KR100646961B1 - Method for controlling effusion cell of deposition system - Google Patents

Abstract

The present invention relates to a method of controlling a deposition source of a deposition system, and more particularly, to a method of controlling a deposition source of a deposition system capable of preventing clogging and splashing of a nozzle portion of a deposition source. In the present invention, there is provided a crucible, an induction furnace, and an injection nozzle unit, and the temperature raising control method of a deposition source comprising a first heating element for heating the crucible and a second heating element for heating the induction furnace and the injection nozzle unit. (a) heating the induction furnace and the injection nozzle unit using the second heating body, and (b) heating the crucible using the first heating body.

The control method of the deposition source according to the present invention has the advantage of improving the uniformity of the organic material layer formed on the substrate by preventing the nozzle or clogging of the spray nozzle by the vaporized deposition material in the crucible.

Heating element, deposition rate, organic vapor phase

Description

Control method of evaporation source of evaporation system {METHOD FOR CONTROLLING EFFUSION CELL OF DEPOSITION SYSTEM}

1 is a schematic view showing a vacuum deposition system in which a control method according to the present invention is implemented;

2 is a schematic view showing a state in which a film forming operation is performed in a vacuum deposition system in which a control method according to the present invention is implemented;

3 is a schematic view showing a deposition source in which a control method according to the present invention is implemented;

4 is a flowchart of a control method of a deposition source according to the present invention;

<Description of Symbols for Major Parts of Drawings>

10: vacuum chamber

20: evaporation source

30: substrate

40: mask

50: Chuck

100: vacuum deposition system

The present invention relates to a method of controlling a deposition source of a deposition system, and more particularly, to a method of controlling a deposition source of a deposition system capable of preventing clogging and splashing of a nozzle portion of a deposition source.

In general, an electroluminescent display device, which is one of flat panel displays, is classified into an inorganic electroluminescent display device and an organic electroluminescent display device according to a material used as a light emitting layer, and the organic electroluminescent display device can be driven at low voltage and is light in weight. It is attracting attention because of its thinness and wide viewing angle as well as fast response speed.

The organic light emitting device of the organic light emitting display device includes an anode, an organic material layer, and a cathode that are stacked on a substrate. The organic material layer includes an organic material layer of an organic light emitting layer that recombines holes and electrons to form excitons and emits light, and also between the cathode and the organic light emitting layer to smoothly transport holes and electrons to the organic light emitting layer to improve luminous efficiency. The organic material layer of the hole injection layer and the electron transport layer is interposed between the anode and the organic light emitting layer while interposing the organic material layer of the electron injection layer and the electron transport layer.

The organic light emitting device having the above-described structure is generally manufactured by a physical vapor deposition method such as a vacuum deposition method, an ion plating method and a sputtering method or a chemical vapor deposition method by a gas reaction. In particular, in order to form an organic material layer of an organic light emitting device, a vacuum deposition method for depositing an organic material evaporated in a vacuum on a substrate is widely used. effusion cells) are used.

The deposition source includes a crucible containing a deposition material, a heating means for heating the crucible, and the deposition source includes a spray nozzle for spraying vaporized deposition material, and vaporized deposition from the crucible to the spray nozzle. An induction furnace for guiding the substance is included. Therefore, in a state where the substrate is mounted in the vacuum chamber, the deposition material heated and evaporated by the heating means is sprayed onto the substrate through the injection nozzle via the induction furnace and deposited.

However, such a deposition source may be accompanied by problems such as clogging and splashing of the spray nozzles, as the vaporized deposition material in the crucible is liquefied or solidified by condensation or the like in an induction furnace or spray nozzle, and as a result, vaporization through the spray nozzle There is a problem in that it causes a non-uniform spraying of the deposited material to act as a cause of reducing the uniformity of the organic material layer formed on the substrate.

The present invention has been proposed to solve the conventional problems as described above, the deposition that can improve the uniformity of the organic material layer formed on the substrate by preventing the nozzle or clogging of the spray nozzle by the vaporized deposition material in the crucible It is to provide a control method of the circle.

In order to achieve the above object, a first aspect of the present invention includes a crucible, an induction furnace and an injection nozzle unit, and includes a first heating element for heating the crucible and a second heating element for heating the induction furnace and the injection nozzle unit. A method for controlling a temperature increase of a deposition source, comprising: (a) heating the induction furnace and the injection nozzle unit using the second heating body, and (b) heating the crucible using the first heating body. It is to provide a temperature control method of the deposition source comprising a step.

According to a second aspect of the present invention, there is provided a cooling control method of a deposition source having a crucible, an induction furnace, and an injection nozzle unit, including (a) cooling the crucible and (b) whether the deposition rate has fallen below 0.1 mW / s. It provides a cooling control method of the deposition source comprising the step of monitoring and (b) cooling the induction furnace and the spray nozzle.

A third aspect of the present invention includes a crucible, an induction furnace, and an injection nozzle unit, and a temperature raising control of a deposition source including a first heating element for heating the crucible and a second heating element for heating the induction furnace and the injection nozzle unit. A method comprising: (a) heating the induction furnace and the injection nozzle unit using the second heating body, (b) heating the crucible using the first heating body, (c) performing deposition (D) cooling the crucible and (e) cooling the induction furnace and the injection nozzle unit.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

1 is a view showing a vertical vacuum deposition system according to an embodiment of the present invention, when the deposition source is in the buffer region. 2 is a view showing a vertical vacuum deposition system according to an embodiment of the present invention, in which the deposition source is in the film formation region.

1 and 2, the vertical vacuum deposition system includes a vacuum chamber 10, a deposition source 20, and a chuck 50, and performs deposition in a state where a substrate 30 and a mask 40 are loaded. do.

The vacuum chamber 10 maintains the interior of the vertical vacuum deposition system under vacuum. The vacuum chamber 10 is divided into a film forming area B corresponding to an installation position of the mask 40 and the substrate 30 and a buffer area A corresponding to a position other than the film forming area B.

The deposition source 20 serves to vaporize the deposition material and supply the vapor deposition material to the substrate 30. In order to enable large area deposition, the deposition source 20 moves vertically in the vacuum chamber 10 by the operation of a moving means (not shown). In order to prevent clogging and splashing of the injection nozzle unit (not shown) and the induction furnace (not shown) of the deposition source 20, the crucible after heating the injection nozzle unit and the induction furnace in the temperature rising process of the deposition source 20 ( (Not shown), and in the cooling process of the deposition source 20, after cooling the crucible, the injection nozzle unit and the induction furnace are cooled. In addition, in order to obtain a uniform deposition rate through stable control of the deposition rate, the deposition source 20 initially operates in a temperature control method, and then performs a deposition rate control method, and the deposition rate is a predetermined deposition rate. If in range, it operates in such a way that deposition is performed. 1 illustrates a case where the deposition source 20 is located in the buffer region A, and FIG. 2 illustrates a case where the deposition source 20 is located in the deposition region B. As shown in FIG.

The chuck 50 performs a function of loading the substrate 30 and the mask 40. In addition, the chuck 50 may perform a function of aligning the mask 40 and the substrate 30.

The substrate 30 and the mask 40 are spaced apart from the deposition source 20. The mask 40 includes a pattern forming part (shown as a virtual line in the drawing) in which the pattern is formed, and a fixing part fixed to the mask frame (not shown) by welding.

3 is a diagram illustrating an example of a deposition source employed in the vertical deposition systems of FIGS. 1 and 2.

Referring to FIG. 3, the deposition source 20 includes a crucible 22, an induction furnace 24, an injection nozzle unit 26, a first heating body 21a and a second heating body 21b.

The deposition material is positioned in the crucible 22 and vaporizes the deposition material by the heating action of the first heater 21a. The induction furnace 24 is a passage through which communication connects the crucible 22 and the injection nozzle unit 26 so that communication is possible, and the injection nozzle unit 26 is a portion through which vaporized deposition material is injected from the crucible. The induction furnace 24 and the injection nozzle part 26 are heated by the 2nd heating body 21b. In this case, the first heating body 21a and the second heating body 21b mean a member that dissipates heat by energization such as a heating wire, but is not limited thereto.

The crucible 22 is heated by the heating action of the first heating body 21a, so that the deposition material stored in the crucible 22 is vaporized. In addition, the heating nozzle 26 and the induction furnace 24 are heated by the heating action of the second heating body 21b so that the organic gaseous substances evaporated from the crucible 22 are injected with the induction furnace 24 without condensation. The nozzle portion 26 passes through the gaseous state and is deposited on the substrate.

4 is a view showing a control method of the vertical vacuum deposition system according to an embodiment of the present invention.

1 to 4, the control method of the vertical vacuum deposition system will be described. First, the induction furnace 24 and the spray nozzle unit 26 of the deposition source 20 are heated (S10). The induction furnace 24 and the spray nozzle part 26 are heated by the 2nd heating body 21b. The reason why the induction furnace 24 and the injection nozzle unit 26 are heated before the crucible 22 is that the vaporized deposition material vaporized in the crucible 22 is liquefied or solidified in the induction furnace 24 or the injection nozzle unit 26. This is to prevent the nozzle from clogging or splashing.

Thereafter, the crucible 22 is heated in a temperature control method (S20). In this step, the temperature of the crucible 22 is measured by a temperature sensor (not shown) located at the deposition source, and the temperature of the crucible 22 is changed in such a manner as to change the power supplied to the first heating body 21a using the measured temperature. Control is made. In this case, the second heating body 21b may also be controlled according to the measured temperature, and the second heating body 21b may be supplied with a predetermined power regardless of the measured temperature.

Thereafter, the crucible 22 is heated in a deposition rate control method (S30). In this step, the deposition rate is measured by the deposition rate sensor, and the deposition rate is controlled by changing the power supplied to the first heater 21a using the measured deposition rate. At this time, the second heater 21b may also be controlled according to the measured deposition rate, and the second heater 21b may be supplied with a predetermined power regardless of the measured deposition rate. Deposition rate may be measured by a deposition rate sensor (not shown), the deposition rate sensor is located in front of the deposition source, a crystal sensor fixed to the deposition source may be used.

Thereafter, it is determined whether the deposition rate is stabilized (S40). For example, it may be determined whether the deposition rate is stabilized by determining whether the deposition rate is within a predetermined range, or it may be determined whether the deposition rate is stabilized by determining whether the deposition rate is within a predetermined range for a predetermined period of time. Can be. The predetermined range may be, for example, within a 5% range above and below the target deposition rate. If the deposition rate is not stabilized, the deposition rate is monitored while the crucible 22 is continuously heated in a deposition rate control method.

When the deposition rate is stabilized, deposition is performed (S50). In steps S10 to S40 before this step, the deposition source 20 is positioned in the buffer region A, but in this step, the deposition source 20 is moved to the deposition region B to perform deposition. Deposition is carried out on the substrate 30 by the vaporized deposition material injected from the injection nozzle unit 26 of the deposition source 20 flying through the vacuum space, passing through the pattern forming unit of the mask 40, and condensing on the substrate 30. It is made in such a way that a deposition pattern of a predetermined pattern is formed. In order to make the thickness of the deposition material deposited on the substrate 30 uniform, the deposition source 20 moves up and down while deposition is performed. At this stage as well, the crucible 22 is heated by the deposition rate control method. When the deposition is performed by replacing the substrate 30, first, the deposition source 20 is moved again to the buffer region A, the substrate 30 is replaced, and the deposition source 20 is checked after stabilization of the deposition rate. ) Is moved to the deposition region B to perform deposition.

When the deposition is stopped, the power is shut off of the heating body (S60). For example, when all of the deposition material stored in the crucible 22 is exhausted, the deposition is stopped.

If it is requested to stop the deposition, first the crucible 22 is cooled (S70). The reason why the crucible 22 is first cooled compared to the induction furnace 24 and the injection nozzle unit 26 is that the vaporized deposition material vaporized in the crucible 22 is liquefied or solidified in the induction furnace 24 or the injection nozzle unit 26. This is to prevent the nozzle from clogging or splashing.

Thereafter, it is determined whether the deposition rate has fallen below a predetermined value (S80). The predetermined value is, for example, 0.1 mW / s. This step (S80) may be omitted, and may operate in a manner of cooling the induction furnace 24 and the injection nozzle unit 26 after a predetermined time elapses after cooling from the crucible 22 (S70).

Thereafter, the induction furnace 24 and the injection nozzle unit 26 are cooled.

The foregoing is merely illustrative of the preferred embodiments of the present invention and those skilled in the art to which the present invention pertains recognize that modifications and variations can be made to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

The control method of the deposition source according to the present invention has the advantage of improving the uniformity of the organic material layer formed on the substrate by preventing the nozzle or clogging of the spray nozzle by the vaporized deposition material in the crucible.

Claims (15)

In the temperature raising control method of the deposition source which comprises a crucible, an induction furnace, and the injection nozzle part, and comprises the 1st heating body which heats the said crucible, and the 2nd heating body which heats the said induction furnace and the said injection nozzle part, (a) heating the induction furnace and the injection nozzle unit using the second heating body; And and (b) heating the crucible using the first heating element. The method of claim 1, Step (b) is (c) heating the crucible in a temperature controlled manner; And and (d) heating the crucible in a deposition rate control method. The method of claim 1, When the steps (a) and (b) is performed, the deposition source is a temperature control method of the deposition source is located in the buffer region. In the cooling control method of the evaporation source provided with a crucible, an induction furnace and an injection nozzle part, (a) cooling the crucible; And (b) monitoring whether the deposition rate has fallen below 0.1 mW / s; And (b) cooling the induction furnace and the spray nozzle unit. The method of claim 4, wherein Cooling control method of the deposition source is located in the buffer area when performing the steps (a) and (b). In the temperature raising control method of the deposition source which comprises a crucible, an induction furnace, and the injection nozzle part, and comprises the 1st heating body which heats the said crucible, and the 2nd heating body which heats the said induction furnace and the said injection nozzle part, (a) heating the induction furnace and the injection nozzle unit using the second heating body; (b) heating the crucible using the first heating body; (c) performing deposition; (d) cooling the crucible; And (e) cooling the induction furnace and the injection nozzle unit. The method of claim 6, Step (b) is (f) heating the crucible in a temperature controlled manner; And (g) heating the crucible by a deposition rate control method. The method of claim 6, Step (c) is (h) determining whether the deposition rate is stabilized; And (i) if it is determined in step (h) that the deposition rate is stabilized, the method of controlling a deposition source comprising moving the deposition source to a deposition region and performing deposition. The method of claim 8, And in the step (h), when the deposition rate is in a range of 5% to 5% of the target deposition rate, determining that the deposition rate is stabilized. The method of claim 6, Monitoring the deposition rate after performing step (d) to perform the step (e) when the deposition rate is 0.1 mW / s or less. The method of claim 6, And the deposition source is located in a buffer area when the steps (a), (b), (d) and (e) are performed. delete delete delete delete

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