JP5265460B2 - Film forming method and film forming apparatus - Google Patents

Description

  The present invention relates to a film forming method and a film forming apparatus for forming an organic thin film.

Conventionally, as a method for forming an organic thin film, a wet method, a vapor deposition polymerization method, or the like is used.
Among these film forming methods, the wet method is a method in which a raw material monomer is dissolved in an appropriate solvent, polymerized, and applied onto a substrate.
On the other hand, the vapor deposition polymerization method is a method in which raw material monomers are evaporated, introduced into a vacuum processing chamber, and polymerized on the surface of a substrate to form a polymer film. This method has an advantage that a film can be formed without using a solvent and the film can be applied to the surface of the substrate.

  As an apparatus used for such a vapor deposition polymerization method, in the vapor deposition polymerization apparatus that evaporates the raw material monomer supplied to the evaporation source container in a vacuum by the heating means, the heating means is provided in the evaporation source storage part of the evaporation source container. The first heating means and the second heating means provided in the evaporation source outlet are disclosed, and the heating temperature of the second heating means is set slightly higher than the heating temperature of the first heating means. (For example, refer to Patent Document 1).

JP-A-5-0656627

  In the above vapor deposition polymerization apparatus, each of the raw material monomers is heated to bring the inside of the evaporation source into a saturated vapor pressure state, and utilizing the pressure difference between the inside of the evaporation source (saturated vapor pressure state) and the film formation chamber (low vacuum state), A source gas is allowed to flow from the evaporation source into the film formation chamber and polymerized on the substrate to form a polymer film having a stoichiometric ratio. Therefore, in this vapor deposition polymerization apparatus, the film formation rate depends on the pressure difference between the evaporation source and the film formation chamber, that is, the heating temperature that sets the saturation vapor pressure of the evaporation source.

  However, if the film formation is repeated while the heating temperature is set to be constant in order to make the film formation rate constant, the raw material monomer is decomposed or self-polymerized by heating and oligomerizes with the passage of time. As a result, the saturated vapor pressure in the evaporation source is reduced, and as a result, the pressure difference between the evaporation source and the film formation chamber is reduced, and the film formation rate may be reduced. In addition, when a film is formed using two raw material monomers, only one of the raw material monomers is altered to lower the saturated vapor pressure, and if the film formation rate is lowered, a polymer film having a desired stoichiometric ratio cannot be formed. There was a thing.

  In this case, even if an attempt is made to increase the saturated vapor pressure by heating the raw material monomer at a higher temperature in order to restore the lowered film formation rate, the raw material monomer has a high heat capacity, so that the original film formation rate is rapidly restored. I can't.

  The present invention has been made in view of the above circumstances, and provides a film forming method and a film forming apparatus capable of flattening the surface of the substrate without considering the residence time of the raw material monomer on the surface of the substrate. The purpose is to do.

In the film forming method of the present invention, the raw material gas obtained by heating and vaporizing two kinds of raw material monomers respectively injected into two evaporation sources is mixed into a mixed gas, and the mixed gas is introduced into the vacuum chamber. And forming a film on the surface of the object to be processed by vapor deposition polymerization of the two kinds of material monomers on the surface of the object to be processed. One of the two raw material monomers is a diisocyanate and the other is a diamine, and the diisocyanate includes tolylene-2,6-diisocyanate, tolylene diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, and wherein 1 Tanedea Rukoto selected from the group of m- xylylene diisocyanate.

The diamine is isophorone diamine, N-ethylethylenediamine, m-xylylenediamine, 1,2-diamino-2-methylpropane, trans-1,2-cyclohexanediamine, 1,2-diaminopropane, 1,3-diamino. Selected from the group of propane, 1,5-diaminopentane, N, N, N ′, N′-tetramethyldiaminomethane, 1,2-diamino-2-methylpropane, 2-methyl-1,5-diaminopentane It is preferable that it is 1 type .

The film forming apparatus of the present invention is a film forming apparatus used in the film forming method of the present invention, and is introduced from the mixing tank for mixing two raw material monomers to form a mixed gas, and the mixing tank. And a treatment tank for forming a coating film on the surface of the object to be treated using the mixed gas .

Wherein the inner wall of the mixing tank, Rukoto have heater provided for heating and diffusing the vapor of the two raw material monomers introduced into the mixing tank is preferred.

  According to the film forming method of the present invention, two raw material monomers having a melting point lower than room temperature are used. Therefore, when performing vapor deposition polymerization of these raw material monomers, these raw material monomers are on the surface of the object to be treated. It is possible to increase the kinetic energy of molecules of these raw material monomers while forming the polymer, so that the surface of the processed material can be obtained without considering the residence time of the raw material monomers on the surface of the processed material. A film (polymer film) having a uniform film thickness can be easily formed on the entire surface. Also, by increasing the kinetic energy of the molecules of the two kinds of raw material monomers, these raw material monomers are sufficiently migrated, and these raw material monomers react with each other to form a polymer film on the surface of the object to be treated. Grows sideways. Therefore, according to this film forming method, even when the surface of the object to be processed is scratched, the surface of the object to be processed is flattened by a film (polymer film) formed by vapor deposition polymerization of two kinds of raw material monomers. can do.

It is a schematic diagram which shows one Embodiment of the film-forming apparatus applied to the film-forming method of this invention. The result of having observed the film obtained in the Example of this invention with the laser microscope is shown, (a) shows the microscope image of the plastic substrate in which the film was formed, (b) is the surface roughness (roughness) of the plastic substrate. ) Is measured.

Embodiments of a film forming method and a film forming apparatus of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

FIG. 1 is a schematic view showing an embodiment of a film forming apparatus applied to the film forming method of the present invention.
A film forming apparatus 10 according to this embodiment includes a vacuum chamber 12 having a vacuum evacuation unit 11, a support unit 14 for holding an object to be processed 13 disposed inside the vacuum chamber 12, and a support unit 14. And a film forming means 20 that discharges a raw material gas toward one surface 13a of the object 13 to be processed and forms a film on the one surface 13a of the object 13 to be processed.
The film forming means 20 includes evaporation sources 21A and 21B, introduction pipes 22A and 22B, valves 25A and 25B, vaporization means 26A and 26B, a heater 27, a heater 28, and a monomer blowing member 29, which will be described later. It is roughly composed.

The vacuum chamber 12 forms a film on the substrate (target object 13) and the mixing tank 12a for mixing the vapors (raw material gases) of the raw material monomers A and B introduced through the introduction pipes 22A and 22B. And a treatment tank 12b for carrying out the treatment.
Here, the mixing tank 12a is connected to two types of evaporation sources 21A and 21B via introduction pipes 22A and 22B attached to the upper part thereof.

 The two evaporation sources 21A and 21B are constituted by housings 23A and 23B and evaporation containers 24A and 24B accommodated in the respective housings 23A and 23B. Then, raw material monomers A and B for forming a film are injected into the evaporation containers 24A and 24B, respectively. In addition, heaters (not shown) for heating the raw material monomers A and B are provided in the vicinity of the evaporation containers 24A and 24B.

A heater 27 is wound around each of the introduction pipes 22A and 22B so that the temperature of the raw material monomers A and B can be controlled to a predetermined temperature.
Valves 25A and 25B for adjusting the supply amounts of the raw material monomers A and B are provided in the middle of the introduction pipes 22A and 22B.
Further, in the middle of each introduction pipe 22A, 22B, between the valves 25A, 25B and the mixing tank 12a, vaporization means 26A, 26B for heating and vaporizing the raw material monomers A, B to form raw material gases are provided. Is provided.

Further, a heater 28 for heating and diffusing the vapors (raw material gases) of the raw material monomers A and B introduced into the mixing vessel 12a is provided on the inner wall of the mixing vessel 12a.
On the other hand, the processing tank 12b is formed in an airtight and integrated manner at the lower part of the mixing tank 12a, and a supporting means 14 for supporting the object to be processed 13 is provided at the lower part thereof. A heater and a refrigerant circulation path (not shown) are provided inside the support means 14 so that the object 13 can be heated or cooled to a predetermined temperature.

Further, a monomer spraying member for uniformly spraying the mixed gas of the raw material monomers A and B mixed in the mixing tank 12a to the object to be processed 13 between the mixing tank 12a and the processing tank 12b. 29 is arranged.
The monomer spray member 29 is made of a metal plate-like member having good thermal conductivity such as aluminum (Al), copper (Cu), stainless steel (SUS), and the like. The monomer blowing member 29 is formed with a plurality of outlets 29a through which a mixed gas can pass.

Further, an arm member 15 for carrying the object to be processed 13 into the vacuum chamber 12 is provided.
When the workpiece 13 is carried into the vacuum chamber 12, the workpiece 13 held by the arm member 15 is carried from a loading / unloading port (not shown) provided in the vacuum chamber 12, and the supporting means. 14 is placed on a support member 14 a extending upward from 14. And the to-be-processed object 13 is hold | maintained on the support means 14 by the support member 14a falling.
On the other hand, when the workpiece 13 is unloaded from the vacuum chamber 12, the workpiece 13 is lifted up by the rising of the support member 14a, held by the arm member 15, and unloaded from the loading / unloading port. .

Next, an embodiment of the film forming method of the present invention will be described.
First, the object to be processed 13 is carried into the vacuum chamber 12 by the arm member 15, and the object to be processed 13 is placed on the support member 14a.
Next, the support member 14 a is lowered, and the object 13 is placed on the support means 14.
Next, the inside of the vacuum chamber 12 and the evaporation sources 21A and 21B are evacuated by the evacuating means 11, and the insides thereof are set to a predetermined atmospheric pressure.

Next, the evaporation containers 24A and 24B are heated by heaters provided in the vicinity of the evaporation containers 24A and 24B, and the evaporation sources 21A and 21B (housings 23A and 23B) are saturated with the raw materials monomers A and B, respectively. Vapor pressure state.
At this time, the heating temperature of the evaporation containers 24A and 24B is set to a temperature at which a predetermined saturated vapor pressure is obtained.

Here, as the raw material monomers A and B, those having a melting point lower than room temperature (20 ± 2 to 3 ° C.) are used.
As the raw material monomer A, diisocyanate is used. Examples of the diisocyanate include tolylene-2,6-diisocyanate (Tolyrene-2,6-diisocyanate), tolylene diisocyanate, Hexamethylene diisocyanate, and dicyclohexylmethane 4,4′-. Examples thereof include one selected from the group of diisocyanate (Dicyclohexylmethane 4,4'-Diisocyanate) and m-xylylene diisocyanate (m-Xylylene Diisocyanate).

  As the raw material monomer B, diamine is used. Examples of the diamine include isophoronediamine, N-ethylethylenediamine, m-xylylenediamine, 1,2-diamino-2-methylpropane (1,2-Diamino-2-). methylpropane), trans-1,2-cyclohexanediamine (trans-1,2-Cyclohexanediamine), 1,2-diaminopropane, 1,3-diaminopropane (1,3-Diaminopropane), 1 , 5-Diaminopentane (1,5-Diaminopentane), N, N, N ′, N′-tetramethyldiaminomethane (N, N, N ′, N′-tetramethyldiaminomethane), 1,2-diamino-2-methylpropane (1,2-Diamino-2-methylpropane), 2-methyl-1,5-diaminopentane (2-Methyl-1,5- 1 type selected from the group of diaminopentane).

  Next, depending on the composition of the coating film (polymer film) formed on one surface 13a of the object 13 to be processed and the film formation time, the flow rate of the raw material monomers A and B (raw material gas) is set. Based on this, the pressure difference between the vacuum chamber 12 and the evaporation sources 21A and 21B is obtained. Based on this pressure difference, the saturated vapor pressures of the raw materials monomers A and B and the set pressures of the valves 25A and 25B are determined. Therefore, the valves 25A and 25B are opened so that these set pressures are obtained, and the mixing tank 12a Vapor (raw material gas) of raw material monomers A and B is introduced inside, and these vapors are mixed to form a mixed gas.

  Next, the mixed gas of the raw material monomers A and B mixed in the mixing tank 12 a is introduced into the processing tank 12 b of the vacuum chamber 12 through the monomer blowing member 29, and the coating on the one surface 13 a of the object 13 to be processed is introduced. Formation (film formation) is started. That is, in this process, the monomer blowing member 29 supplies the mixed gas of the raw material monomers A and B uniformly onto one surface 13a of the object 13 to be processed.

  Thereby, the vapor deposition polymerization reaction of the raw materials monomers A and B proceeds on one surface 13a of the object 13 to be processed, and a film (polymer film) made of polyurea is formed on the entire surface 13a of the object 13 to be processed. ) Is formed.

In the film forming method of this embodiment, the thickness of the coating film formed on the one surface 13a of the object 13 can be set to 10 nm to 300 μm depending on the application.
Moreover, control of the thickness (film thickness) of a film can be performed by applying a well-known technique. For example, the film thickness can be controlled by installing a film thickness monitor using a crystal oscillator method and measuring the film thickness or by controlling the film formation time.

  According to the film forming method of this embodiment, since the raw material monomers A and B are those having a melting point lower than room temperature, when the raw material monomers A and B are subjected to vapor deposition polymerization, the raw material monomers A and B are covered. Since the kinetic energy of the molecules of the raw material monomers A and B stays on one surface 13a of the processed body 13 and forms a polymer, the raw material monomer A on the one surface 13a of the processed body 13 can be increased. A film (polymer film) having a uniform film thickness and a transparent polyurea is easily formed on the entire surface 13a of the object 13 without considering the residence time of B. be able to. Moreover, by increasing the kinetic energy of the molecules of the raw material monomers A and B, the raw material monomers A and B sufficiently migrate, and the raw material monomers A and B react with each other, so that one surface 13a of the object 13 is processed. In this case, the polymer film grows isotropically. Therefore, according to this film forming method, even when one surface 13a of the object to be processed 13 is scratched, the object to be processed 13 is formed by the film (polymer film) formed by vapor deposition polymerization of the raw materials monomers A and B. The one surface 13a can be flattened.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

"Example"
A film made of polyurea was formed on one surface 13a of the object to be processed 13 made of a plastic substrate using the film forming apparatus 10 as shown in FIG.
First, the object 13 to be processed is disposed on the support member 14a in the vacuum chamber 12, and the vacuum chamber 12 and the evaporation sources 21A and 21B are evacuated by the evacuation unit 11, and the interior of the vacuum chamber 12 is 10 ^{−. The} pressure was reduced to ² Pa, and the inside of the evaporation sources 21A and 21B was reduced to 0.1 Pa.
Next, the evaporation container 24A is heated to 100 ° C. and the evaporation container 24B is heated to 90 ° C. by a heater provided in the vicinity of the evaporation containers 24A and 24B. A saturated vapor pressure state of raw material monomers A and B is set.
Here, hexamethylene diisocyanate (melting point −67 ° C.) was used as the raw material monomer A, and isophorone diamine (melting point 10 ° C.) was used as the raw material monomer B.
Next, the valves 25A and 25B are opened so that the flow rates of the raw material monomers A and B become a predetermined amount, and the mixed gas of the raw material monomers A and B mixed in the mixing tank 12a is passed through the monomer blowing member 29. Then, it was introduced into the treatment tank 12b of the vacuum chamber 12, and a film made of polyurea was formed on the entire surface 13a of the object 13 to be treated.

The coating film obtained in this example was observed with a laser microscope (manufactured by Keyence Corporation). The results are shown in FIG. FIG. 2A shows a microscopic image of a plastic substrate on which a film is formed, and FIG. 2B shows a result of measuring the surface roughness (roughness) of the plastic substrate.
As a result, the thickness of the film made of polyurea is 70 μm and the surface roughness of the plastic substrate is 0.33 μm, whereas the surface roughness of the portion flattened by the film made of polyurea (the surface of the film). Was confirmed to be reduced to 0.15 μm.

  The present invention can be widely applied to a film forming method and a film forming apparatus suitable for producing a polymer film made of an organic material.

DESCRIPTION OF SYMBOLS 10 ... Film-forming apparatus, 11 ... Vacuum exhaust means, 12 ... Vacuum chamber, 13 ... To-be-processed object, 14 ... Support means, 15 ... Arm member, 20 ... Composition Membrane means, 21A, 21B ... evaporation source, 22A, 22B ... introduction tube, 23A, 23B ... housing, 24A, 24B ... evaporation container, 25A, 25B ... valve, 26A, 26B ... Vaporization means, 27, 28 ... Heater, 29 ... Monomer spraying member.

Claims (4)

The raw material gases obtained by heating and vaporizing the two raw material monomers respectively injected into the two evaporation sources are mixed to form a mixed gas, and the mixed gas is introduced into the vacuum chamber, and is applied to the surface of the object to be processed. A film forming method in which the two raw material monomers are vapor-deposited to form a film on the surface of the object to be processed,
As the two kinds of raw material monomers, those having a melting point lower than room temperature are used .
One of the two kinds of raw material monomers is diisocyanate and the other is a diamine.
The diisocyanates, tolylene-2,6-diisocyanate, diisocyanate, tolylene, dicyclohexylmethane 4,4'-diisocyanate, 1 Tanedea Rukoto selected from the group of m- xylylene diisocyanate A characteristic film forming method. The diamine is isophorone diamine, N-ethylethylenediamine, m-xylylenediamine, 1,2-diamino-2-methylpropane, trans-1,2-cyclohexanediamine, 1,2-diaminopropane, 1,3-diamino. Selected from the group of propane, 1,5-diaminopentane, N, N, N ′, N′-tetramethyldiaminomethane, 1,2-diamino-2-methylpropane, 2-methyl-1,5-diaminopentane The film forming method according to claim 1 , wherein the film forming method is one type. A film forming apparatus used in the film forming method according to claim 1 or 2,
A mixing tank for mixing two kinds of raw material monomers to form a mixed gas, and a processing tank for forming a film on the surface of the object to be processed using the mixed gas introduced from the mixing tank are separately provided. A film forming apparatus provided as a body. The film formation according to claim 3, wherein a heater for heating and diffusing the vapors of the two kinds of raw material monomers introduced into the mixing tank is provided on an inner wall of the mixing tank. apparatus.

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