TW425495B - A polarization mask without chromium - Google Patents

Abstract

The present invention proposes a polarization mask without chromium, which includes a transparent plate, a first polarization layer on one portion of region of the transparent plate, and a second polarization layer located on the transparent plate and one portion of region on the first polarization plate overlapped with the first polarization layer, wherein the polarization direction of the second polarization layer is perpendicular to the first polarization layer. The present invention provides a method to form a polarization mask, which includes providing a transparent plate, forming the first polarization layer on the transparent plate, and etching the first polarization layer. Then form the second polarization layer on the transparent plate and the first polarization plate, and etch one portion of the second polarization layer on the first polarization layer, so that the first polarization layer and the second polarization layer has an overlapped region.

Description

42549 5 V. Description of the invention ο) 5-1 Field of the invention: The present invention relates to a polarization exposure device, and more particularly to a polarization mask without chromium and a method for manufacturing the same. 5-2 Background of the Invention: As critical dimensions continue to shrink, optical lithography technology has advanced to the analytical limit. One way to increase optical resolution and reduce pattern spacing is to use a dual image exposure system. As shown in the first figure, a conventional lithography device using a two-layer chrome mask is shown. In the first picture, a light source (not shown) emits light from above when it passes through the first mask and is blocked by the chromium 120 of a transparent plate 130, and then passes through the second mask and is covered by another transparent plate. Chromium on 132 is covered by 22. Finally, it is projected onto a wafer i 00, so that the photoresist 110 on the wafer 100 is exposed. This method solves the problem that the distance between the figures cannot be too close in the conventional photomask technology, thereby improving the optical resolution. However, although this method can increase the optical resolution, the yield and the accuracy of optical alignment are still the key considerations. This is because optical interference and scattering between the first mask and the first mask still exist. Another way to increase optical resolution is to use optical polarization. As shown in the second figure, a photomask has a transparent flat plate 134, and a chromium pattern 124 is formed on the transparent flat plate 134 after the chromium is transferred by a pattern. A first polarizing plate is formed on the chrome pattern 1 24 and the transparent flat plate 34 respectively.

5. Description of the invention (2) 150 is perpendicular to a second polarizing plate 152, where the direction of the two polarizing plates 52 of the first polarizing plate 15 is perpendicular. If the polarizing plate between the photomask and the light source, one of the polarizing plates is oriented in the same direction as the first polarizing plate, and the other polarizing plate is oriented in the same direction as the second polarizing plate j 5 2 The light of the polarizer plate 152 cannot pass through the second polarizer plate 152, and the light of the polarizer plate 152 cannot pass through the first polarizer plate 152. Compared with the first optical device, it is equivalent to increase the resolution as if two photomasks are applied, and at the same time, it solves the problem of optical interference between the two photomasks. However, the photomask formed in this way requires three chrome-forming and two polarizing plates) to complete a photomask. Furthermore, the complicated steps are prone to particle contamination (particle coontami 3 purpose and summary of the invention: the direction is the same as that of the first two places 50, then the optical and scattering steps (shape 'its (Comparative nation) In view of the many shortcomings of the above-mentioned inventions, the present invention mainly refers to the light generated by the traditional polarized photomask. Among them, Πίίϊΐ is to provide a polarization without a way / the more traditional polarization The photomask is simple and simple. Another purpose is to reduce the polarized pollution particles by the step of forming the photomask. According to the objectives M and ^ sJ described above, the present invention provides a non-polarized light. Hood 'which contains-transparent flat plate made of quartz with chrome located on transparent Π page 5 4254 9 5

V. Description of the invention (3) Intent; The above-mentioned purpose of the present invention is shown in the following. The following examples and drawings are used to explain the details below, including: It is a schematic diagram of the structure of a conventional dual-layer device, especially the first exposure device; the first diagram is a schematic diagram of the structure of a traditional polarizing mask; a part of the area on the bright plate is located on the transparent plate and The second polarizing layer is overlapped with the first polarizing layer. The present invention provides a method including providing a transparent flat plate, and then etching the first polarizing layer to form a second polarizing layer. On the second polar layer, make the first overlapping area. Brief description of the drawings: The third diagram is based on the schematic diagram of the present invention; the fourth diagram shows the partial poles of the two polarisation layers on a partial region of the first polarisation layer and a second polarisation layer of the first polarisation layer of the present invention. Direction and the first method of forming a polarizing mask, and then forming a first polarization on a transparent flat plate. Afterwards, two polarizers are formed on the transparent plate and the first polarizer and the etching is partially located on the photomask having the structure of the first polarizer, the second polarizer layer, and the second polarizer layer having a polarized mask without chromium. Polar plate polar direction

4254 9 b V. Description of the invention (4) Figures A through F through D are schematic diagrams of steps in forming a polarized photomask without chromium according to the technology disclosed in the present invention; and Figure 6 This is a polarized photomask without chromium according to the present invention, and should be a schematic diagram of an exposure device. Symbols of important parts ... 1 light source 2 focusing lens group 3 reduced projection lens group 4 wafer 5 polarizing plate 10 transparent flat plate 20 first polarizing layer 22 second polarizing layer 25 overlapping area 30 does not have chrome bias Polarizing mask 40 Photoresist layer 100 Substrate 110 Photoresist 120 Chrome 122 Chrome 124 Chrome

4 25 4 ..

V. Description of the invention (5) 130 transparent plate 132 transparent plate 134 transparent plate 15 0 first polar layer 15 2 second polar layer 5-5 Detailed description of the invention: Some embodiments of the present invention will be described in detail as follows. However, in addition to the detailed description, the present invention can also be widely implemented in other embodiments, and the scope of the present invention is not limited, which is subject to the scope of subsequent patents. Because the traditional photomask first forms a chrome pattern on a transparent flat plate, however, the process of forming the chrome pattern will inevitably produce pollution. The present invention mainly uses the characteristics of optical polarization to replace the chrome pattern, so the reticle of the present invention does not need to form a chrome pattern again. Next, the polarizing mask of the present invention will be described first, and then the manufacturing method of forming the mask of the present invention will be described. Finally, the photomask of the present invention is applied to an exposure device in a lithography process. As shown in the third figure, it is a schematic structural diagram of a polarized photomask 30 without chromium according to the present invention. A transparent flat plate 10 has two polar layers 20, 22 on it. The material of the transparent plate 10 is usually quartz, but other transparent materials can be used. There is a first polarizing layer 20 and a second polarizing layer 22 on the transparent flat plate 10, wherein the first polarizing layer 20 and the second polarizing layer 22 overlap

Page 8 425495 V. Description of Invention (6) Zone 25. The present invention uses this overlapping area 25 instead of conventional chromium. Since the chromium on the conventional photomask has a path for blocking light, the overlapping region 25 of the first polar layer 20 and the second polar layer 22 in the third figure must also have the ability to block the light path. The main key of the present invention is to make the polarization direction of the first polarization layer 20 perpendicular to the polarization direction of the second polarization layer 22, as shown in the fourth figure. Therefore, the overlapping area 25 on the transparent plate can replace the conventional chromium. After the lithography of the polarized light, the pattern of the overlapping area 25 is projected on a wafer to form a pattern of the integrated circuit. Next, the structure of each step when the polarized photomask disclosed according to the present invention is introduced is first provided with a transparent flat plate 10, and the layer 40 is sequentially formed on the transparent flat plate in a systematic manner. Then, a pattern is transferred to the light to etch the first polarizing layer 20 as a mask, and the photoresist layer 40 is removed in a conventional manner. A part of the second deviation is shown in the same manner as the fifth is the same as that described above on the transparent flat plate 10. The removed second polarizing layer 22 is above, so that the technique of the first polarizing layer 20 and the second exposure is illustrated. If the quality is usually stone, a fifth A is formed, and a first polarizing layer 20 and the light does not have the photo shown in the figure and a photoresistive layer 40 is passed, as shown in the figure 5B and the figure C A polar layer 22 is removed from a part of the polar layer 22 with a resistance layer 40. After that, it was transmitted in the first polar layer. Finally, the above “such as the fifth polarizing layer of the first polarizing layer 2 in the fifth figure D.” The following describes the application of the polarizing mask without chromium 3 of the present invention. 3025 ^ 5. Description of the invention ¢ 7) Polarization exposure device. As shown in the sixth figure, the polarization exposure device includes a light source 1 for generating light, and two sets of polarizing plates 5a and 5b respectively for polarizing the light generated by the light source 1 into two directions. A focusing lens group 2 is used to focus the light, a mask 30 is used to selectively pass the light, and a reduction projection lens group 3 is used to reduce the light and project it onto a wafer 4. In the use of the polarized polarizing mask 30 without chromium of the present invention, two sets of polarizing plates 5a and 5b are located between the light source 1 and the focusing lens group 2, and the light emitted by the light source 1 is polarized separately. The polarization direction is the same as that of the polar layer on the photomask 30. The polarized polarizing mask 3 without chromium, which allows light to pass through the preset lens through the focusing lens group 2, is located between the focusing lens group 2 and the reduced projection lens group 3. Therefore, the light emitted from the light source 1 can only pass through one of the two sets of polarizing plates 5a and 5b. If the light passes through the first polarizing plate 5a, the light is polarized in the direction of the first polarizing plate 5a. The polarized light is focused by the focusing lens group 2 and radiated onto a polarizing mask 30 having no chromium. Since the photomask 30 has two types of polarizing layers 20 and 22, the light on the photomask 30 can only pass through it—a kind of polarizing layer ', such as the polarizing layer 20 (excluding the overlapping area 25). After that, the light is projected onto the wafer 4 through the reduction projection lens group 3, wherein the surface of the wafer 4 has a photoresist layer (not shown in the figure). On the contrary, after passing through the second polarizing plate 5b, the light can only pass through another polarizing layer 2 2 (excluding the overlapping area 2 5) on the photomask 30, and then pass through

(8) The small projection lens group 3 projects light onto the wafer 4. According to the above, the manufacturing of the polarized photomask 30 without chromium of the present invention has only two steps (two polarized layers), which reduces the number of steps compared with the conventional polarized photomask manufacturing process. Not only can increase the yield and output of mask manufacturing, but also reduce the occurrence of particulate pollution. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of applying for patents. month

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Claims (1)

425495 VI. Scope of patent application 1_ A polarizing mask including at least: a transparent flat plate; a partial area; and a first polarizing layer on the polar layer on the transparent flat plate: one: thirty-two The transparent flat plate and a part of the first-polarity layer are overlapped with the first-polarity layer, and the polarization direction of the first-polarity layer is perpendicular to the first-polarity layer. ， M 光 Mask of the first scope of the patent scope 'wherein the material of the above-mentioned transparent flat plate declares the mask of the first scope of the patent scope, wherein the overlapping area of the second polar layer and the first polar layer of the above-mentioned is projected to— Integrated circuits are formed after the wafer. 4. A method of forming a polarizing mask, the method at least comprising: providing a transparent flat plate; forming a first-polarizing layer on the transparent flat plate; leaving a part of the first polarizing layer in a moment; A second polarizing layer is formed on the transparent flat plate and the first polarizing layer; and the second polarizing layer is partially located on the first polarizing layer, so that the first polarizing layer and the first The bipolar layer has an overlapping area. Page 12 4 2549 5 6. Scope of patent application 5. For the method of the fourth scope of patent application, the material of the transparent flat plate is quartz. 6. The method according to item 4 of the scope of patent application, wherein the overlapping area of the second polar layer and the first polar layer described above is projected onto a wafer via lithography to form an integrated circuit. 7. The method according to item 4 of the scope of patent application, wherein the polarization direction of the second polarization layer is perpendicular to the polarization direction of the first polarization layer. Page 13