KR20080060428A - Mask change process - Google Patents

Abstract

A mask changing process is provided to reduce a tact time of a deposition process by simultaneously changing masks of deposition chambers based on one counting reference. A mask changing process includes the steps of: cumulatively counting the frequency of movement of a substrate(G) on the basis of a first deposition chamber according to first to third references; changing all masks of first type deposition chambers(203,204,205) whenever the cumulatively counted frequency reaches the n multiple of the first reference; changing all the masks of the first type deposition chambers and second type deposition chambers(201,202,206,207) whenever the cumulatively counted frequency reaches the n multiple of the second reference; and changing all the masks of the first and second type deposition chambers and third type deposition chambers(208,209) whenever the cumulatively counted frequency reaches the n multiple of the third reference. In the second to fourth steps, the n is an integer greater than zero.

Description

Mask change process

1 is a schematic diagram showing a mask replacement process according to the prior art.

2 is a schematic diagram showing a mask replacement process according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

201 to 209: deposition chamber TR: transfer chamber

BF: buffer chamber G: substrate

The present invention relates to a mask replacement process.

Recently, various flat panel display devices that can reduce weight and volume, which are disadvantages of cathode ray tubes, have emerged. Such flat panel displays include a liquid crystal display, a field emission display, a plasma display panel, and a light emitting device. Among them, the electroluminescent device has a high response time with a response speed of 1 ms or less, and has been studied as a next-generation display due to characteristics such as low power consumption, wide viewing angle, and high contrast.

The electroluminescent device included an emissive layer (EML) positioned between an anode and a cathode on a substrate. One or more charge injection / transfer layers could be located between the light emitting layer and the anode and cathode. The charge / injection transfer layer and the light emitting layer of the electroluminescent device could be formed by a deposition method using a mask.

In the deposition process, substrates were transferred according to a series of deposition sequences, and deposition chambers to which masks were applied were divided into process steps based on transfer chambers, and transfer chambers were connected through buffer chambers.

1 is a schematic diagram showing a mask replacement process according to the prior art.

Referring to Figure 1, the structure of the conventional deposition chambers are as follows.

Each of the deposition chambers 101 to 109 is divided into a series of deposition units based on the transfer chambers TR1, TR2, TR3, and TR4 according to a sequence of deposition processes. Each of the deposition chambers 101 to 109 may be classified into first to third types T1, T2, and T3 based on the number of available masks to be applied. For example, an emission layer may be formed in the deposition chambers 103, 104, and 105 of the first type T1, and charge may be formed in the deposition chambers 101, 102, 106, and 107 of the second type T2. A common layer could be formed including the injection / transfer layer. In addition, metal electrodes may be formed in the deposition chambers 108 and 109 of the third type T3. According to the type classification of the deposition chambers 101 to 109, for example, in the case of the first type T1, the number of times the mask can be used is 100 times, and the second type T2 and the third type T3 are used. ) Could be 300 times each. This was the life criterion of the mask to ensure the precision and uniformity of the deposition process.

Each transfer chamber TR1, TR2, TR3, TR4 is connected via a buffer chamber BF2, BF3, BF4, BF5. In addition, chambers M1, M2, and M3 accommodating replacement masks may be located in the transfer chambers TR2, TR3, and TR4.

Referring to the conventional mask replacement process through the deposition chambers of the above structure is as follows.

The substrate G having a patterned first electrode, for example, ITO, was transferred from the first transfer chamber TR1 to the second transfer chamber TR2 through the second buffer chamber BF2. The substrate G transferred to the second transfer chamber TR2 was transferred to the first deposition chamber 101. In the first deposition chamber 101, a hole injection layer HIL is formed on the substrate G. At this time, in the first deposition chamber 101, the first movement frequency N1 of the substrate G was accumulated and counted.

Subsequently, in the second deposition chamber 102, the hole transport layer HTL was formed on the substrate G transferred from the first deposition chamber 101. In the third deposition chamber 103, a blue light emitting layer was formed. In the third deposition chamber 103, the second movement frequency N2 of the substrate G is accumulated and counted separately so as to be distinguished from the first movement frequency N1 of the substrate G in the first deposition chamber 101. .

The substrate G, which has undergone the deposition process of the third deposition chamber 103, is transferred to the third transfer chamber TR3 through the third buffer chamber BF3. The substrate G transferred from the second transfer chamber TR2 to the third transfer chamber TR3 is transferred to the fourth deposition chamber 104 to form a red light emitting layer. In addition, a green light emitting layer is formed on the substrate G through the fifth deposition chamber 105, and a charge adjusting layer HBL is formed through the sixth deposition chamber 106. In addition, an electron transport layer ETL was formed through the seventh deposition chamber 107. As such, the substrate G, which has undergone a series of lamination processes in the third transfer chamber TR3, is transferred to the fourth transfer chamber TR4 through the fourth buffer chamber BF4.

In the fourth transfer chamber TR4, chambers 108 and 109 of the third type T3, which form metal electrodes, are positioned. The substrate G transferred to the fourth transfer chamber TR4 was alternately transferred to the eighth deposition chamber 108 and the ninth deposition chamber 109. For example, when the substrate G was transferred to the fourth transfer chamber TR4, if the eighth deposition chamber 108 was empty, the substrate G was transferred to the eighth deposition chamber 108. On the other hand, if the substrate G is present in the eighth deposition chamber 108, the substrate G is transferred to the ninth deposition chamber 109.

In the eighth deposition chamber 108, the third movement frequency N3 of the substrate G is accumulated and counted with respect to the substrates G transferred to the fourth transfer chamber TR4.

In the transfer process of the substrate G between the transfer chambers TR1, TR2, TR3, and TR4 as described above, the first movement frequency N1 of the substrate G accumulated in the first deposition chamber 101 is When 300n + 1 (n is an integer, n> 0), the masks of the deposition chambers 101, 102, 106, and 107 of the second type T2 were all replaced.

Meanwhile, when the second movement frequency N2 of the substrate G accumulated in the third deposition chamber 103 becomes 100n + 1 (n is an integer, n> 0), the deposition chamber of the first type T1 is used. The masks of the fields 103, 104, 105 have all been replaced.

In addition, when the third movement frequency N1 of the cumulatively counted substrate G in the eighth deposition chamber 108 becomes 300n + 1 (n is an integer, n> 0), the deposition chamber of the third type T3 is used. Both masks 108 and 109 have been replaced.

The mask replacement process according to the first to third movement times N1, N2, and N3 as described above had to satisfy the preceding condition that the substrate should be present in the deposition chamber to replace the mask.

In such a conventional mask replacement process, for example, when a problem occurs in the substrate G in the third deposition chamber 103, the third chamber 103 may be actuated and the third chamber 103 may be taken. All processes before the third deposition chamber 103 had to be stopped until all processes in the third and fourth transfer chambers TR3 and TR4 thereafter proceeded. Accordingly, when an accident occurs in the previous stage of the replacement criterion of the mask when the second movement count N2 counted in the third deposition chamber 103 is replaced, the masks of the corresponding deposition chambers of the fourth transfer chamber TR4 are simultaneously replaced. An unavoidable problem occurred. For example, when the number of second movements N2 is counted 101 times, the masks of the first type deposition chambers should be replaced. In the third deposition chamber 103, the 99th substrate G is accidentally damaged. In case of occurrence, when the process is resumed according to the above-described accident treatment process and the second number of movements N2 is counted 101 times, the substrate G has not yet been transferred to the fifth deposition chamber 105. Since the automatic replacement is impossible, a problem arises in that the substrate G must be manually transported. In this way, as the manual process needs to adjust the number of substrates G, there is a problem that the process time (Tact time) increases in the conventional mask replacement process.

In addition, the seventh deposition chamber positioned immediately before the substrate G is transferred from the third transfer chamber TR3 to the fourth transfer chamber TR4 in which the deposition chambers 108 and 109 of the third type T3 are located. If a problem occurs in the substrate G at 107, the same accident action process as the case in which the accident occurred in the third deposition chamber 103 described above proceeds, so that only the substrate G is in the eighth deposition chamber 108. There is a problem that the transfer of the) is biased. The problem of the eccentric transfer of the substrate G is when the third movement frequency N3 is interlocked with the first movement frequency N1 in order to simultaneously perform mask replacement of the deposition chambers of the second type and the third type. As a result, the lifetime limit of the mask in the eighth deposition chamber 108 may be elapsed. For example, since the substrate G is alternately transferred to the eighth and ninth deposition chambers 108 and 109, the third movement frequency N3 may be interlocked by twice the first movement frequency N1. (N3 = 2N1) Accordingly, as the precision and uniformity of the deposition process are lowered in the eighth deposition chamber 108, there is a problem that the yield and reliability of the deposition process are deteriorated.

Accordingly, an object of the present invention is to provide a mask replacement process that can shorten the process time of the deposition process and prevent the degradation of precision and uniformity, thereby improving the yield and reliability of the process.

In order to achieve the above object, the present invention provides a plurality of deposition chambers, which are classified into first to third types based on the number of times of use of a mask to be applied, and a plurality of deposition chambers in a predetermined number of units according to a series of deposition procedures of a deposition process. In the deposition apparatus comprising a transfer chamber for separating, and a buffer chamber connecting the transfer chamber,

Accumulating counting by dividing the number of movement of the substrate based on the first deposition chamber of the deposition chamber into the first reference, the second reference, and the third reference, and the cumulative counting number is n of the first reference. Replacing all the masks of the first type deposition chamber every time the multiple (n is an integer, n> 0), and every time the cumulative counting reaches the n multiple of the second criterion (n is an integer, n> 0) Replacing both masks of the type 1 deposition chamber and the type 2 deposition chamber, each time the cumulative counting number reaches an n-fold (n is an integer, n> 0) of the third criterion; A mask replacement process is provided that includes replacing all of the masks.

The first to third criteria may be classified in order of increasing number of times of use of a mask applied to the first to third type deposition chambers.

The first to third criteria may have a correlation of n times (n is an integer, n> 0).

The mask replacement process may be applied to the deposition process of the electroluminescent device.

The first type deposition chamber may form an emission layer (EML).

The second type deposition chamber may form a common layer that includes a charge injection / transfer layer.

The third type deposition chamber may form a metal electrode.

Hereinafter, a mask replacement process according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram showing a mask replacement process according to an embodiment of the present invention.

Referring to Figure 2 describes the structure of the deposition chambers according to an embodiment of the present invention.

Each of the deposition chambers 201 to 209 may be divided into a series of deposition units based on the transfer chambers TR1, TR2, TR3, and TR4 according to a sequence of deposition processes. Each of the deposition chambers 201 to 209 may be classified into first to third types T1, T2, and T3 based on the number of available masks to be applied. For example, a light emitting layer may be formed in the deposition chambers 203, 204, and 205 of the first type T1, and charge may be formed in the deposition chambers 201, 202, 206, and 207 of the second type T2. A common layer can be formed including the injection / transfer layer. In addition, metal electrodes may be formed in the deposition chambers 208 and 209 of the third type T3. According to the type classification of the deposition chambers 201 to 209, for example, in the case of the first type T1, the available number of masks is 100 times, and the second type T2 and the third type ( In the case of T3) may be 300. This is the life criterion of the mask to ensure the precision and uniformity of the deposition process.

Each transfer chamber TR1, TR2, TR3, TR4 is connected via a buffer chamber BF2, BF3, BF4, BF5. In addition, in the transfer chambers TR2, TR3, and TR4, chambers M1, M2, and M3 may be located to accommodate the replacement mask.

Referring to the mask replacement process according to an embodiment of the present invention through the deposition chambers of the above structure as follows.

The substrate G, on which the first electrode, for example, ITO, is patterned, is transferred from the first transfer chamber TR1 to the second transfer chamber TR2 through the second buffer chamber BF2. The substrate G transferred to the second transfer chamber TR2 is transferred to the first deposition chamber 201. In the first deposition chamber 201, a hole injection layer HIL may be formed on the substrate G. In this case, the first deposition chamber 201 accumulates and counts the number of movements N4 of the substrate G.

Subsequently, in the second deposition chamber 202, a hole transport layer HTL may be formed on the substrate G transferred from the first deposition chamber 201. In the third deposition chamber 203, a blue light emitting layer may be formed on the substrate G transferred from the second deposition chamber 202.

The substrate G, which has undergone the deposition process of the third deposition chamber 203, is transferred to the third transfer chamber TR3 through the third buffer chamber BF3. The substrate G transferred from the second transfer chamber TR2 to the third transfer chamber TR3 may be transferred to the fourth deposition chamber 204 to form a red light emitting layer. In addition, the green emission layer may be formed on the substrate G through the fifth deposition chamber 205, and the charge control layer HBL may be formed through the sixth deposition chamber 206. In addition, an electron transport layer ETL may be formed through the seventh deposition chamber 207. As described above, the substrate G, which has undergone a series of stacking processes in the third transfer chamber TR3, is transferred to the fourth transfer chamber TR4 through the fourth buffer chamber BF4.

In the fourth transfer chamber TR4, chambers 208 and 209 of a third type T3 forming metal electrodes are positioned. The substrate G transferred to the fourth transfer chamber TR4 may be alternately transferred to the eighth deposition chamber 208 and the ninth deposition chamber 209. For example, when the substrate G is transferred to the fourth transfer chamber TR4, if the eighth deposition chamber 208 is empty, the substrate G is transferred to the eighth deposition chamber 208. However, if the substrate G is present in the eighth deposition chamber 208, the substrate G is transferred to the ninth deposition chamber 209.

Although not shown, the substrate G, which has undergone the metal electrode deposition process in the fourth transfer chamber TR4, is transferred to the fifth transfer chamber TR5 through the fifth buffer chamber BF5.

In the transfer process of the substrate G between the transfer chambers TR1, TR2, TR3, and TR4 as described above, the number of movements N4 of the substrate G accumulated in the first deposition chamber 201 is 100 When n times (n is an integer, n> 0), the masks of the deposition chambers 203, 204, and 205 of the first type T1 are all replaced.

In addition, when the number of movements N4 of the cumulatively counted substrate G becomes an n multiple of 300 (n is an integer, n> 0), deposition chambers of the first type T1 and the second type T2 ( 201, 202, 203, 204, 205, 206, 207 are all replaced.

In addition, when the number of movements N4 of the cumulatively counted substrate G becomes n multiples of n (n is an integer, n> 0), deposition chambers of the first to third types T1, T2, and T3 ( The masks of 201, 202, 203, 204, 205, 206, 207, 208, and 209 are all replaced.

Detailed description of the mask replacement process is as follows.

For example, assuming that the number of movements N4 of the accumulated counted substrate G is counted only from 100 to 600 in the entire deposition process, the number of movements N4 of the accumulated counted substrate G is 100, 200, 400 , The mask is replaced only in the deposition chambers 203, 204, and 205 of the first type T1 when 500. In addition, the deposition chambers 201, 202, 203, 204, 205, 206, and 207 of the first type T1 and the second type T2 when the number of movements N4 of the cumulatively counted substrate G is 300. All masks are replaced. Subsequently, when the number of movements N4 of the cumulatively counted substrate G reaches 600, the deposition chambers 201, 202, 203, 204, 205, and 206 of the first to third types T1, T2, and T3 may be used. 207, 208, 209 are all replaced.

The mask replacement process according to the embodiment of the present invention as described above divides the number of life cycles of the mask that can be applied to the deposition chambers of the first to third types (T1, T2, T3) by the first to third criteria When the number of movements N4 of the cumulatively counted substrate G in the first deposition chamber 201 is satisfied with the conditions compared to the first to third criteria, all the masks of the deposition chamber of the type are replaced. At this time, the replacement condition of the mask depends only on whether the number of movements N4 of the cumulatively counted substrate G in the first deposition chamber 201 meets any one of the first to third criteria, and from other conditions Independent. In other words, whether or not a substrate is present in the chamber applied in the conventional process does not affect the step of replacing the mask.

Accordingly, the mask replacement process according to an embodiment of the present invention may proceed with the deposition process only by taking action on the chamber even if an accident occurs in any deposition chamber. In addition, the mask replacement of the chamber, which was previously divided into the first to third types (T1 or T2 or T3) as the other counting standard, applies one unchanged counting criterion, and n multiples between each criterion (n is an integer, n> By introducing the correlation of 0), it is possible to simultaneously perform the mask replacement work that is divided into the first to third types (T1 or T2 or T3). Accordingly, the overall process time of the deposition process may be greatly shortened. Also, in no case does a case exceed the lifetime limit of the mask applied to a particular chamber. Accordingly, the mask replacement process according to the present invention can prevent a decrease in process yield and reliability that may occur during deposition of the light emitting layer of the device.

In one embodiment of the present invention, five transfer chambers (including TR1, TR2, TR3, TR4 and not shown TR5), four buffer chambers (BF2, BF3, BF4, and BF5) and nine deposition chambers 201 to 209. In the case of a deposition process and a mask replacement process performed in a deposition system consisting of), for example, the present invention is not limited to the number of transfer chambers, buffer chambers or deposition chambers.

In addition, in one embodiment of the present invention, the deposition process of the electroluminescent device has been described as an example, but the present invention may be applied to the deposition process of forming various types of thin films as well as the electroluminescent device.

 Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the above-described technical configuration of the present invention may be embodied in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

The present invention can provide a mask replacement process that can shorten the process time of the deposition process and prevent degradation of precision and uniformity, thereby improving the yield and reliability of the process.

Claims (7)

A plurality of deposition chambers classified into first to third types based on the number of times of use of a mask to be applied, a transfer chamber that divides the plurality of deposition chambers into a predetermined number of units according to a series of stacking procedures of a deposition process, and the transfer chamber In the deposition apparatus comprising a buffer chamber for connecting the liver, Cumulative counting by dividing the number of movements of the substrate based on a first deposition chamber that is the first of the deposition chambers into a first reference, a second reference, and a third reference; Replacing all of the masks of the first type deposition chamber whenever the cumulative counting number reaches n times the first criterion (n is an integer, n> 0); Replacing both masks of the first type deposition chamber and the second type deposition chamber whenever the cumulative counting number reaches n times the second reference (n is an integer, n> 0); And replacing all of the masks of the first to third type deposition chambers whenever the cumulative counting number reaches an n-fold (n is an integer, n> 0) of the third criterion. The method of claim 1, The first to third criteria are mask replacement processes are divided in order of increasing the number of times the mask is applied to the first to third type deposition chamber. The method according to claim 1 or 2, And wherein the first to third criteria have a correlation of n times (n is an integer, n> 0). The method of claim 1, The mask replacement process is a mask replacement process applied to the deposition process of the electroluminescent device. The method of claim 4, wherein And the first type deposition chamber forms an Emissive Layer (EML). The method of claim 4, wherein And the second type deposition chamber forms a common layer comprising a charge injection / transfer layer. The method of claim 4, wherein And the third type deposition chamber forms a metal electrode.

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