Method for manufacturing vapor deposition masks and electronic devices

Abstract

The objective is to provide a deposition mask capable of forming a deposition film with excellent pattern dimensions, and a method for manufacturing an electronic device using the deposition mask. [Solution] The vapor deposition mask of the present invention has a first surface and a second surface opposite to the first surface, and a plurality of openings are formed penetrating between the first surface and the second surface, wherein a protruding portion is formed on the side wall surface of the opening, extending from the first surface side to the second surface side, and the ratio of the protrusion of the protruding portion to the opening width of the opening is 0.001 or more and 0.018 or less.

Description

Technical Field

[0001] The present invention relates to a vapor deposition mask and a method for manufacturing an electronic device.

Background Art

[0002] For example, a vapor deposition mask used for coating three colors of RGB in the production of an organic EL display is known.

[0003] Patent Document 1 describes a vapor deposition mask in which a mask pattern is formed on a silicon layer. It is disclosed that the mask pattern is formed by etching. Patent Document 2 describes a vapor deposition mask having a large number of pixel openings. It is disclosed that the pixel openings are formed by etching.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Due to the uneven shape of the side wall surface of the opening, the vapor deposition material accumulates on the side wall surface, resulting in a problem that the pattern dimensions of the vapor deposition film deteriorate.

[0006] An object of the present invention is to provide a vapor deposition mask capable of forming a vapor deposition film having excellent pattern dimensions and a method for manufacturing an electronic device using the vapor deposition mask.

Means for Solving the Problems

[0007] The vapor deposition mask of this embodiment has a first surface and a second surface opposite to the first surface, and is characterized in that a plurality of openings are formed penetrating between the first surface and the second surface, and the side walls of the openings have protruding portions that extend from the first surface side to the second surface side, and the ratio of the protrusion of the protruding portions to the opening width of the openings is 0.001 or more and 0.018 or less. [Effects of the Invention]

[0008] According to the present invention, by controlling the protrusion ratio of the ridges formed on the side walls of the openings of the deposition mask, a deposition film with excellent pattern dimensions can be stably formed. Furthermore, the frequency of cleaning the deposition mask can be reduced, making quality control of the deposition mask easier. In addition, the occurrence of clogging of the openings can be reduced, extending the lifespan of the deposition mask. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing an example of a vapor deposition mask according to this embodiment. [Figure 2] This is an enlarged plan view of the opening. [Figure 3] This is an enlarged front view of the side wall surface revealed by cutting through the opening. [Figure 4] Figure 4A is an SEM image showing the standard for measuring the protruding dimensions of the ridge, and Figure 4B is a schematic diagram thereof. [Figure 5] Figure 5A is an SEM image showing a magnified portion of the aperture, and Figure 5B is a schematic diagram thereof. [Figure 6] Figures 6A to 6E are schematic diagrams illustrating the method for calculating the opening width. [Figure 7] Figure 7A is an SEM image of the side wall surface of the opening, and Figure 7B is a schematic diagram thereof. [Figure 8] This is an illustrative diagram showing how vapor deposition material is deposited on the side wall surface of an opening. [Figure 9] This is a process diagram showing an example of a method for manufacturing the vapor deposition mask of this embodiment. [Figure 10]It is a process diagram showing an example of a method for manufacturing a vapor deposition mask according to this embodiment. [Figure 11] It is a cross-sectional view showing a method for manufacturing an electronic device using the vapor deposition mask according to this embodiment. [Figure 12] It is a cross-sectional view showing an example of a vapor deposition mask according to another embodiment. [Figure 13] It is a cross-sectional view showing an example of a vapor deposition mask according to another embodiment. [Figure 14] It is a cross-sectional view showing an example of a vapor deposition mask according to another embodiment. [Figure 15] It is a cross-sectional view showing an example of a vapor deposition mask according to another embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described with reference to the drawings. However, the drawings are schematic or conceptual, and dimensions and ratios in each drawing are not necessarily the same as those in reality. Also, even when representing the same part between the drawings, the dimensional relationships and ratios may be represented differently. In particular, the embodiments shown below are examples of structures for embodying the technical idea of the present invention, and do not specify the technical idea of the present invention. In the following description, elements having the same function and configuration are denoted by the same reference numerals, and overlapping descriptions are omitted. Also, the lower limit value and the upper limit value of the numerical range include the error range. Also, the notation "~" includes the lower limit value and the upper limit value.

[0011] <Background of the Invention> Vapor deposition masks used for coating three colors of RGB in the production of OLED displays are known, and the need for vapor deposition masks for RGB coating is increasing.

[0012] The vapor deposition mask includes a plurality of openings corresponding to the vapor deposition film, and the opening accuracy of the vapor deposition mask is important in order to improve the pattern dimensions of the vapor deposition film.

[0013] The evaporation mask is disposed between the substrate to be evaporated and the evaporation source, and the evaporation material reaches the surface of the substrate to be evaporated from the evaporation source through the openings of the evaporation mask. At this time, if the evaporation material accumulates on the side wall surface of the opening, the opening width becomes narrower than the actual width, making it difficult to form an evaporation film with excellent pattern dimensions.

[0014] FIG. 8 shows an image in which the evaporation material 12 accumulates on the side wall surface 52 of the opening 51 formed in the membrane 50. Thus, when the evaporation material 12 accumulates on the side wall surface 52 of the opening 51, a shadow effect occurs.

[0015] During the manufacture of a high-resolution OLED display device, the shadow effect reduces the pattern dimensions of the evaporation film. And the reduction of the pattern dimensions affects the performance of the device and becomes a limiting factor for the resolution of the OLED microdisplay device.

[0016] As a result of intensive research, the inventors of the present invention focused on the fact that the evaporation material accumulates on the step of the vertical streaks (protruding portions) generated on the side wall surface when the opening is processed by dry etching, and by optimizing the protruding ratio of the protruding portions with respect to the opening width, they developed an evaporation mask capable of increasing the pattern dimensions of the evaporation film. <00,00105> <Overview description of the evaporation mask 1 in the present embodiment> FIG. 1 is a cross-sectional view of the evaporation mask 1 in the present embodiment. FIG. 2 is an enlarged plan view of the opening. FIG. 3 is an enlarged front view of the side wall surface revealed by cutting the opening. FIG. 4A is a SEM image showing the reference for measuring the protruding dimension of the protruding portion, and FIG. 4B is a schematic diagram thereof. FIG. 5A is a SEM photograph showing a part of the opening enlarged, and FIG. 5B is a schematic diagram thereof. FIG. 7 is a SEM image of the side wall surface of the opening.

[0018] The evaporation mask 1 has a laminated structure of a membrane 2 and a support substrate 3. The membrane 2 is a substrate having a first surface 2a and a second surface 2b facing each other in the thickness direction. Although the thickness of the membrane 2 is not limited, it is about 1 μm to 300 μm.

[0019] The outer shape of membrane 2 is preferably a rectangular or disc-shaped wafer, and while there is no limit to the diameter (or the length of one side in the case of a rectangular shape), it is preferably about 100 mm to 500 mm.

[0020] While not limited to these, membrane 2 is formed as a single layer or multiple layers. For example, membrane 2 is preferably formed as a SiN layer or a SiN layer / SiO2 layer stacked structure.

[0021] As shown in Figure 1, multiple cell regions 4 are formed in the membrane 2. Between adjacent cell regions 4, there are regions where no openings 8 are formed (referred to as "boundary regions 5"). In a plan view, the multiple cell regions 4 are arranged in a matrix via the boundary regions 5. The collective region of the multiple cell regions 4 will be referred to as the cell array region 6. The area between the cell array region 6 and the edge of the membrane 2 is the outer peripheral region 7.

[0022] As shown in Figure 1, multiple openings 8 are formed in each cell region 4. These openings 8 penetrate from the first surface 2a to the second surface 2b of the membrane 2.

[0023] As shown in Figure 11, the first surface 2a is the surface facing the substrate 10 to be deposited, and the second surface 2b is the back surface facing the deposition source 11.

[0024] As shown in Figure 1, the opening width of the opening 8 gradually narrows, for example, from the second surface 2b to the first surface 2a. Therefore, the side wall surface 9 of the opening 8 is inclined.

[0025] The planar pattern of the opening 8 (the shape viewed from directly above the membrane 2 toward the first surface 2a) is not limited, but examples include rectangles (including squares), polygons other than rectangles, circles, and ellipses. Furthermore, all openings 8 may have the same planar pattern, or some may differ. In addition, each opening 8 may be arranged regularly, irregularly, or a mixture of regular and irregular arrangements.

[0026] While this does not limit the width dimension of the boundary region 5 between each cell region 4, when viewed from the first surface 2a side, the width dimension is approximately 1 mm to 10 mm.

[0027] As shown in Figure 1, a support substrate 3 is provided on the second surface 2b side of the membrane 2. The support substrate 3 is, for example, a silicon substrate. While there is no limit to the thickness of the support substrate 3, it is typically around 100 μm to 1000 μm.

[0028] As shown in Figure 1, the support substrate 3 is provided on the outer peripheral region 7 and the boundary region 5 on the second surface 2b of the membrane 2. Thus, the support substrate 3 is not provided in the cell region 4, and the cell region 4 is open to both the first surface 2a and the second surface 2b. The support substrate 3 may also be provided only in the outer peripheral region 7. The membrane 2 can maintain a taut state with the support substrate 3, eliminating the need for tensioning, and the deposition mask 1 of this embodiment can be brought into close contact with the substrate 10 to be deposited using an electrostatic chuck that utilizes electrostatic force. As shown in Figure 1, the support substrates 3 provided in the boundary region 5 and the outer peripheral region 7 are all the same height, but for example, the height of the support substrate 3 provided in the boundary region 5 may be lower than the support substrate 3 provided in the outer peripheral region 7. However, maintaining the same height allows for better strength.

[0029] <Detailed description of the opening 8 of the deposition mask 1 in this embodiment> As shown in the plan view of the opening 8 in Figure 2 and the front view of the opening 8 revealed by cutting the opening 8 in Figure 3 (both sides of the opening 8 are shown as cross-sections), multiple protrusions 20 are formed on the side wall surface 9 of the opening 8, extending from the first surface 2a to the second surface 2b. In this embodiment, the protrusions 20 may be referred to as "vertical lines". Since the protrusions 20 protrude from the side wall surface 9 toward the inside of the opening 8, the side wall surface 9 has an uneven, stepped surface as shown in Figures 2 and 3.

[0030] The height (length) of the protruding portion 20 from the first surface 2a to the second surface 2b may be the same as, or shorter than, the height (length) from the first surface 2a to the second surface 2b. In other words, the protruding portion 20 is formed in the height region between the first surface 2a and the second surface 2b, and may include portions that are interrupted in the middle. However, it is preferable that the height of the protruding portion 20 is the same as the height (length) from the first surface 2a to the second surface 2b. This ensures that the protruding portion 20 is continuous without interruption in the height direction between the first surface 2a and the second surface 2b, eliminating or reducing the difference in unevenness in the height direction, thereby reducing the amount of deposited material.

[0031] Furthermore, the shape of the protruding portion 20 is not limited to a straight line formed from the first surface 2a to the second surface 2b; it can also be curved, meandering, or have a shape that changes midway (the direction of extension changes midway). However, it is preferable that the protruding portion 20 be straight. "Straight" does not mean a straight line in the strict sense, and some variation is permitted. Although not limited, for example, if the direction of extension changes by approximately 5 degrees or less with respect to the direction perpendicular to the height, it can be considered straight. By making the protruding portion 20 straight, the region where the direction of extension changes can be eliminated or reduced, thereby reducing the amount of deposited material.

[0032] The opening 8 shown in Figure 2 is roughly polygonal, but it may also be circular or elliptical. As shown in Figure 2, the protrusions 20 are formed evenly around the opening 8, but the density of the protrusions 20 may differ depending on the location on the side wall surface 9. For example, the density of the protrusions 20 may change from the middle of the height direction of the side wall surface 9.

[0033] [Method for calculating protruding dimensions] Figure 4A is an SEM image of aperture 8, and Figure 4B is a schematic diagram thereof. The SEM (scanning electron microscope) image of aperture 8 was obtained, for example, using a Hitachi High-Tech Regulus 8220.

[0034] Furthermore, Figure 5A is a magnified image of the area enclosed by region A in the SEM photograph of Figure 4A, and Figure 5B is a schematic diagram thereof.

[0035] The following section describes the case where the opening 8 is approximately polygonal, as shown in Figures 4A and 4B.

[0036] As shown in Figures 4A and 4B, a straight reference line L1 is drawn on each side of the aperture 8 so as to be tangent to the outside of the unevenness or steps of the aperture 8. At this time, as shown in Figures 5A and 5B, it is preferable to draw the reference line L1 so as to be tangent to multiple contact points B. Furthermore, except for areas where the unevenness or steps of the aperture 8 change drastically, or areas where the SEM image is unclear and it is difficult to distinguish the unevenness or steps, the reference line L1 is drawn so as to be tangent to as many contact points B as possible.

[0037] Then, the reference line L1 was divided into three equal parts, and the protruding dimensions H1, H2, and H3 (hereinafter sometimes referred to as "protruding dimension H") of the protruding ridges 20 that extend inward from the central reference line L1 were measured. The vertices of each protruding dimension H1, H2, and H3 were defined as the positions that protruded the most from the central reference line L1.

[0038] Then, the average protrusion dimension AveH of the protrusion dimensions H1, H2, and H3 of each protrusion 20 is calculated.

[0039] If the shape of the opening 8 is a circle or an ellipse, a curved reference line L1 is drawn along that shape. Then, the reference line is divided into multiple sections, and one of these sections is used to determine the protruding dimension of the ridge.

[0040] In the above example, the reference line L1 was divided into three equal parts, and the protruding dimension H of the protruding portion 20 was measured. However, dividing it into three equal parts is just one example. Also, in the above example, the number of protruding portions 20 obtained from the reference line L1 is not limited, but it can be between 2 and 50, preferably 30 or less, and more preferably 20 or less. Furthermore, it is preferable to measure 2 or more portions, preferably 5 or more. This makes it possible to improve the dimensional accuracy of the average protruding dimension AveH of the protruding portion 20. Furthermore, in this embodiment, a measurement error of ±10% or less, preferably ±5% or less, is acceptable for the average protrusion dimension AveH of the protruding portion 20.

[0041] [Method for calculating opening width W1] As shown in Figures 1 and 3, for example, the opening 8 gradually narrows from the second surface 2b to the first surface 2a, and the opening width differs depending on the measurement location. However, in this embodiment, the opening width W1 of the opening 8 is defined as the side of the first surface 2a facing the substrate 10 to be deposited.

[0042] The aperture width W1 can be determined from the SEM image obtained using the eCD-2 manufactured by KLA-Tencor.

[0043] The opening width W1 can be determined from the reference line L1 used to determine the protruding dimension H of the protruding portion 20. However, if the calculation is attempted using the reference line L1, a large difference between the area enclosed by the reference line L1 and the area of ​​the opening 8 means that the discrepancy between the reference line L1 and the opening 8 will increase, which tends to reduce the accuracy of the calculation of the opening width W1. For example, if the area difference is 10% or more, preferably 5% or more, it is desirable to calculate the opening width W1 using the following method.

[0044] In other words, the longest distance between each vertex 8a of the opening 8 in Figure 6 and the intersection point 8c where the line L2 passing from vertex 8a through the center O of the ellipse 14 intersects with the side 8b of the opening 8 is defined as the opening width W1.

[0045] Figure 6 is a schematic diagram illustrating the method for calculating the opening width W1. In Figure 6A, the opening 8 is approximately hexagonal. Therefore, there are six vertices 8a and six edges 8b of the opening 8 that appear on the first face 2a side. Edge 8b is the regression line. The regression line can be found using the least squares method.

[0046] Next, draw an ellipse 14 that circumscribes each vertex 8a. The ellipse 14 also contains a circle. Then, find the center O of the ellipse 14.

[0047] A line L2 is drawn from each vertex 8a through the center O, and the intersection point 8c is found where line L2 intersects with side 8b of the opening 8. Then, the distance between vertex 8a and intersection point 8c is calculated. In Figure 6A, there are a total of 6 vertices 8a, so this distance is calculated 6 times from each vertex 8a, and the longest distance is taken as the opening width W1.

[0048] In Figure 6B, the opening 8 is a triangle; in Figure 6C, the opening 8 is a pentagon; and in Figures 6D and 6E, the polygon is a special, irregular shape. In Figures 6B to 6E, white circles indicate vertices 8a, and black circles indicate intersections 8c. As explained in Figure 6A, draw an ellipse 14 that circumscribes each vertex 8a to find the center O of the ellipse 14. Then, draw a line L2 from each vertex 8a through the center O, find the intersection 8c where this line L2 intersects with a side 8b of the opening 8, calculate the distance between vertex 8a and intersection 8c, and the longest distance is taken as the opening width W1.

[0049] When drawing the ellipse 14, depending on the shape of the opening, it may be difficult to draw an ellipse 14 that circumscribes all vertices 8a. In this case, the ellipse 14 is drawn to circumscribe as many vertices 8a as possible, and for the vertices 8a that are not circumscribed, the ellipse 14 is drawn to be as close as possible to the curve of the ellipse 14. Also, it is acceptable for parts of the ellipse 14 to be drawn so as to extend inside the opening 8.

[0050] [Method for calculating the protrusion ratio of the protruding portion 20] As described above, the average protrusion dimension AveH of the protruding section 20 and the opening width W1 of the opening 8 are determined, and the protrusion ratio (average protrusion dimension AveH / opening width W1) R is calculated.

[0051] A small protrusion ratio R means that, assuming the average protrusion dimension AveH of the protruding portion 20 is constant, the opening width W1 is large, or conversely, if the opening width W1 is constant, the average protrusion dimension AveH of the protruding portion 20 is small. On the other hand, a large protrusion ratio R means that, assuming the average protrusion dimension AveH of the protruding portion 20 is constant, the opening width W1 is small, or conversely, if the opening width W1 is constant, the average protrusion dimension AveH of the protruding portion 20 is large. Thus, in this embodiment, the protrusion ratio R can be controlled to fall within a predetermined range by adjusting either or both of the average protrusion dimension AveH and the opening width W1 of the protruding portion 20.

[0052] [Method for calculating the taper angle θ1 of opening 8] In this embodiment, the taper angle θ1 of the aperture 8 is determined as follows. That is, as shown in Figure 3, the end of the aperture width W1 in the plane direction along the first surface 2a and the end of the aperture width W2 in the plane direction along the second surface 2b are connected by a straight line, and the angle of inclination between this straight line and the first surface 2a can be set as the taper angle θ1 of the aperture 8. The taper angle θ1 was determined by measuring the length from an SEM image obtained using a Hitachi High-Tech Regulus8220.

[0053] <Characteristic configuration of aperture parameters in this embodiment> The deposition mask 1 in this embodiment is (1) A protruding portion 20 is formed on the side wall surface 9 of the opening 8, extending from the first surface 2a to the second surface 2b. (2) The protrusion ratio R of the projection portion 20 to the opening width W1 of the opening 8 is 0.001 or more and 0.018 or less.

[0054] The protruding portion 20 shown in (1) above is caused by the dry etching process used to form the opening 8. In other words, the protruding portion 20 is a processing shape unique to dry etching and occurs as vertical lines in the height direction (vertical direction) of the opening 8.

[0055] The protruding portion 20 causes the deposition of the vapor-deposited material 12, as explained in Figure 8, leading to vapor deposition defects. The protruding portion 20 is a processing shape unique to dry etching, but conventionally, the dimensions of the protruding portion 20 have not been adjusted.

[0056] Therefore, in this embodiment, the protrusion ratio R of the ridge portion 20 is defined so that the pattern width W3 of the vapor-deposited film 13 can be adjusted to 70% or more of the aperture size (aperture width W1).

[0057] The characteristics of the protrusion ratio R are shown in (2) above. That is, in this embodiment, by adjusting the protrusion ratio R of the ridge portion 20 to the opening width W1 of the opening to 0.001 or more and 0.018 or less, the pattern width W3 of the deposited film 13 can be appropriately and easily adjusted to 70% or more of the opening size (opening width W1).

[0058] Furthermore, in this embodiment, the protrusion ratio R is more preferably 0.014 or less. This allows the pattern width W3 of the deposited film 13 to be appropriately and easily adjusted to 80% or more, preferably 85% or more, and more preferably 90% or more, of the aperture size (aperture width W1). While there is no lower limit to the protrusion ratio R, it is set to 0.001 or more, 0.002 or more, 0.003 or more, or 0.004 or more, depending on the dry etching conditions.

[0059] Furthermore, by setting the protrusion ratio R to 0.001 or higher, impurities contained in the deposition material (deposited particles) 12 from the deposition source 11 shown in Figure 11 can be captured by the sidewall surface 9 of the opening 8, thereby reducing the amount of impurities contained in the deposited film 13. In other words, particles scattered from the deposition source 11 toward the substrate 10 to be deposited contain impurities. Since the deposition conditions are set so that the deposited particles 12 adhere from a direction perpendicular to the surface of the substrate 10 to be deposited, impurities that deviate from these conditions tend to scatter obliquely from a direction perpendicular to the surface of the substrate 10 to be deposited. For this reason, by not setting the protrusion ratio R to zero, but specifically to 0.001 or higher, it becomes easier to capture impurities with the sidewall surface 9.

[0060] Furthermore, in this embodiment, the average protrusion dimension AveH of the protruding portion 20 is preferably 150 nm or less, more preferably 145 nm or less, and even more preferably 143.5 nm or less. This allows the protrusion ratio R of the protruding portion 20 with respect to the opening width W1 of the opening 8 to be appropriately and easily adjusted to 0.001 to 0.018.

[0061] Furthermore, in this embodiment, the maximum protrusion dimension of the ridge portion 20 is preferably 200 nm or less, more preferably 185 nm or less, and even more preferably 181 nm or less. This eliminates extremely large ridge portions 20 and effectively suppresses deposition defects. In addition, it becomes easier to appropriately and easily adjust the protrusion ratio R of the ridge portion to 0.001 to 0.018.

[0062] In this embodiment, the aperture width W1 is preferably 10 μm or less. While not limiting the lower limit, it can be 1 μm or more. This ensures that the requirements for the deposition mask 1 equipped with the membrane 2 are met, and in particular, for deposition masks used for RGB color separation in the manufacturing process of OLED microdisplays, it is necessary to further reduce the aperture width W1.

[0063] In this embodiment, by reducing the opening width W1 of the opening 8 and adjusting the protrusion ratio R of the strip to 0.001 or more and 0.018 or less, it can be effectively applied as a deposition mask 1 used in the manufacture of high-resolution OLED display devices.

[0064] As shown in Figure 11, the deposition material (deposited particles) 12 from the deposition source 11 passes through the opening 8 of the deposition mask 1 and reaches the surface 10a of the substrate 10 to be deposited, and a deposited film 13 is formed. When the pattern width W3 of the deposited film 13 is measured and the ratio with the opening width W1 is calculated, if the protrusion ratio R is 70% or more, it is designated as this embodiment, and if the protrusion ratio R is less than 70%, it is designated as a comparative example.

[0065] Furthermore, in this embodiment, the opening width W1 of the opening 8 gradually narrows from the second surface 2b side to the first surface 2a side, but it is not limited to this, and it may gradually widen from the second surface 2b side to the first surface 2a side. Although the taper angle is not limited, the taper angle θ1 is preferably 60° or more and 120° or less, more preferably 70° or more and 110° or less, and even more preferably 80° or more and 105° or less. Preferably, the side wall surface 9 of the opening 8 is tapered from the second surface 2b to the first surface 2a. By making the side wall surface 9 tapered in the opposite direction from the second surface 2b to the first surface 2a on the deposition source 11 side (see Figure 11), it becomes easier for the deposited particles 12 to pass from the deposition source 11 to the substrate 10, and a deposited film 13 with excellent pattern dimensions can be formed.

[0066] <Regarding the manufacturing method of the vapor deposition mask 1 in this embodiment> Figure 9 is a process diagram showing the manufacturing method of the deposition mask 1 of this embodiment. Here, the deposition mask 1 in the manufacturing process shown in Figure 9 and Figure 10 (described later) only shows the vicinity of one cell region 4, but in reality, multiple cell regions 4 as shown in Figure 1 are formed simultaneously.

[0067] In Figure 9A, for example, a support substrate 21 made of Si is prepared, and in Figure 9B, a membrane 2 is formed on the surface of the support substrate 21. For example, the membrane 2 has a laminated structure of an SiO2 layer 22 and a SiN layer 23.

[0068] While this does not limit the diameter of membrane 2, in this embodiment, it can accommodate sizes up to approximately 500 mm.

[0069] In Figure 9C, a protective material 24 is formed over the entire surface of the membrane 2. Additionally, a mask layer 25 is formed on the back surface of the support substrate 21. The mask layer 25 is a resist pattern. As shown in Figure 9C, the mask layer 25 is not formed in the opposing areas of the membrane 2 that will become the cell regions 4.

[0070] Then, in the process shown in Figure 9D, the support substrate 21 that is not covered by the mask layer 25 is removed by dry etching. As a result, the support substrate 3 is formed on the second surface 2b of the membrane 2, except for the location of the cell region 4. Then, the mask layer 25 is removed.

[0071] Next, in the process shown in Figure 9E, a resist layer is applied from the support substrate 3 to the second surface 2b of the cell region 4, forming a mask layer 26 with an opening pattern 26a on the resist layer. The opening pattern 26a is a pattern for forming an opening 8 in the membrane 2, and the membrane 2 exposed from the opening pattern 26a is removed by dry etching. This allows the opening 8 to be formed in the membrane 2.

[0072] In Figure 9F, the mask layer 26 and protective material 24 are removed. This completes the deposition mask 1, which has a membrane 2 with multiple openings 8 in the cell region 4 and a support substrate 3 formed on the second surface 2b side of the membrane 2. In the manufacturing method shown in Figure 9, the taper angle θ1 of the openings 8 can be formed with a tapered surface of 90° or less.

[0073] The manufacturing method for the deposition mask 1 shown in Figure 10 will now be explained. The steps in Figures 10A and 10B shown in Figure 10 are the same as those in Figures 9A and 9B.

[0074] In Figure 10C, mask layers 27 and 28 are formed on both the first surface 2a of the membrane 2 and the back surface of the support substrate 21. It is preferable that both mask layers 27 and 28 are formed of resist.

[0075] As shown in Figure 10C, the mask layer 28 formed on the back surface of the support substrate 21 is not formed in the cell region 4 of the membrane 2. In addition, a mask layer 27 formed on the first surface 2a of the membrane 2 has multiple opening patterns 27a. These opening patterns 27a allow for the formation of multiple openings 8 in the membrane 2.

[0076] In FIG. 10D, the membrane 2 exposed from the opening pattern 27a of the mask layer 27 is removed by dry etching. Thereby, a plurality of openings 8 can be formed in the membrane 2.

[0077] Next, the support substrate 21 not covered by the mask layer 28 is removed. Thereby, the cell region 4 of the membrane 2 is also opened to the second surface 2b. Then, the mask layers 27 and 28 are removed.

[0078] Thereby, as shown in FIG. 10E, the deposition mask 1 having the membrane 2 with a plurality of openings 8 in the cell region 4 and the support substrate 3 formed on the second surface 2b side of the membrane 2 is completed. In the manufacturing method shown in FIG. 10, the taper angle θ1 of the opening 8 can be formed with an inverse taper surface of 90° or more.

[0079] As shown in FIGS. 9E and 10D, the conditions of the dry etching used when forming the openings 8 in the membrane 2 are adjusted as follows, for example. As the etching conditions, they can be adjusted by various gas flow rates, chamber pressure, power of the plasma generation source, etc.

[0080] As an example, as the etching gas, CF4 gas and O2 gas are used, the CF4 gas is 0.1 to 100 sccm, and the O2 gas is 1 to 200 sccm. Also, the Platen LF is 500 to 3000 W, the Coil RF is 500 to 4000 W, the chamber pressure is 1 to 10 Pa, the etching time is about several minutes, and various conditions are adjusted. Regarding the gas flow rates of the CF4 gas and the O2 gas, it is preferable to adjust so that the flow rate of the CF4 gas < the flow rate of the O2 gas. Thereby, the protruding dimension of the number of vertical stripes (ridge portions) (which may be read as the groove depth between the vertical stripes) can be reduced. Specifically, the protruding ratio R of the ridge portion 20 with respect to the opening width W1 of the opening 8 can be appropriately adjusted to be 0.001 or more and 0.018 or less.

[0081] Furthermore, one or more fluorine compounds can be selected from, for example, CF4, SF6, NF3, BF3, PF5, and F2, and one or more noble gases can be selected from helium and argon, but their use is not required. Furthermore, the protruding dimension of the ridge portion 20 can be reduced by laser hydrogen annealing or the like.

[0082] <Method of manufacturing an electronic device according to this embodiment> In this embodiment, as shown in Figure 11, the deposition mask 1 is placed between the substrate 10 to be deposited and the deposition source 11. At this time, the first surface 2a of the membrane 2 of the deposition mask 1 is oriented toward the substrate 10, and the second surface 2b of the membrane 2 is oriented toward the deposition source 11. Multiple openings 8 are formed in the membrane 2, and for example, the opening width is narrower on the first surface side than on the second surface side.

[0083] The deposition mask 1 is placed in a holder (not shown) of the deposition apparatus, and at this time, the deposition mask 1 and the substrate 10 to be deposited can be fixed with an electrostatic chuck. In Figure 11, the membrane 2 and the substrate 10 to be deposited are separated, but they may be in contact. The deposition mask 1 and the substrate 10 to be deposited are rotated around the axis of rotation of the holder's axis. The deposition material (deposited particles) 12 from the deposition source 11 reaches the surface 10a of the substrate 10 through the opening 8 of the deposition mask 1, and a deposition film 13 is formed.

[0084] In this embodiment, examples of electronic devices include OLED microdisplay panels, liquid crystal panels, and solar cells, and it is particularly suitable for manufacturing OLED microdisplay panels as organic electronic devices.

[0085] By using the deposition mask 1 of this embodiment, the pattern width W3 of the deposited film 13 can be secured to be 70% or more of the opening width W1, preferably 75% or more, and more preferably 80% or more. In this way, a deposited film 13 with excellent pattern dimensions can be formed.

[0086] <Regarding the effects of using the deposition mask 1 of this embodiment> In this embodiment, by defining the protrusion ratio of the ridge portion 20 in the opening 8 of the deposition mask 1, a high pattern dimension of the deposition film 13 can be obtained. Furthermore, since the amount of deposition material can be reduced, the frequency of cleaning the deposition mask 1 can be reduced, and quality control of the deposition mask 1 can be easily performed. In addition, the occurrence of clogging of the opening 8 can be reduced, and the lifespan of the deposition mask 1 can be extended.

[0087] Although embodiments and modifications have been described, other embodiments may include combinations of the above embodiments and modifications, either entirely or partially.

[0088] Furthermore, the present invention is not limited to the embodiments and modifications described above, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Moreover, if the technical idea can be realized in a different way by advances in the art or by other derived arts, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea.

[0089] An embodiment with a different layer configuration from the deposition mask 1 shown in Figure 1 will be described. For example, as shown in Figure 12, a membrane 31 made of SiN or SiO2 may be formed on the surface of a frame-shaped silicon substrate 30, and multiple openings 8 may be formed in the membrane 31 in the central region where the silicon substrate 30 has been removed. The membrane is formed by CVD, but it is preferable to use SiN from the viewpoint of easier stress control.

[0090] In another embodiment shown in Figures 13 to 15, an SOI substrate 39 is used. In Figure 13, a SiN layer 45 is formed on the back side of the SOI substrate 39 (the side facing the support substrate 44, the side facing the deposition source 11). In Figure 14, a SiN layer 45 is formed on the front side of the SOI substrate 39 (the side facing the semiconductor layer 42, the side facing the substrate to be deposited 10). In Figure 15, a SiN layer 45 is formed on both the back and front sides of the SOI substrate 39. In the configuration where the SiN layer 45 is formed on the front side of the SOI substrate 39 (the side facing the semiconductor layer 42), an opening 8 is formed continuously with the semiconductor layer 42.

[0091] By providing the SiN layer 45, it becomes easier to control the stress on the deposition mask and suppress strain and other distortions. Furthermore, it is preferable that the SiN layer 45 formed on the surface side of the SOI substrate 39 is thinner than the SiN layer 45 formed on the back side of the SOI substrate 39. Although not limited to these, the thickness of the SiN layer 45 formed on the surface side of the SOI substrate 39 is approximately 0.05 μm to 0.5 μm, and the thickness of the SiN layer 45 formed on the back side of the SOI substrate 39 is approximately 0.05 μm to 3 μm. The semiconductor layer 42 is thinner than the support substrate 44, and since the semiconductor layer 42 also has many openings 8 formed therein, the SiN layer 45 formed on the surface side of the SOI substrate 39 is made thinner than the SiN layer 45 formed on the back side of the SOI substrate 39 in order to control stress in a balanced manner between the surface and back sides.

[0092] Furthermore, the SOI substrate 39 can be formed using the Bosch process, and the SiN layer 45 can be formed using dry etching.

[0093] Furthermore, at least one of the support substrate 3 and membrane 2 shown in Figure 1 may be a polycrystalline silicon structure. This makes the polycrystalline structure less susceptible to fracture in the cleavage direction than single-crystal silicon, which has cleavage planes, because the polycrystalline structure does not have distinct cleavage planes. Furthermore, while it is technically difficult to fabricate large substrates from single-crystal silicon material, by making the deposition mask 1 a polycrystalline silicon structure, silicon substrates larger than those made from single-crystal silicon substrates can be easily formed. In addition, by making the planar shape of the deposition mask 1 a polygonal shape (for example, a square shape), the chamfering efficiency can be increased compared to making the deposition mask 1 a round shape, and the number of surfaces can also be increased. It should be noted that a large silicon substrate is preferably 500 mm x 500 mm or larger. [Examples]

[0094] The effects of the present invention will be explained below with reference to examples and comparative examples of the present invention. However, the present invention is not limited in any way by the following examples.

[0095] <Sample manufacturing of vapor deposition masks> Multiple deposition mask samples were manufactured using the manufacturing method shown in Figure 9 or Figure 10. In this process, the membrane was constructed with a SiO2 / SiN layered structure. In the experiment, various dry etching conditions were used to form the membrane openings, and multiple samples (Experimental Examples 1-30) with different protrusion dimensions of the ridges were prepared.

[0096] <About the SEM image of the protruding section> Figure 7A is an SEM image of the side wall surface of the opening, and Figure 7B is a schematic diagram thereof. As shown in Figures 7A and 7B, the SEM images confirmed that multiple vertical ridges (protrusions) extending in the height direction are formed on the side wall surface.

[0097] <Regarding the deposition conditions in the experiment> Next, using Experimental Examples 1-6 shown in Table 1 (aperture width W1 of 3 μm), the deposition material was vacuum deposited onto the substrate to be deposited. Then, the pattern width W3 of the deposited film was measured using a laser microscope (model: VKX-210 (manufactured by Keyence Corporation)), and the ratio of the deposition pattern width to the aperture width W1 of the deposition mask aperture (converted to 100%) was determined.

[0098] In this case, regarding the amount (time) of deposition applied to the experiment, the deposition conditions for Experimental Example 7 and beyond were defined as the case where one or more samples from Experimental Examples 1 to 6 had a deposition pattern width ratio of less than 70%.

[0099] <Judgment criteria> Experiments with a pattern width ratio of less than 70% were marked with ×, experiments with a pattern width ratio of 70-85% were marked with ○, and experiments with a pattern width ratio exceeding 85% were marked with ◎. The experimental results are shown in Table 1 below.

[0100] [Table 1]

[0101] As shown in Table 1, by setting the protrusion ratio, calculated as (average protrusion dimension / opening width of the opening), to 0.018 or less, it was found that the pattern width ratio could be set to 70% or more (judgment is ○ or ◎), and the deposited film could be formed with a stable pattern width dimension.

[0102] Furthermore, it was found that by setting the protrusion ratio, calculated as (average protrusion dimension / opening width of the opening), to 0.014 or less, the pattern width ratio could be made to over 85% (judged as ◎), allowing for more stable formation of the pattern width accuracy of the deposited film.

[0103] Furthermore, a smaller lower limit for the protrusion ratio is preferable, and it was set at 0.001 or higher. Experimental examples also showed that a protrusion ratio of 0.004 or higher is possible.

[0104] Furthermore, the average protrusion dimension of the ridge portion was set to 150 nm or less, more preferably 145 nm or less, and even more preferably 143.5 nm or less.

[0105] Furthermore, the maximum protruding dimension of the ridge was set to 200 nm or less, more preferably 185 nm or less, and even more preferably 181 nm or less.

[0106] Furthermore, the aperture width is preferably 10 μm or less. The lower limit of the aperture width is 1 μm or more, and may be 3 μm or more depending on the experimental example.

[0107] Note that the "taper angle" shown in Table 1 is a representative value, and it was confirmed that all experimental examples fell within ±3° of each representative value.

[0108] This application is based on Japanese Patent Application No. 2024-097401, filed on June 17, 2024. All of its contents are included here.

Claims

1. A vapor deposition mask having a first surface and a second surface opposite to the first surface, wherein a plurality of openings are formed penetrating between the first surface and the second surface, A protruding portion is formed on the side wall surface of the opening, extending from the first surface to the second surface. The ratio of the protrusion of the ridge to the opening width of the opening is 0.001 or more and 0.018 or less. A vapor deposition mask characterized by the following features.

2. The aforementioned protrusion ratio is 0.014 or less. The vapor deposition mask according to feature 1.

3. When the substrate side to be deposited is referred to as the first surface and the deposition source side as the second surface, The aforementioned opening width is defined by the opening width on the first surface side. The vapor deposition mask according to feature 1.

4. The average protrusion dimension of the aforementioned ridge is 150 nm or less. The vapor deposition mask according to feature 1.

5. The maximum protrusion dimension of the aforementioned ridge is 200 nm or less. The vapor deposition mask according to feature 1.

6. The aperture width is 10 μm or less. The vapor deposition mask according to feature 1.

7. The deposition mask has a configuration in which a membrane having the opening is supported on a support substrate, and the membrane is composed of a single-layer silicon nitride film structure or a multilayer structure of silicon nitride film and silicon oxide film. The vapor deposition mask according to feature 1.

8. The deposition mask has a membrane with the openings, and is composed of an SOI substrate in which a support substrate, an insulating layer, and a semiconductor layer are stacked in that order from the deposition source side to the substrate to be deposited. The semiconductor layer is the membrane, The vapor deposition mask according to claim 1, characterized in that a SiN layer is formed on the surface side of the membrane which is the substrate to be vapor-deposited, or on the back side of the support substrate which is the vapor deposition source side, or on both the surface side and the back side.

9. The deposition mask has a configuration in which a membrane having the opening is supported on a support substrate. The vapor deposition mask according to claim 1, characterized in that at least one of the membrane or the support substrate has a polycrystalline silicon structure.

10. The deposition mask described in claim 1 is placed between the substrate to be deposited and the deposition source such that the first surface faces the substrate to be deposited and the second surface faces the deposition source. The deposition material is deposited onto the surface of the substrate to be deposited through the opening. A method for manufacturing an electronic device characterized by the following:

Images