JP7390195B2 - Silicon film formation method - Google Patents

Description

TECHNICAL FIELD The disclosed embodiments relate to a silicon deposition method.

Patent Document 1 discloses a technique of forming a silicon film by forming a coating film using a silicon-containing solution containing a silicon compound by spin coating or the like, and heating the coating film at a predetermined temperature.

JP2009-259958A

The present disclosure provides a technique for forming a silicon film with good uniformity.

A silicon film forming method according to one embodiment of the present disclosure is a silicon film forming method by spin coating using a silicon-containing solution. The silicon film forming method includes a first step of dropping a silicon-containing solution onto the substrate while rotating a stage on which a substrate is mounted at a first rotation speed, and a step of dropping silicon-containing solution onto the substrate by rotating the stage at a second rotation speed. The method includes a second step of diffusing the silicon-containing solution on the substrate, and a third step of maintaining the stage rotated at a third rotation speed for a predetermined period of time so that the vaporized components of the silicon-containing solution are vaporized.

According to the present disclosure, a silicon film with good uniformity can be formed.

FIG. 1 is a flowchart illustrating an example of a silicon film forming method according to an embodiment. FIG. 2A is a diagram showing the state of a substrate when a silicon film is formed by the silicon film forming method according to the embodiment. FIG. 2B is a diagram showing the state of the substrate when a silicon film is formed by the silicon film forming method according to the embodiment. FIG. 2C is a diagram showing the state of the substrate when a silicon film is formed by the silicon film forming method according to the embodiment. FIG. 3 is a diagram showing a schematic configuration of the coating device according to the embodiment. FIG. 4 is a flowchart showing the process flow when applying a silicon-containing solution to a substrate in the silicon film forming method according to the embodiment. FIG. 5 is a diagram showing the results of an experiment in which a silicon film was formed.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the silicon film forming method disclosed in the present application will be described in detail with reference to the drawings. Note that the disclosed silicon film forming method is not limited by this embodiment.

By the way, when a coating film is formed by a spin coating method, defects such as crater-shaped holes may be formed on the surface of the coating film. When defects are formed on the coating film, defects are also formed on the silicon film formed by heating the coating film at a predetermined temperature. Therefore, it is expected to form a silicon film with good uniformity.

(Embodiment)
(Silicon film formation method)
A silicon film forming method according to an embodiment will be described. FIG. 1 is a flowchart illustrating an example of a silicon film forming method according to an embodiment. In this embodiment, a silicon film is formed on the substrate W according to the procedure shown in the flowchart of FIG. Below, the state of the substrate W when forming a silicon film according to the procedure shown in the flowchart of FIG. 1 will be explained with reference to FIGS. 2A to 2C. 2A to 2C are diagrams showing the state of the substrate W when a silicon film is formed by the silicon film forming method according to the embodiment.

A silicon-containing solution is applied to the substrate W to be processed (step S10). The substrate W has a structure as shown in FIG. 2A, for example. A cross-sectional view of the substrate W is shown in FIG. 2A. The substrate W is, for example, a silicon substrate such as a semiconductor wafer. For example, the first solvent contains a 6- to 8-membered monocyclic saturated carbocycle in its molecule and has a boiling point of less than 160°C, and the first solvent contains a saturated or partially saturated carbocyclic ring in its molecule and has a boiling point of 160°C or higher. A silicon-containing solution (hereinafter also referred to as "silane polymer solution") in which a silane polymer is dissolved in a mixed solvent containing a certain second solvent is applied to the substrate W to form a coating film as shown in FIG. 2B. 11 is formed.

Next, the substrate W is fired to solidify the silicon-containing solution and form a silicon film (step S11). The heating conditions are not particularly limited, and conditions conventionally used for forming a silicon film from a silane polymer may be employed. For example, when forming an amorphous silicon film, the coating film may be heated at 300 to 600°C (preferably 350 to 500°C) for 30 seconds to 300 minutes. For example, the substrate W is heated at 400° C. for 15 minutes. As a result, on the substrate W, the coating film 11 of the silicon-containing solution progresses in solidification. As shown in FIG. 2C, on the substrate W, the coating film 11 is solidified and converted into an amorphous silicon film 12 by being fired.

Next, the first solvent, second solvent, silane polymer, mixed solvent, and silane polymer solution used in the silicon film forming method according to the embodiment will be explained.

(First solvent)
The first solvent contains a 6- to 8-membered monocyclic saturated carbon ring in its molecule and has a boiling point of less than 160°C. By using the first solvent, it is possible to prepare silane polymer solutions using silane polymers of a wide range of molecular sizes. In addition, in this specification, "boiling point" means the boiling point under atmospheric pressure.

From the viewpoint of solubility of the silane polymer, in particular the ability to dissolve a silane polymer with a large molecular size, the first solvent preferably contains one 6- to 8-membered monocyclic saturated carbon ring in the molecule. It is more preferable that the compound contains one 7- or 8-membered monocyclic saturated carbon ring.

The 6- to 8-membered monocyclic saturated carbon ring may have a substituent as long as the solubility of the silane polymer is not impaired. The substituent is not particularly limited, and includes, for example, an alkyl group having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms). The number of substituents is not limited, and when a plurality of substituents are present, they may be the same or different from each other.

Examples of the first solvent include cyclohexane (81°C), cycloheptane (112°C), cyclooctane (151°C), methylcyclohexane (101°C), ethylcyclohexane (132°C), and dimethylcyclohexane (120 to 130°C). ), n-propylcyclohexane (157°C), isopropylcyclohexane (155°C), trimethylcyclohexane (136-145°C), and methylethylcyclohexane (148°C) (the boiling point is in parentheses).

Among these, from the viewpoint of being able to dissolve silane polymers having a wide range of molecular sizes, the first solvent is preferably a cycloalkane having 6 to 8 carbon atoms, more preferably a cycloalkane having 7 or 8 carbon atoms, and particularly preferably a cycloalkane having 7 or 8 carbon atoms. It is a cycloalkane having 8 carbon atoms. Therefore, in one particularly preferred embodiment, the first solvent is cyclooctane.

The lower limit of the boiling point of the first solvent is preferably 100°C or higher, more preferably 110°C or higher, 120°C or higher, or 130°C or higher, since the combination with the second solvent described later provides excellent silicon film forming properties. ℃ or higher.

As the first solvent, a solvent other than the solvent containing a monocyclic saturated carbon ring may be used. Examples of solvents other than those containing a monocyclic saturated carbon ring include toluene and benzene. Examples of toluene and benzene include hydrocarbon solvents such as n-heptane, n-octane, decane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydronaphthalene, and cyclohexylbenzene; ethylene glycol dimethyl ether; Ether solvents such as ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, p-dioxane; and propylene Mention may be made of aprotic polar solvents such as carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, dimethylsulfoxide, and cyclohexanone.

(Second solvent)
The second solvent contains a saturated carbocycle or a partially saturated carbocycle in its molecule and has a boiling point of 160°C or higher. By using the second solvent in combination with the first solvent, it becomes possible to form a silicon film with good film formability from silane polymers with a wide range of molecular sizes. As used herein, "partially saturated carbocycle" refers to a carbon ring in which any number of double bonds, excluding at least one double bond, of an unsaturated carbocycle are converted into single bonds by hydrogenation. It refers to a ring.

Here, when forming a silicon film from a silane polymer with a large molecular size or when forming a silicon film using a low concentration silane polymer solution, it has been difficult to form a silicon film on the entire surface of the substrate. There was a tendency to On the other hand, with a silane polymer solution that uses a second solvent in combination with a first solvent, even when using a silane polymer with a large molecular size or a low concentration silane polymer solution, the entire surface of the substrate can be coated. It is possible to form a silicon film on.

From the viewpoint of forming a silicon film with good film-forming properties from a silane polymer with a wide range of molecular sizes, especially a silane polymer with a large molecular size that has been considered difficult to form into a film, the second solvent has 8 to 12 molecules in the molecule. It is preferable to contain one member saturated carbocycle or partially saturated carbocycle. The saturated carbocycle or partially saturated carbocycle is preferably a polycyclic saturated carbocycle or partially saturated carbocycle, and more preferably a bicyclic saturated carbocycle or partially saturated carbocycle. When the second solvent contains a polycyclic partially saturated carbocyclic ring in its molecule, at least one ring constituting the polycyclic ring preferably has a saturated carbocyclic structure (that is, the degree of unsaturation is 0). . For example, when the second solvent contains a bicyclic partially saturated carbocyclic ring in its molecule, it is preferable that one ring of the bicyclic ring has a saturated carbocyclic structure and the other ring has an unsaturated carbocyclic structure. . Among these, in combination with the first solvent, the second solvent preferably contains a polycyclic saturated carbocycle in its molecule, and particularly preferably contains a bicyclic saturated carbocycle. In the second solvent, the saturated carbocycle or partially saturated carbocycle may have a substituent as long as it does not impede the film-forming properties of the silicon film. The substituent is not particularly limited, and includes, for example, an alkyl group having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms). The number of substituents is not limited, and when a plurality of substituents are present, they may be the same or different from each other.

Examples of the second solvent include decahydronaphthalene (decalin) (193°C), 1,2,3,4-tetrahydronaphthalene (tetralin) (207°C), methyldecahydronaphthalene (210°C), dimethyldecahydro Examples include naphthalene (224°C), ethyldecahydronaphthalene (226°C), and isopropyldecahydronaphthalene (241°C) (boiling point in parentheses).

Among these, the second solvent is preferably a bicycloalkane having 8 to 12 carbon atoms, from the viewpoint that in combination with the first solvent, a silicon film can be formed with particularly good film formability from silane polymers with a wide range of molecular sizes. , more preferably a bicycloalkane having 10 to 12 carbon atoms, particularly preferably a bicycloalkane having 10 carbon atoms. Therefore, in one particularly preferred embodiment, the second solvent is decahydronaphthalene.

The boiling point of the second solvent is preferably 20°C or more higher than the boiling point of the first solvent in order to form a silicon film with good film formation properties from silane polymers with a wide range of molecular sizes in combination with the first solvent. Preferably, the temperature is higher by 30°C or more, more preferably by 40°C or more. The upper limit of the boiling point of the second solvent is not particularly limited as long as a mixed solvent can be prepared in combination with the first solvent, but it can usually be 250°C or lower, 240°C or lower, or the like.

From the viewpoint of forming a silicon film with particularly good film formability from silane polymers having a wide range of molecular sizes, in a mixed solvent, when the volume of the first solvent is 1, the volume of the second solvent is preferably 2 or less. , more preferably 1 or less, further preferably 0.7 or less, or 0.5 or less. In particular, when using a mixed solvent in which the volume of the second solvent is 0.5 or less when the volume of the first solvent is 1, the molecular size such that the weight average molecular weight (Mw) exceeds 100,000 is Even when a very large silane polymer is used, it is possible to form a silicon film with good film formability.

If even a small amount of the second solvent is included in the mixed solvent, the advantages of using the mixed solvent can be enjoyed. For example, in a mixed solvent, when the volume of the first solvent is 1, the volume of the second solvent may be 0.001 or more, preferably 0.005 or more, more preferably 0.01 or more, 0. It is .02 or more, or 0.03 or more. In this specification, the volume ratio of the first solvent and the second solvent is a value calculated based on the volume of the first solvent and the volume of the second solvent at room temperature.

(silane polymer)
The silane polymer is not particularly limited as long as it can form a silicone film by heating. For example, a silane polymer (preferably polydihydrosilane) manufactured by a conventionally known method obtained by irradiating a photopolymerizable silane compound with light may be used. It's fine.

Examples of photopolymerizable silane compounds include chain silane compounds, cyclic silane compounds, and cage-shaped silane compounds. Among these, cyclic silane compounds are preferred because they have excellent photopolymerizability. Examples of the cyclic silane compound include cyclic silane compounds having one cyclic silane structure such as cyclotrisilane, cyclotetrasilane, cyclopentasilane, cyclohexasilane, cycloheptasilane, neopentasilane, and trisilane; 1,1 '-bicyclobutasilane, 1,1'-bicyclopentasilane, 1,1'-bicyclohexasilane, 1,1'-bicycloheptasilane, spiro[2,2]pentasilane, spiro[3,3]heptasilane, spiro [4,4] Cyclic silane compounds having two cyclic silane structures such as nonasilane; examples include silane compounds in which some or all of the hydrogen atoms are substituted with silyl groups or halogen atoms in these cyclic silane compounds.

In particular, from the viewpoint of easy synthesis with high purity, cyclopentasilane, cyclohexasilane, and cycloheptasilane are preferred, and cyclohexasilane is more preferred. Accordingly, in one embodiment, the silicon film deposition method may include the step of preparing a silane polymer by irradiating cyclohexasilane with light.

Light irradiation can be carried out under any conventionally known conditions. For example, the irradiation wavelength may range from 300 to 420 nm and the irradiation time may range from 0.1 seconds to 600 minutes.

(silane polymer solution)
The silane polymer solution can be prepared by dissolving the silane polymer in a mixed solvent containing the first solvent and the second solvent. This mixed solvent allows the preparation of silane polymer solutions using silane polymers of a wide range of molecular sizes.

The concentration of the silane polymer in the silane polymer solution (hereinafter also simply referred to as "solution concentration") depends on the molecular size of the silane polymer, but can be adjusted within a range of, for example, 30% by volume or less. From the viewpoint of forming a thin silicon film, the solution concentration is preferably 20% by volume or less, more preferably 10% by volume or less, even more preferably 5% by volume or less. Conventionally, when the solution concentration becomes low, it tends to become difficult to form a silicon film over the entire surface of the substrate W. On the other hand, the silane polymer solution of this embodiment can form a silicon film over the entire surface of the substrate W even when the solution concentration is low. In addition, the silane polymer solution of this embodiment has the advantage of being able to use a silane polymer with a large molecular size (as mentioned above, it can form a silicon film even at low concentrations), and has the advantage of being able to form an extremely thin silicon film on a substrate. It can be formed on the entire surface of W. The silane polymer solution of the present embodiment can have a solution concentration as low as 4% by volume or less, 3% by volume or less, or 2% by volume or less without deteriorating film formability. The lower limit of the solution concentration of the silane polymer solution of this embodiment is not particularly limited, but from the viewpoint of silicon film formability, it is usually 0.1 volume % or more, 0.3 volume % or more, 0.5 volume % The above may be possible. In this specification, the concentration of the silane polymer in the silane polymer solution is a value calculated based on the volume of the mixed solvent and the volume of the silane polymer at room temperature.

The silane polymer solution of this embodiment can be easily prepared to a predetermined concentration by mixing the silane polymer in a mixed solvent and stirring in a mild environment (preferably at room temperature and atmospheric pressure).

The silane polymer solution may contain other components as long as they do not inhibit the film-forming properties of the silicon film. Examples of such other components include dopants, surface tension modifiers, and the like. As the dopant, any known dopant conventionally used in forming n-type and p-type silicon films may be used. As the surface tension regulator, conventionally known surface tension regulators such as fluorine-based and silicone-based ones may be used.

(Application of silane polymer solution)
Examples of the method for applying the silane polymer solution to the substrate W include a spin coating method, a roll coating method, a curtain coating method, a dip coating method, a spray method, an inkjet method, and the like. Among these, from the viewpoint of forming a silicon film on the substrate W with good film-forming properties, it is preferable to apply the silane polymer solution by a spin coating method.

(Device configuration of coating device)
An example of a coating device that applies a silicon-containing solution using a spin coating method will be described with reference to FIG. 3. FIG. 3 is a diagram showing a schematic configuration of the coating device 50 according to the embodiment.

The coating device 50 includes a chamber 51, a stage 52, a rotation mechanism 53, a nozzle 54, and a cup 56.

Chamber 51 accommodates stage 52, rotation mechanism 53, nozzle 54, and cup 56. Note that an FFU (Fan Filter Unit), not shown, is provided on the ceiling of the chamber 51. The FFU forms a downflow within the chamber 51.

The stage 52 is provided approximately at the center of the chamber 51. The stage 52 is, for example, a porous chuck, and holds the substrate W horizontally by suction. The rotation mechanism 53 rotates the stage 52 around a vertical axis. As a result, the substrate W held on the stage 52 rotates in the horizontal direction.

The nozzle 54 is connected to a solution supply source 542 that supplies a silicon-containing solution via a supply equipment group 541 that includes a valve, a flow rate controller, and the like. The nozzle 54 discharges the silicon-containing solution supplied from the solution supply source 542 onto the substrate W.

The cup 56 is arranged so as to surround the substrate W held on the stage 52, and receives the silicon-containing solution scattered outward from the substrate W due to the rotation of the stage 52. A drain port 561 is formed at the bottom of the cup 56, and the silicon-containing solution received by the cup 56 is discharged to the outside of the coating device 50 from the drain port 561. Furthermore, an exhaust port 562 is formed at the bottom of the cup 56 for discharging downflow gas supplied from an FFU (not shown) to the outside of the coating device 50.

By the way, as described above, when the coating film 11 is formed by the spin coating method, defects such as crater-shaped holes may be formed on the surface of the coating film 11. When a defect is formed on the coating film 11, a defect is also formed on the amorphous silicon film 12.

Therefore, in the silicon film forming method according to the embodiment, the coating film 11 is formed by applying a silicon-containing solution as follows. When applying the silicon-containing solution, the substrate W is placed on the stage 52 of the application device 50.

The coating device 50 rotates the substrate W by driving the rotation mechanism 53 to rotate the stage 52 around the vertical axis. The coating device 50 then supplies the silicon-containing solution from the solution supply source 542 and supplies the silicon-containing solution from the nozzle 54 to the rotating substrate W. The coating device 50 changes the rotation speed of the substrate W in stages during coating of the silicon-containing solution. For example, the coating device 50 performs the first to third steps described below. FIG. 4 is a flowchart showing the process flow when applying a silicon-containing solution to the substrate W in the silicon film forming method according to the embodiment. FIG. 4 shows the detailed process flow of step S10 in FIG.

For example, in the first step, the coating device 50 supplies the silicon-containing solution from the solution supply source 542 while rotating the stage 52 at a first rotation speed, and supplies the silicon-containing solution from the nozzle 54 to the rotating substrate W. Drop it (S20). The first rotation speed is, for example, 500 to 1000 rpm. The rotation time is, for example, in the range of 1 to 3 seconds.

Next, as a second step, the coating device 50 rotates the stage 52 at a second rotation speed to diffuse the dropped silicon-containing solution on the substrate W (S21). It is assumed that the second rotational speed is slower than the first rotational speed. For example, the second rotation speed is 300 to 800 rpm. The rotation time is, for example, in the range of 10 to 20 seconds.

Then, as a third step, the coating device 50 shakes off the silicon-containing solution by maintaining the state in which the stage 52 is rotated at the third rotational speed for a predetermined period of time so that the vaporized components of the silicon-containing solution are vaporized (S22). It is assumed that the third rotational speed is faster than the first rotational speed and the second rotational speed. For example, the third rotation speed is 2400 to 5100 rpm. The ratio of the third rotational speed to the second rotational speed is preferably 3.0 to 17.0. The predetermined time for rotating at the third rotation speed is made longer than the time for the second step. For example, the predetermined period of time for rotating at the third rotation speed is in the range of 20 to 60 seconds.

As described above, in the silicon film forming method according to the embodiment, the coating film 11 of the silicon-containing solution is formed on the substrate W with good uniformity by performing the first to third steps and applying the silicon-containing solution. can. By baking the substrate W on which the coating film 11 is formed, a silicon film can be formed on the substrate W with good uniformity.

Next, the results of an experiment in which a silicon film was formed using the silicon film forming method according to the embodiment will be described. FIG. 5 is a diagram showing the results of an experiment in which a silicon film was formed. In the experiment, a silicon-containing solution was applied to three substrates W with IDs "1" to "3" while changing the rotation speed and rotation time of the first to third steps of the silicon film forming method according to the embodiment. A coating film 11 was formed by coating. The silane polymer solution was prepared by dissolving the silane polymer in a mixed solvent in which the first solvent was cyclooctane and the second solvent was decahydronaphthalene. The solution concentration of the silane polymer in the silane polymer solution was 20% by volume. Then, each substrate W was baked at 400° C. for 15 minutes to form an amorphous silicon film 12.

“Spin coat” in FIG. 5 shows changes in rotation speed and rotation time when spin coating a silicon-containing solution on substrates W with IDs “1” to “3”. The period of the first step is shown as t1, the period of the second step is shown as t2, and the period of the third step is shown as t3. For IDs "1" to "3", the rotation speed of the first step is 1000 rpm and the rotation time is 1 second, and the rotation speed of the second step is 500 rpm and the rotation time is 15 seconds. For ID "1", the rotation speed in the third step is 2500 rpm and the rotation time is 2 seconds. In ID "2", the rotation speed in the third step is 2500 rpm and the rotation time is 20 seconds. In ID "3", the rotation speed in the third step is 5000 rpm and the rotation time is 20 seconds. ID "2" and "3" are those obtained by applying the silane polymer solution by carrying out the first to third steps of the silicon film forming method according to the embodiment. On the other hand, ID "1" is a product in which the first and second steps of the silicon film forming method according to the embodiment were performed, but the period t3 of the third step was shortened to about 2 seconds and the silane polymer solution was applied. It is.

“SEM image” in FIG. 5 schematically shows the state of the amorphous silicon film 12 that has been formed. For ID "1", the period t3 of the third step is as short as about 2 seconds. As a result, with ID "1", a defect 13 is formed in the amorphous silicon film 12. The reason why Defect 13 is formed in this way is that during spin coating, the silane polymer solution has fluidity in the film at room temperature, so if the period t3 of the third step is short, the vaporized components of the silicon-containing solution will continue to vaporize even after the rotation has stopped. This is thought to be due to the formation of defects due to

Therefore, in the silicon film forming method according to the embodiment, in the third step, the state in which the stage 52 is rotated at the third rotational speed is maintained for a predetermined period of time so that the vaporized components of the silicon-containing solution are vaporized, and the silicon-containing solution is I'm shaking it off. For example, for IDs "2" and "3", the period t3 of the third step is longer than the period t2 of the second step. As a result, for IDs "2" and "3", no defects were formed in the amorphous silicon film 12, and amorphous silicon films 12 with good uniformity were formed. In this way, according to the silicon film forming method according to the embodiment, a silicon film with good uniformity can be formed.

[effect]
As described above, the silicon film forming method according to the embodiment includes the first step of dropping a silicon-containing solution onto the substrate W while rotating the stage 52 on which the substrate W is placed at the first rotation speed, and the first step of dropping the silicon-containing solution onto the substrate W. a second step in which the dropped silicon-containing solution is diffused on the substrate W by rotating at a second rotation speed; and a second step in which the stage 52 is rotated at a third rotation speed at a predetermined level so that the vaporized components of the silicon-containing solution are vaporized. and a third step of maintaining the time. Thereby, the silicon film forming method according to the embodiment can form a silicon film with good uniformity.

Further, in the silicon film forming method according to the embodiment, the second rotational speed is slower than the first rotational speed, and the third rotational speed is faster than the first rotational speed and the second rotational speed. , the predetermined time is set to be longer than the time of the second step. Thereby, in the silicon film forming method according to the embodiment, the vaporized components of the silicon-containing solution can be vaporized in the third step, so that a silicon film with good uniformity can be formed.

Further, in the silicon film forming method according to the embodiment, the first rotation speed is 500 to 1000 rpm, the second rotation speed is 300 to 800 rpm, and the third rotation speed is 2400 to 5100 rpm. Thereby, the silicon film forming method according to the embodiment can uniformly apply the silicon-containing solution to the substrate W.

Further, in the silicon film forming method according to the embodiment, the predetermined time of the third step is 20 to 60 seconds. Thereby, in the silicon film forming method according to the embodiment, the vaporized components of the silicon-containing solution can be vaporized in the third step, so that a silicon film with good uniformity can be formed.

Further, in the silicon film forming method according to the embodiment, the ratio of the third rotational speed to the second rotational speed is 3.0 to 17.0. Thereby, in the silicon film forming method according to the embodiment, the silicon-containing solution remaining on the etched portion of the substrate W can be shaken off in the third step, and the silicon-containing solution can be uniformly applied to the substrate W.

In addition, the silicon-containing solution contains a first solvent that contains a 6- to 8-membered monocyclic saturated carbocycle in its molecule and has a boiling point of less than 160°C, and a first solvent that contains a saturated or partially saturated carbocycle in its molecule and has a boiling point of less than 160°C. This is a solution in which a silane polymer is dissolved in a mixed solvent containing a second solvent whose temperature is 160°C or higher. By using such a silicon-containing solution, a silicon film can be formed from a silane polymer having a large molecular size with good film formability.

Although various exemplary embodiments have been described above, various additions, omissions, substitutions, and changes may be made without being limited to the exemplary embodiments described above. Also, elements from different embodiments may be combined to form other embodiments.

For example, in the above embodiment, the case where the substrate W is a silicon substrate has been described as an example, but the present invention is not limited to this. The substrate W includes, for example, a silicon substrate; a glass substrate; a transparent electrode such as ITO; a metal substrate such as gold, silver, copper, palladium, nickel, titanium, aluminum, or tungsten; a plastic substrate; and a substrate made of a composite material thereof. Can be mentioned.

11 Coating film 12 Amorphous silicon film 50 Coating device 51 Chamber 52 Stage 53 Rotating mechanism 54 Nozzle 56 Cup W Substrate

Claims (5)

A method for forming a silicon film by spin coating using a silicon-containing solution, the method comprising:
A first step of dropping the silicon-containing solution onto the substrate while rotating a stage on which the substrate is placed at a first rotation speed;
a second step of rotating the stage at a second rotational speed slower than the first rotational speed and diffusing the dropped silicon-containing solution on the substrate;
The stage is rotated at a third rotational speed faster than the first rotational speed and the second rotational speed for a period longer than the second step so that the vaporized components of the silicon-containing solution are vaporized. a third step of maintaining for a predetermined time;
A silicon film deposition method, including: The first rotation speed is 500 to 1000 rpm,
The second rotation speed is 300 to 800 rpm,
The silicon film forming method according to claim 1 , wherein the third rotation speed is 2400 to 5100 rpm. The silicon film forming method according to claim 1 or 2 , wherein the predetermined time is 20 to 60 seconds. The silicon film forming method according to any one of claims 1 to 3 , wherein the ratio of the third rotational speed to the second rotational speed is 3.0 to 17.0. The silicon-containing solution includes a first solvent that contains a 6- to 8-membered monocyclic saturated carbocycle in its molecule and has a boiling point of less than 160°C, and a first solvent that contains a saturated or partially saturated carbocycle in its molecule and has a boiling point of less than 160°C. The silicon film forming method according to any one of claims 1 to 4, wherein the solution is a solution in which a silane polymer is dissolved in a mixed solvent containing a second solvent having a temperature of 160° C. or higher.

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