JP2012528353A - Halftone mask and manufacturing method thereof - Google Patents

Abstract

The present invention provides a halftone mask and a method of manufacturing the same that can reduce time and cost by reducing the number of semi-transmissive materials and the number of steps for forming a multiple semi-transmissive portion.
A halftone mask according to the present invention includes a substrate, a transmission region that is formed on the substrate and transmits light of a predetermined wavelength band to be irradiated, and at least two semitransparent materials are alternately formed on the substrate. And a semi-transmission region having multiple semi-transmission portions having different transmittances depending on the number of the semi-transmission materials laminated.
[Selection] Figure 1

Description

  The present invention relates to a halftone mask capable of reducing time and cost by reducing the number of semi-transmissive materials and the number of steps forming a multiple semi-transmissive portion, and a manufacturing method thereof.

  Generally, a liquid crystal display device displays an image by adjusting the light transmittance of a liquid crystal having dielectric anisotropy using an electric field. For this purpose, the liquid crystal display device includes a liquid crystal display panel that displays an image, a drive circuit that drives the liquid crystal display panel, and a backlight assembly that provides light to the liquid crystal display panel.

  The liquid crystal display panel includes a color filter substrate and a thin film transistor substrate bonded with a sealing material with a liquid crystal interposed therebetween.

  The color filter substrate includes a black matrix, a color filter, and a common electrode stacked on an insulating substrate.

  The thin film transistor substrate includes a gate line and a data line formed to intersect with each other on the lower insulating substrate, and a thin film transistor connected between the gate line, the data line, and the pixel electrode. The thin film transistor supplies a data signal from the data line to the pixel electrode in response to a scan signal from the gate line.

  Such a thin film transistor substrate is formed using a number of mask processes, and in order to reduce the mask process, the process of forming the source and drain electrodes and the semiconductor pattern is performed in one mask process using a halftone mask. Form.

  In this case, the halftone mask includes a blocking region that blocks ultraviolet rays, a semi-transmissive region that partially transmits ultraviolet rays, and a transmissive region that transmits ultraviolet rays. The semi-transmission region of such a halftone mask may be formed by multiple semi-transmission portions having different transmittances. In order to form a multiple semi-transmissive portion, a large number of semi-transmissive materials having different transmittances are used. That is, in order to form three halftone masks having different transmittances, three semipermeable materials having different semitransmissive materials are required. As described above, in the method of forming the halftone mask having three or more different semi-transmissive portions, the first semi-transmissive material is stacked, and after the first semi-transmissive material is patterned in the photolithography process and the etching process, The second semi-transmissive material is again laminated, and the second semi-transmissive material is patterned by the photolithography process and the etching process, and then the third semi-transmissive material is laminated, and the third semi-transmissive material is formed by the photolithography process and the etching process. By patterning, three semi-transmissive regions having different transmittances can be formed.

  However, in order to form a multiple semi-transparent portion, it is necessary to perform a photolithography process and an etching process on each of different semi-transparent materials, which increases the number of processes, and accordingly increases the time and cost. there were.

  In order to solve the above problems, the present invention provides a halftone mask and a method of manufacturing the same that can reduce the cost and time by reducing the number of halftone materials and the number of steps for forming a multiple transflective portion.

  In order to achieve the above technical problem, a halftone mask according to the present invention includes a substrate, a transmission region formed on the substrate and transmitting light of a predetermined wavelength band to be irradiated, and at least 2 on the substrate. And a semi-transmission region having multiple semi-transmission portions each having a transmittance different from each other depending on the number of the semi-transmission materials stacked. .

  Here, the halftone mask may further include a blocking region having a blocking layer formed on an upper portion or a lower portion of the plurality of semi-transmissive materials stacked alternately.

  Here, the multiple transflective portions are formed to transmit light at different transmittances in the range of 5 to 80% according to the number of the stacked layers.

The translucent material is a composite material in which Cr, Si, Mo, Ta, Ti, and Al are main elements, and at least two of these main elements are mixed, or the main elements include CO _x , O It is a substance to which at least one of _x and N _x is added.

  Each of the at least two semi-permeable materials is formed of a semi-permeable material having different etching ratios.

  The semi-transmission region is formed by alternately stacking the first semi-transmission material and the second semi-transmission material when the first and second semi-transmission materials are alternately formed, and transmits X% of light. The first semi-transmissive portion, the first semi-transmissive material and the second semi-transmissive material are alternately formed, and the number of the first and second semi-transmissive materials stacked on the first semi-transmissive portion is larger. The first and second semi-transmitting portions are formed and alternately formed with the second semi-transmitting portion that transmits Y% of light, and the first semi-transmitting material and the second semi-transmitting material are stacked on the second semi-transmitting portion. And a third semi-transmissive portion that is formed more than the number of layers of the transmissive material and transmits Z% of light.

  In order to achieve the above technical problem, a method of manufacturing a halftone mask according to the present invention includes a step of alternately stacking at least two semi-transparent materials on a substrate, and a step of alternately stacking at least two semi-transparent materials. The step of laminating the barrier layer on the permeable material and the number of layers of the at least two semi-permeable materials alternately stacked are made different by etching to form multiple semi-transmissive portions having different heights. And a step of performing.

  Here, the multiple semi-transmission part is formed to transmit light at different transmittances in the range of 5 to 80% according to the number of laminated semi-transmission materials.

  In addition, the step of forming the multiple semi-transmissive portions having different heights by etching the number of the laminated layers of the at least two semi-transmissive materials that are alternately laminated to each other includes the step of: After the photoresist is laminated on the blocking layer on the transmissive material, the photoresist is formed to have a step, and the exposed blocking layer is alternately stacked using the photoresist having the step as a mask. Etching at least two semi-transparent materials in order to have different heights from each other.

  The at least two translucent materials may be materials having different etching ratios.

The translucent material is a composite material in which Cr, Si, Mo, Ta, Ti, and Al are main elements, and at least two of these main elements are mixed, or the main elements include CO _x , O It is a substance to which at least one of _x and N _x is added.

  The halftone mask according to the present invention includes multiple semi-transmissive portions in which two semi-transmissive materials are alternately laminated so that the light transmittance varies depending on the stack height of the two semi-transmissive materials.

  In this case, by using semi-permeable materials having different etching ratios for the two semi-permeable materials, by etching the two semi-permeable materials alternately stacked in stages to make the stack heights different, Multiple semi-transmissive portions having different light transmittances depending on the height are formed.

  As described above, the number of semi-transmissive materials and the number of steps can be reduced by using at least two semi-transmissive materials and forming multiple semi-transmissive portions having different transmittances by performing etching step by step. Thereby, the process is simplified, the time and cost required for the process can be reduced, and as a result, the productivity can be improved.

It is sectional drawing which shows the halftone mask which concerns on the Example of this invention. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the manufacturing method of the halftone mask which concerns on the Example of this invention shown in FIG. It is sectional drawing which shows the halftone mask which concerns on the other Example of this invention.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a cross-sectional view showing a halftone mask according to an embodiment of the present invention.

  As shown in FIG. 1, the halftone mask 100 includes a blocking region S1, semi-transmissive regions S3, S4, and S5 having multiple semi-transmissive portions, and a transmissive region S2 on the substrate 102.

  The substrate 102 is a transparent substrate that completely transmits light of a predetermined wavelength band irradiated on the substrate 102. For example, the substrate 102 may be formed of quartz, and any transparent material that can transmit light can be used. is there.

  The semi-transmissive regions S3, S4, and S5 include multiple semi-transmissive portions so as to transmit light of a predetermined wavelength band irradiated on the substrate 102 with different transmittances. Such semi-transmissive regions S3, S4, and S5 may be formed with photoresist patterns having different thicknesses after the development process by partially transmitting ultraviolet rays during the exposure process in the photoresist process.

  Specifically, the semi-transmissive regions S3, S4, and S5 are regions including multiple semi-transmissive portions having different transmittances by using at least two semi-transmissive materials 112 and 114. That is, in the semi-transmissive regions S3, S4, and S5, a plurality of at least two semi-transmissive materials 112 and 114 are alternately stacked, and the transmittance varies depending on the number of the at least two semi-transmissive materials 112 and 114 formed alternately. A multiple semi-transmissive portion having the following can be formed.

  Here, the case where the semi-transmissive regions S3, S4, and S5 form four layers of the first and second semi-transmissive materials 112 and 114 alternately as a semi-transmissive material will be described.

  In other words, the semi-transmissive regions S3, S4, and S5 are formed on the first semi-transmissive portion 114 and the first semi-transmissive portion 114 on which the first semi-transmissive material 114 is formed on the substrate 102 and transmits X% light. Two semi-transparent materials 112 are laminated to form a second semi-transmissive portion S4 that transmits Y% of light, and three layers of first semi-transmissive material 114 and second semi-transmissive material 112 are alternately formed to transmit Z% of light. A third semi-transmissive portion S5 to be made. Here, X%, Y%, and Z% mean transmittances that transmit 5 to 80% of the irradiated light, respectively. That is, the multiple semi-transmissive portion can transmit the irradiated light with different transmittances in the range of 5 to 80% according to the number of laminated semi-transmissive materials.

Here, the first and second semi-permeable materials 112 and 114 are mainly composed of Cr, Si, Mo, Ta, Ti, and Al, and a compound in which at least two of these main elements are combined, or the main element is CO. A compound in which at least one of _x , O _x and N _x is bonded is preferable. The subscript is a natural number that varies depending on the main element to be bound.

As the composition of the first and second translucent materials 112 and 114, various materials that can transmit only a part of the irradiated light of a predetermined wavelength band can be used. In the present invention, Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , Si _x O _y , Si _x O _y N _z , Si _x CO _y , Si _x CO _y N _z , Mo _x Si _y , Mo _x O _y , Mo _x O _y N _z , Mo _x CO _y , Mo _x O _y N _z , Mo _x Si _y O _z , Mo _x Si _y O _z N, Mo _x Si _y CO _z N, Mo _x Si _{y CO z, Ta x O y} , Ta x O y N z, Ta x CO y, Ta x O y N z, Al x O y, Al x CO y, Al x O y N z, Al x CO y N The first and second semi-transmissive materials 112 and 114 may be formed of any one of _z , Ti _x O _y , Ti _x O _y N _z , and Ti _x CO _y or a combination thereof.

Most preferably, when the first semi-transmissive material 112 is formed of Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , the first semi-transmissive material 112 can be selectively etched with Cr among the semi-transmissive materials listed above. Two semi-permeable material 114 is used. That is, the first and second semi-transmissive materials 112 and 114 must be formed of semi-transmissive materials having different etching ratios from the semi-transmissive materials listed above.

  As described above, a plurality of first and second semi-transmissive materials 112 and 114 are alternately formed, and the first to m-th semi-transmissive portions having different transmittances can be formed according to the number of the first and second semi-transmissive materials 112 and 114. Here, m is a natural number greater than 1. This will be described with reference to FIG.

  As shown in FIG. 13, in the semi-transmissive regions S3, S4, and S5, the first semi-transmissive portion is formed by alternately forming multiple layers of the first semi-transmissive material 114 and the second semi-transmissive material 112 and transmits X% of the light. S3, the first semi-transmissive material 114 and the second semi-transmissive material 112 are alternately formed, and are formed in a number larger than the number of the first and second semi-transmissive materials 112 and 114 stacked on the first semi-transmissive portion S3. Thus, the second semi-transmissive portion S4 that transmits Y% of light, the first semi-transmissive material 114 and the second semi-transmissive material 112 are alternately formed, and are stacked on the second semi-transmissive portion S4. A third semi-transmissive portion S5 that is formed more than the number of the semi-transmissive materials 112 and 114 and transmits Z% of light may be included.

  That is, it is possible to obtain a halftone mask having a semi-transmission region having multiple semi-transmission portions in which at least two semi-transmission substances are alternately laminated and the transmittance varies according to the number of lamination.

  In the blocking area S1, the photoresist pattern remains after the development process by blocking the ultraviolet rays during the exposure process. For this purpose, the blocking region S1 is formed by stacking blocking layers on the multiple first semi-transmissive materials 114 and the multiple second semi-transmissive materials 112 to block ultraviolet rays.

  A process of forming a halftone mask including the transmissive region S2, the blocking region S1, and the semi-transmissive regions S3, S4, and S5 will be described with reference to FIGS.

  2 to 12 are cross-sectional views showing a method of manufacturing the halftone mask according to the embodiment of the present invention shown in FIG. The first and second semipermeable materials may be alternately stacked to form a plurality of layers. Here, a case where four layers of the first and second semipermeable materials are alternately formed will be described.

  Referring to FIG. 2, four layers of the first semi-transmissive material 114 and the second semi-transmissive material 112 are alternately stacked on the substrate 102 by using a sputtering method, a chemical vapor deposition method, etc. A resist 120 is sequentially stacked.

Specifically, the first and second translucent materials 112 and 114 include Cr, Si, Mo, Ta, Ti, and Al as main elements, and a compound in which at least two of these main elements are bonded, or main elements. It is preferable to use a compound in which at least one of CO _x , O _x , and N _x is bonded. The subscript is a natural number that varies depending on the main element to be bound.

As the composition of the first and second translucent materials 112 and 114, various materials that can transmit only a part of the irradiated light of a predetermined wavelength band can be used. In the present invention, Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , Si _x O _y , Si _x O _y N _z , Si _x CO _y , Si _x CO _y N _z , Mo _x Si _y , Mo _x O _y , Mo _x O _y N _z , Mo _x CO _y , Mo _x O _y N _z , Mo _x Si _y O _z , Mo _x Si _y O _z N, Mo _x Si _y CO _z N, Mo _x Si _{y CO z, Ta x O y} , Ta x O y N z, Ta x CO y, Ta x O y N z, Al x O y, Al x CO y, Al x O y N z, Al x CO y N The first and second semi-transmissive materials 112 and 114 may be formed of any one of _z , Ti _x O _y , Ti _x O _y N _z , and Ti _x CO _y or a combination thereof.

Most preferably, when the first semi-transmissive material 112 is formed of Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , the first semi-transmissive material 112 can be selectively etched with Cr among the semi-transmissive materials listed above. Two semi-permeable materials 114 can be used. That is, the first and second semi-transmissive materials 112 and 114 must be formed of semi-transmissive materials having different etching ratios from the semi-transmissive materials listed above.

The blocking layer 110 may be formed of a material that can block ultraviolet rays, and may be formed of a film made of Cr and Cr _x O _y , for example.

  Referring to FIG. 3, the photoresist 120 formed on the blocking layer 110 is drawn and then developed to form first and second photoresist patterns 120a and 120b having steps, and the transmission region S2. The blocking layer is exposed at the position where the is formed.

  Specifically, by adjusting the intensity of the laser beam and irradiating the photoresist 120, first and second photoresist patterns 120a and 120b having different thicknesses are formed. The first photoresist pattern 120a is located in a region where the blocking region S1, the first semi-transmissive portion S3, and the third semi-transmissive portion S5 are formed, and the second photoresist pattern 120b is formed by the second semi-transmissive portion S4. It will be located in the area. The blocking layer 110 is exposed at a position where the transmission region S2 is formed.

  Referring to FIG. 4, using the first and second photoresist patterns 120a and 120b left on the blocking layer 110 as a mask, the exposed blocking layer 110 and the first and second translucent materials 112 and 114 are etched. Is removed.

  Specifically, the transmissive region S2 is formed by exposing the substrate 120 by an etching process using the blocking layer 110, the first and second translucent materials 112 and 114 as a mask, and the first and second photoresist patterns as a mask. The

Referring to FIG. 5, the first photoresist pattern 120a is thinned and the second photoresist pattern 120b is removed by an ashing process using oxygen (O ₂ ) plasma. By removing the second photoresist pattern 120b, the blocking layer 110 is exposed at the position where the second semi-transmissive portion S4 having the light transmittance Y% is formed.

  Referring to FIG. 6, the first photoresist pattern 120a left on the blocking layer 110 is used as a mask, and the blocking layer 110, the second semi-transmitting material 112, which are exposed at a position where the second semi-transmitting portion S4 is formed, The first semipermeable material 114 is sequentially removed by an etching process. Thus, the second semi-transmissive portion S4 in which the first and second semi-transmissive materials 112 and 114 are stacked is formed on the substrate 102. Thereafter, the first photoresist pattern 120a remaining on the substrate 102 is removed by a strip process.

  Referring to FIG. 7, a photoresist 120 is formed on the substrate 102 on which the blocking region S1, the transmissive region S2, and the second semi-transmissive portion S4 are formed, and the photoresist 120 is drawn and then developed. First and second photoresist patterns 120a and 120b having a step are formed.

  Specifically, by adjusting the intensity of the laser beam and irradiating the photoresist 120, first and second photoresist patterns 120a and 120b having different thicknesses are formed. The first photoresist pattern 120a is located in a region where the blocking region S1, the transmissive region S2, and the second semi-transmissive portion S4 are formed, and the second photoresist pattern 120b is a region where the third semi-transmissive portion S5 is formed. Will come to be located. The blocking layer 110 is exposed at the position where the first semi-transmissive portion S3 is formed.

  Referring to FIG. 8, using the first and second photoresist patterns 120a and 120b as masks on the substrate 102, the exposed blocking layer 110, second semi-transmissive material 112, and first semi-transmissive material 114 are etched. Removed in order. As a result, the first and second semipermeable materials 112 and 114 are left in the region where the first semipermeable portion S3 is formed.

Referring to FIG. 9, the first photoresist pattern 120a is thinned and the second photoresist pattern 120b is removed by an ashing process using oxygen (O ₂ ) plasma. By removing the second photorest pattern 120b, the blocking layer 110 is exposed at the position where the third semi-transmissive portion S5 having the light transmittance Z% is formed.

  Referring to FIG. 10, after the exposed blocking layer 110 is removed by an etching process using the first photoresist pattern 120a as a mask on the substrate 102, the second semi-transmissive material 112 is formed as shown in FIG. Removed.

  Thereafter, referring to FIG. 12, the first photoresist 120a remaining on the substrate 102 is removed in a strip process, thereby forming a halftone mask having multiple transflective portions having different transmittances. The

  As a result, four layers of the first semi-transmissive material 114 and the second semi-transmissive material 112 are alternately stacked on the substrate 102, and the transmissive region S2 exposing the substrate 102 so as to transmit the light irradiated on the substrate 102. The blocking region S1 having the blocking layer 110 formed thereon is formed. The semi-transmission region having the multiple semi-transmission portions having different transmittances is formed by laminating the first semi-transmission material on the substrate, the first semi-transmission portion S3 having the light transmittance X%, And the second semi-transparent materials 112 and 114 are laminated to form a second semi-transmissive portion S4 having a light transmittance Y%, and the first and second semi-transmissive materials 112 and 114 are alternately laminated to form a light beam. A third semi-transmissive portion S5 having a transmittance Z% is formed.

  As described above, the first and second semi-transmissive materials 112 and 114 are formed by alternately forming semi-transmissive materials having different etching ratios, and multiple transflective portions having different transmittances by a stepwise etching process. Can be formed.

  That is, a halftone mask having multiple semi-transmissive portions having different transmittances using only the first and second semi-transmissive materials can be obtained.

  Meanwhile, as an embodiment of the present invention, a method of forming only the first to third semi-transmissive portions using the first and second semi-transmissive materials has been described. However, depending on the number of stacked first and second semi-transmissive materials. Various multiple translucent portions having different transmittances may be formed.

  In addition to the first and second semi-transmissive materials, the first to n-th semi-transmissive materials are stacked, and an etching process is performed step by step, thereby providing a multiple semi-transmissive portion having the first to m-th semi-transmissive portions. May be formed. Here, n and m are natural numbers larger than 1.

  While the foregoing detailed description has described the invention with reference to the preferred embodiment of the invention, it should be understood that those skilled in the art or those having ordinary knowledge in the art will be It will be apparent that various modifications and changes may be made in the present invention without departing from the spirit and scope of the invention as set forth in the appended claims.

102 substrate 110 blocking layer 112 second semi-transparent material 114 first semi-transparent material 120 photoresist

Claims (11)

A substrate,
A transmission region formed on the substrate and transmitting light of a predetermined wavelength band to be irradiated;
A semi-transmissive region having multiple semi-transmissive portions formed of multiple layers in which at least two semi-transmissive materials are alternately laminated on the substrate and having different transmittances depending on the number of the semi-transmissive materials stacked;
The halftone mask characterized by including.   The halftone mask of claim 1, further comprising a blocking region having a blocking layer formed on an upper portion or a lower portion of the plurality of semi-transmissive materials stacked alternately.   2. The halftone mask according to claim 1, wherein the multiple transflective portions are formed to transmit light at different transmittances in a range of 5 to 80% according to the number of the stacked layers. The translucent material is any one of Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, MgO—Al ₂ O ₃ , and Si ₃ N ₄ . A single substance, a composite substance in which at least two of them are mixed, or at least one of CO _x , O _x , N _x , C _x , F _x , and B _x is added to the single substance or the composite substance The halftone mask according to claim 1, wherein the subscript x is a natural number and represents the number of each chemical element.   The halftone mask according to claim 1, wherein each of the at least two translucent materials is formed of a translucent material having different etching ratios. The semi-transmissive region is formed when the first and second semi-permeable materials are alternately formed.
A first semi-transmission part in which the first semi-transmission substance and the second semi-transmission substance are alternately laminated, and transmits X% of light;
The first semi-transmissive material and the second semi-transmissive material are alternately formed, and are formed in a number larger than the number of layers of the first and second semi-transmissive materials stacked on the first semi-transmissive portion. A second semi-transmissive portion to transmit,
The first semi-transmissive material and the second semi-transmissive material are alternately formed and formed more than the number of layers of the first and second semi-transmissive materials stacked in the second semi-transmissive portion, and transmit Z% of light. A third translucent part to be made,
The halftone mask according to claim 1, comprising: Alternately laminating at least two translucent materials on a substrate,
Laminating a barrier layer on the alternately laminated at least two semipermeable materials;
Etching the step-by-step stacking layers of the at least two semi-transparent materials alternately stacked to form different semi-transmission portions having different heights; and
A method for producing a halftone mask, comprising:   The multi-transmission part may be formed to transmit light at different transmittances in a range of 5 to 80% according to the number of the semi-transmission materials stacked. Halftone mask manufacturing method. Etching the number of the alternately laminated at least two semi-transparent materials to be different according to the steps, and forming multiple semi-transmissive portions having different heights from each other,
Forming a step on the photoresist after laminating a photoresist on the barrier layer on the alternately laminated at least two semi-transparent materials;
Etching the exposed barrier layer and the alternately laminated at least two semi-transmissive materials in order to have different heights using the photoresist having the step as a mask,
The manufacturing method of the halftone mask of Claim 7 characterized by the above-mentioned.   The method of claim 7, wherein materials having different etching ratios are used for each of the at least two semi-transmissive materials. The translucent material is any one of Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, MgO—Al ₂ O ₃ , and Si ₃ N ₄ . A single substance, a composite substance in which at least two of them are mixed, or at least one of CO _x , O _x , N _x , C _x , F _x , and B _x is added to the single substance or the composite substance The method of manufacturing a halftone mask according to claim 7, wherein the subscript x is a natural number and represents the number of each chemical element.

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