JP2000034558A - Evaporating source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporating source capable of charging a large quantity of evaporating material, suitable for a film forming device for production and moreover excellent in the control of the amt. to be evaporated by a high vapor pressure material such as an organic material or the like. SOLUTION: This source has a resistance heating vessel 11 composed of a planar resistor 12 and an upper cover resistor 13, the electric current controlled by a detected signal from a crystal oscillator type film thickness instrument is made to flow to each resistor to generate heat, by which an evaporating material 16 is evaporated, and the evaporated particles are released from a blow-off hole 17 disposed on the resistance heating vessel, moreover, the resistance heating vessel is provided with a material vessel 15 large in volume, this material vessel is filled with a large quantity of evaporating material 16, and, a part of the charged evaporating material is brought into contact with the planar resistor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporation source, and more particularly, to a resistance heating device suitable for a production apparatus, which is used in a film forming apparatus for forming a thin film on a substrate by evaporating a material having a high vapor pressure in a vacuum vessel. It relates to an evaporation source applying the principle.

[0002]

2. Description of the Related Art A conventional evaporation source used in a film forming apparatus (evaporation apparatus) for forming a film on a substrate by evaporating a material having a high vapor pressure (such as an organic substance for organic EL) is a resistance heating using a resistor. Evaporation sources and cell-type evaporation sources with a heating wire wound around a crucible are roughly classified. A conventional resistance heating evaporation source and a cell type evaporation source will be described with reference to the drawings.

FIG. 6 shows a typical configuration of a resistance heating evaporation source. As shown in FIG. 6, a vacuum vessel 7 for forming a film forming apparatus
1, a resistance heating evaporation source 72 is provided at a lower position,
A substrate 74 supported by the holder 73 is disposed at an upper position. The holder 73 has a ring shape, and the lower surface of the substrate 74 faces downward, and a high vapor pressure material that evaporates and arrives from below is formed on the lower surface. In the vicinity of the substrate 74, a detector 76 of a quartz oscillator type film thickness meter 75 for outputting a detection signal for controlling the amount of evaporation of the material in the resistance heating evaporation source 72.
Is arranged. Evaporated particles emitted from the resistance heating evaporation source 72 as indicated by an arrow 77 adhere to the detector 76 of the film thickness meter 75 in addition to the lower surface of the substrate 74. Resistance heating evaporation source 72
Are the lower boat-shaped resistor 78 and the upper lid-shaped resistor 7
9 and a plate-shaped resistor 80 interposed therebetween, the three resistors are overlapped as shown in the figure, and both ends are sandwiched and fixed between the electrode portions 81 and 82. The boat-shaped resistor 78 functions as a container for filling the evaporation material 83. In the lid-shaped resistor 79 and the plate-shaped resistor 80, blowout holes 79a, 80a through which the evaporated particles of the evaporation material 83 pass.
Are formed. Each resistor 7 of the resistance heating evaporation source 72
Current is supplied to the power supply 8, 79, 80 from the power supply 84 via the electrode portions 81, 82, and the resistor generates heat. The amount of current supplied from the power supply 84 is controlled based on a detection signal from the film thickness meter 75. When the resistors 78, 79, and 80 generate heat, the evaporation material 83 filled in the boat-shaped resistor 78 starts to evaporate at a temperature unique to the material. The evaporating particles of the evaporating material 83 are blown out from the blowing holes 80a, 7
It is discharged to the space around the resistance heating evaporation source 72 through 9a. The evaporating particles thus emitted are deposited on the lower surface of the substrate 74 and the lower surface of the detector 76 as described above. The quartz-crystal vibrating tonometer 75 is a device that controls the amount of evaporation by utilizing the fact that the oscillation frequency changes when the evaporated particles adhere to the detector 76. The film thickness meter 75 sends a signal to the power supply 84 via a signal cable so as to obtain a desired evaporation amount while monitoring the amount of the evaporated particles attached to the detector 76, and changes the output of the power supply 84 to change the resistance. Body 78 ~
The amount of heat generated by the evaporating material 83 is controlled by changing the amount of heat generated by the evaporator 80.

Next, FIG. 7 shows a typical configuration of a cell type evaporation source. In FIG. 7, elements substantially the same as the elements described in FIG. 6 are denoted by the same reference numerals. As shown in FIG. 7, in a vacuum vessel 71 forming a film forming apparatus, a cell type evaporation source 85 is provided at a lower position, and a substrate 74 supported by a holder 73 is arranged at an upper position. Holder 73
The lower surface of the substrate 74 faces downward through the substrate, and a high vapor pressure material that evaporates and arrives from below is formed on the lower surface. The cell-type evaporation source 85 is composed of a crucible 86 and a heating wire 87 wound around the lower part of the crucible 86. When a current is passed from the power supply 88 to the heating wire 87, the heating wire 87 generates heat. By raising the temperature of the material 86, the material 83 filled in the crucible 86 starts to evaporate at a material-specific temperature. When the material of the crucible 86 is made of a substance that easily transmits infrared wavelengths, such as quartz, the material 83 is directly heated by radiant heat from the heating wire 87. The evaporating particles are emitted from the opening 86a of the crucible 86 into the space around the evaporation source as indicated by an arrow 89. Part of the released evaporating particles reaches the surface of the substrate 74. The evaporation amount is controlled by monitoring the crucible temperature with a temperature controller 90 using a thermocouple installed outside the crucible 86 and changing the output of the power supply 88.

[0005]

The conventional resistance heating evaporation source has a small heat capacity of the resistor, a good response to a change in the temperature of the material with respect to a change in the current value of the resistor, and an excellent controllability of the evaporation amount. I have. On the other hand, from the viewpoint of exhibiting such features, since the form of the boat-shaped resistor 78 for filling the evaporating material is determined, a large amount of evaporating material cannot be filled, and it is difficult to evaporate for a long time. It has the disadvantage of not being suitable for devices.

On the other hand, the conventional cell-type evaporation source has a feature that it is suitable for a production apparatus because it can structurally fill a large amount of evaporation material. However, due to the large amount of evaporating material, the heat capacity is large, and the evaporation of the material is controlled by heat radiation from the outside of the crucible. And it is difficult to control at a particularly high evaporation rate. Further, since the temperature change of the outer peripheral portion of the crucible 86 is monitored, there is a drawback that the temperature of the material is different and the evaporation amount is different with the change of the amount of the material in the crucible.

At present, a cell type is mainly used as an evaporation source from the viewpoint of a filling amount of a material suitable for a production apparatus.
However, because of the above-mentioned drawbacks, an evaporation source with higher controllability of the evaporation rate is desired.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is possible to fill a large amount of evaporating material, so that it is suitable for a film forming apparatus for production. To provide an evaporation source.

[0009]

The evaporation source according to the present invention is constituted as follows to achieve the above object. The first evaporation source (corresponding to claim 1) has a resistance heating container formed of a resistor, and causes a current controlled by a detection signal from a quartz oscillator type film thickness meter to flow through the resistor to generate heat. It is configured to evaporate the evaporating material and discharge the evaporating particles from the blowing holes provided in the resistance heating container, and further provide a large-capacity material container in the resistance heating container, and fill the material container with a large amount of the evaporating material, And it is comprised so that a part of filled evaporation material may contact the said resistor. The evaporation source according to the present invention can evaporate a large amount of evaporation material by providing a large-capacity material container based on the configuration of the resistance heating type evaporation source, and has a configuration suitable as a production device. Further, when a large amount of evaporating material filled in the material container goes out of the material container, a part of the material comes into contact with the resistor and causes partial evaporation. This makes it possible to evaporate a large amount of evaporating material without bias.
Further, since the structure of the resistance heating evaporation source is used, it is possible to perform high control on the evaporation amount. In the second evaporation source (corresponding to claim 2), in the first configuration, the resistance heating container includes a plate-shaped resistor and an upper lid resistor, and the upper lid resistor includes a material container and forms a blowing hole. Then, the lower opening of the material container is provided close to the plate-shaped resistor. The material container filled with the evaporating material is arranged upside down, and the opening of the material container is located at the lower part and is provided close to the plate-shaped resistor. The evaporative material in the material container moves downward, and the evaporative material located at the lowest position contacts the plate-shaped resistor. In a third evaporation source (corresponding to claim 3), in the first configuration, the resistance heating container includes an upper lid resistor having a material container, a boat-shaped resistor having a blowing hole, and an upper lid resistor. It is provided with a plate-shaped resistor provided between the boat-shaped resistors and having a passage hole for evaporating particles. The lower opening of the material container is provided close to the plate-shaped resistor.
According to this configuration, an evaporation source having a depot-down structure suitable for a production apparatus is provided, including a material container capable of filling a large amount of evaporation material. In a fourth evaporation source (corresponding to claim 4), in the first configuration, the resistance heating container has an upper lid resistor having a blowing hole, a boat-shaped resistor having a material container,
Consisting of a plate-shaped resistor provided between the upper lid resistor and the boat-shaped resistor and having a passage hole for evaporating particles, the upper opening of the material container is provided close to the plate-shaped resistor, and the material container has
A heating wire is provided to generate heat with a current controlled by a detection signal from the temperature controller to evaporate the evaporation material. This evaporation source combines a resistance heating structure and a cell type structure, prepares a large amount of evaporation material, is suitable for a production apparatus, and can enhance the control of the evaporation amount of the evaporation material. The fifth evaporation source (corresponding to claim 5) may be configured such that:
The material container is preferably a crucible having insulation properties.

[0010]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 3 show a first embodiment of an evaporation source according to the present invention. FIG. 1 shows the external appearance of the container portion viewed obliquely from above, FIG. 2 shows the internal structure, and FIG. 3 shows a cross-sectional view taken along line AA in FIG. The evaporation source according to this embodiment has a configuration in which a resistance heating evaporation source is applied. The evaporation source container 11 includes a plate-shaped resistor 12 forming a bottom,
This is a resistance heating container composed of the upper lid resistor 13.
In the plate-like resistor 12, a partition wall 14 is formed at the center. The upper lid resistor 13 has the same form as the lid resistor of the conventional resistance heating evaporation source, and is provided with an elongated material container 15 in an upright posture on one side in the longitudinal direction. I have. The plate-shaped resistor 12 and the upper lid resistor 13 are made of a high melting point metal (tungsten, molybdenum or the like) that generates heat when an electric current is applied, and the material container 15 is made of, for example, quartz having an insulating property. Material container 1 as shown in FIG.
The upper end of 5 is closed and the lower end is open. The opening at the lower end is used as a port for filling the material container 15 with the evaporating material 16 and as a port for taking out the evaporating material 16 when evaporating. The plate-shaped resistor 12 and the upper cover resistor 13 are used by being overlapped as shown in FIG.
The container 11 is formed. The material container 15 provided in the upper lid resistor 13 has an opening at the lower end thereof close to the plate-shaped resistor 12, and a desired gap is formed when they are overlapped. The length of the material container 15 is determined according to the amount of the evaporating material 16 to be filled. When the plate resistor 12 and the upper lid resistor 13 are overlapped to form the evaporation source container 11, the material container 15
The second partition wall 14 is configured to be located on one side (the left side in FIG. 2). In addition, the upper lid resistor 13 is provided at a portion opposite to the material container 15 with the partition wall 14 as a boundary,
For example, one blowout hole 17 for discharging particles evaporated from the evaporation material 16 to the space around the container 11 is formed. Partition wall 14 of plate-shaped resistor 12 and upper lid resistor 1
3, a gap 18 is formed. Evaporated particles are
It moves as indicated by the arrow 19 and is discharged from the blowout hole 17. The reason why the partition plate 14 is provided is that the conductance of the passage of the evaporated particles is reduced to provide a pressure gradient. When a pressure gradient is applied, the diffusion of the evaporated particles becomes remarkable.

As shown in FIG. 2, both ends of the superposed plate-shaped resistor 12 and upper cover resistor 13 are superposed and fixed by the electrode portions 20 and 21. Electrode part 2
Reference numerals 0 and 21 each have a structure in which two plate members are stacked and fixed with screws or the like, thereby sandwiching and fixing the both ends.
As shown in the figure, the plate-shaped resistor 12 and the upper lid resistor 13 are held in a state where their respective peripheral portions are in contact with each other.
Both are kept closed so that the evaporating material 16 that melts and evaporates on the two does not leak outside. In order to create this closed state, it is also preferable to provide a folded portion at the edge of the plate-shaped resistor 12 or the upper lid resistor 13.

The evaporation source having the above configuration is used in an apparatus similar to the conventional film forming apparatus described with reference to FIG. That is, current is supplied from the power source 22 to the plate-shaped resistor 12 and the upper lid resistor 13 of the evaporation source via the electrode portions 20 and 21. When an electric current flows through the plate-shaped resistor 12 and the upper lid resistor 13, the lowermost portion of the evaporated material 16 in contact with the plate-shaped resistor 12 melts out of the large amount of the evaporated material 16 filled in the material container 15. And evaporate. The evaporated particles move as indicated by an arrow 19, and are discharged from the outlet 17 into the surrounding space. The evaporating particles released from the blowing hole 17 of the upper lid resistor 13 of the container 11 rise and adhere to the lower surface of the substrate 74 as shown in FIG. The control of the amount of evaporation of the evaporation material 16 in the evaporation source is the same as in the prior art, and is controlled by adjusting the amount of current flowing through the resistor based on the detection signal from the crystal unit thin film meter. According to the evaporation source according to the present embodiment, it is possible to fill a large amount of evaporation material, and it is configured to gradually evaporate from the lower evaporation material. It can be used, can appropriately control the amount of evaporation, and can perform evaporation with low power.

In the above embodiment, it is also possible to provide a structure in which the upper part of the material container 15 is opened and the evaporation material 16 can be supplied appropriately.

Referring to FIG. 4, the second embodiment of the evaporation source according to the present invention will be described.
An embodiment will be described. This embodiment is a modification of the first embodiment, and FIG. 4 is a view corresponding to FIG. The evaporation source according to this embodiment has a deposit down structure that emits evaporation particles downward. In FIG. 4, the same elements as those described in the above embodiment are denoted by the same reference numerals. An evaporation source container (resistance heating container) 31 includes an upper lid resistor 32, a boat-shaped resistor 33 forming a lower portion of the container, and a plate-shaped resistor 34 located in the middle.
It is composed of The basic forms of the upper lid resistor 32 and the plate-shaped resistor 34 are similar to those of the first embodiment. The basic configuration of the boat-shaped resistor 33 is similar to that of the prior art.
The upper lid resistor 32 is provided with the aforementioned material container 15 at a substantially central position thereof. At least two holes 35 are formed on both sides of the plate-shaped resistor 34 as passages for evaporated particles. At least one blowout hole 36 is formed substantially at the center of the boat-shaped resistor 33. The point that the material container 15 is filled with a large amount of the evaporation material 16
This is the same as the first embodiment in that a part of the solvent evaporates from the lower part. Other configurations are the same as those described in the first embodiment.

According to the present embodiment, a resistance heating evaporation source having a deposit down structure can be realized, and further, the same effect as that of the first embodiment can be exerted. That is, a large amount of evaporating material can be filled, continuous film formation can be performed for a long time, and it can be used for a production apparatus, and the amount of evaporation can be appropriately controlled.

The structures according to the first and second embodiments are particularly effective for sublimable substances such as organic materials. Also, by adjusting the gap between the material container 15 and the plate-shaped resistor 12 or the gap between the material container 15 and the plate-shaped resistor 34, the same can be achieved without flowing out even in the molten material 16 due to the effect of surface tension. The effect is obtained.

Next, a third embodiment of the evaporation source according to the present invention will be described with reference to FIG. The evaporation source according to this embodiment is configured by combining the structure of the resistance heating evaporation source and the structure of the cell type evaporation source. FIG. 5 shows the configuration of an evaporation source and the configuration of a system for controlling evaporation. In FIG. 5, the same reference numerals are given to substantially the same elements as those described in the above-described embodiments.

In a vacuum vessel 41 forming a film forming apparatus, an evaporation source 42 according to the present embodiment is provided at a lower position, and a substrate 44 supported by a ring-shaped holder 43 is disposed at an upper position. The lower surface of the substrate 44 on the holder 43 faces downward, and a high vapor pressure material is formed on the lower surface. In the vicinity of the substrate 44, a detector 46 of a quartz oscillator type film thickness meter 45 that outputs a detection signal for controlling the amount of evaporation of the material in the evaporation source 42 is arranged. Evaporated particles emitted from the evaporation source 42 adhere to the lower surface of the substrate 44 and the detection surface of the detector 46.

The resistance heating vessel of the evaporation source 42 includes an upper lid resistor 47, a lower boat-shaped resistor 48, and a plate-shaped resistor 49 interposed therebetween. The bodies are overlapped as shown in the figure, and both ends are sandwiched and fixed between the above-mentioned electrode portions 20 and 21. The boat-shaped resistor 48 is provided with a material container 15 in which a large amount of the evaporating material 16 can be filled at a substantially central position. The material container 15 is used such that the opening is located on the upper side. In addition, the upper cover resistor 47 and the plate-shaped resistor 49 are formed with blowout holes 50 and 51 through which evaporated particles from the evaporation material 16 pass.
A current is supplied from the power source 52 to the resistors 47, 48, and 49 of the evaporation source 42 via the electrode portions 20 and 21 to generate heat. The amount of current supplied from the power supply 52 is
Is controlled based on the detection signal from Each resistor 47, 4
8 and 49 are assembled as shown in FIG.
A desired gap is formed between the upper end opening of the fifth resistor 5 and the plate-shaped resistor 49.

The material container 15 contains the required evaporating material 1.
6 has a sufficient capacity to accommodate 6 and is made of, for example, quartz. A configuration of a cell type evaporation source is further added to the configuration related to the material container 15. That is, the material container 15
Functions as a crucible, and a heating wire 53 is wound thereunder. The heating wire 53 is connected to a power source 54,
When the current flows through the heating wire 53, the heating wire 53 generates heat, and the radiant heat raises the temperature of the material container 15 so that the evaporating material 16 filled in the material container 15 evaporates at a temperature unique to the material. . Further, since the material container 15 is made of quartz that easily transmits infrared wavelengths, the evaporating material 16 is directly heated by radiant heat from the heating wire 53. The evaporating particles are emitted from the upper end opening of the material container 15. The amount of evaporation from the material container 15 is controlled by monitoring the temperature with a temperature controller 55 using a thermocouple installed outside the material container 15 and controlling the power supply 5.
4 is changed.

Further, the evaporated particles released from the upper end opening of the material container 15 are, as indicated by an arrow 56, a plate-like resistor 49.
Through the air outlet 51 of the upper cover resistor 47 and the air outlet 50 of the upper lid resistor 47. At this time, the resistors 47, 48, and 49 are in a heating state. The evaporating particles thus released are deposited on the lower surface of the substrate 44 and the detection surface of the detector 46 of the film thickness gauge 45 as described above. The crystal oscillator type film pressure gauge 45 controls the amount of evaporation by utilizing the fact that the oscillation frequency changes when the evaporated particles adhere to the detector 46. The film thickness meter 45 sends a signal to the power supply 52 so as to obtain a desired evaporation amount while monitoring the amount of the evaporated particles attached to the detector 46, and changes the output of the power supply 52 to change the resistors 47 and 48. , 49 to control the amount of evaporation of the evaporation material 16.

According to the third embodiment, the material container 1
The evaporating material 16 filled in 5 starts to evaporate at its own temperature based on the heat generating action of the heat generating wire 53. The evaporating particles from the evaporating material 16 adhere to the surfaces of the boat-shaped resistor 48 and the plate-shaped resistor 49 on the upper side of the material container 15, but receive the heat from these resistors and evaporate again. It moves like this and is discharged from the outlet hole 50 of the upper lid resistor 47 to the outside space. The released evaporating particles adhere to the substrate 44 and the detector 46. The crystal oscillator type film pressure gauge 45 sends a signal to the power supply 52 based on the obtained information and changes the output to change the amount of heat generated by the resistors 47, 48 and 49 and control the amount of evaporation. Since the amount of evaporation is controlled by a temperature change caused by passing a current directly to the resistor, the responsiveness to a change in the evaporation rate is good, and the material container 15 can be filled with a large amount of material. Suitable for.

[0024]

As is apparent from the above description, according to the present invention, when a resistance heating container comprising a resistor and a material container capable of filling a large amount of evaporating material are combined, and the evaporating material is evaporated, Since the evaporating material in the portion is configured to be in contact with the resistor, the evaporating material can be stably evaporated for a long time, and the amount of evaporation can be effectively controlled. Therefore, an evaporation source suitable for a production device can be realized. Further, an evaporation source having a deposit-down structure can be obtained.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of an evaporation source according to the present invention, and is an external view of a container portion viewed obliquely from above.

FIG. 2 is a longitudinal sectional view showing the internal structure of the evaporation source according to the first embodiment.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a longitudinal sectional view showing an internal structure of an evaporation source according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing the entire structure and apparatus of an evaporation source according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a conventional resistance heating evaporation source.

FIG. 7 is a configuration diagram of a conventional cell-type evaporation source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Container (resistance heating container) 12 Plate-shaped resistor 13 Upper resistor 15 Material container 16 Evaporation material 17 Blow-out hole 20, 21 Electrode part 31 Container (resistance heating container) 32 Upper lid resistor 33 Boat-shaped resistor 34 Plate-shaped resistor Body 41 Vacuum container 42 Evaporation source 44 Substrate 46 Detector 47 Upper lid resistor 48 Boat resistor 49 Plate resistor 53 Heating wire

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takayuki Moriwaki 5-8-1, Yotsuya, Fuchu-shi, Tokyo Anelva Corporation F-term (reference) 4K029 DB12 DB13 DB18

Claims (5)

[Claims] 1. A resistance heating container comprising a resistor, wherein a current controlled by a detection signal from a film thickness meter is passed through the resistor to generate heat and evaporate an evaporation material. In the evaporation source that emits evaporation particles from the blowing holes, a large-capacity material container is provided in the resistance heating container, a large amount of the evaporation material is filled in the material container, and a part of the filled evaporation material is the An evaporation source characterized by contacting a resistor. 2. The resistance heating container comprises a plate-shaped resistor and an upper-lid resistor, the upper-lid resistor being provided with the material container and forming the blowout hole, and a lower opening of the material container being formed in the plate-shaped resistor. 2. The evaporation source according to claim 1, wherein the evaporation source is provided close to the resistor. 3. The resistance heating container is provided with an upper lid resistor provided with the material container, a boat-shaped resistor having the blowout hole, and provided between the upper lid resistor and the boat-shaped resistor. The evaporation source according to claim 1, comprising a plate-shaped resistor having a hole for passing particles, wherein a lower opening of the material container is provided close to the plate-shaped resistor. 4. The resistance heating container includes an upper lid resistor having the blowout hole, a boat-shaped resistor provided with the material container, and the evaporator provided between the upper lid resistor and the boat-shaped resistor. A plate-shaped resistor having a passage hole for particles, an upper opening of the material container provided close to the plate-shaped resistor, and a current controlled by a detection signal from a temperature controller in the material container. 2. The evaporation source according to claim 1, further comprising: a heating wire for generating heat by evaporating the evaporation material. 5. The evaporation source according to claim 1, wherein the material container is a crucible having an insulating property.