KR101076435B1 - Method for detecting a misalignment between a substrate and a mask - Google Patents

Abstract

The present invention provides a method for detecting misalignment between a mask and a substrate that can easily determine whether the alignment between the mask and the substrate is correctly maintained. According to the present invention, a method for detecting misalignment of a substrate and a mask may include forming a first layer in each cell formation region of the substrate and forming an alignment mark in each scribe region; Forming a second layer in each cell formation region and each scribe region using a mask; And determining whether the second layer forming mask and the substrate are misaligned by comparing the positions of the second layer and the alignment mark formed in each scribe area. The alignment marks formed in the scribe region of the substrate are composed of first, second and third marks having a predetermined width, and the marks adjacent to each other maintain a width equal to the width of the second layer to be formed in each cell region. .

Board, Mask, Alignment

Description

Method for detecting a misalignment between a substrate and a mask}

1 is a schematic plan view of an organic electroluminescent device.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a plan view of the substrate after the ITO electrode forming step;

FIG. 4 is a detail view of the alignment mark shown in FIG. 5. FIG.

5 is a plan view of an organic material deposition mask used in the present invention, for convenience, a view showing only a part of the cell-forming pattern and an alignment pattern formed therebetween.

Fig. 6 is a partial detail view of the scribe region of the substrate after the organic material layer forming step is completed.

The present invention relates to a method for detecting alignment between a mask and a substrate, and more particularly, to a method of detecting an alignment state between a mask and a substrate by forming an alignment mark on a predetermined region of the substrate and forming an alignment layer on the alignment mark. .                         

In organic electroluminescence, electrons and holes injected through a cathode and an anode are recombined to form an exciton in an organic (low molecular or polymer) thin film, and light of a specific wavelength is generated by energy from the excitons formed. This is a phenomenon that occurs.

1 is a plan view of an organic electroluminescent device, and FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1 and schematically illustrates a basic structure of the organic electroluminescent device using the above-mentioned organic electroluminescent phenomenon.

 The basic configuration of the organic electroluminescent element is an indium tin oxide layer 2 formed on the glass substrate 1 and the glass substrate 1 and acting as an anode electrode (hereinafter referred to as "ITO layer"). ), An organic electroluminescent layer 3 composed of an organic material layer, and a metal layer 4 serving as a cathode electrode are sequentially stacked.

An organic electroluminescent device having such a structure is manufactured through the following steps.

First, the ITO layer 2 is deposited on the glass substrate 1 by using a vacuum deposition method, and the ITO layer 2 is patterned by photolithography to form an ITO electrode. The insulating layer 5a is formed in the predetermined area | region above the ITO layer 2, and the partition 5 is formed on this insulating layer 5a.

Subsequently, the organic electroluminescent layer 3 and the metal layer 4 including the insulating layer and the organic material layer are sequentially formed on the entire structure including the partition wall 5. Here the ITO layer 2 arranged on the transparent substrate 1 performs the function of an anode electrode, and the metal layer 4 performs the function of a cathode electrode.                         

The above process, i.e., the formation of the ITO layer 2, the insulating layer 5a and the organic electroluminescent layer 3 and the metal layer 4, is performed using a mask on which a pattern is formed. The most important factor in the formation of each layer is alignment between the mask and the substrate. If a misalignment occurs between the substrate and the mask in one process, all the processed substrates are regarded as defective and discarded.

While there are various ways to maintain accurate alignment between the substrate and the mask, it is very difficult to accurately maintain the alignment of the mask and the substrate. Further, even when an external shock is applied to the mask, misalignment occurs between both members.

Due to this problem, after the deposition process is completed, the operator should visually inspect all the substrates to determine the deposition failure caused by misalignment of the substrate and the mask. However, it is difficult to accurately observe whether a fine deposition layer is formed at a predetermined position, and thus, when a deposition failure is not detected, a problem arises in that the deposition process is performed without leaving misalignment between the substrate and the mask.

An object of the present invention is to provide an alignment detection method between a mask and a substrate that can easily determine whether the alignment between the mask and the substrate is correctly maintained.

According to the present invention, there is provided a method of detecting alignment between a substrate and a mask, the method comprising: forming a first layer in each cell formation region of the substrate and forming an alignment mark in each scribe region; Forming a second layer in each cell formation region and each scribe region using a mask; And determining whether the second layer forming mask and the substrate are misaligned by comparing the positions of the second layer and the alignment mark formed in each scribe area.

The alignment marks formed in the scribe region of the substrate are composed of first, second and third marks having a predetermined width, and the marks adjacent to each other maintain a width equal to the width of the second layer to be formed in each cell region. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As described with reference to FIG. 1, an ITO layer 2 is deposited on the glass substrate 1, and the ITO layer 2 is patterned to form an ITO electrode.

In the mask used for forming the ITO layer 2, an alignment pattern is formed at a portion corresponding to the scribe region between the cell formation regions of the substrate. Therefore, an alignment mark is formed in the substrate 1 after the ITO electrode forming step, that is, the scribe region between the cell forming regions.

FIG. 3 is a plan view of the substrate after the ITO electrode forming process, and shows, for convenience, some of the cell forming regions A and the alignment marks M formed in the scribe regions S therebetween, wherein the cell forming regions A are boxes. Shown in form.

FIG. 4 is a detailed view of the alignment mark M shown in FIG. 3, wherein the alignment marks M formed in the respective scribe regions S of the substrate 1 are the first, second and third marks M1 and M2. , M3). Each mark M1, M2, M3 has a predetermined width and maintains a predetermined distance from adjacent marks.

On the other hand, as shown in Figure 4, each mark (M1, M2, M3) has a cross shape, but the shape is not limited. In addition, the width of each mark M1, M2, M3 is equal to the width of the pixel (organic layer) formation region in the cell formation region A, and the interval therebetween is equal to the width of the insulating film formed between the pixels. It is preferable to form.

FIG. 5 is a plan view of the mask for forming an organic material layer used in the present invention. For convenience, only some cell-forming patterns (shown in the form of boxes for convenience) and alignment patterns formed therebetween are shown.

The cell formation patterns 20A of the mask 20 correspond to the cell formation regions A of the substrate 1, respectively, and the alignment pattern 20B corresponds to the alignment mark M of the substrate 1. Meanwhile, the width of the alignment pattern 20A is equal to the width of the organic material layer in the cell formation region A of the substrate 1.

An organic material layer and an insulating layer are formed on the substrate shown in FIG. 3 using the mask shown in FIG. 5. After the organic material layer forming step, a predetermined organic material layer is formed in the cell formation region A of the substrate 1, and an organic material layer is also formed in the scribe region S in which the alignment mark M is formed.

FIG. 6 is a partial detailed view of the scribe region S of the substrate after the organic layer forming process is completed, and is formed by the alignment mark M formed in the scribe region S and the alignment pattern 20B of the mask 20. The relationship of the organic material layer P is shown. In FIG. 6, the organic material layer is represented by a diagonal line with a width a and the insulating layer with a width b (diagonal line P).

As described above, the width of the first alignment mark M1 formed in the scribe region S of the substrate is equal to the width of the pixel (organic layer) formed in the cell formation region A of the substrate 1. Therefore, the process worker has the organic material layer (width a) accurately formed on the first alignment mark M1 through the microscope, and the organic material layer P between the first alignment mark M1 and the second alignment mark M2. When confirming the state in which this is formed correctly, it turns out that the alignment of the mask 20 and the board | substrate 1 was correctly maintained.

If misalignment occurs due to misalignment of the mask 20 or the substrate 1, the organic layer (width a) formed in the scribe region S of the substrate deviates from the first alignment M1 and is further insulated from the insulating layer P. Is spaced apart from the space between the first alignment mark M1 and the second alignment mark M2 toward one of the marks. This means that the organic material layer is not formed in the region where the organic layer is formed in the cell formation region A of the substrate 1, that is, the alignment between the substrate 1 and the mask 20 is misaligned. The process operator views the deposition state of the organic layer and the insulating layer to adjust the alignment of the substrate and the mask.

In the above description, the cell formation region A of the substrate and the scribe region S therebetween have been described as an example, but the alignment marks and the alignment confirmation organic layer are formed over all the scribe regions. Therefore, since the organic material layer (P in FIG. 7) is formed between the alignment marks on all the scribe regions of the substrate, the operator calculates an average value of the degree of distortion of the organic material layer and adjusts the alignment of the substrate and the mask based on the average value.

In the present invention as described above, it is possible to easily check whether the substrate is aligned with the mask through the position of the alignment mark and the deposition film formed in the scribe area of the substrate in the deposition process through the mask. Therefore, defects of the device can be prevented by continuing the process after adjusting misalignment between the substrate and the mask.

The present invention described above has been disclosed for the purpose of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Accordingly, such modifications, changes and additions should be considered to be within the scope of the following claims.

For example, it is a matter of course that the object of the present invention can be achieved by changing the number and shape of the alignment marks formed in the scribe region of the substrate and the formation position thereof.

Claims (2)

In the alignment detection method of the substrate and the mask, Forming a first layer serving as an electrode layer in each cell formation region of the substrate and forming an alignment mark in each scribe region; Forming a second layer serving as an organic material layer on each cell formation region and each scribe region using a mask; And And comparing the position of the alignment mark with the second layer formed in each scribe area, and determining whether the mask for forming the second layer is aligned with the substrate. 2. The alignment mark of claim 1, wherein the alignment mark comprises first, second, and third marks having a predetermined width, wherein adjacent marks are adjacent to each other by a width equal to a width of the second layer to be formed in each of the cell regions. Alignment detection method to maintain.

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