JP2012251178A - Film forming apparatus, method for calculating film formation rate, film forming method, and method for producing organic light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus, a method for calculating a film formation rate, a film forming method, and a method for producing an organic light-emitting element, which efficiently form a good-quality film by swiftly calculating a film formation rate and maintaining a generally constant concentration of organic material gas which is delivered to a substrate to be treated, and which enable easy maintenance.SOLUTION: A process controller 11 in a film forming apparatus 1 produces a calibration curve of a film formation rate which shows relation between: the difference between (Ii/Ie)when only delivery gas is conducted to an ion gauge 10 and (Ii/Ie) when organic material and delivery gas are conducted to the same; and a film formation rate D/R. The process controller 11 performs film forming by calculating (Ii/Ie) upon film forming, obtaining D/R by using the calibration curve of a film formation rate, controlling a mass flow controller 5 based on the obtained D/R, and controlling the flow rate of the delivery gas.

Description

  The present invention relates to a film forming apparatus for forming a film by supplying an organic material to a substrate to be processed by a carrier gas, a film forming speed calculating method for calculating a film forming speed, and a film forming speed calculated by the film forming speed calculating method. And a method for manufacturing an organic light-emitting element including a step of forming a film by the film forming method.

  In recent years, organic EL devices using electroluminescence (EL) have been developed. Organic EL devices have lower power consumption than cathode ray tubes, etc., and are self-luminous, so they have advantages such as better viewing angles than liquid crystal displays (LCDs), and future development is expected. Yes.

  The most basic structure of the organic EL element is a sandwich structure in which an anode (anode) layer, a light emitting layer and a cathode (cathode) layer are formed on a glass substrate. In order to extract light from the light emitting layer to the outside, a transparent electrode made of ITO (Indium Tin Oxide) is used for the anode layer on the glass substrate.

  In addition, on the cathode side of the organic EL element, an electron transport layer and an electron injection layer (work function adjustment layer) are sequentially formed on the light emitting layer in order to bridge the movement of electrons from the cathode layer to the light emitting layer. It is filmed. As the electron injection layer, an alkali metal having a small work function, such as Cs or Li, is used. As the electron transport layer, for example, Alq3 (tris (8-hydroxyquinolinato) aluminum) is used as an electron transporting organic material. . The electron transport layer and the electron injection layer are each formed by vapor deposition.

  Patent Document 1 discloses a film forming apparatus for forming a layer made of an organic material of the organic EL element described above. The film forming apparatus includes a processing chamber for forming a glass substrate, which is a substrate to be processed, and a steam generation unit that generates a vapor of an organic material by being heated by a heater is disposed outside the processing chamber. . An upper part of the processing chamber is provided with a vapor deposition head that is connected to the vapor generation unit by piping and ejects the vapor of the organic material generated in the vapor generation unit toward the glass substrate.

  In the above-described conventional film forming apparatus, keeping the vaporization rate (evaporation rate, in other words, the concentration of the material gas) of the film forming material constant improves the film forming rate, so that a high-quality film can be processed. It is important to form efficiently on top and improve product performance. For this reason, as disclosed in Patent Document 2, a film thickness sensor (film formation rate sensor) is provided in the vicinity of the substrate to be processed, and the heater temperature and the conveyance are determined based on the result detected by the film thickness sensor. By adjusting the gas flow rate, the vaporization rate of the material is controlled to be constant.

Examples of the deposition rate sensor, that is, a sensor for detecting the concentration of the material gas include QCM (Quarts Crystal Microbalance) and FT-IR (Fourier transform infrared spectrophotometer).
QCM measures a very small amount of mass change by utilizing the property that when a film forming material adheres to the electrode surface of a crystal resonator, the resonance frequency varies (decreases) in accordance with the mass of the material.
In FT-IR, a film-forming material is irradiated with infrared rays and transmitted light is dispersed to obtain a spectrum and measure a minute concentration change.

JP 2008-38225 A JP 2005-325425 A

When the film thickness is monitored by the above-mentioned quartz crystal microbalance (QCM), there is a problem that maintenance and management are complicated because a certain amount of film forming material must be replaced and cleaned.
In addition, when the vapor amount (film formation rate) is monitored by Fourier transform infrared spectroscopy (FT-IR), the measurement takes about 1 minute.

  The present invention has been made in view of such circumstances, and it is possible to quickly form a film forming speed and efficiently form a high-quality film by making the concentration of the organic material gas supplied to the substrate to be processed substantially constant. It is possible to provide a film forming apparatus, a film forming speed calculation method, a film forming method, and a method for manufacturing an organic light emitting element having a step of forming a film by the film forming method.

  A film forming apparatus according to the present invention includes a processing chamber for forming a film on a substrate to be processed, an evaporation unit that evaporates an organic material, and the organic material evaporated in the evaporation unit is transferred by a carrier gas, and the substrate to be processed In a film forming apparatus including an organic material supply unit that ejects toward the surface, a thermoelectron source that emits thermoelectrons, a grid to which a positive voltage is applied, and the emitted thermoelectrons collide with the molecules of the organic material and the carrier gas. And an ion gauge having a collector that captures positive ions generated in this manner, an ion current measurement unit that measures an ion current that flows when the positive ions are captured by the collector, and the thermal electrons are generated by entering the grid Deposition rate calculation means for determining the film formation rate of the organic material based on the ion current value Ii measured by the ion current measurement unit when the electron current value Ie is kept constant Characterized in that it comprises a.

  The film formation speed calculation method according to the present invention is a film formation speed calculation in which an organic material is evaporated, the evaporated organic material is transferred by a transfer gas, and supplied to a substrate to be processed to form a film formation speed. In the method, a thermoelectron source that emits thermoelectrons when an acceleration voltage is applied, a grid that is applied with a positive voltage, and traps positive ions generated when the emitted thermoelectrons collide with the organic material and carrier gas molecules. And an ion gauge having an ion current measuring unit that measures an ion current that flows when the positive ions are trapped by the collector, and a current value Ie of an electron current generated when the thermoelectrons enter the grid is calculated. The film deposition rate is calculated based on the current value Ii of the ion current measured by the ion current measurement unit when the ion current is held constant.

  In the film forming method according to the present invention, the film forming speed is calculated by the above-described film forming speed calculating method, the flow rate of the carrier gas is controlled based on the calculated film forming speed, and the organic material is applied to the substrate to be processed. It is characterized by forming a film.

  The organic light-emitting device manufacturing method according to the present invention is a method of manufacturing an organic light-emitting device in which an anode, a light-emitting layer, and a cathode are provided on a substrate, and a film constituting the organic light-emitting device is formed by the film forming method described above. It has the process to perform.

  According to the present invention, the deposition rate can be calculated and the flow rate of the carrier gas can be feedback controlled with good responsiveness, and the evaporation rate (material gas concentration) of the organic material during deposition can be kept constant. A simple film can be formed efficiently, and maintenance management is also easy.

It is a sectional side view which shows typically the structure of the film-forming apparatus which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the structure of an ion gauge. It is a graph showing the relationship between the grid voltage Vg and _{SA / SB (SAr / SN 2} ). It is a graph showing the relationship between the acceleration voltage Vacc and the _{SA / SB (SAr / SN 2} ). It is a graph which shows the relationship between reference | standard vacuum gauge value (CM) and Ii / Ie when the grid voltage Vg is 180V and the acceleration voltage Vacc is 45V. It is a graph which shows the relationship between CM and Ii / Ie when the grid voltage Vg is 50V and the acceleration voltage Vacc is 50V. It is a graph which shows the relationship between the flow volume of Ar, and (DELTA) P. It is a sectional side view which shows the state made to flow carrier gas. It is a graph which shows the relationship between the flow volume of carrier gas, and (Ii / Ie) ₀ . It is a sectional side view which shows the state made to flow carrier gas and material gas. It is a graph which shows the relationship between the flow volume of carrier gas, and (Ii / Ie). It is a graph which shows a film-forming rate calibration curve. It is a flowchart which shows the procedure of the process of the flow volume setting by a process controller. It is a flowchart which shows the procedure of the film-forming process by a process controller. It is explanatory drawing which illustrates notionally the structure of the film-forming system provided with the film-forming apparatus which concerns on this invention. It is sectional drawing which showed typically the organic EL element formed into a film using the film-forming system. It is a schematic diagram which shows the structure of the film-forming apparatus which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows the state made to flow carrier gas and material gas. It is a flowchart which shows the procedure of the calibration process of the film-forming speed | rate calibration curve by a process controller. It is a schematic diagram which shows the structure of another film-forming apparatus.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
Embodiment 1 FIG.
FIG. 1 is a side sectional view schematically showing a configuration of a film forming apparatus 1 according to Embodiment 1 of the present invention.
The processing chamber 2 has a hollow, substantially rectangular parallelepiped shape whose longitudinal direction is the transport direction, and is made of aluminum, stainless steel, or the like. Transport ports 211 and 211 for transporting the substrate to be processed G into and out of the processing chamber 2 are formed on the surfaces on both ends in the longitudinal direction of the processing chamber 2, and the transport ports 211 and 211 are opened and closed by the gate valves 212 and 212. Is configured to do. An exhaust pipe 213 is provided at an appropriate location in the processing chamber 2, and an exhaust apparatus 214 including a high-speed vacuum pump is connected to the exhaust pipe 213. By operating the exhaust device 214, the inside of the processing chamber 2 can be depressurized to a predetermined pressure, for example, 0.01 Pa.

  At the bottom of the processing chamber 2, a transfer device 202 that transfers the target substrate G carried into the processing chamber 2 is installed. The transfer device 202 includes a guide rail provided along the longitudinal direction at the bottom of the processing chamber 2, and a moving member that is guided by the guide rail and is movable in the transfer direction, that is, the longitudinal direction. A support base 203 that supports the substrate G to be processed substantially horizontally is provided at the upper end of the moving member. An electrostatic chuck that holds the substrate to be processed G, a heater that keeps or heats the temperature of the substrate to be processed G, a refrigerant pipe, and the like are provided inside the support base 203. The support base 203 is configured to move by a linear motor.

  A vapor deposition head 241 for forming an organic material on the substrate G to be processed by a vacuum vapor deposition method is provided in the upper portion of the processing chamber 2 and substantially in the center in the transport direction. The vapor deposition head 241 is provided with a head cover 204, and the head cover 204 has a built-in heater.

  The steam generation unit 3 includes a container 31 and a heating mechanism 32 disposed inside the container 31. The heating mechanism 32 has a container-like portion that can store the vapor of the organic material, and is configured to heat the organic material with electric power supplied from the power source 33. For example, the organic material is heated with an electric resistor. The organic material accommodated in the heating mechanism 32 is heated to generate vapor of the organic material.

Further, a carrier gas supply pipe 4 that supplies a carrier gas made of an inert gas such as Ar to the substrate G to be processed is connected to the container 31. The carrier gas opens the valve 41 by the mass flow controller 5 and is supplied to the steam generation unit 3 by the carrier gas supply pipe 4 in a state in which the flow rate is adjusted, and together with the organic material vapor generated in the steam generation unit 3, the organic material supply pipe 6 to be supplied to the vapor deposition head 241 through 6. A pipe 7 is connected to the middle part of the organic material supply pipe 6, and an organic material and a carrier gas are sent out to the ion gauge 10 and the outside by opening a valve 71.
Connected to the downstream side of the valve 71 is a pipe 8 for sending the carrier gas to the ion gauge 10 side in a state where the opening and closing of the valve 81 is controlled by the mass flow controller 15 and the flow rate is adjusted. An ion gauge conduit 9 for sending the carrier gas and the organic material to the ion gauge 10 is connected to the middle portion of the pipe 7 on the downstream side of the connection portion with the pipe 8. An orifice is provided between the connecting portion of the pipe 7 and the ion gauge conduit 9 so that the pressure can be measured. The carrier gas supply pipe 4, the organic material supply pipe 6, and the pipes 7 and 8 are configured to be heated by a heater so that the organic material does not accumulate on the inner surface of the pipe.
Since the ion gauge conduit 9 is provided to be branched from the organic material supply pipe 6 through which the organic material flows, the organic compound generated by the decomposition of the material gas in the ion gauge 10 is supplied to the vapor deposition head 241 and formed. There is no filming.

The film forming apparatus 1 includes a process controller 11 that controls each component of the film forming apparatus 1. Connected to the process controller 11 is a user interface 12 through which a process manager performs a command input operation in order to manage the film forming apparatus 1. Further, the process controller 11 stores a control program for realizing various processes executed by the film forming apparatus 1 under the control of the process controller 11 and a process control program in which process condition data is recorded. 13 is connected. The process controller 11 calls and executes an arbitrary process control program according to an instruction from the user interface 12 from the storage unit 13, and performs a required process in the film forming apparatus 1 under the control of the process controller 11.
Here, an example in which the substrate to be processed G is transferred has been described. However, the support base 203 may be fixed and the substrate processing head 241 may be transferred to the substrate to be processed G.

FIG. 2 is a schematic diagram showing the configuration of the ion gauge 10.
The ion gauge 10 includes a filament 102 that emits a thermoelectron 101 when an acceleration voltage Vacc is applied, a grid 103 that is applied with a positive voltage Vg (grid voltage), and the emitted thermoelectron 101 includes the organic material and the carrier gas. A collector 106 that captures positive ions 104 generated by colliding with the molecule 110, and an ion current measuring unit 107 that measures a current value Ii of an ion current that flows when the positive ions 104 are captured by the collector 106. In addition, the ion gauge 10 includes an electron current measuring unit 108 that measures a current value Ie of an electron current that is generated when thermoelectrons 101 (including secondary electrons 105 generated by colliding with the molecules) enter the grid 103, a filament, And a filament current measuring unit 109 that measures a current value If of 102.
In FIG. 2, Vf is a filament voltage.

The following equation (1) is established between Ii and Ie.
Ii = S · Ie · P (1)
S: sensitivity coefficient, P: pressure When acceleration voltage Vacc and grid voltage Vg are controlled so that Ie is constant, Ii is proportional to P.
When formula (1) is transformed, formula (2) is obtained.
Ii / Ie = S · P (2)
That is, by measuring Ii and giving S based on the gas type as a parameter to Equation (1), the gas pressure P can be obtained.
Therefore, when (Ii / Ie) ₀ (the measured value Ii obtained by the ion current measuring unit 107 is divided by the measured value Ie obtained by the current measuring unit 108) when only the carrier gas A is passed through the ion gauge 10, the carrier gas is used. By obtaining the difference from (Ii / Ie) when A and the material gas B are passed, it is possible to correspond to the partial pressure (concentration) of the material gas.

Hereinafter, a method for obtaining the film formation rate D / R of the organic material on the substrate G to be processed will be described in detail. Since the gas pressure P changes depending on the temperature, hereinafter, the temperature is kept constant.
(Measurement condition setting)
Only the carrier gas A is used, the acceleration voltage Vacc is kept constant, the grid voltage Vg is changed, and the relationship between Ii / Ie and the pressure P is obtained. For each grid voltage Vg, the slope of the graph representing the relationship between Ii / Ie and pressure P (sensitivity coefficient SA of carrier gas A) is obtained. Similarly, for the material gas B, the relationship between Ii / Ie and pressure P when the acceleration voltage Vacc is constant and the grid voltage Vg is changed in a plurality is obtained, and for each grid voltage Vg, Ii / Ie and pressure P The slope of the graph representing the relationship (the sensitivity coefficient SB of the material gas B) is obtained. Then, the ratio (specific sensitivity coefficient) SA / SB of the sensitivity coefficients SA and SB at each grid voltage Vg is obtained.

  Next, only the carrier gas A is used, the grid voltage Vg is made constant, the acceleration voltage Vacc is changed in plural, and the relationship between Ii / Ie and the pressure P is obtained. For each acceleration voltage Vacc, the slope of the graph representing the relationship between Ii / Ie and pressure P (sensitivity coefficient SA of carrier gas A) is obtained. Similarly, for the material gas B, the grid voltage Vg is made constant, the acceleration voltage Vacc is changed, and the relationship between Ii / Ie and the pressure P is obtained. Is obtained (slope SB of the material gas B). Then, the ratio (specific sensitivity coefficient) SA / SB of the sensitivity coefficients SA and SB at each acceleration voltage Vacc is obtained.

FIG. 3 is a graph showing the relationship between the grid voltage Vg and SA / SB (SAr / SN ₂ ) when Ar is used as the carrier gas A and N ₂ is used as the reference gas instead of the material gas B. In FIG. 3, Vacc = 0.
FIG. 4 is a graph showing the relationship between the acceleration voltage Vacc and SA / SB (SAr / SN ₂ ) when Ar is used as the carrier gas A and N ₂ is used as the reference gas instead of the material gas B. In FIG. 4, there are three types of grid voltages Vg: 50V, 100V, and 150V.
3 that the specific sensitivity coefficient SA / SB is the highest when the grid voltage Vg is 50V, and the specific sensitivity coefficient SA / SB is the highest when the acceleration voltage Vacc is 50V.

FIG. 5 is a graph showing the relationship between the reference vacuum gauge value (CM) and Ii / Ie when the grid voltage Vg is 180V and the acceleration voltage Vacc is 45V.
FIG. 6 is a graph showing the relationship between CM and Ii / Ie when the grid voltage Vg is 50V and the acceleration voltage Vacc is 50V.
Since the specific sensitivity coefficients SAr / SN _{2 in} the case of FIGS. 5 and 6 are 1.345 and 1.813, respectively, it can be seen that the specific sensitivity coefficient SAr / SN ₂ is improved in the case of FIG.
As described above, the grid voltage Vg and the acceleration voltage Vacc are set.

  When forming an organic material into a film in a manufacturing process of an organic EL element or the like, the partial pressure of the material gas B is generally 5% or less and small. By setting the grid voltage Vg and the acceleration voltage Vacc so that the specific sensitivity coefficient SA / SB is increased, the ionization probability of the material gas B is increased, and the sensitivity to changes in the partial pressure of the material gas B can be improved. . For example, molecules of an organic material having a plurality of rings such as Alq3 are decomposed into a large number of compounds by the ion gauge 10, so that Ii can be increased and the effect of increasing the sensitivity coefficient SB can be further increased. .

When the organic material is deposited on the substrate G to be processed, the carrier gas and the vaporized organic material are mixed and ejected from the vapor deposition head 241. When the carrier gas and the material gas are mixed, The presence or absence of changes in the sensitivity coefficient of the carrier gas was investigated.
It is assumed that Ar is used as the carrier gas A and the reference gas N ₂ is used as the material gas B.
From the above equation (2),
Ii / Ie = SAr · PAr + SN ₂ · PN ₂
Since SN ₂ = 1,
Ii / Ie = PN ₂ + SAr · PAr
Therefore, the following equation (3) is obtained.
SAr · PAr = Ii / Ie-PN ₂ (3)

FIG. 7 is a graph showing the relationship between the flow rate of Ar and [(Ii / Ie) −PN ₂ ] (ΔP). The flow rate of N ₂ is set to 0 for each point of the flow rate of Ar (0.5, 1.0, 1.5, 2.0, _2.5 , 3.0, 4.0, 4.5 (sccm)). , 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, and 4.5 (sccm), respectively, ΔP was obtained.
From FIG. 7, it was confirmed that SAr is substantially constant even when the mixing ratio of Ar and N ₂ is different. Accordingly, even when the mixing ratio of the carrier gas A and the material gas B is changed, SAr is substantially constant, and the difference between (Ii / Ie) ₀ and (Ii / Ie) is obtained to obtain the material gas B It was confirmed that the partial pressure of can be monitored.

(Creation of deposition rate calibration curve)
First, using only the carrier gas A, the relationship between the flow rate of the carrier gas A and (Ii / Ie) ₀ is obtained. Here, Ar is given as an example of the carrier gas A.
As shown in FIG. 8, the valves 41 and 71 are closed, the valve 81 is opened, and the carrier gas Ar is caused to flow through the pipe 8 and the ion gauge conduit 9.
FIG. 9 is a graph showing the relationship between the flow rate of the carrier gas Ar and (Ii / Ie) ₀ . (Ii / Ie) ₀ corresponds to the pressure of the carrier gas Ar.

Next, using the carrier gas A and the material gas B, the relationship between the flow rate of the carrier gas A and (Ii / Ie) is obtained.
As shown in FIG. 10, the valve 81 is closed, the valves 41 and 71 are opened, and Ar is allowed to flow through the carrier gas supply pipe 4, the organic material supply pipe 6, the pipe 7, and the ion gauge pipe 9, thereby providing an organic material. The gas is caused to flow through the organic material supply pipe 6, the pipe 7, and the ion gauge conduit 9.
FIG. 11 is a graph showing the relationship between the flow rate of the carrier gas Ar and (Ii / Ie). FIG. 11 also shows a graph showing the relationship between the flow rate of the carrier gas Ar and the film formation rate D / R (nm / sec). (Ii / Ie) corresponds to the total pressure of the carrier gas Ar and the material gas.

Then, a film formation speed calibration curve is created based on FIGS.
FIG. 12 shows a film formation rate calibration curve. The horizontal axis represents the film formation speed D / R, and the vertical axis corresponds to the difference between (Ii / Ie) ₀ and (Ii / Ie), that is, the differential pressure ΔP.
This film formation speed calibration curve is stored in the storage unit 13.
The organic material is supplied into the processing chamber 2 by the transport gas, calculates the case of forming the substrate to be processed G, by measuring the Ii by the ion current measuring section 107 (Ii / Ie), ( Ii / Ie) 0 And the film formation rate calibration curve is used to obtain the film formation rate (D / R) at the time of measuring Ii, in other words, the concentration of the material gas.

(Deposition process)
Hereinafter, the film forming process using the film forming speed calibration curve will be described in detail.
FIG. 13 is a flowchart illustrating a flow rate setting process performed by the process controller 11. As shown in FIG. 10, the valve 81 is closed and the valves 41 and 71 are opened.
First, the process controller 11 sets the temperature and sets the flow rate of the carrier gas Ar (S1).
Next, the process controller 11 supplies an organic material to the ion gauge 10 using the carrier gas Ar, and causes the ion current measuring unit 107 to measure Ii to calculate Ii / Ie (S2).
Then, the process controller 11 calculates [(Ii / Ie) ₀ − (Ii / Ie)] at the flow rate (S3), and calculates the film formation speed D / R using the film formation speed calibration curve (S4). ).
The process controller 11 determines whether or not a ≦ D / R ≦ b (S5). a and b are appropriately set according to the desired error range of the film formation rate.

If the process controller 11 determines that a ≦ D / R ≦ b is not satisfied (S5: NO), the process returns to step S1. The process controller 11 controls the mass flow controller 5 to satisfy a ≦ D / R ≦ b and changes the flow rate of the carrier gas Ar.
If the process controller 11 determines that a ≦ D / R ≦ b is satisfied (S5: YES), the process substrate 11 transports the substrate G to be processed in the processing chamber 2, performs a film forming process (S6), and ends the process. .

FIG. 14 is a flowchart showing the procedure of the film forming process performed by the process controller 11.
First, the process controller 11 sets the temperature, the stage speed, and the flow rate of the carrier gas Ar (S11).
Next, the process controller 11 supplies an organic material to the processing chamber 2 and the ion gauge 10 using the carrier gas Ar, and causes the ion current measuring unit 107 to measure Ii to calculate Ii / Ie (S12).
Then, the process controller 11 calculates (Ii / Ie) _0- (Ii / Ie) (S13), and calculates D / R using the film formation rate calibration curve (S14).
The process controller 11 determines whether or not a ≦ D / R ≦ b (S15).

If the process controller 11 determines that a ≦ D / R ≦ b is not satisfied (S15: NO), the process returns to step S11. The process controller 11 changes the flow rate of the carrier gas Ar, the material temperature, and the stage speed. Here, since the deposition rate calibration curve is created based on the flow rate of the carrier gas Ar, it is preferable to first change the flow rate of the carrier gas Ar using the mass flow controller 5. The stage speed and the adjustment of the film formation amount are associated in advance. If the D / R is greatly deviated, the process returns to the process before film formation.
When it is determined that a ≦ D / R ≦ b is satisfied (S15: YES), the process controller 11 determines whether or not the film formation on the end portion of the substrate G to be processed has been completed (S16).
If the process controller 11 determines that the film formation has not ended (S16: NO), the process returns to step S12.
If the process controller 11 determines that the film formation has ended (S16: YES), the film formation process ends.

  In the present embodiment, since the ion gauge 10 is used, measurement conditions such as applied voltage can be set quickly. Then, since the film formation speed D / R is obtained by the ion gauge 10, the flow rate of the carrier gas can be feedback controlled with good responsiveness, and a high quality film is formed with a constant evaporation rate (concentration) of the organic material. And the yield of products can be improved. Further, as in the case of using the QCM as the film thickness sensor, there is no loss of the organic material, the use efficiency of the material is improved, and the maintenance management is easy. As described above, since the sensitivity coefficient S is increased, the change in the pressure of the organic material gas (change in the amount of vapor) is monitored and the film formation rate D / R is appropriately controlled while the sensitivity is improved. be able to.

The case where layers, such as an electron carrying layer which comprise the organic EL element of an organic EL device, are formed using the film-forming apparatus 1 below is demonstrated.
FIG. 15 is an explanatory diagram conceptually illustrating a configuration of a film forming system including the film forming apparatus 1 according to the present invention, and FIG. 16 is an organic EL element 120 formed using the film forming system according to the present embodiment. It is sectional drawing which showed typically.
The film forming system according to the present embodiment includes a loader 90, a transfer chamber 91, a film forming apparatus 100, a transfer chamber 92, an etching apparatus 93, a transfer chamber 94, and sputtering that are arranged in series in the transport direction of the substrate G to be processed. An apparatus 95, a transfer chamber 96, a CVD apparatus 97, a transfer chamber 98, and an unloader 99 are provided.
The film forming apparatus 100 is formed by using a vacuum evaporation method on the substrate G to be processed, a hole injection layer 123a, a hole transport layer 123b, a blue light emission layer 123c, a red light emission layer 123d, a green light emission layer 123e, an electron transport layer 123f, and an electron. An injection layer 123g is formed. The film forming apparatus 1 described above is included in the film forming apparatus 100, and is used for forming the electron transport layer 123f using Alq3 or the like as an organic material.
The etching apparatus 93 is an apparatus for adjusting the shape of the organic layer to a predetermined shape.
The sputtering apparatus 95 is an apparatus that forms the cathode layer 122 on the electron injection layer 123g by sputtering, for example, silver Ag, magnesium Mg / silver Ag alloy using a pattern mask.
The CVD apparatus 97 is an apparatus for forming a sealing layer 124 made of, for example, silicon nitride by the CVD method and sealing each layer formed on the substrate G to be processed.
The unloader 99 is an apparatus for carrying the substrate to be processed G out of the film forming system.

  When the electron transport layer 123f is formed, the partial pressure of the gas of the organic material such as Alq3 is 5% or less, which is small, but according to the film formation apparatus 1 of the present embodiment, the sensitivity is improved. Since the change in pressure (change in vapor amount and concentration) of the gas of the organic material can be monitored, the electron transport layer 123f can be satisfactorily formed by properly controlling the film formation rate D / R. .

Embodiment 2. FIG.
The film forming apparatus 111 according to the second embodiment of the present invention has the same configuration as the film forming apparatus 1 according to the first embodiment, and further includes a Fourier transform infrared spectrometer (FT-IR) 20. Is different from the film forming apparatus 1.
FIG. 17 is a schematic diagram showing the configuration of the film forming apparatus 111 according to Embodiment 2 of the present invention. In the figure, the same parts as those in FIG. Here, the case where Ar is used as the carrier gas will be described.
The FT-IR 20 includes an FT-IR light source 21 that irradiates the carrier gas Ar and the organic material with infrared rays, a spectroscopic unit 22 that obtains a spectrum by dispersing transmitted light, and an FT-IR that detects a spectrum obtained by the spectroscopic unit 22. IR light source 23 is provided.
With the valve 81 opened by the mass flow controller 15 and the flow rate adjusted, the carrier gas Ar flows through the FT-IR 20 via the pipe 8 and further flows through the ion gauge conduit 9 and is sent to the ion gauge 10. , Discharged outside.
In addition, the carrier gas Ar is supplied to the vapor generating unit 3 through the carrier gas supply pipe 4 in a state where the valve 41 is opened by the mass flow controller 5 and the flow rate is adjusted, and together with the organic material vapor generated in the vapor generating unit 3 After the FT-IR 20 is passed through the pipes 16 and 8 with the valve 161 opened, it is passed through the ion gauge conduit 9 and sent to the ion gauge 10 and discharged to the outside. It is configured to be supplied to the vapor deposition head 241 through the organic material supply pipe 17 in a state in which 171 is open. Further, the organic material and the carrier gas Ar are also configured to be supplied to the vapor deposition head 241 through the organic material supply pipe 6 with the valve 61 opened.

In the present embodiment, as in the first embodiment, first, measurement conditions such as voltage values of the acceleration voltage Vacc and the grid voltage Vg are set.
Then, under the set conditions, as shown in FIG. 17, the valves 41, 61, 161, 171 are closed, the valve 81 is opened, and the carrier gas Ar is allowed to flow through the pipe 8 through the FT-IR 20. The ion gauge conduit 9 is caused to flow. Then, similarly to the case shown in FIG. 9, the relationship between the flow rate of the carrier gas Ar and (Ii / Ie) ₀ is obtained.

Next, the valves 61, 81, 171 are closed, the valves 41, 161 are opened, the carrier gas Ar is supplied to the steam generation unit 3 via the carrier gas supply pipe 4, and the gaseous state generated in the steam generation unit 3 is supplied. Together with the organic material, the FT-IR 20 is allowed to flow through the pipe 8 and then the ion gauge conduit 9 is allowed to flow.
Then, similarly to the case shown in FIG. 11, the graph showing the relationship between the flow rate of the carrier gas Ar and (Ii / Ie), and the flow rate of the carrier gas Ar and the deposition rate D / R (nm / sec). Create a graph that represents the relationship. At this time, D / R is obtained using FT-IR20. By using FT-IR20, the accuracy of quantification is improved.
Next, a film formation rate calibration curve is created in the same manner as in the first embodiment, as in the case shown in FIG. In the present embodiment, since the accuracy of D / R quantification is good, the accuracy of the film formation rate calibration curve is also good.

As shown in FIG. 18, the process controller 11 controls the film forming process with the valves 61, 81 closed and the valves 41, 161, 171 opened.
First, the process controller 11 performs a flow rate setting process in the same procedure as the flowchart shown in FIG. 13, and performs a film forming process in the same procedure as in the flowchart shown in FIG. The process controller 11 does not use the FT-IR 20 at the time of film formation, but calculates D / R with reference to the film formation rate calibration curve based on Ii measured using the ion gauge 10.

The process controller 11 calibrates the film formation speed calibration curve when a predetermined time T has elapsed.
FIG. 19 is a flowchart showing the procedure of the process for calibrating the deposition rate calibration curve by the process controller 11.
First, the process controller 11 determines whether or not a predetermined time T has elapsed (S21). If the process controller 11 determines that the predetermined time T has not elapsed (S21: NO), the determination is repeated.

When the process controller 11 determines that the predetermined time T has elapsed (S21: YES), the carrier gas Ar and the organic material are transferred to the FT-IR 20 and the ion gauge 10 before the substrate G to be processed is transported in the processing chamber 2. Then, D / R is calculated based on the measured value of Ii by the ion gauge 10 (S22).
At the same time, the process controller 11 obtains D / R (2) using the FT-IR 20 (S23).

The process controller 11 determines whether or not the absolute value of the difference between D / R and D / R (2) is equal to or less than a predetermined value c (S24). The predetermined value c is set to an appropriate value. If the process controller 11 determines that the absolute value is equal to or smaller than the predetermined value c (S24: YES), the process ends.
If the process controller 11 determines that the absolute value is not less than or equal to the predetermined value c (S24: NO), the film formation speed calibration curve is calibrated (S25), and the process ends. The process controller 11 calibrates the film formation speed calibration curve by associating a plurality of D / R (2) obtained by the FT-IR 20 with (Ii / Ie) _0- (Ii / Ie). The calibration of the film formation rate calibration curve is not limited to this method.
After the calibration of the deposition rate calibration curve, the deposition process is performed in the same manner as described above.

In the present embodiment, since the film formation rate calibration curve is created using the FT-IR 20, the accuracy (quantitativeness) is improved as described above. Since the FT-IR 20 can calibrate the deposition rate calibration curve, the vaporization rate (evaporation rate, concentration) of the organic material can be kept more constant, and a higher quality film can be formed on the substrate G to be processed. The final product can be homogenized.
And since D / R is detected using the ion gauge 10 at the time of film-forming, responsiveness is favorable. In addition, you may decide to detect D / R using FT-IR20 together at the time of film-forming.
Further, even when the organic material is composed of a plurality of components, the D / R of each component is obtained by separation using the spectrum obtained by the FT-IR 20, and the total value thereof is calculated as (Ii / Ie) _0- (Ii / Ie) can be associated with each other to create a film formation rate calibration curve, and the film formation rate can be detected satisfactorily.

FIG. 20 is a schematic diagram showing the configuration of another film forming apparatus 112. In the figure, the same parts as those in FIG.
The film forming apparatus 112 is configured so that the carrier gas Ar and the organic material are supplied to the vapor deposition head 241 and the ion gauge 10 using the pipe 18 without flowing through the FT-IR 20 during film formation. ing.
In this case, there is no loss of organic material due to the flow of FT-IR 20, and the yield of the product is improved.

In the first and second embodiments, a film formation rate calibration curve indicating the relationship between the difference between (Ii / Ie) ₀ and (Ii / Ie) and the film formation rate D / D is created. Although described, the present invention is not limited to this. A calibration curve indicating the relationship between the difference between (Ii / Ie) ₀ and (Ii / Ie) and the concentration of the material gas may be created.
Further, the configuration of the film forming apparatus is not limited to that described in the first and second embodiments.
The film formation speed calculation method and film formation method of the present invention can also be applied to film formation of elements other than organic EL elements.

DESCRIPTION OF SYMBOLS 1, 111, 112 Film-forming apparatus 2 Processing chamber 202 Conveyance apparatus 204 Head cover 241 Deposition head 3 Vapor generation part (evaporation part)
31 Container 32 Heating Mechanism 4 Carrier Gas Supply Pipe 5, 15 Mass Flow Controller 6 Organic Material Supply Pipe 7, 8 Pipe 9 Ion Gauge Conduit 10 Ion Gauge 102 Filament 103 Grid 104 Collector 107 Ion Current Measuring Unit 11 Process Controller 13 Storage Unit 20 FT -IR
21 FT-IR light source 22 Spectrometer 23 FT-IR detector G Substrate

Claims (10)

A processing chamber for forming a film on a substrate to be processed, an evaporation unit for evaporating an organic material, and an organic material supply unit for transferring the organic material evaporated in the evaporation unit by a transfer gas and ejecting the organic material toward the substrate to be processed A film forming apparatus comprising:
A thermoelectron source that emits thermoelectrons, a grid to which a positive voltage is applied, a collector that captures positive ions generated when the emitted thermoelectrons collide with molecules of the organic material and the carrier gas, and the positive ions An ion gauge having an ion current measurement unit that measures an ion current flowing when captured by the collector;
When the current value Ie of the electron current generated when the thermoelectrons enter the grid is kept constant, the deposition rate of the organic material is determined based on the current value Ii of the ion current measured by the ion current measurement unit. A film forming speed calculating means for obtaining The relationship between the difference between (Ii / Ie) ₀ when only the carrier gas is passed and (Ii / Ie) when the organic material and the carrier gas are passed, and the film formation speed Comprising means for creating a deposition rate calibration curve as shown in FIG.
The film forming apparatus according to claim 1, wherein the film forming speed calculating unit calculates the film forming speed based on the film forming speed calibration curve.   The film forming apparatus according to claim 1, further comprising a Fourier transform infrared spectrophotometer. A first flow pipe through which the organic material and carrier gas flow from the evaporation section to the organic material supply section;
4. A second flow pipe that branches from the first flow pipe and flows the organic material and carrier gas to the ion gauge. 5. Deposition device.   The film forming apparatus according to claim 1, further comprising means for heating the first and second flow pipes and the organic material supply unit. In the film formation speed calculation method for calculating the film formation speed for evaporating the organic material, transporting the evaporated organic material with a carrier gas, and supplying the film to the substrate to be processed.
A thermoelectron source that emits thermoelectrons upon application of an accelerating voltage, a grid to which a positive voltage is applied, a collector that captures positive ions generated by collision of the emitted thermoelectrons with the organic material and carrier gas molecules; And an ion gauge having an ion current measuring unit that measures an ion current flowing when the positive ions are trapped by the collector,
When the current value Ie of the electron current generated when the thermoelectrons enter the grid is kept constant, the deposition rate is calculated based on the current value Ii of the ion current measured by the ion current measuring unit. A method for calculating a film forming speed. The relationship between the difference between (Ii / Ie) ₀ when only the carrier gas is passed and (Ii / Ie) when the organic material and the carrier gas are passed, and the film formation speed Creating a deposition rate calibration curve as shown,
The film formation speed calculation method according to claim 6, wherein the film formation speed is calculated based on the created film formation speed calibration curve. Setting the acceleration voltage and the positive voltage so that the ratio of the sensitivity coefficient S represented by the following formula (1) of each of the carrier gas and the organic material is increased,
8. The deposition rate calculation method according to claim 7, wherein the (Ii / Ie) ₀ and the (Ii / Ie) are obtained by applying the acceleration voltage and the positive voltage set in this step.
S = Ii / (Ie · P) (1)
[Wherein P is pressure]   A film formation speed is calculated by the film formation speed calculation method according to any one of claims 6 to 8, and the flow rate of the carrier gas is controlled based on the calculated film formation speed, so that the organic material is applied to the substrate to be processed. A film forming method characterized by forming a film. In the method of manufacturing an organic light emitting device in which an anode, a light emitting layer, and a cathode are provided on a substrate,
A method for producing an organic light emitting device, comprising the step of forming a film constituting the organic light emitting device by the film forming method according to claim 9.

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