JP4201968B2 - Resist pattern manufacturing method, thin film patterning method, and microdevice manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resist pattern manufacturing method, a thin film patterning method, and a microdevice manufacturing method.
[0002]
[Prior art]
Thin film patterning methods include a method using a milling method, a method using a lift-off method, and a method using both a milling method and a lift-off method. The resist pattern used for patterning the thin film is, for example, a so-called Bi-layer type resist pattern having a two-layer structure of a polymethylglutarimide layer (PMGI layer) and a photoresist layer.
[0003]
1 to 5 are process diagrams showing a method for producing such a Bi-layer type resist pattern.
First, as shown in FIG. 1, a PMGI layer 3 is applied and formed on a predetermined substrate 1, and heat treatment is performed as necessary. Next, as shown in FIG. 2, a photoresist layer 5 is applied and formed on the PMGI layer 3, and heat treatment is performed as necessary. Thereafter, as shown in FIG. 3, the photoresist layer 5 is subjected to an exposure process by, for example, irradiating UV through a predetermined mask 7.
[0004]
Thereafter, the photoresist layer 5 is subjected to a development process, and the PMGI layer 3 is partially removed with an alkaline aqueous solution, whereby a resist pattern 9 as shown in FIG. 4 or a resist pattern 10 as shown in FIG. Get.
[0005]
The main body portion 9-1 of the resist pattern 9 is composed of the photoresist layer 5, and the attached portion 9-2 that is narrowed to the main body portion and supports the main body portion is formed from the PMGI layer 3. It is composed. Similarly, the main body portion 10-1 of the resist pattern 10 is composed of the photoresist layer 5, and the attached portion 10-2 is composed of the PMGI layer 3.
[0006]
[Problems to be solved by the invention]
When thin film patterning is performed by, for example, the milling method using the resist pattern 9 as shown in FIG. 4, a milling material may adhere to a relatively large amount on the side wall of the attached portion 9-2. Therefore, when the resist pattern 9 is finally dissolved and removed, there is a case where the solvent is insufficiently wound by the milling material adhering to the side wall of the attached portion 9-2 and the resist pattern 9 cannot be completely dissolved and removed. .
Further, if the extension of the bottom of the attachment portion 9-2 becomes large, there is a problem that the attachment portion is affected by the patterning of the thin film.
[0007]
Further, in the resist pattern 10 as shown in FIG. 5, the support of the main body portion 10-1 by the attached portion 10-2 becomes insufficient, and thus the main body portion 10-1 is removed during patterning of the thin film. Was produced.
[0008]
The present invention provides a method for producing a resist pattern capable of providing a resist pattern having a novel configuration without causing the above-described problems, and patterning a thin film using the resist pattern produced by such a method. It is an object to provide a method and a method for manufacturing a microdevice.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing a resist pattern of the present invention comprises:
Forming a polymethylglutarimide layer on a predetermined substrate;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer by UV irradiation or ion irradiation ;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
Wherein the polymethyl glutarimide layers viewed including the step of partially removed by using an alkaline aqueous solution, to form the semi-cured layer by UV irradiation, the irradiation intensity in the UV irradiation, 0.75～5.65MW characterized in that it is a / cm ^2.
[0010]
In order to remove the difficulty in dissolving and removing the resist pattern due to the adhesion of the milling material to the attached portion as described above, the present inventors have conducted intensive studies to explore a new resist pattern configuration. . As a result, it has been found that these phenomena are caused by the fact that the attached portion constituting the resist pattern has a positive taper as shown in FIGS.
Therefore, the present inventors have earnestly studied why the sidewall of the attached portion of the resist pattern as shown in FIG. 4 or 5 becomes tapered by producing the resist pattern through the steps shown in FIGS. Study was carried out.
[0011]
As a result, the upper part of the PMGI layer has a relatively high concentration of thermal polymerization, and the dissolution rate of this part in the developer is much higher than that of the part where thermal polymerization is sufficiently performed. Found it expensive. Therefore, in the development process shown in FIG. 3, since the upper layer portion of the PMGI layer is dissolved and removed at a higher rate than the lower layer portion, the attached portion composed of the PMGI layer of the finally obtained resist pattern is shown in FIG. It was found that a taper shape as shown in 4 or 5 was exhibited.
[0012]
Accordingly, it has been conceived that a part where thermal polymerization of the PMGI layer is sufficient and an insufficient part are covered by forming a semi-cured layer on the surface of the PMGI layer. Thus, since the dissolution rate of the PMGI layer to a developer is determined by the semi-cured layer, regardless present in how inadequate part of the thermal polymerization, the PMGI layer uniform to the developer It will dissolve at the rate.
As a result, the side wall of the attached portion of the resist pattern becomes almost vertical, and the above-mentioned problem caused by having a positive taper can be solved.
[0013]
The thin film patterning method of the present invention is characterized by patterning using the resist pattern of the present invention.
Furthermore, the microdevice manufacturing method of the present invention is characterized by using the thin film patterning method of the present invention.
[0014]
The “predetermined base material” in the present invention includes not only a single substrate but also a case where a predetermined underlayer constituting a milled thin film or a microdevice shown below is formed on the substrate.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments of the present invention in association with the drawings.
In the method for producing a resist pattern of the present invention, it is necessary to form a semi-cured layer on the surface of the PMGI layer constituting the resist pattern. This semi-cured layer can be composed of a third film or layer different from the PMGI layer and the photoresist layer, such as a coating film newly formed on the surface of the PMGI layer, or a surface-cured layer formed by ion implantation or the like. .
[0016]
However, since the semi-cured layer can be easily formed without impairing the characteristics as a resist pattern, it is preferable to form the semi-cured layer by applying UV irradiation or ion irradiation to the PMGI layer.
[0017]
When forming a semi-cured layer by UV irradiation, it is preferable that the irradiation intensity is 0.75~5.65mW / cm ^2, preferably further is 1.5~3.8mW / cm ^2. Thereby, the semi-hardened layer which is the object of the present invention can be efficiently formed only on the surface without deteriorating the inside of the PMGI layer constituting the attached portion of the resist pattern.
In addition, when forming a semi-hardened layer by UV irradiation of the above irradiation intensity, the irradiation time is 2 to 5 minutes normally.
[0018]
When a semi-cured layer is formed by ion irradiation, it is generally preferable to use an inert gas that has low reactivity with the surface and high irradiation efficiency. And when such an inert gas is used, it is preferable that the acceleration voltage is 250-1500V, Furthermore, it is preferable that it is 500-1000V. It is preferable that current density is 0.25~1.0mA / cm ^2, preferably further is 0.4~0.6mA / cm ^2.
Accordingly, as described above, the semi-cured layer targeted by the present invention can be efficiently formed only on the surface of the PMGI layer without deteriorating the inside of the PMGI layer.
In addition, when performing ion irradiation on such conditions, the irradiation time is 5 to 10 seconds normally.
[0019]
Moreover, when forming a semi-hardened layer as mentioned above, the whole base material containing a PMGI layer is suitably heated to the temperature at which a semi-hardened layer is easy to form as needed.
The semi-cured layer is formed by the above-described UV irradiation or ion irradiation after forming a PMGI layer and performing heat treatment as necessary in the step shown in FIG.
[0020]
When forming a semi-cured layer by UV irradiation, for example, by performing UV irradiation for 2 minutes at an irradiation intensity of 1.5 mW / cm ² using a mercury lamp with the temperature of the substrate including the PMGI layer being 100 ° C. A resist pattern in which the side wall of the attached portion is vertical can be obtained.
[0021]
When a semi-cured layer is formed by ion irradiation, for example, the temperature of the substrate including the PMGI layer is set to 80 ° C., and argon gas is used for 5 seconds under conditions of an acceleration voltage of 500 V and a current density of 0.5 mA / cm ^2. By performing this ion irradiation, it is possible to obtain a resist pattern in which the side wall of the attached portion is vertical.
[0022]
FIG. 6 is a block diagram showing an example of a resist pattern obtained by the method for producing a resist pattern of the present invention. As is apparent from FIG. 6, the resist pattern 20 has a main body portion 20-1 having a substantially rectangular longitudinal section and an attachment portion 20 narrowed with respect to the main body portion 20-1 and having a vertical side wall. -2.
[0023]
Therefore, adhesion of the milling material to the attached portion 20-2 can be suppressed, and the resist pattern 20 can be easily removed. In addition, since the bottom of the attached portion 20-2 can be prevented from spreading, the influence of this portion on the thin film patterning is reduced.
Furthermore, since the main body portion 20-1 can be sufficiently supported, it is possible to prevent separation during patterning of the thin film.
[0024]
Next, a case where a thin film is patterned using the resist pattern will be described. 7 to 13 show a case where a resist pattern is prepared according to the method for forming a resist pattern of the present invention, and a thin film is patterned using a milling method.
[0025]
First, as shown in FIG. 7, a thin film to be milled 32 is formed on a substrate 31 by sputtering or the like. Next, as shown in FIG. 8, a PMGI layer 33 is applied and formed on the milled thin film 32, and heat treatment is performed as necessary. Next, as shown in FIG. 9, the surface of the PMGI layer 33 is subjected to, for example, UV irradiation or ion irradiation to form a semi-cured layer 33A. Next, as shown in FIG. 10, for example, a positive photoresist layer 35 is applied and formed on the PMGI layer 33 including the semi-cured layer 33A.
[0026]
After that, as shown in FIG. 11, the photoresist layer 35 is exposed through a predetermined mask 37, for example, by UV irradiation, and development processing is performed. Next, the remaining portion of the PMGI layer 33 is removed with a predetermined alkaline aqueous solution or the like, thereby obtaining a resist pattern 40 having a vertical side wall attached portion.
[0027]
Next, by milling the milled thin film 32 through the resist pattern 40, the milled thin film 32 can be finely patterned as shown in FIG. it can. The resist pattern 40 is finally dissolved and removed with a predetermined solvent.
[0028]
Next, a case where a resist pattern is produced according to the method for producing a resist pattern of the present invention and a thin film is patterned by a lift-off method will be described. 14 to 20 are process diagrams showing a thin film patterning method in this case.
[0029]
First, as shown in FIG. 14, a PMGI layer 43 is applied on a substrate 41, and heat treatment is performed as necessary. Next, as shown in FIG. 15, the semi-cured layer 43 </ b> A is formed on the surface of the PMGI layer 43 by, for example, UV irradiation or ion irradiation. Next, as shown in FIG. 16, for example, a positive photoresist layer 45 is applied and formed on the PMGI layer 43 including the semi-cured layer 43A.
[0030]
Next, as shown in FIG. 17, for example, UV is irradiated through a predetermined mask 47, and the photoresist layer 45 is exposed and developed. Next, the remaining part of the PMGI layer 43 is removed with a predetermined alkaline aqueous solution or the like to obtain a resist pattern 50 as shown in FIG.
[0031]
Next, as shown in FIG. 19, a thin film to be patterned 48 is formed on the substrate 41 so as to cover the resist pattern 50. Thereafter, as shown in FIG. 20, the resist pattern 50 is dissolved and removed using a predetermined organic solvent to obtain a patterning thin film 49.
[0032]
Next, a case will be described in which a resist pattern is produced according to the method for producing a resist pattern of the present invention, and thin film patterning is performed using both the milling method and the lift-off method. 21 to 23 are process diagrams showing the thin film patterning method in this case.
[0033]
First, a pre-patterned thin film 56 and a resist pattern 60 are formed on a substrate 51 as shown in FIG. 21 according to the steps of the thin film patterning method using the milling method shown in FIGS. Next, as in the case of the lift-off method, a thin film 58 to be patterned is formed on the substrate 51 so as to cover the resist pattern 60 as shown in FIG. Thereafter, the resist pattern 60 is dissolved and removed to form a patterning thin film 59 as shown in FIG.
[0034]
The method for producing a resist pattern and the method for patterning a thin film using the resist pattern of the present invention can be suitably used in the production of microdevices such as semiconductor lasers, optical isolators, microactuators, and thin film magnetic heads. In particular, it can be suitably used in a thin film magnetic head that requires element miniaturization from the viewpoint of high-density recording and reproduction.
[0035]
A case will be described in which a giant magnetoresistive element (hereinafter sometimes referred to as “GMR element” for short) of a thin film magnetic head is formed using the resist pattern manufacturing method and thin film patterning method of the present invention. 24 to 27 are process diagrams for forming the GMR element. 24 to 27 show a cross section parallel to the air bearing surface (medium facing surface) of the magnetic pole portion.
[0036]
First, as shown in FIG. 24, an insulating layer 102 made of alumina (A1 ₂ O ₃ ), for example, is formed on a substrate 101 made of, for example, AlTiC (A1 ₂ O ₃ .TiC). Next, a lower shield layer 103 for a reproducing head made of a magnetic material is formed on the insulating layer 102. Next, a first shield gap thin film 104 a made of an insulating material such as alumina is formed on the lower shield layer 103.
[0037]
Next, a second shield gap thin film 104b made of an insulating material such as alumina is formed on the first shield gap thin film 104a except for a region where a GMR element to be described later is to be formed. Next, a magnetic layer 105a to form a GMR element is formed on the second shield gap thin film 104b. Next, on the substrate 101 including the magnetic layer 105a as an underlayer, the steps shown in FIGS. 7 to 13 are performed to form a resist pattern 60 at a position where a GMR element is to be formed.
[0038]
Next, as shown in FIG. 25, the GMR element 105 is formed by selectively etching the magnetic layer 105a by ion milling or the like using the resist pattern 60 as a mask. Next, as shown in FIG. 26, the GMR element 105 is electrically connected to the entire surface of the first shield gap thin film 104a, the second shield gap thin film 104b, and the resist pattern 10 according to the process shown in FIG. A pair of lead layers 106 to be formed are formed in a predetermined pattern. Thereafter, the resist pattern 60 is dissolved and removed.
[0039]
That is, in the steps of FIGS. 24 to 26, a patterning thin film including the GMR element 105 and the pair of lead layers 106 is obtained by using both the milling method and the lift-off method.
[0040]
Next, as shown in FIG. 27, a third shield gap thin film 107a made of an insulating material such as alumina is formed on the shield gap thin films 104a and 104b, the GMR element 105, and the lead layer 106, and the GMR element 105 is shielded. It is buried between the gap thin films 104a and 107a. Next, a fourth shield gap thin film 107 b made of an insulating material such as alumina is formed on the third shield gap thin film 107 a except the vicinity of the GMR element 105.
[0041]
Thereafter, an upper shield layer / lower magnetic pole layer 108 (hereinafter referred to as “upper shield layer”), a recording gap layer 112, an upper magnetic pole layer 114, a thin film coil (not shown), a protective layer 115, and the like are sequentially formed, and an air bearing The surface is polished to obtain a thin film magnetic head. FIG. 27 shows a trim structure in which the side walls of the upper shield layer are vertically formed in a self-aligning manner.
[0042]
As described above, the present invention has been described according to the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and all modifications and changes may be made without departing from the scope of the present invention. Is possible.
[0043]
【The invention's effect】
As described above, according to the method for producing a resist pattern of the present invention, a resist pattern including an attached portion having a vertical side wall can be produced. Therefore, it is possible to prevent the milling material from adhering to the attached portion. For this reason, the wraparound of the organic solvent can be improved, and the resist pattern can be easily dissolved and removed.
Furthermore, it is possible to effectively prevent the bottom of the attached portion from spreading. Therefore, the influence of the attached portion at the time of patterning can be effectively prevented, and thin film patterning can be performed accurately.
[0044]
Further, the main body portion can be firmly supported in the attached portion of the resist pattern, and as a result, the main body portion can be prevented from being detached during the thin film patterning and the thin film patterning can be performed accurately.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first step in a conventional method for producing a resist pattern.
FIG. 2 is a diagram showing a step subsequent to the step shown in FIG.
3 is a diagram showing a step subsequent to the step shown in FIG. 2. FIG.
FIG. 4 is a view showing an example of a conventional resist pattern.
FIG. 5 is a diagram showing another example of a conventional resist pattern.
FIG. 6 is a diagram showing an example of a resist pattern according to the present invention.
FIG. 7 is a diagram showing a first step in the thin film patterning method of the present invention.
FIG. 8 is a diagram showing a step subsequent to the step shown in FIG.
9 is a diagram showing a step subsequent to the step shown in FIG. 8. FIG.
10 is a diagram showing a step subsequent to the step shown in FIG. 9. FIG.
11 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 12 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 13 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 14 is a diagram showing a first step in another example of the thin film patterning method of the present invention.
FIG. 15 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 16 is a diagram showing a step subsequent to the step shown in FIG.
17 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 18 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 19 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 20 is a diagram showing a step subsequent to the step shown in FIG.
FIG. 21 is a diagram showing a process in another example of the thin film patterning method of the present invention.
FIG. 22 is a diagram showing a step subsequent to the step shown in FIG. 21.
FIG. 23 is a diagram showing a step subsequent to the step shown in FIG. 22;
FIG. 24 is a diagram showing a process for manufacturing a thin film magnetic head using the resist pattern manufacturing method and the thin film patterning method of the present invention.
FIG. 25 is a diagram showing a step subsequent to the step shown in FIG. 24.
FIG. 26 is a diagram showing a step subsequent to the step shown in FIG. 25.
FIG. 27 is a diagram showing a step subsequent to the step shown in FIG. 26.
[Explanation of symbols]
1, 31, 41, 51 Substrate 3, 33, 43 Polymethylglutarimide layer (PMGI layer)
5, 35, 45 Photoresist layer 7, 37, 47 Mask 9, 10, 20, 40, 50, 60 Resist pattern 9-1, 10-1, 20-1 Main part 9-2, 10-2 of resist pattern 20-2 Attached part of resist pattern 32 Milling films 39, 49, 59 Patterning thin film 48, 58 Patterning thin film 56 Pre-patterning thin film

Claims (14)

Forming a polymethylglutarimide layer on a predetermined substrate;
Forming a semi-cured layer by UV irradiation on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution;
Wherein the irradiation intensity of the UV irradiation, characterized in that it is a 0.75~5.65mW / cm ^2, the resist pattern manufacturing method of. Forming a polymethylglutarimide layer on a predetermined substrate;
Forming a semi-cured layer by ion irradiation on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
And a step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution. The ion irradiation, an inert gas, the acceleration voltage 250～1500V, and carrying out at a current density of 0.25~1.0mA / cm ^2, a manufacturing method of a resist pattern according to claim 2 . Forming a milled thin film on a predetermined substrate;
Forming a polymethylglutarimide layer on the milled thin film;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Milling the object to be milled thin film through the resist pattern, seen including a step of forming a patterned thin film, the semi-cured layer is be formed by UV irradiation to the surface of the polymethyl glutarimide layer A method for patterning a thin film. Forming a polymethylglutarimide layer on a predetermined substrate;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Forming a thin film to be patterned so as to cover the resist pattern on the substrate;
Lifting off the resist pattern to form a patterned thin film;
And the semi-cured layer is formed by irradiating UV on the surface of the polymethylglutarimide layer . Forming a milled thin film on a predetermined substrate;
Forming a polymethylglutarimide layer on the milled thin film;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Milling the milled thin film through the resist pattern to form a patterned pre-patterned thin film;
Forming a thin film to be patterned so as to cover the resist pattern on the substrate;
Is lifted off the resist pattern, the saw including a step of forming a patterned thin film comprising a pre-patterned film, the semi-cured layer is be formed by UV irradiation to the surface of the polymethyl glutarimide layer A method for patterning a thin film. The thin film patterning method according to claim 4, wherein an irradiation intensity in the UV irradiation is 0.75 to 5.65 mW / cm ² . Forming a milled thin film on a predetermined substrate;
Forming a polymethylglutarimide layer on the milled thin film;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Said resist pattern through the milling of the object to be milled thin film, seen including a step of forming a patterned thin film, the semi-cured layer, forming by ion irradiation on the surface of the polymethyl glutarimide layer A method for patterning a thin film. Forming a polymethylglutarimide layer on a predetermined substrate;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Forming a thin film to be patterned so as to cover the resist pattern on the substrate;
The resist pattern is lifted off the, seen including a step of forming a patterned thin film, the semi-cured layer, and forming by ion irradiation on the surface of the polymethyl glutarimide layer, a thin film Patterning method. Forming a milled thin film on a predetermined substrate;
Forming a polymethylglutarimide layer on the milled thin film;
Forming a semi-cured layer on the surface of the polymethylglutarimide layer;
Forming a photoresist layer on the polymethylglutarimide layer including the semi-cured layer;
Exposing the photoresist layer through a predetermined mask;
Developing the photoresist layer;
A step of partially removing the polymethylglutarimide layer using an alkaline aqueous solution to form a resist pattern;
Milling the milled thin film through the resist pattern to form a patterned pre-patterned thin film;
Forming a thin film to be patterned so as to cover the resist pattern on the substrate;
Is lifted off the resist pattern, the saw including a step of forming a patterned thin film comprising a pre-patterned film, the semi-cured layer is be formed by ion irradiation on the surface of the polymethyl glutarimide layer A method for patterning a thin film. The ion irradiation, an inert gas, the acceleration voltage 250～1500V, and carrying out at a current density of 0.25~1.0mA / cm ^2, according to any one of claims 8 to 10 Thin film patterning method. A method for producing a microdevice, comprising producing a microdevice using the thin film patterning method according to claim 4 . The method of manufacturing a micro device according to claim 12 , wherein the micro device is a thin film magnetic head. The method of manufacturing a microdevice according to claim 13 , wherein a magnetoresistive thin film element is formed using the thin film patterning method according to claim 4 .

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