TW472172B - Method to repair the attenuated phase shift mask by optical proximity effect correction technology - Google Patents

Abstract

The present invention provides a method to repair the attenuated phase shift mask by optical proximity correction (OPC), wherein the OPC pattern whose image not formed on the photoresist is designed around the abnormatity defect portion by the etching or deposition of the repairing machine. These OPC pattern can enhance or attenuate the light intensity on the region to be repaired, so as to achieve the goal of repairing the abnormatity defect of the attenuated phase shift mask.

Description

472172 V. Description of the invention (1) Field of the invention: a new kind of invention This invention relates to the manufacture of photomasks in semiconductor manufacturing processes. In particular, the repair method is used to repair attenuation phase shift photomasks. Background of the Invention: Integrated Circuits (ICs) are constantly evolving and improving in technology, increasing the number of electronic element components, such as 1 m, 1 m, and 1 m, and increasing the number of electrons. Increasing the density of electrons has suddenly become a trend. . In order to make semiconductor wafers have a higher component density, the industry continues to work towards shrinking components (1 丨 1116113 丨 〇1 ^). In order for Yuancheng to achieve such a high degree of component packaging, it is necessary to have smaller and smaller external circuits. “Dimensions” This may include the width and spacing of interconnects, and the surface geometry of various circuit shapes such as corners, edges, etc. Therefore, the role of lithographic processes is also important. Mainly, lithographic processes provide a variety of Pattern transfer between media, accurate alignment between multiple layers. Lithography and etching include forming a photoresist pattern as a mask, in order to build a half with a very fine pattern: J Wu: 'Therefore, a deep sub-micron resolution is needed Ability of lithography 5 Ϊ two lithography systems include a light source and a device containing the intended to be formed on the wafer ;: a device for alignment. The traditional optical army includes a glass stone: the plate is a T-transmissive part. The special wavelength The light passes through the photomask to the wafer using this method. The pattern on the photomask is exposed on this photoresist. On the circle. A: This photomask can be used as a stencil to transfer the desired pattern to multiple crystalline polymers. ; Son, taxi ^ The area where the light is blocked by an appropriate wavelength ’is removed. This photoresist removes this exposed change: it becomes a component that can be decomposed by the developer, and the photoresist in the first area. There is also the opposite situation of the developer.

Page 4 472172 V. Description of the invention (2) The unexposed photoresist is decomposed to leave exposed parts, depending on the designer's needs.

At present, users mainly use phase shift masks, which play an important role in the application of deep ultraviolet technology. Among them, attenuation phase shift masks are the most common. Generally, a quartz substrate is prepared, and a phase shifting layer is deposited on the above-mentioned quartz substrate, and a chromium layer is successively formed thereon. A photoresist is applied to the chromium layer using conventional techniques to help define the pattern of the chromium layer. The specific area of the photoresist is scanned with an electron beam to define an area to be exposed, so as to facilitate pattern generation. Thereafter, the above-mentioned photoresist is developed and heat-treated to produce a pattern. The above photoresist pattern is used as an etching mask to etch the chrome layer by wet etching, and then dry-etch the silver phase shifter (attenuated phase shifter). The principle is to place the adjacent transparent area but make it transparent. The 180 degree reverse phase of the light beam makes the resolution or depth of field of the exposure system greatly increased. The material used for the shielding layer can be chromium, aluminum, or molybdenum silicide; the phase shift layer can be MoSiON, SiNx, CrF, or amorphous carbon. One of the previous technologies can be found in Michael E. Kling, et a 1. " Practicing extension of 248nm DUV optical lithography using trim-mask PSM " SPIE Microlithography 1999, pp. 10-17. Masanobu Hasegana, et a 1. " Practical applications of IDEAL exposure method ”SPIE Vol. 3873, pp66-77o When the size of the pattern on the wafer is reduced,

Page 5 472172 V. Description of the invention (3) The under mask is also “more sleepy.” If there are any defects on the mask that are not calculated in y ^ ectsh, they will be transferred to each manufactured wafer. For, on these wafers The formed integrated circuit has a harmful effect. 10. Ruoshi: trapped: With the shape & accumulated by two different layers, it will become particularly difficult to avoid. First f: defects occur. For example, $, before any etching Defects in the photoresist will be transferred to the chrome film, and any depressions in the chrome film will also exist like H in the photomask. The defects of the photomask layer are generally bubbles or Defects created during other pattern generation processes. In order to correct defects in these masks, sophisticated and expensive mask inspections and processes have been developed to repair these mask layers. For example, the use of removing defective The photomask layer is replaced by a new photomask layer. Another known method is to use ion beam sputtering or laser to remove unwanted photomask material, so that the area of the photomask that wants to be completely transparent can be completely transparent. Light. Similarly, you can deposit In areas where light transmission is not desired, see United States Patent 6, 1 1 4, 0 73: Method for repairing phase shifting masks. The development of Optical Proximity Correction technology is to improve the pattern on the mask The fidelity transferred to the photoresist or even the wafer. As a result of the optical diffraction effect, for example, a rectangular pattern is finally imaged on the wafer 'the four corners of the rectangle are round corners. Optical Proximity effect correction technology, forming an auxiliary pattern in the vicinity of the main pattern, making the imaged image more in line with expectations. For 0PC, please refer to " Pratical Optical Proximity Effect

Page 6 472172 V. Description of the invention (4)

Correct ion Adopting Process Latitude Consideration, Keisuke Tsudaka et a 1., Jpn. J. Appl. Phys. Vol. 34 (1 9 9 5) pp. 6552-65 5 9, Parti, No. 12B, Dec. 1995. ", " Evaluation of OPC Efficacy, FM Schellenberg et al., 680 / SPIE vol. 2726, pp. 680-688. &Quot; Object and Summary of the Invention: The object of the present invention is to provide a method for repairing an attenuating phase shift mask. The present invention provides a repaired attenuated phase shift mask.

The Phase Shift Mask (APSM) method uses optical proximity effect correction technology (Optical proximity c〇rrection, 0pc) to repair the engraved or deposited effect of the machine's name to design different colors around the abnormal defect. 0PC pattern of agricultural image on t. These 0PC patterns will be able to enhance or weaken the purpose of the abnormality of the agricultural 1. The intensity of the agriculture ’I. phase_shift mask. Detailed description of the invention: Each of the present invention provides a method for repairing a photomask. The principle of optical proximity effect repair technology is used to etch or deposit some patterns around opaque defects and light transmitting defects to strengthen or resist them. The light of the pin defect pattern has the effect of repairing the defect of the mask. The detailed description is as follows.

Page 7 472Π2 V. Description of the Invention (5) The preferred embodiment is described only for the purpose of not limiting the present invention. The pattern defects on the reticle are divided into opaque defects and transparent opaque defects as shown in Figure 2A. The original pattern in the attenuation phase shift reticle ^, the square transparent area 100, due to impurities or This area is too large, causing the pattern imaged on the wafer to be not large enough, as shown in Figure 2 2-$ 小 '. α / νΓ is not true, and the range of total h is 101. A directional gate repair machine at an angle of -45 degrees of the original pattern area 100 is used to deposit a square pattern with an area of about 1/3 to 1/2 of the area 1 0 0. The area and position of this repair pattern 10 are based on conventional technology. Calculated by the neighbor-revision principle. After that, the light was repaired after this repair.

Develop on the photoresist to form a larger pattern as expected, as shown in Figure 2. The range within the J line is 1 0 3 ea. Refer to Figure 2. 2B 'is another embodiment of the present invention. 0 0 is an opaque defect that is insufficiently imaged on the wafer. The shape modifier is used to form an optical proximity effect correction pattern around the pattern 100. A scattering bar is formed from the pattern 100. The distance from the pattern 100 is the effect of respecting the light intensity, and the fixed distance is based on conventional optics. Proximity effect is calculated. As known in the prior art, this allows light to pass through the figure Λ '. Due to the reduction of the diffraction offset effect, the photoresist receives a greater energy than the pattern 100: case, and obtains a larger amount on the wafer. The pattern of 1. 3, 丄 Erguang :: Figure 2 2D shows another kind of repair situation, ffl case Ϊ0 0 in b is larger than expected. A scattering bar is deposited on the immediate side of pattern 100. Using optical proximity effect, the scattering strip pattern emits attenuation

472172 V. Description of the invention (6) The effect of reducing the light intensity of the subtractive phase shift mask extends into the pattern 1000, so that the light energy passing through the pattern 100 is reduced, causing the pattern to be slightly reduced in size. It is shown that an OPC pattern is formed around the original image N / E 100 by an etching attenuation phase shift mask, and the optical proximity effect caused by the OPC pattern is used to produce a repair effect on the original pattern. As shown in FIG. 3 and 3, two repair patterns 16 are engraved on the diagonal of the pattern 100 on the reticle. Using this repair pattern 16, the optical proximity effect on the diagonal increases the light in the diagonal direction. Within the pattern 100, the result of the dashed line pattern 103 shown in FIG. 3a is thus generated. Figure 3 3B uses a etched scattering bar on the right side of the pattern 100 on the photomask to change the imaging on the wafer from ιοί to 103. Similarly, as shown in 3D% of FIG. 3, a scattering strip 20 is etched on the upper and lower sides of the pattern 100 on ff, and imaged after the wafer is repaired. It can be known from the embodiment of the present invention that the purpose of repairing the original pattern can be achieved by using the OPC pattern '. The repairing machine used in the above-mentioned embodiments is a focused ion beam (FIB), which is currently a more general-purpose machine for repairing '... other repairing machines have laser beams and phase shift masks. , „Ηηρ1 ·., By a scanning tunnel ng (ng micr〇sc〇pe) f repairable machine is ⑯, the focus of the present invention is to use optical proximity correction technology, A μ-pattern is used to form a repair pattern around the door case to correct the imaging effect of the missing pattern on the wafer. The advantage of the present invention is that the optical proximity correction technology used is conventional.

472172

V. Description of the invention (7) The principle of repairing the defect pattern of the photomask by this technology is not as unpredictable as currently used, and it is easy to control in operation. It can estimate the situation of the image after the repair. We can use Micro-lithography Simulation Microscope (MSM) to predict the critical width (CD) and simulate the result of using the 0pc method to repair the pattern. The invention also has an advantage that it is not directly etched or deposited on the defect pattern, so it will not cause damage to the light-transmitting substrate of the original defect pattern, such as gallium, dyeing or engraving & forming the surface of the light-transmitting substrate. The roughening of the wafer makes it impossible to image on the wafer. & Another advantage of the present invention is that the added repair pattern will not be imaged on the photoresist or wafer because the light itself is sufficient. Because the conventional technique directly affects the defect pattern, its mistakes may cause other defects. That is, the present invention is described above with a preferred embodiment, and the technical decoration in this field is familiar, without departing from the spirit of the present invention, it can be made a little more dynamic, and the scope of protection should be treated as the attached patent. Scope and its equivalent

Page 10 4Ϋ2172 Brief description of the drawings The preferred embodiment of the present invention will be described in more detail with the following figures in the following description: Fig. 1 is a diagram illustrating a mask pattern repair method of the prior art. Figure 2 is a schematic diagram of a repair pattern deposited on a photomask using the optical proximity effect correction principle of the present invention. FIG. 3 is a schematic diagram of a repair pattern etched on a photomask using the optical proximity effect correction principle of the present invention.

Page 11

Claims (1)

472172 6. Scope of patent application 1. A method for repairing a mask pattern, the method at least comprises: providing a mask with an opaque defect pattern, wherein the opaque defect pattern does not match a desired pattern; using an optical proximity effect The size, shape and position of the repair pattern are obtained by the correction principle; the repair pattern is formed on the periphery of the opaque defect pattern on the photomask using a repair machine. 2. The method for repairing a mask pattern according to item 1 of the scope of the patent application, wherein the mask is a subtle phase shift mask. 3. The method for repairing a mask pattern according to item 1 of the patent application, wherein the repair pattern is a rectangular shape having an area smaller than the area of the opaque defect pattern, and is formed at a corner of the opaque defect pattern. 4. The method for repairing a mask pattern according to item 1 of the scope of the patent application, wherein the repair pattern is at least two rectangles having an area smaller than the area of the opaque defect pattern, each formed on a plurality of diagonal corners of the opaque defect pattern . 5. The method for repairing a mask pattern according to item 1 of the patent application, wherein the repair pattern is a scattering bar formed on one side of the opaque defect pattern. 6. The method for repairing the photomask pattern according to item 1 of the patent application, wherein Page 12 472172 6. Scope of patent application The repair pattern is two scattering strips formed on both sides of the opaque defect pattern. The case of the French method in the report is covered by the light repairing item. Item 1 1st Divide around the norm. 7 Fixing the case of Thursday ’s plan is lacking in light and not in shape. The case is covered by light. The lack of light is not necessary. The repair should be based on the field item light 1 ^ through the range product fL. The figure is as shown in Supplement 8. The method for repairing the photomask pattern as described in the first item of the patent application scope, wherein the repairing machine is to etch out the transparent area to repair the opaque defect. 10. The method for repairing a mask pattern according to item 1 of the patent application scope, wherein the repairing machine is a focused ion beam (FIB). 1 1. The method for repairing a photomask pattern according to item 1 of the patent application scope, wherein the repairing machine is a scanning tunneling microscope. 1 2. The method for repairing a mask pattern according to item 1 of the patent application scope, wherein the repairing machine is a laser beam. 1 3. A method for repairing a mask pattern, the method at least comprising: providing a mask with a light-transmitting defect pattern, wherein the light-transmitting defect pattern and the period Page 13 472172 VI. Patent application scope The pattern does not match; the size, shape and position of the repair pattern are obtained by using the optical proximity effect correction principle; the repair machine is used to form the repair pattern on the periphery of the light-transmitting defect on the mask. 1 4 · The method for repairing a photomask pattern according to item 13 of the scope of patent application, wherein the photomask is an attenuation phase shift photomask. 15. The method for repairing a mask pattern according to item 13 of the scope of the patent application, wherein the repair pattern is a rectangle having an area smaller than the area of the opaque defect pattern, and is formed at a corner of the transmissive defect pattern. 16. The method for repairing a mask pattern according to item 14 of the scope of the patent application, wherein the repair pattern is at least two rectangles having an area smaller than the area of the opaque defect pattern, each formed on a plurality of pairs of the transmissive defect pattern angle. 1 7. The method for repairing a mask pattern according to item 13 of the scope of the patent application, wherein the repair pattern is a scattering bar formed on one side of the transmissive defect pattern. 1 8. The method for repairing a mask pattern according to item 13 of the scope of the patent application, wherein the repair pattern is two scattering stripes formed on both sides of the light transmission defect pattern. Page 14 472172 VI. Applying for a patent scope i9 Repair H Please use the 13th method of repairing the mask pattern 'where you are' The case is a plurality of scattering strips, and the four repairs formed on the light transmission defect pattern are patented Range 帛 13 methods for repairing a mask pattern, wherein the pattern is to deposit a light-transmitting area to repair the transmission defect. ΫMethod 13 for repairing a mask pattern for a patent application, wherein the c > repair pattern is etching The transmissive area is repaired to repair the transmissive defect. 2 2. Shen Shizhuo Kui 11 The method of repairing the reticle pattern of item 13 of the repair machine 'wherein' machine 15 is a focused ion beam (FIB). The repair application \ Patent No. 13 Method for repairing the mask pattern, where m: is for scanning tunneling micr〇scope 〇2 4. If you have applied for the scope of No. 13 A method for repairing a reticle pattern, wherein the > repairing device is a laser beam.