JP2018154904A - Film deposition method, production method of organic electronic device, and film deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition method and the like capable of further reducing a time for film deposition.SOLUTION: A film is deposited on a substrate using a vapor deposition apparatus and an organic raw material in a film deposition method. The method includes a supply step for supplying the organic material of an amount to be used for film deposition to a heating unit of the vapor deposition apparatus and a total-amount vaporization step for heating and vaporizing a total amount of the organic material supplied in the supply step to deposit a film on the substrate. Because the total amount of the raw material supplied to the heating unit is vaporized for film deposition, a time for stabilizing a rate is not required. Further, a process for carefully measuring a time corresponding to a target film thickness through monitoring is not required. Time reduction in film deposition brings about a long-life organic device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film forming method, a method for producing an organic electronic device, and a film forming apparatus, and more particularly to a film forming method for forming a film on a substrate using an organic substance as a material and using a vapor deposition apparatus.

  The inventor of the present application has developed a film forming method and the like for forming a film state having better thermal response than heating of the powder in order to shorten the time for stabilizing the rate when forming the film using the vapor deposition apparatus. (See Patent Document 1).

  Furthermore, the inventors of the present application have obtained knowledge that the durability time of the organic device tends to be increased by reducing the time required for film formation (see Non-Patent Document 1).

International Publication No. 2011/071064

Hiroshi Fujimoto, 7 others, “Influence of vacuum chamber impurities on the lifetime of organic light-emitting diodes”, SCIENTIFIC REPORTS, 6, 38482, 2016

  However, the conventional method leaves room for shortening the time required for film formation.

  Accordingly, an object of the present invention is to provide a film forming method and the like that can further reduce the time required for film formation.

  A first aspect of the present invention is a film forming method for forming a film on a substrate using an organic material as a material using a vapor deposition apparatus, and supplying the organic substance in an amount used for film formation to a heating unit provided in the vapor deposition apparatus A film forming method comprising: a step; and a total amount vaporizing step of vaporizing the entire amount of the organic substance supplied in the supplying step by heating to form a film on the substrate.

  A second aspect of the present invention is the film forming method according to the first aspect, wherein, in the supplying step, the organic substance is supplied to the heating unit in a film-formed state.

  A third aspect of the present invention is the film forming method according to the second aspect, further including a dissolving step of dissolving the organic substance in a solvent before the supplying step.

  A fourth aspect of the present invention is the film forming method according to the third aspect, further comprising a pre-vaporization film forming step in which the organic solution is heated to form a film between the dissolving step and the supplying step. In addition, in the film formation step before vaporization, the film is formed by heating at a temperature not lower than the boiling point of the solvent and not higher than the evaporation temperature of the organic matter.

  According to a fifth aspect of the present invention, there is provided a film forming method according to any one of the second to fourth aspects, wherein, in the supplying step, the organic substance is formed on the wound sheet in a state of being formed into a wound sheet. Supplied while being sent out.

  According to a sixth aspect of the present invention, there is provided a film forming method according to the fifth aspect, wherein the substrate is formed into a sheet shape, and in the supplying step, the wound sheet is moved to the heating unit. The movement of the substrate is controlled to interlock.

  A seventh aspect of the present invention is a method for producing an organic electronic device including a film forming step of forming a film by the film forming method according to any one of the first to sixth aspects.

  An eighth aspect of the present invention is a film forming apparatus for forming a film on a substrate by vapor deposition using an organic substance as a material, a material holding part for holding the organic substance, a heating source for heating the material holding part, and the substrate And a substrate holding unit for holding the film.

  According to a ninth aspect of the present invention, there is provided the film forming apparatus according to the eighth aspect, wherein the material holding portion is in a sheet shape, and the material is fed out from the sheet-like material holding portion toward the heating source. A sheet feeding unit is further provided.

  According to a tenth aspect of the present invention, there is provided the film forming apparatus according to the ninth aspect, wherein the substrate is in a sheet shape, a substrate feeding portion that feeds the sheet-shaped substrate, the material sheet feeding portion, and The apparatus further includes a feed control unit that controls the substrate feed unit so that the material holding unit and the substrate are interlocked.

  An eleventh aspect of the present invention is a heating device used in a film forming apparatus for forming a film on a substrate by vapor deposition using an organic material as a material, the material holding unit holding the organic material, and heating for heating the material holding unit Source.

  A twelfth aspect of the present invention is a method for producing an organic thin film from an organic solution, a film forming step of developing the solution to form a film, a boiling point of the solvent of the solution or more, and the organic material A heating step of heating at a temperature below the evaporation temperature is included.

  A thirteenth aspect of the present invention is a material sheet manufacturing apparatus for forming an organic thin film from an organic solution.

  According to each aspect of the present invention, since the entire amount of the material supplied to the heating unit is formed by vapor deposition, time for stabilizing the rate becomes unnecessary. In addition, a process for forming a film while carefully measuring the time corresponding to the desired film thickness while looking at the monitor becomes unnecessary. Therefore, it is possible to further reduce the time required for film formation and supply a long-life organic device.

  According to the 2nd viewpoint of this invention, since it supplies to a heating part in the state formed into a film with good thermal responsiveness, it becomes still easier to shorten heating time. Unlike the conventional method described in Patent Document 1, it is not necessary to adjust the rate, and this effect is even more remarkable.

  According to the 3rd viewpoint of this invention, it becomes easy to adjust the quantity of the material used for film forming precisely rather than adjusting the quantity of organic substance with powder.

  Generally, in the vapor deposition process, the solvent is an impurity. For this reason, it is considered that dissolving the powder material in the solution before vapor deposition would increase the impurities and cause the device to deteriorate, which has been a hindrance factor.

  In this respect, the present invention is characterized as a novel technical idea in that importance is placed on the precision of quantitative determination of the material in order to vaporize the entire amount of the organic material accommodated in the heating unit to obtain a desired film.

  Furthermore, according to the fourth aspect of the present invention, by evaporating the solvent at a high temperature in the pre-vaporization film-forming step before vapor deposition, the solvent that becomes an impurity is maintained while maintaining a precisely adjusted amount of the organic material. It becomes easy to remove. For this reason, it becomes easier to supply a long-life organic device.

  Furthermore, according to the fifth and ninth aspects of the present invention, it is possible to continuously supply an organic material having a good thermal response in a film state to the heating unit. Therefore, it becomes easy to form a film including a thick film in a short time.

  Furthermore, according to the sixth and tenth aspects of the present invention, the sheet on which the organic material is formed and the sheet-like substrate can be interlocked, and the film is formed in a short time by vacuum deposition over a large area. Easy to do.

  Furthermore, according to the 12th viewpoint of this invention, it becomes easy to produce the material sheet which does not contain much the solvent used as an impurity. Conventionally, vaporizing a solvent at a high temperature before using a film formed by a wet process as a functional film has been avoided because the film is roughened. That is, there was an inhibiting factor in removing the solvent at a temperature higher than the glass transition temperature after film formation from the solution. In the present invention, since the film is formed before heating with a vapor deposition apparatus, the roughness of the film surface is not a problem at all, and the solvent can be evaporated at a temperature higher than the glass transition temperature of the organic material and lower than the evaporation temperature. In this respect, it can be said that this is a method for producing a novel organic thin film for the film forming method according to the present invention.

It is a flowchart which shows an example of the vapor deposition method which concerns on a present Example. It is a figure which shows the example of a part of crucible type vapor deposition apparatus of Example 1. FIG. It is a figure which shows an example of the high-speed vapor deposition using the roller type vapor deposition apparatus of Example 2. FIG.

  The film forming apparatus of this example forms an organic material by vapor deposition. The film forming apparatus includes a material holding unit, a heating source, a substrate holding unit, a material sheet feeding unit, a substrate feeding unit, and a feeding control unit.

  The material holding unit has a sheet shape and holds an organic material to be formed. The heating source heats the organic material held in the material holding unit. The substrate holding unit holds a substrate on which an organic material is formed by vapor deposition. The material sheet feeding unit feeds the sheet-shaped material holding unit toward the heating source. The substrate feeding unit feeds a sheet-like substrate. The feed control unit controls the feed speed of the material sheet feed unit and the substrate feed unit.

  In FIG. 1, in step S01, an organic material to be deposited is dissolved in a solvent to prepare a solution controlled at a constant concentration. In step S <b> 02, the organic material solution adjusted in step S <b> 01 is formed on the sheet-like material holding unit 3 so that a sufficient amount of organic material necessary for vapor deposition adheres to the material holding unit 3. The film forming method at this time may be a spin coating method or an ink jet method as long as a necessary and sufficient amount is formed, and may be another coating method. It is necessary to determine in advance how much coating is necessary and sufficient. In step S03, unnecessary solvent is evaporated by drying. At this time, the solvent component is evaporated as much as possible at the glass transition temperature or more and the evaporation temperature or less of the organic material. In step S04, the heating source 5 heats and deposits the entire film formed on the substrate. During this time, the feed control unit 13 controls the feed speeds of the material sheet feed unit 9 and the substrate feed unit 11 so that the film thickness on the substrate becomes a predetermined film thickness. When the entire amount deposited on the material holding unit 3 is deposited, the flow is finished.

  In the crucible type vapor deposition apparatus 21 shown in FIG. 2, the crucible 23 includes a lid 25 having a hole and an organic material 27. An organic material evaporated from the crucible 23 heated by a heating unit (not shown) is deposited on the substrate 29 to form a film. The rate sensor 31 measures the deposition rate for confirmation. As the substrate rotates, the elements installed at the same distance from the rotation shaft 33 are formed with the same film thickness. Height hp from crucible upper end 35 to substrate 29, distance dp from rotation axis 33 of substrate 29 to center axis 37 of crucible 23, height hs from crucible upper end 35 to rate sensor 31, rate sensor 31 to center axis 37 The distance ds to is appropriately designed.

  Here, when filling a pot-like crucible with a material and evaporating it, the amount of material filling and the way of flying the evaporated molecules change depending on the material bias. bad. Therefore, it is possible to reproduce even if the amount of material and the bias of the material in the crucible are different by providing a nozzle etc. on the crucible so that the molecules do not fly directly to the substrate but hit the nozzle and then fly to the substrate. A film can be formed. This is because in the case of a molecular flow region in which the mean free path is longer than 1/3 of the size of the container, such that the vaporized molecules collide with the walls in the crucible before colliding with each other, the molecules after colliding with the walls This is because the way of flying flies in the direction of the probability according to the cosine law, and the way the molecules fly from the nozzle to the substrate always has the same shape. However, even when such a nozzle is provided, if the vapor deposition rate becomes too high, molecules that have evaporated before colliding with the wall of the evaporation source collide (intermediate flow region, viscous flow region). Changes the film thickness and film thickness distribution depending on the rate. For this reason, it is necessary to calculate the conductance and mean free path from the deposition rate, the amount of evaporation of the material from the crucible, the temperature, the molecular weight of the material, the nozzle shape, etc., and design the nozzle so as to be in the molecular flow region. .

  FIG. 3 is a diagram showing an example of high-speed vapor deposition using a roller-type film forming apparatus 41. The film forming apparatus 41 includes a material holding unit 43, a material sheet feeding unit, a roller 45, a substrate 49, a substrate feeding unit, and a feeding control unit. The material holding unit 43 is a sheet-like substrate having an organic film 47 that is a formed organic material on the surface. The material sheet feeding unit feeds the material holding 43 toward the heated roller 45. The material holding unit 43 and the roller 45 are made of metal at least on the surface, and can efficiently transfer heat to the organic film 47. A portion of the material holding portion 43 that is in contact with the roller 45 is separated from the substrate 49 by about 100 mm. The organic material 47 heated by the roller 45 is formed as an organic film 51 on the substrate 49.

  In the present embodiment, a material holding unit holding at least two kinds of materials was prepared. According to the film forming method according to the present embodiment, since the entire amount is deposited, the organic material is not excessively evaporated. For this reason, it becomes possible to deposit at high temperature and high speed. As the deposition rate, the film can be formed at 1 to 5 nm / second, which is 20 times or more high-speed deposition. For example, even a five-layer organic thin film can be formed within 5 minutes. In addition, although the vapor deposition rate was described for reference, a waiting time for stabilizing the rate is unnecessary. Moreover, it is not necessary to deposit at low speed for stabilization. These also contribute to the high speed of the vapor deposition method according to the present embodiment.

  Moreover, since the entire amount is deposited, it is possible to suppress the organic material from remaining in the film forming apparatus, particularly in the material holding portion. As a result, it is possible to minimize the risk that the organic material used during the previous vapor deposition is mixed in the film forming apparatus.

  Further, the feed control unit can sufficiently form a film even if the substrate feed unit is fed at 100 mm / second. This is a speed 5 times or more that of the prior art, and remarkably improves the production speed of the organic thin film.

  The material sheet feeding unit may be formed by rolling a plate-shaped or flexible film-shaped material holding unit in a roll shape.

  Moreover, the structure which hold | maintains an organic material in the state by which the organic material was apply | coated and formed into the inner side of a crucible instead of a sheet-like board | substrate may be sufficient as a material holding | maintenance part. Alternatively, the shape of the material holding portion is not limited as long as the organic material can be held in a film-formed state such as on a block or in a groove instead of a crucible.

  21; Film forming apparatus, 23; Crucible, 25; Lid, 27; Organic material, 29; Substrate, 31; Rate sensor, 41; Film forming apparatus, 43; Material holder, 45; Roller, 47; Substrate, 51; organic film

Claims (4)

A film forming method for forming a film on a substrate using an organic material as a material using a vapor deposition device,
A supply step of supplying an amount of the organic substance used for film formation to a heating unit provided in the vapor deposition device;
And a vaporization step of vaporizing the entire amount of the organic substance supplied in the supply step to form a film on the substrate by heating.   The film forming method according to claim 1, wherein in the supplying step, the organic material is supplied to the heating unit in a film-formed state.   A method for producing an organic electronic device, comprising a film forming step of forming a film by the film forming method according to claim 1. A film forming apparatus for forming a film on a substrate by vapor deposition using an organic material as a material,
A material holding part for holding the organic substance;
A heating source for heating the material holding unit;
A film forming apparatus comprising: a substrate holding unit that holds the substrate.