JP2003257630A - Vacuum evaporation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent destruction of TFT formed on a glass substrate and variation of characteristics when forming a pattern by evaporation. <P>SOLUTION: Upon completion of pattern formation by evaporation, a magnet 120 is moved upward and is peeled off the glass substrate 130. At this point, for example, a plus charge is generated on the glass substrate 30 by peeling and charging. Then, ultraviolet ray is irradiated into a chamber of a vacuum evaporation device 100 from an ultraviolet ray irradiation device 200. Ultraviolet ray is applied to molecules remaining in the chamber to generate a positive or negative ion. This negative ion is attracted to a positive charge on the glass substrate 130, they are mutually connected, and mutual charges are eliminated, and electricity is removed from the glass substrate 130. Consequently, it is possible to prevent destruction of a device such as TFT and variation of characteristics. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum vapor deposition method, and in particular, an insulating substrate is interposed between a magnet and a vapor deposition mask made of a magnetic material in a vacuum vapor deposition apparatus, and the magnet is interposed therebetween. A vacuum deposition method for forming a pattern by depositing a deposition material on a surface of the insulating substrate from a deposition source through an opening of the deposition mask in a state where the insulating substrate and the deposition mask are in close contact with each other. .

[0002]

2. Description of the Related Art In recent years, electroluminescence (Elec
tro Luminescence: Hereinafter referred to as "EL". ) EL display device using an element has attracted attention as a display device replacing a CRT or LCD. For example, a thin film transistor (Th) is used as a switching element for driving the EL element.
in Film Transistor: Hereinafter referred to as "TFT". ) Are also being researched and developed.

FIG. 7 is a plan view showing the vicinity of the display pixel of the organic EL display device, FIG. 8A is a sectional view taken along the line AA in FIG. 1, and FIG. 7 is a sectional view taken along line BB in FIG.

As shown in FIGS. 7 and 8, the display pixels 115 are formed in a region surrounded by the gate signal lines 51 and the drain signal lines 52 and are arranged in a matrix.

In the display pixel 115, an organic EL element 60, which is a self-luminous element, and a switching TFT 3 for controlling the timing of supplying a current to the organic EL element 60.
0 and a driving TFT that supplies a current to the organic EL element 60
40 and a storage capacitor are arranged. In addition, organic EL
The element 60 includes an anode 61 which is a first electrode, a light emitting element layer which is made of a light emitting material, and a cathode 63 which is a second electrode.

That is, a first TFT 30, which is a switching TFT, is provided near the intersection of both signal lines 51 and 52, and the source 33 s of the TFT 30 has a capacitance forming a capacitance with the storage capacitance electrode line 54. It also serves as the electrode 55 and is connected to the gate 41 of the second TFT 40, which is the EL element driving TFT, and the source 4 of the second TFT.
3s is connected to the anode 61 of the organic EL element 60, and the other drain 43d is connected to the drive power supply line 53 which is a current source supplied to the organic EL element 60.

A storage capacitor electrode line 54 is arranged in parallel with the gate signal line 51. This storage capacitor electrode line 54
Is made of chrome or the like and accumulates charges between the source 33 s of the TFT and the capacitance electrode 55 connected to the source 33 s via the gate insulating film 12 to form a capacitance. This holding capacity 56
Are provided for holding the voltage applied to the gate electrode 41 of the second TFT 40.

As shown in FIG. 8, the organic EL display device is
A TFT and an organic EL element are sequentially laminated on a substrate 10 such as a substrate made of glass or synthetic resin, a substrate having conductivity, or a semiconductor substrate. However, substrate 1
When a conductive substrate and a semiconductor substrate are used as 0, an insulating film such as SiO ₂ or SiN is formed on the substrate 10 and then the first and second TFTs and the organic EL are formed.
Form an element. Each of the TFTs has a so-called top gate structure in which the gate electrode is above the active layer via the gate insulating film.

First, the first TFT 30, which is a switching TFT, will be described.

As shown in FIG. 8A, an amorphous silicon film (hereinafter referred to as "a-Si film") is CV on an insulating substrate 10 made of quartz glass, non-alkali glass or the like.
A film is formed by the D method or the like, and the a-Si film is irradiated with laser light to be melted and recrystallized to form a polycrystalline silicon film (hereinafter referred to as “p-
"Si film". ), And this is the active layer 33.
A single layer or a laminated body of a SiO ₂ film and a SiN film is formed thereon as the gate insulating film 32. On top of that, C
It is provided with a gate signal line 51 also serving as a gate electrode 31 made of a refractory metal such as r and Mo and a drain signal line 52 made of Al, which is a driving power source for an organic EL element and is Al.
Drive power supply line 53 is arranged.

Then, the gate insulating film 32 and the active layer 33.
An interlayer insulating film 15 in which a SiO ₂ film, a SiN film, and a SiO ₂ film are laminated in this order is formed on the entire upper surface, and a drain in which a metal such as Al is filled in a contact hole provided corresponding to the drain 33d. An electrode 36 is provided, and a flattening insulating film 17 made of an organic resin is formed on the entire surface to make the surface flat.
Are formed.

Next, the second TFT 40, which is a driving TFT for the organic EL element, will be described. As shown in FIG. 8B, on the insulating substrate 10 made of quartz glass, non-alkali glass or the like, the active layer 43 and the gate insulating film 12 are formed by irradiating the a-Si film with laser light to polycrystallize it. , And C
A gate electrode 41 made of a refractory metal such as r and Mo is formed in order, and a channel 43 is formed in the active layer 43.
c, and a source 43s and a drain 43d are provided on both sides of the channel 43c. Then, an interlayer insulating film 15 in which a SiO ₂ film, a SiN film, and a SiO ₂ film are laminated in this order is formed on the entire surface of the gate insulating film 12 and the active layer 43, and Al is formed in a contact hole provided corresponding to the drain 43d. A driving power supply line 53 filled with a metal such as the above and connected to the driving power supply is arranged. Further, a flattening insulating film 17 made of, for example, an organic resin for flattening the surface is provided on the entire surface. Then, a contact hole is formed in the flattening insulating film 17 at a position corresponding to the source 43s, and the ITO is brought into contact with the source 43s through the contact hole.
A transparent electrode made of, that is, an anode 61 of an organic EL element is provided on the flattening insulating film 17. The anode 61 is separately formed in an island shape for each display pixel.

The organic EL element 60 has a general structure and includes an anode 61 made of a transparent electrode such as ITO (Indium Thin Oxide), MTDATA (4,4-bis (3-methylphenylph).
first hole transport layer composed of enylamino) biphenyl), TP
D (4,4,4-tris (3-methylphenylphenylamino) triphenyl
a hole transporting layer 62 comprising a second hole transporting layer comprising anine) and B containing a quinacridone derivative
luminescent layer 63 made of ebq2 (10-benzo [h] quinolinol-beryllium complex), electron transport layer 64 made of Bebq2, cathode 6 made of magnesium-indium alloy or aluminum, or aluminum alloy.
5 is a structure in which layers are formed in this order.

In the organic EL element 60, the holes injected from the anode 61 and the electrons injected from the cathode 65 are recombined inside the light emitting layer to excite the organic molecules forming the light emitting layer to generate excitons. Occurs. Light is emitted from the light emitting layer in the process of radiation deactivation of the excitons, and this light is emitted to the outside from the transparent anode 61 through the transparent insulating substrate.

The above-mentioned technique is disclosed in, for example, Japanese Patent Laid-Open No.
No. 283182.

Organic E used in the hole transport layer 62, the light emitting layer 63, and the electron transport layer 64 of the organic EL device 60 described above.
Since the L material has the characteristics of low solvent resistance and weakness to moisture, the photolithography technique in the semiconductor process cannot be used. Therefore, the hole transport layer 62, the light emitting layer 63, and the electron transport layer 64 of the organic EL element 60 are patterned by vapor deposition using a so-called shadow mask.

Problems of the pattern forming method by vapor deposition of the organic EL material will be described with reference to FIGS. 9 and 10. Reference numeral 100 is a vacuum vapor deposition apparatus, 101 is an exhaust system attached to the vacuum vapor deposition apparatus 100, 110 is a support stand installed in the chamber of the vacuum vapor deposition apparatus, and nickel (Ni) or Invar alloy (Fe ₆₄ N
A shadow mask (vapor deposition mask) 111 made of a magnetic material such as i ₃₆ ) is placed. A plurality of openings 112 are provided at predetermined positions on the shadow mask 111.

Then, the shadow mask 111 is brought into close contact with the glass substrate 130 by the magnet 120, and a pattern is formed by depositing a vapor deposition material from the vapor deposition source 140 on the surface of the glass substrate 130 through the opening 112 of the shadow mask 111. .

After the pattern formation by the vapor deposition is completed, the magnet 120 is moved upward to separate it from the glass substrate 130 as shown in FIG. 9, and the glass substrate 130 is shadowed as shown in FIG. Mask 111
Peel from. Then, the glass substrate 130 is transported to the next work position by a transport mechanism (not shown).

[0020]

However, as shown in FIG. 9, when the magnet 120 is peeled from the glass substrate 130, peeling charge occurs, and the glass substrate 130 is charged with, for example, positive static electricity. Therefore, the surface potential of the glass substrate 130 is in a high voltage state of several KV. Then, the TFT of the display pixel 115 formed on the glass substrate 130 is destroyed, or the threshold value Vth thereof fluctuates, for example, so that the display pixel 115 may be defective.

It is considered that such peeling charging also occurs when the glass substrate 130 is peeled from the shadow mask 111 as shown in FIG.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a vacuum vapor deposition method in which device destruction and characteristic variation due to peeling charging are prevented.

[0023]

According to the vacuum vapor deposition method of the present invention, an insulating substrate is inserted between a magnet and a vapor deposition mask made of a magnetic material in a vacuum vapor deposition apparatus, and the magnet is used to form the insulating substrate. A step of bringing the vapor deposition mask into close contact, a step of forming a pattern by vapor depositing a vapor deposition material from the vapor deposition source on the surface of the insulating substrate through an opening of the vapor deposition mask, and the insulating property after the pattern formation is completed. It is characterized by including a step of separating the substrate and the magnet from each other, and a step of irradiating the vacuum vapor deposition apparatus with ultraviolet rays.

According to the present invention, since a step of irradiating the vacuum vapor deposition apparatus with ultraviolet rays is newly provided, positively and negatively charged ions are generated in the vacuum vapor deposition apparatus by the ultraviolet ray irradiation, and the ions are charged. However, since it acts so as to neutralize the electric charge of the insulating substrate charged by the peeling charge, the insulating substrate is promptly diminished to prevent destruction of the device formed on the insulating substrate and characteristic fluctuation. be able to.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 6 are diagrams illustrating a vacuum vapor deposition method according to an embodiment of the present invention. 1 to 6, the same components as those in FIGS. 9 and 10 are designated by the same reference numerals.

First, in FIG. 1, 100 is a vacuum vapor deposition apparatus, 101 is an exhaust system attached to the vacuum vapor deposition apparatus 100,
Reference numeral 110 denotes a support table installed in the chamber of the vacuum vapor deposition apparatus. On the support table 110, a shadow mask (deposition mask) 111 made of a magnetic material such as nickel (Ni) or Invar alloy (Fe ₆₄ Ni ₃₆ ). Is placed. A plurality of openings 112 are provided at predetermined positions on the shadow mask 111. The opening 112 is provided at a position where the vapor deposition material is vapor deposited on the glass substrate 130.

A magnet 120 is vertically movably arranged on a shadow mask 111 placed on a support 110. Reference numeral 130 is a glass substrate called mother glass which is interposed between the magnet 120 and the shadow mask 111. This glass substrate 140 is already EL
A TFT that drives the element is formed. 140 is disposed below the shadow mask 111, and the shadow mask 1
11 is a vapor deposition source that can be moved in the left and right directions. Further, reference numeral 200 is an ultraviolet irradiation device provided alongside the vacuum vapor deposition device 100.

In FIG. 1, it is assumed that the inside of the chamber of the vacuum vapor deposition apparatus 100 is kept in a vacuum state by the exhaust system 101. Therefore, the glass substrate 130 is transferred to the magnet 120 and the shadow mask 11 by a transport mechanism (not shown).
It is inserted between 1. Then, as shown in FIG. 2, the glass substrate 130 is placed on the shadow mask 111 by the transport mechanism.

Next, as shown in FIG.
0 is moved downward to a position where it contacts the upper surface of the glass substrate 130. Then, the shadow mask 111 receives the magnetic force of the magnet 120 and is brought into close contact with the lower surface of the glass substrate 130, that is, the pattern forming surface.

Next, as shown in FIG. 4, the shadow mask 111 is moved while the vapor deposition source 140 is moved horizontally from the left end to the right end of the glass substrate 130 by a moving mechanism (not shown).
The organic EL material and the material of the cathode 65 (for example, aluminum) on the surface of the glass substrate 130 through the opening 112 of
Vapor deposition is performed. Here, the vapor deposition source 140 is composed of a crucible extending in a direction perpendicular to the paper surface of FIG. 1, and the vapor deposition material housed in the crucible is heated by a heater to be vaporized.

When the pattern formation by vapor deposition is completed, the magnet 120 is moved upward and separated from the glass substrate 130. At this time, for example, positive charge is generated on the glass substrate 130 due to peeling charging. Therefore, as shown in FIG. 5, ultraviolet rays are emitted from the ultraviolet ray irradiation device 200 into the chamber of the vacuum vapor deposition device 100. Then, the molecules remaining in the chamber are irradiated with ultraviolet rays to generate positive and negative ions.

The negative ions are attracted to the positive charges on the glass substrate 130, and the combined charges cancel each other's charges, whereby the glass substrate 130 is discharged. As a result, destruction of devices such as TFTs and characteristic fluctuations are prevented.

Here, the ultraviolet ray from the ultraviolet ray irradiating device 200 is radiated from the transparent portion which is provided on the wall of the chabber of the vacuum vapor deposition device 100 and which allows the ultraviolet ray to pass therethrough. However, the ultraviolet irradiation device 200 may be installed in the chamber.

Further, the degree of vacuum in the chamber during the ultraviolet irradiation is preferably from 10- ² ~10- ⁶ torr. The required slow electrification time is about 1 second or less. If the vacuum is lower than this range, the movement of ions due to the irradiation of ultraviolet rays becomes slow, and the time required for the slow discharge becomes long. Further, if the vacuum is higher than this range, the number of molecules that contribute to ionization decreases, and the slow electric charge time also increases.

Further, it is preferable that the ultraviolet irradiation is performed in the space between the glass substrate 130 and the magnet 120 moved upward. This is because the distance between the generation position of ions generated by ultraviolet irradiation and the glass substrate 130 is shortened, and the ions reach the glass substrate 130 promptly.

Next, as shown in FIG. 6, the glass substrate 13
0 is stripped from the shadow mask 111 by the transport mechanism and is transported to the work position of the next process. Also at this time, for example, a positive charge is generated on the glass substrate 130 due to the peeling charge. Therefore, similarly, the ultraviolet irradiation device 200
By irradiating the inside of the chamber of the vacuum vapor deposition device 100 with ultraviolet light, the glass substrate 130 is gradually discharged, and then the glass substrate 130 is transported to the carrying position of the next step.

Here, the UV irradiation is performed on the glass substrate 130.
Is preferably performed in a space between the shadow mask 111 and the shadow mask 111. This is because the distance between the generation position of ions generated by ultraviolet irradiation and the glass substrate 130 is shortened, and the ions reach the glass substrate 130 promptly.

Further, in the case where the ultraviolet irradiation is collectively performed, when the glass substrate 130 is peeled from the shadow mask 111 by the transport mechanism, the space between the glass substrate 130 and the shadow mask 111 and the magnet 120 are removed. It is considered preferable to irradiate each of the spaces with the glass substrate 130.

In the above-described embodiment, the case where the magnet 120 is moved and peeled from the glass substrate 130 after the pattern formation by vapor deposition has been described.
Similar effects can be obtained by irradiating ultraviolet rays after moving the glass substrate 130 to separate the magnet 120.

As shown in FIG. 6, the glass substrate 13
Although 0 is peeled from the shadow mask 111, the same effect can be obtained by irradiating ultraviolet rays after peeling the shadow mask 111 from the glass substrate 130.

[0041]

According to the vacuum vapor deposition method of the present invention, since a step of irradiating ultraviolet rays in the vacuum vapor deposition apparatus is newly provided, the insulating substrate on which the pattern is formed by vapor deposition is
It is possible to prevent the device formed on the insulative substrate from being destroyed or the characteristics thereof to be changed, as soon as the electricity is gradually reduced. In particular, by applying it to the manufacture of an organic EL display device, it is possible to contribute to the improvement of the yield and the quality of the display device.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a vacuum vapor deposition method according to an embodiment of the present invention.

FIG. 7 is a plan view of a conventional EL display device.

8 is a cross-sectional view taken along the line BB in FIG.

FIG. 9 is a diagram illustrating a vacuum vapor deposition method according to a conventional example.

FIG. 10 is a diagram illustrating a vacuum vapor deposition method according to a conventional example.

[Explanation of symbols]

100 vacuum deposition apparatus 110 exhaust system 111
Shadow mask 112 Opening 120 Magnet 130 Glass substrate 140 Deposition source 200 Ultraviolet irradiation device

Claims (4)

[Claims] 1. A step of inserting an insulating substrate between a magnet and a vapor deposition mask made of a magnetic material in a vacuum vapor deposition apparatus, and bringing the magnet into close contact with the insulating substrate and the vapor deposition mask. From the step of performing pattern formation by performing vapor deposition of a vapor deposition material on the surface of the insulating substrate through the opening of the vapor deposition mask, and a step of peeling the insulating substrate and the magnet from each other after the pattern formation is completed, And a step of irradiating the inside of the vacuum vapor deposition apparatus with ultraviolet rays. 2. The vacuum vapor deposition method according to claim 1, wherein in the step of irradiating the vacuum vapor deposition apparatus with ultraviolet light, the space between the insulating substrate and the magnet is irradiated with ultraviolet light. 3. A step of inserting an insulating substrate between a magnet and a vapor deposition mask made of a magnetic material in a vacuum vapor deposition apparatus, and bringing the magnet into close contact with the insulating substrate and the vapor deposition mask. From the step of performing pattern formation by performing vapor deposition of a vapor deposition material on the surface of the insulating substrate through the opening of the vapor deposition mask, and a step of peeling the insulating substrate and the magnet from each other after the pattern formation is completed, A vacuum vapor deposition method comprising: a step of separating the insulating substrate and the vapor deposition mask from each other; and a step of irradiating the vacuum vapor deposition apparatus with ultraviolet rays. 4. The step of irradiating ultraviolet rays into the vacuum vapor deposition apparatus irradiates ultraviolet rays to a space between the magnet and the insulating substrate or / and a space between the insulating substrate and the vapor deposition mask. A vacuum vapor deposition method characterized by the above.