectangle 804, a rectangle 806, a rectangle 808, a rectangle 810, and a rectangle 812. In addition, four extra rectangular portions are displayed: rectangle 814, rectangle 816, rectangle 818, and rectangle 820. It can be seen that the rectangles are arranged in a straight line in a regular pattern, wherein adjacent straight lines are separated by a space 830, and wherein adjacent rectangles in the row are separated by a space 832.

Pattern group 800 can be written to a surface using a VSB shot for each pattern in pattern group 800 using a conventional non-overlapping VSB shot. Thus, FIG. 8A can also be viewed as a group of shots 800, including shots 802, 804, 806, 808, 810, 812, 814, 816, 818, and 820. FIG. 8B shows an example of a set of simulated patterns 850 that may be generated from shot group 800 in the presence of mid-range scattering. The set of patterns 850 includes six complete patterns including a pattern 852, a pattern 854, a pattern 856, a pattern 858, a pattern 860, and a pattern 862. Pattern group 850 also includes four additional patterns, with Figure 8B showing only a portion of the pattern, including pattern 864, pattern 866, pattern 868, and pattern 870. The pattern in pattern group 850 exhibits corner rounding due to beam simulation, an example of which is corner 872. Moreover, the middle portion of the pattern in the middle two straight rows measured in the y-direction is narrower in the x-direction than the rest of the pattern, as shown by the mid-portion 874 of the pattern 858. This narrowing is the result of having less intermediate-path scattering energy reaching the middle portion 874 of the pattern 858 than other portions of the arriving pattern 858. In pattern 858, the pattern narrowing in region 874 is due to the gap between shots 814 and 806 and the gap between shots 818 and 812. Compared to the opposite shots 814, 806, 818, and 812, there is less intermediate-range scattering energy reaching the resist near the pattern 858 opposite the gaps. The outer straight lines 852, 854, 868, 862, and 870 exhibit asymmetric narrowing because they have adjacent shots on only one of the left or right side. The inner facing has a similar narrowing as the pattern 858, as shown by the narrowing zone 876 of the pattern 862. On the outwardly facing edge, such as the edge 878 of the pattern 862, the absence of an adjacent pattern causes lower mid-range scattering energy to be received along the entire edge, with the result that the overall edge 878 is offset in the -x (negative x) direction, resulting in a pattern 862. The width 882 is less than the width 880 of the pattern 858. This simulated mid-range scattering system is similar to the mid-range scattering of the reticle for EUV optical lithography in the range of effect, but the medium-range scattering system simulated in the pattern group 850 is more than the current EUV standard. Lines are often produced with a higher intensity. Pattern group 850 shows how mid-range scattering with a sufficient magnitude can affect the pattern written by charged particle beam lithography.

In another embodiment of the invention, overlapping shots may be utilized to perform mask process correction, thereby producing a higher fidelity pattern in the presence of mid-range scattering. Figure 9A shows a shot group 900 of one of the patterns 800 that can be used to generate a group. Shooting group 900 includes rectangular shots 902, 904, 906, 908, 910, and 912. Shooting group 900 also includes rectangular shots 914, 916, 918, and 920, showing only a portion of it. Compared to shooting group 800, shooting group 900 includes the following:

‧ The shot on the outside straight line is widened on its outer edge. This includes shots 902, 904, 918, 912, and 920. In shot 912, for example, edge 936 is moved in the +x direction as compared to shot 812.

‧ Add an extra shot to prevent the pattern in the middle portion of the pattern from narrowing, as shown by pattern group 850. The added shots include shots 922, 924, 926, 928, 930, and 932. These added shots deliver an additional dose to the zone, with the exception of the outer edge of the shot that will receive the smaller mid-range scattering dose on the outside. Due to the narrowing of the pattern 902, 904, 918, 912 and 920 on the outer edge of the shooting group 900 on the outside, the overlapping shots 922, 924 and 932 are positioned away from the shot by widening the shots 902, 904, 918, 912 and 920 on their outer edges as described above. The outer edges of 902, 904, and 912 are widened to prevent excessive mid-portions of the pattern formed by shots 902, 904, and 912.

Figure 9B shows an example of a pattern 950 that can be generated from a group of shots 900 on a surface. The pattern 950 of the group includes patterns 952, 954, 956, 958, 960, and 962, and partial patterns 964, 966, 968, and 970. As can be seen, in the presence of mid-range scattering, the exposure variation shown in the shot 900 of the group compared to the shot 800 of the group improves the fidelity of the pattern produced on the surface. The middle part of the pattern is not narrowed. Further, the width of the outer straight line pattern such as the width of the pattern 962 is equivalent to the width of the inner straight line pattern such as the width 980 of the pattern 958.

The calculations described or referenced in the present invention can be achieved in a variety of different ways. In general, calculations can be made by in-process, pre-process, or post-process methods. The calculation in the process involves performing a calculation when the results are needed. The pre-process calculation involves pre-calculation, then storing the results for later retrieval during a subsequent processing step, and can improve processing performance, especially for repeatable calculations. The calculation can also be deferred from a processing step and then performed at a later post-processing step. An example of pre-process calculations is a shot group that is a pre-calculation of dose pattern information for one or more shots associated with a given input pattern or set of input pattern features. The shooting group and associated input patterns can be stored in a library of pre-computed shooting groups, so that the group of shots containing the shooting group can be quickly generated for additional cases of the input pattern without patterning recalculate. In some embodiments, the pre-computation system can include a simulation of the dose pattern that the shot group will produce on a resist coated surface. In other embodiments, the firing group can be determined without simulation, such as by utilizing a correct-by-construction technique. In some embodiments, the pre-computed shooting group can be stored in the shooting group library in the form of a shooting list. In other embodiments, the pre-computed firing group may be stored in the form of a computer code that produces a shot for one or more particular types of input patterns. In still other embodiments, the plurality of pre-computed shot groups may be stored in a table format, wherein the logins in the table correspond to different input patterns or input pattern features such as pattern width, and wherein each form registration system provides shooting A shot of a list in a group, or how to generate an appropriate set of shots. In addition, different shooting groups can be stored in different ways in the shooting group library. In some embodiments, the dose pattern that can be generated for a given shot group can also be stored in the shot group library. In one embodiment, the dose pattern can be stored as a two-dimensional (X and Y) dose map called a glyph.

Figure 10 is a conceptual flow diagram 1050 of how to prepare a reticle for use in fabricating a surface such as an integrated circuit on a wafer. In a first step 1052, a physical design, such as a physical design of an integrated circuit, is designed. This may include determining logic gates, transistors, metal layers, and other items found in a physical design, such as found in an integrated circuit. The physical design can be straight, partially curved, or completely curved. Next, in a step 1054, optical proximity correction is determined. In one embodiment of the disclosure, this may include obtaining a library of pre-computed shot groups from a shot group library 1074 as an input. This may also be added or replaced by taking a library of pre-designed characters 1080 as input, including complex characters that would be retrieved on a template 1084 in a step 1062. In an embodiment of the disclosure, an OPC step 1054 may also include simultaneous optimization of the shot count or write time, and may also include a break operation, a shot placement operation, a dose assignment operation, or may also include a Shooting sequence optimization operations, or other mask data preparation operations, where some or all of these operations are simultaneous or combined in a single step. The OPC step can generate a partial or complete curved pattern. The output of OPC step 1054 is a mask design 1056.

The mask process correction (MPC) 1057 is optional on the mask design 1056. The MPC system modification will be written to the pattern of the reticle to compensate for effects such as narrowing of the pattern of less than about 100 nm wide. In a step 1058, a mask data preparation (MDP) operation, which may include a rupture operation, a shot placement operation, a dose assignment operation, or a shot sequence optimization, may occur. The MDP can use the results of the mask design 1056 or MPC 1057 as input. In some embodiments of the invention, the MPC can be performed as part of a break or other MDP operation. Other corrections can also be made for breaks or other parts of the MDP operation. Possible corrections include: forward scatter, resist diffusion, Coulomb effect, etching, backscattering, atomization, loading, resist filling, and EUV mid-range scattering. The result of the MDP step 1058 is a shot list 1060. OPC step 1054 or MDP step 1058, or a separate program 1072, may include pre-computing one or more shot groups available for a given input pattern and storing this information in a shot group library 1074. In this disclosure, it is intended to see any or all of the different operations of combining OPC and mask preparation in one step. The mask data preparation step 1058, which may include a break operation, may also include a pattern matching operation to match the pre-computed shot groups to create a mask that closely matches the mask design. Mask data preparation may also include reducing the sensitivity of the pattern written in step 1062 to manufacturing variations. The mask data preparation may also include: inputting a pattern to be formed on a surface, wherein the patterns are slightly different, and selecting a set of characters to be used to form the number of patterns, the set of characters being fitted to a template cover On-the-scenes, the set of characters may include complex and VSB characters, and the set of characters is based on the changed character dose or changed character position, or changes the beam blur radius or applies one word within the set of characters Partial exposure or dragging of a character to reduce the shot count or total write time. A slightly different set of patterns on the surface can be designed to produce substantially the same pattern on a substrate. Also, the set of characters can be selected from a predetermined set of characters. In one embodiment of the disclosure, a set of characters that can be quickly selected during the mask writing step 1062 and that can be taken on a template in a step 1080 can be prepared for a particular mask design. In this embodiment, once the mask data preparation step 1056 is completed, a template is prepared in a step 1084. In another embodiment of this disclosure, a template is prepared in step 1084 prior to or concurrent with the MDP step 1058 and may be independent of the particular mask design. In this embodiment, in step 1082, the character and template layouts available in step 1080 are designed to provide a general output for a number of potential mask designs 1056 to incorporate a particular OPC program 1054 or a particular MDP program. 1058 or a pattern output by a particular type of design that provides features of physical design 1052, such as memory, flash memory, system wafer design, or a particular process technology designed to be located in physical design 1052, or used in physical design 1052 A particular cell library in the middle, or any other common feature that can form a different set of slightly different patterns in the mask design 1056. The template may include a set of characters, such as a limited number of characters determined in step 1058.

A shot list 1060 is utilized to generate a surface in a mask write step 1062 that uses a charged particle beam writer, such as an electron beam writer system. The mask writing step 1062 can use a template 1084 containing a plurality of complex characters, or a template containing a VSB opening can be used. The electron beam writer system projects a beam of electrons through a stencil onto a surface to form a pattern on a surface, as shown in step 1064. The finished surface can then be used in an optical lithography implement, which is shown in a step 1066. Finally, in a step 1068, a substrate such as a germanium wafer is produced. As previously described, in step 1080, the characters can be provided to OPC step 1054 or MDP step 1058. Step 1080 also provides a character to a character and template design step 1082 or a shot group generation step 1072. The character and template design step 1082 provides an input to the template step 1084 and is provided to the character step 1080. The shooting group generation step 1072 provides information to the shooting group library 1074. Also, a shot group pre-calculation step 1072 can use the physical design 1052 or mask design 1056 as input, and can pre-compute one or more shot groups, which are stored in a shot group library 1074.

Model-based fracture systems can be combined with Xijian fractures in a single step. This would allow model-based fractures to be used in such areas where they would provide the greatest benefit, while for other parts of the design, less computationally intensive fractures were used. As previously indicated, in the fracture, the overlap of shots is avoided as much as possible, and all shots have a normal dose before long-range correction. In Figure 11A, concept flow diagram 1100 shows one embodiment of how the merged and model-based fractures can be combined. The input system for the combined fracture process is the mask design 1102. The mask design 1102 may be the mask design 1056 from Figure 10, or it may be part of the mask design 1056, or a modified form of the mask design 1056, such as from MPC 1057. A see-through break 1104 is performed on the mask design 1102 to generate a look-ahead shot list 1106. Alternatively, a break can be made on the portion of the mask design 1102 to keep portions unbroken. A model-based rupture step 1108 then enters the shot list 1106 and modifies, adds, or deletes shots in a complex region of a shot. The complex area may include, for example, an area having a minimum pattern or an area having a curved pattern. Complex regions may also include regions with high impact from mid-range scattering. Complex areas may also include "hot spots" with specific sensitivities in manufacturing. The "complex" term for this context may not represent the geometric complexity of the shape. In some embodiments, the model-based fracture 1108 can include determining in which region the modified shots are modified and/or the model-based shots are substituted for the learned shots. In other embodiments, the complex region can be determined in a separate step 112, automatically from the mask design 1056 or manually. In either case, the model-based fracture 1108 produced shots, some of which partially overlapped with other shots. The model-based fracture 1108 system may have replaced or modified some or all of the simulated shots in the designed or determined complex portion of the shot using shots determined by model-based techniques. The output of the model-based fracture step 1108 is a final shot list 1110 containing both the conventional and model-based shots. The final shot list 1108 corresponds to the shot list 1060 of FIG. For parallel processing of coarse particles in the steps of the conceptual flow diagram, the mask design 1102 may be part of the design, or it may be an overall design in which the steps can be performed in parallel.

Figure 11B Conceptual Flowchart 1120 shows another embodiment of how the merged and model-based fractures can be combined. The input system for the combined fracture process is the mask design 1122. The mask design 1122 may be the mask design 1056 from step 10, or it may be part of the mask design 1056, or a modified form of the mask design 1056, such as from MPC 1057. In FIG. 11B, the mask design 1122 is processed by patterning step 1124 of dividing the pattern data into non-complex pattern regions 1126 and complex pattern regions 1128. A custom fracture step 1130 uses the uncomplicated pattern region 1126 as an input. Xi see the break 1130 output a list of the habit shot 1136. An additional output is PEC Information 1132. In some embodiments, this information may be in one or more forms that can be used directly by the PEC. In other embodiments, the PEC information may be, for example, a look-up list itself from which PEC information may be calculated. The complex pattern area 1128 is broken using a model-based fracture 1134. Model-based fracture 1134 may use PEC Information 1132 as input, and this information is processed if appropriate PEC corrections for model-based shots within the range of effects for long-range effects need to be derived from the practice shot. In other embodiments, the PEC information may also be output by model-based fracture 1134, and it is known that fracture 1130 may use this information in some manner. Model-based fracture 1134 generates a model-based shot list 1138. The see-through shot list 1136 and the model-based shot list 1138 are then merged into a merged shot list 1140, which corresponds to the shot list 1060 of FIG. For the parallel processing of the coarse particles of the steps in the conceptual flow diagram 1120, the mask design 1122 may be a partial design, or it may be an overall design in which the steps may be performed in parallel.

The rupture, mask data preparation, proximity effect correction, and shot group generation processes described in the present disclosure can be implemented using a general purpose computer having an appropriate computer software as an arithmetic unit. Multiple computers or processor cores can also be used in parallel due to the large amount of computation required. In one embodiment, the operations may be subdivided into a plurality of two-dimensional geometric regions for one or more computationally intensive steps in the process to support parallel operations. In another embodiment, a special purpose hardware device, either alone or in multiple uses, can be used to perform one or more steps of operation at a higher speed than with a general purpose computer or processor core. In one embodiment, the special purpose hardware device may be a graphics processing unit (GPU). In another embodiment, the optimization and simulation process described in this disclosure may include an iterative process of revising and recalculating possible solutions to minimize the total number of shots, or the total charged particle beam write time, or some Other parameters. In yet another embodiment, a set of initial shots can be determined via a correct-by-construction method, so no shot modification is required.

Although the specification has been described in detail with reference to the specific embodiments, it will be understood that These and other modifications and variations of the methods for rupture, mask data preparation, proximity effect correction, and optical proximity correction may be performed by those of ordinary skill in the art without departing from the subject matter that is more specifically established by the scope of the claims. Spirit and scope. It is to be understood that those skilled in the art will understand that the above description is for illustrative purposes only and is not intended to be limiting. Steps may be added, deleted or modified for the steps in this specification without departing from the scope of the invention. In general, any of the proposed flows is only intended to indicate a possible sequence of basic operations to achieve a function, and may have many variations. Therefore, the subject matter of the subject matter is intended to cover such modifications and variations within the scope of

100. . . Electron beam writer system

112. . . Electron beam source

114,120,134. . . Electron beam

116. . . Opening plate

118. . . Opening

122. . . Rectangular perforated plate or stencil mask

124. . . Opening or opening

126,126A. . . Character

130. . . surface

132. . . Substrate

136. . . Black area

138. . . Electromagnetic or electrostatic reduction lens

140. . . Reduced electron beam

142. . . Bias

148,412,512,602,612,712,722,732,800,852,854,856,858,860,862,864,866,868,870,950,952,954,956,958,960,962. . . pattern

150. . . Positioning mechanism

202,222. . . Cross-sectional dose curve

204,224. . . Higher threshold

206,226. . . Lower threshold

214,216,234,236,604. . . width

302,402,502. . . Design pattern

304, 404, 504, 514, 606. . . Line end

306,406,508. . . Constant width

312,412,850. . . Simulated pattern

314. . . Line end portion of pattern 312

316,318. . . Section around the pattern

408,506. . . reference line

414. . . Line end portion of pattern 412

416,418. . . Part of the periphery of the pattern 412

518. . . Peripheral area of pattern 512

608. . . dotted line

622,632,642,900‧‧‧ Shooting group

624,626,634,636,638,644,646,648,650,802,804,806,808,810,812,814,816,818,820,922,924,926,928,930,932‧‧‧ shot

628‧‧‧ Shooting width of 624

714,716,734,736‧‧‧The surrounding area

724‧‧‧ line end corner of pattern 722

800‧‧‧Rectangular pattern

830,832‧‧‧ space

872‧‧‧ corner

874‧‧‧The middle part of the pattern 858

876‧‧‧Narrowing area of pattern 862

878‧‧‧The edge of the pattern 862

880‧‧‧ width of pattern 858

882‧‧‧Width of pattern 862

902,904,906,908,910,912,914,916,918,920‧‧‧Rectangular shots

Edge of 936‧‧

964,966,968,970‧‧‧Partial pattern

980‧‧‧ width of pattern 958

1050‧‧‧Flowchart

1052,1054,1056,1057,1058,1060,1062,1064,1066,1068,1072,1074,1080,1082,1084,1102,1104,1106,1108,1110,1112,1122,1124,1126,1128, 1130, 1132, 1134, 1136, 1138, 1140‧ ‧ steps

1100, 1120‧‧‧ concept flow chart

Figure 1 shows an example of a character projected charged particle beam system;

Figure 2A shows an example of a cross-sectional dose pattern depicting the aligned pattern width for each of the two resist thresholds;

Figure 2B shows an example of a cross-sectional dose pattern similar to Figure 2A but with a higher dose edge slope than Figure 2A;

Figure 3A shows an example of a desired 100 nm line end pattern to be formed on one of the reticle sheets;

Figure 3B shows an example of a simulated pattern formed by shots generated by the technique of breaking the pattern of Figure 3A using conventional techniques;

Figure 4A shows an example of a desired 80 nm line end pattern to be formed on one of the reticle sheets;

Figure 4B shows an example of a simulated pattern formed by a shot produced by breaking the pattern of Figure 4A using conventional techniques;

Figure 5A shows an example of a desired 60 nm line end pattern to be formed on one of the reticle sheets;

Figure 5B shows an example of a simulated pattern formed by a shot produced by breaking the pattern of Figure 5A using a technique;

Figure 6 shows a different example of a shot that can be used to form a group of 80 nm line end patterns;

Figure 7 shows the simulated pattern formed by the different shooting groups of Figure 6;

Figure 8A shows an example of a rectangular pattern to be formed on a group on a surface;

Figure 8B shows an example of how the pattern of Figure 8A, which is formed on a surface by a non-overlapping VSB shot, can be utilized in the presence of mid-range scattering;

Figure 9A shows an example of a VSB shot that can be used to form a set of patterns of Figure 8A on a surface;

Figure 9B shows an example of a pattern that can be formed on a surface from a shot of Figure 9A;

Figure 10 shows a conceptual flow diagram of how to prepare a surface, such as a reticle, for use in optical lithography to fabricate a substrate such as an integrated circuit on a wafer;

Figure 11A shows a conceptual flow diagram of a method of combining model-based and acquaintance fractures in the same design;

Figure 11B shows a conceptual flow diagram of another method of combining model-based and occlusion fractures in the same design.

602,612‧‧‧ pattern

604‧‧‧Width

606‧‧‧ line end

608‧‧‧dotted line

622,632,642‧‧‧ Shooting group

624,626,634,636,638,644,646,648,650‧‧ shot

628‧‧‧ Shooting width of 624

Claims (22)

A method for optical proximity correction (OPC), the method comprising the steps of: inputting an input pattern; inputting a set of OPC instructions; and using a shaped beam-charged particle beam writer to determine that a pattern is to be formed on a surface a plurality of charged particle beam shots, (i) wherein at least two of the plurality of charged particle beam shots overlap, and (ii) wherein the pattern is changed to include the input pattern a version of optical proximity correction, and (iii) wherein the pattern on the surface is less sensitive to manufacturing variations, wherein instead of using non-overlapping normal dose variable shaped beam (VSB) shots to form a pattern, The sensitivity of manufacturing variations is reduced by increasing the edge slope, and wherein the determining step is performed using one or more computing hardware processors. The method of claim 1, wherein the determining step comprises: calculating the pattern on the surface from the plurality of charged particle beam shots. The method of claim 2, wherein the calculation comprises a charged particle beam simulation. The method of claim 2, further comprising an operation step of calculating whether the calculated pattern on the surface is to be formed on the substrate to a predetermined tolerance when transferred to the substrate by an optical lithography process Each is equal to one of the desired patterns for the substrate, wherein the operational step includes at least one of lithography simulation and etch simulation. A method for fracturing or mask data preparation or mask process correction or proximity effect correction of charged particle beam lithography, the method comprising the steps of: using a shaped beam charged particle beam writer to determine Forming a plurality of charged particle beam shots on a surface, wherein at least two of the plurality of charged particle beam shots partially overlap, and wherein the pattern on the surface is for manufacturing variation The sensitivity is reduced, wherein the determining step is performed using one or more computing hardware processors, and wherein manufacturing is compared to using non-overlapping normal dose variable shaped beam (VSB) shots to form a pattern The sensitivity of the variation is reduced by increasing the edge slope. The method of claim 5, wherein the determining step comprises: calculating the pattern on the surface from the plurality of charged particle beam shots. The method of claim 6, wherein the calculation comprises a charged particle beam simulation. The method of claim 7, wherein the charged particle beam simulation comprises at least one of a group of short-range effects consisting of forward scatter, resist diffusion, Coulomb effect, and etching. The method of claim 7, wherein the surface is an extreme ultraviolet (EUV) reticle, and wherein the charged particle beam simulation comprises EUV mid-range scattering. The method of claim 7, wherein the charged particle beam simulation comprises at least one of a group of long-range effects consisting of backscattering, atomization, loading, and resist filling. The method of claim 5, wherein each of the plurality of charged particle beam shots comprises a specified dose, and wherein one of the plurality of charged particle beam shots before the long range correction The specified dose of the first charged particle beam shot is different from the specified dose of the second charged particle beam shot of the plurality of charged particle beam shots. The method of claim 5, wherein in the determining step, the pattern on the surface is a first pattern, the method further comprising a generating step of generating a second pattern on the surface A set of non-overlapping normal dose variable shaped beam (VSB) shots, wherein the first pattern and the second pattern are adjacent. The method of claim 12, wherein the short-range and/or long-range effects from the set of non-overlapping VSB shots are used in the determining step. The method of claim 5, wherein the plurality of charged particle beam shots of the plurality of charged particle beam shots are variable shaped beam (VSB) shots. The method of claim 5, wherein the plurality of charged particle beam shots are exposed in a single exposure pass. The method of claim 5, further comprising the steps of: inputting a set of non-overlapping variable shaped beam (VSB) shots having a normal dose to form the pattern on the surface; and determining the plurality of A charged particle beam shot replaces some or all of the VSB shots in the set of VSB shots. A fracture or mask material preparation for charged particle beam lithography or A method of mask process correction or proximity effect correction comprising the steps of: inputting a desired pattern to be formed on a surface; and using a shaped beam-charged particle beam writer to determine that the pattern will be formed on the surface And a plurality of charged particle beam shots, wherein at least two charged particle beam shooting systems of the plurality of charged particle beam shots partially overlap, and wherein the plurality of charged particle beam shots form a pattern on the surface And the pattern is closer to the desired pattern than the pattern formed by non-overlapping normal dose variable shaped beam (VSB) shots, wherein the determining step is performed using one or more computing hardware processors, and wherein The sensitivity to manufacturing variations is reduced by increasing the edge slope compared to using non-overlapping normal dose VSB shots to form a pattern. The method of claim 17, wherein the determining step comprises: calculating the pattern on the surface from the plurality of charged particle beam shots. The method of claim 18, wherein the calculation comprises a charged particle beam simulation. A method for mask process correction for charged particle beam lithography, the method comprising the steps of: inputting a desired pattern to be formed on a reticle; and determining for writing a charged beam of a shaped beam a plurality of charged particle beam shots, wherein at least two charged particle beam firing systems of the plurality of charged particle beam shots partially overlap, wherein the plurality of charged particle beam shots form the desired pattern on the line On-chip, and wherein the plurality of charged particle beam firing systems are incorporated into a mask process correction, and The decision step is performed using one or more computing hardware processors. A system for fracture or mask data preparation or mask process correction or proximity effect correction for charged particle beam lithography, comprising: a device for determining a plurality of charged particles that will form a pattern on a surface Beam shooting in which at least two charged particle beam firing systems of the plurality of charged particle beam shots partially overlap, and wherein the sensitivity of the pattern on the surface to manufacturing variations is reduced, and wherein The sensitivity to manufacturing variations is reduced by increasing the edge slope in terms of overlapping normal dose variable shaped beam (VSB) shots to form a pattern. A system for optical proximity correction (OPC) of a design, the design comprising a pattern to be formed on a surface, the system comprising: a desired pattern for one of the substrates; and a device for determining a plurality of charged particle beam shots, (i) wherein at least two of the plurality of charged particle beam shots overlap, (ii) wherein the plurality of charged particle beam shots form a pattern on the surface And the desired pattern for the substrate will be formed when the pattern is used in the optical lithography process, and (iii) the sensitivity of the pattern on the surface to manufacturing variations is reduced.