TW201602714A - Method of manufacturing mask for fabrication of organic light emitting device - Google Patents

Abstract

A method of manufacturing a mask for fabrication of an organic light emitting device includes forming a first patterned photoresist layer on a first surface of a substrate. The substrate is etched according to the first patterned photoresist layer to form a first opening, in which the first opening has a bottom surface. A second patterned photoresist layer is then formed on the bottom surface of the first opening. The substrate beneath the bottom surface of the first opening is etched according to the second patterned photoresist layer to form a plurality of second openings separated to each other and through the substrate and thus directly communicated to the first opening.

Description

Method for manufacturing mask for manufacturing organic light-emitting device

The present invention relates to a method of fabricating a mask, and more particularly to a method of fabricating a mask for fabricating an organic light-emitting device.

Currently, masks used in the manufacture of organic light-emitting devices are usually formed by chemical etching to form a desired pattern on a substrate. In order to increase the pixel density of the organic light-emitting device (for example, pixel per inch (PPI)), the smaller the opening size of the mask, the better. However, since the chemical etching is an isotropic etching, it is necessary to use a thinner substrate to form an opening having a smaller top view size. If a thick substrate is used, incomplete etching may occur, resulting in an opening with a small top view that does not completely penetrate the substrate.

However, when the mask prepared by using the thinner substrate is stretched, the middle portion of the mask may collapse downward, causing the mask to be uneven and the opening to be deformed. Therefore, how to make the mask have sufficient support so as not to collapse when the net is stretched, and at the same time has a small opening size to increase the pixel density of the organic light-emitting device has become an important subject in this field.

An object of the present invention is to provide a method for manufacturing a mask for manufacturing an organic light-emitting device, which is capable of forming a small-sized opening while maintaining sufficient support for the mask, thereby effectively solving the problems faced by the prior art. problem.

One aspect of the present invention provides a method of fabricating a mask for fabricating an organic light-emitting device, comprising forming a first patterned photoresist layer over a first surface of a substrate. The substrate is etched according to the first patterned photoresist layer to form a first opening, the first opening having a bottom surface. Forming a second patterned photoresist layer over the bottom surface of the first opening. The substrate under the bottom surface of the first opening is etched according to the second patterned photoresist layer to form a plurality of second openings separated from each other and penetrate the substrate, and the second openings directly communicate with the first opening.

According to an embodiment of the invention, the ratio of the depth of the first opening to the thickness of the substrate is from 1/5 to 3/5.

According to an embodiment of the invention, the substrate has a thickness of from 30 to 50 microns.

According to an embodiment of the invention, the vertical projected area of the first opening is greater than the sum of the vertical projected areas of the second opening.

According to an embodiment of the present invention, the step of etching the substrate according to the first patterned photoresist layer to form the first opening comprises etching the substrate according to the first patterned photoresist layer to form a plurality of first openings separated from each other.

According to an embodiment of the present invention, the step of etching the substrate under the bottom surface of the first opening according to the second patterned photoresist layer comprises patterning according to the second pattern The photoresist layer etches the substrate below the bottom surface of each of the first openings to form the second openings separated from each other and through the substrate, and each of the first openings directly communicates with at least one of the second openings.

According to an embodiment of the invention, the vertical projected area of each of the first openings is greater than the vertical projected area of the directly connected second openings.

According to an embodiment of the invention, the substrate comprises a metal, an alloy or a crucible.

According to an embodiment of the invention, the mask is used in an evaporation process.

According to an embodiment of the invention, the step of forming the first patterned photoresist layer and the step of forming the second patterned photoresist layer are applied to the same side of the substrate.

S1, S2, S3, S4, S5‧‧ steps

10‧‧‧Substrate

10a‧‧‧ first surface

10b‧‧‧second surface

10P‧‧‧The peripheral part of the substrate

10S‧‧‧ Separate part of the substrate

20‧‧‧First patterned photoresist layer

30‧‧‧Second patterned photoresist layer

110‧‧‧ first opening

110a‧‧‧Bottom of the first opening

120‧‧‧second opening

d‧‧‧Depth of the first opening

t‧‧‧The thickness of the substrate

Figure 1 is a flow chart of a method of manufacturing a mask in accordance with the present invention.

2 to 6 are schematic cross-sectional views showing respective stages of a method of manufacturing a mask in accordance with a first embodiment of the present invention.

Figure 7 is a top plan view of a mask in accordance with an embodiment of the present invention.

8-12 are schematic cross-sectional views showing stages of a method of manufacturing a mask in accordance with a second embodiment of the present invention.

Figure 13 is a top plan view of a mask in accordance with an embodiment of the present invention.

The present invention provides a method of manufacturing a mask for manufacturing an organic light-emitting device. In one embodiment, the organic light-emitting device is an organic light-emitting diode device including one or more organic light-emitting diodes. In one embodiment, the mask is used to form an organic light-emitting layer in the organic light-emitting diode. For example, the organic light-emitting layer can be formed by using an evaporation process in combination with a mask made according to an embodiment of the present invention. The material of the organic light-emitting layer may be, for example, a red, green or blue organic light-emitting material.

Figure 1 is a flow chart of a method of manufacturing a mask in accordance with the present invention. As shown in FIG. 1, the manufacturing method of the mask includes providing a substrate (step S1), forming a first patterned photoresist layer (step S2), etching the substrate according to the first patterned photoresist layer to form a first opening. (Step S3), forming a second pattern photoresist layer (step S4) and etching the substrate under the bottom surface of the first opening according to the second patterned photoresist layer to form a plurality of second openings (step S5). As shown in Fig. 2, in step S1, a substrate 10 is provided. The substrate 10 has a first surface 10a and a second surface 10b, and the second surface 10b is opposite to the first surface 10a. In several embodiments, substrate 10 comprises a metal, alloy or tantalum. For example, the substrate 10 is, for example, a nickel-cobalt alloy substrate. In several embodiments, the thickness t of the substrate 10 is 30 to 50 microns, but is not limited thereto.

Then, in step S2, the first patterned photoresist layer 20 is formed over the first surface 10a of the substrate 10, as shown in FIG. The first patterned photoresist layer 20 is used to define the size and position of the first opening. For example, a photoresist layer (not shown) may be formed on the first surface 10a, for example, by spin coating. The photoresist layer is then subjected to a lithography process to form a first patterned photoresist layer 20.

In step S3, the substrate 10 is etched according to the first patterned photoresist layer 20 to form the first opening 110, and the first patterned photoresist layer 20 is stripped, as shown in FIGS. 3-4. The first opening 110 has a bottom surface 110a. Step S3 is for thinning the thickness of the substrate 10 at which the second opening having a smaller size (i.e., step S5) is subsequently formed. In this way, when the second opening is formed by the etching process, only the thickness of the thinned substrate 10 is considered, without considering the thickness t of the substrate 10. That is, the size of the second opening is not limited to the thickness t of the substrate 10. In one embodiment, the ratio of the depth d of the first opening 110 to the thickness t of the substrate 10 is 1/5 to 3/5, but the invention is not limited thereto.

In step S4, the second patterned photoresist layer 30 is formed above the bottom surface 110a of the first opening 110, as shown in FIG. The second patterned photoresist layer 30 can directly contact the bottom surface 110a. The second patterned photoresist layer 30 is used to define the size and position of the second opening. For example, a photoresist layer (not shown) may be formed on the bottom surface 110a, for example, by spin coating. In one embodiment, the bottom surface 110a is substantially parallel to the second surface 10b to form a flat photoresist layer on the bottom surface 110a. The photoresist layer is then subjected to a lithography process to form a second patterned photoresist layer 30. It is important that after the steps S2 and S3, when the second patterned photoresist layer 30 is formed on the bottom surface 110a, no flipping is required. That is, the first patterned photoresist layer 20 (ie, step S2) and the second patterned photoresist layer 30 (ie, step S4) are applied to the same side of the substrate 10, and the second pattern is not required to be turned over. The photoresist layer 30 is formed to reduce the complexity of the process.

In step S5, as shown in Figures 5-6, according to the second patterning The photoresist layer 30 etches the substrate 10 under the bottom surface 110a of the first opening 110 to form a plurality of second openings 120 separated from each other and through the substrate 10 such that the second openings 120 directly communicate with the first openings 110. Finally, the second patterned photoresist layer 30 is removed to form the mask shown in FIG.

In the present embodiment, the vertical projected area of the first opening 110 is greater than the sum of the vertical projected areas of all the second openings 120. As used herein, "vertical projection" refers to the projection of the first opening 110 or the second opening 120 in the vertical direction (or thickness direction) of the substrate 10. In detail, please refer to FIG. 7, which is a top plan view of a mask in accordance with an embodiment of the present invention. As shown in FIG. 7, the upper viewing area (i.e., the vertical projected area) of the first opening 110 is greater than the sum of the upper viewing areas (i.e., the vertical projected areas) of all the second openings 120.

It is to be noted that since the step S3 is to thin the substrate 10 at which the second opening 120 is to be formed, in the etching step (ie, step S5), only the thickness of the thinned substrate 10 needs to be considered, without The original thickness t of the substrate 10 needs to be considered. As such, the second opening 120 having a smaller size can be easily formed by chemical etching (ie, isotropic etching). Therefore, the embodiment of the present invention can easily prepare a mask having a high resolution.

Further, as shown in Figs. 6 and 7, the peripheral portion 10P of the substrate 10 is retained, and the peripheral portion 10P still has a thickness t, so that the mask has a certain degree of support. In this way, when the mask is stretched, the peripheral portion 10P can be supported, so that the second opening 120 is not easily collapsed, and the second opening 120 is not deformed.

8-12 are a system for masking according to a second embodiment of the present invention. A schematic cross-sectional view of each stage of the fabrication process. Hereinafter, please refer to the steps in FIG. 1 and the cross-sectional views in FIGS. 8-12.

In step S1, a substrate 10 is first provided, as shown in FIG. The substrate 10 has a first surface 10a and a second surface 10b, and the second surface 10b is opposite to the first surface 10a. In several embodiments, substrate 10 comprises a metal, alloy or tantalum. For example, the substrate 10 is, for example, a nickel-cobalt alloy substrate. In several embodiments, the thickness t of the substrate 10 is 30 to 50 microns, but is not limited thereto.

In step S2, a first patterned photoresist layer 20 is formed over the first surface 10a of the substrate 10, as shown in FIG. The first patterned photoresist layer 20 is used to define the size and position of the first opening. For example, a photoresist layer (not shown) may be formed on the first surface 10a, for example, by spin coating. The photoresist layer is then subjected to a lithography process to form a first patterned photoresist layer 20.

In step S3, the substrate 10 is etched according to the first patterned photoresist layer 20 to form a plurality of first openings 110 separated from each other, as shown in FIG. The difference between Fig. 10 and Fig. 4 is that the first opening 110 in Fig. 10 is plural. However, similarly, step S3 is for thinning the thickness of the substrate 10 at which the second opening having a smaller size (i.e., step S5) is subsequently formed. In this way, when the second opening is formed by the etching process, only the thickness of the thinned substrate 10 is considered, without considering the thickness t of the substrate 10.

Subsequently, in step S4, a second patterned photoresist layer 30 is formed over the bottom surface 110a of each of the first openings 110, as shown in FIG. The second patterned photoresist layer 30 is used to define the size and position of the second opening. Lift For example, a photoresist layer (not shown) may be formed on the bottom surface 110a, for example, by spin coating. The photoresist layer is then subjected to a lithography process to form a second patterned photoresist layer 30. It is important that after the steps S2 and S3, when the second patterned photoresist layer 30 is formed on the bottom surface 110a, no flipping is required. That is, the first patterned photoresist layer 20 (ie, step S2) and the second patterned photoresist layer 30 (ie, step S4) are applied to the same side of the substrate 10, and the second pattern is not required to be turned over. The photoresist layer 30 is formed to reduce the complexity of the process.

In step S5, as shown in FIGS. 11-12, the substrate 10 under the bottom surface 110a of each of the first openings 110 is etched according to the second patterned photoresist layer 30 to form a plurality of second openings 120. The second openings 120 are separated from each other and penetrate the substrate 10, and each of the first openings 110 directly communicates with at least one of all of the second openings 120. In other words, each of the first openings 110 and the second openings 120 may be disposed one to one or one to many. In the present embodiment, as shown in FIG. 12, the first opening 110 and the second opening 120 are provided one-to-one, but the present invention is not limited thereto.

In the present embodiment, the vertical projected area of the first opening 110 is greater than the vertical projected area of the directly connected second opening 120. "Vertical projection" as used herein refers to the projection of the first opening 110 or the second opening 120 in the vertical direction with respect to the substrate 10. In detail, please refer to Fig. 13, which is a top plan view of a mask in accordance with an embodiment of the present invention. As shown in FIG. 13, the upper view area (i.e., the vertical projected area) of the first opening 110 is larger than the upper view area (i.e., the vertical projected area) of the directly connected second opening 120.

Since step S3 is to form the substrate 10 at the second opening 120 Thinning, therefore, in the etching step (ie, step S5), only the thickness of the thinned substrate 10 needs to be considered, without considering the original thickness t of the substrate 10. As a result, the second opening 120 having a smaller size can be easily formed by chemical etching.

Further, as shown in Figs. 12 and 13, the peripheral portion 10P of the substrate 10 and the partition portion 10S are retained, each having a thickness t, which gives the mask a better support. In this way, when the mask is stretched, it can be supported by the peripheral portion 10P and the partition portion 10S, so that the second opening 120 is not easily collapsed, and the second opening 120 is not deformed.

In summary, the present invention provides several embodiments for fabricating a mask that is capable of forming a smaller opening while still providing sufficient support for the mask to effectively address the problems faced in the prior art. In the above embodiment, the first opening having a larger size is formed by two lithography etchings, and the second opening having a smaller size is formed. Since the thickness of the substrate below the first opening is thinned after the first opening is formed, when the second opening having a small size is formed, it is not limited by the original thickness of the substrate. Therefore, the prepared mask can have a high resolution, and the organic light-emitting device produced by using the mask has a higher pixel density. Moreover, since the peripheral portion of the substrate is retained, when the mesh is masked, it can be supported through the peripheral portion, so that the second opening is not easily collapsed, and the second opening is not deformed. In addition, the step of forming the first patterned photoresist layer and the step of forming the second patterned photoresist layer are applied to the same side of the substrate, and the second patterned photoresist layer is not required to be turned over, thereby reducing the complexity of the process.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and those skilled in the art may, without departing from the spirit of the invention. And the scope of the invention is defined by the scope of the appended claims.

S1, S2, S3, S4, S5‧‧ steps

Claims (10)

A method for fabricating a mask for fabricating an organic light-emitting device, comprising: forming a first patterned photoresist layer over a first surface of a substrate; etching the substrate according to the first patterned photoresist layer Forming a first opening having a bottom surface; forming a second patterned photoresist layer over the bottom surface of the first opening; and etching the first layer according to the second patterned photoresist layer The substrate below the bottom surface of the opening is separated from and separated from the substrate by a plurality of second openings, and the second openings directly communicate with the first opening. The method of manufacturing a mask according to claim 1, wherein a ratio of a depth of the first opening to a thickness of the substrate is from 1/5 to 3/5. The method of manufacturing a mask according to claim 1, wherein the substrate has a thickness of 30 to 50 μm. The method of manufacturing a mask according to claim 1, wherein a vertical projected area of the first opening is greater than a sum of vertical projected areas of the second openings. The method of manufacturing a mask according to claim 1, wherein the etching the substrate according to the first patterned photoresist layer to form the first opening step comprises etching the substrate according to the first patterned photoresist layer to form The plurality of first openings are separated from each other. The method of manufacturing the mask of claim 5, wherein the step of etching the substrate under the bottom surface of the first opening according to the second patterned photoresist layer comprises etching each of the photoresist layers according to the second patterned photoresist layer The substrate below the bottom surface of the first opening is formed to separate the second openings from each other and penetrate the substrate, and each of the first openings directly communicates with at least one of the second openings. The method of manufacturing a mask according to claim 6, wherein a vertical projected area of each of the first openings is greater than a vertical projected area of the second openings directly connected. The method of manufacturing a mask according to claim 1, wherein the substrate comprises a metal, an alloy or a crucible. A method of manufacturing a mask according to claim 1, wherein the mask is used in an evaporation process. The method of manufacturing a mask according to claim 1, wherein the step of forming the first patterned photoresist layer and the step of forming the second patterned photoresist layer are applied to the same side of the substrate.