JP2020136560A - Pretreatment method for dopant diffusion treatment and substrate processing apparatus - Google Patents

Abstract

To provide a pretreatment method for dopant diffusion treatment that can increase the thickness of a dopant film.SOLUTION: A pretreatment method for dopant diffusion treatment includes a placement step, a coating agent supply step, and a humidity adjustment step. In the placement step, a substrate is placed on a substrate holder. In the coating agent supply step S52, after the placement step, a coating agent containing a dopant is supplied to the surface of the substrate, and a liquid film of the coating agent is formed on the surface of the substrate. In the humidity adjustment step S51, the humidity of the upper atmosphere of the surface of the substrate is adjusted to within a predetermined first humidity range according to the coating agent. During at least a partial period of the coating agent supply step S52, the humidity of the upper atmosphere is maintained within the first humidity range.SELECTED DRAWING: Figure 5

Description

The present application relates to a pretreatment method for dopant diffusion treatment and a substrate processing apparatus.

Conventionally, a dry process such as an ion implantation method has been used as a method for adding impurities (dopants) to a semiconductor substrate. However, in such a dry step, when a tall three-dimensional fine structure (pattern) is formed on the surface of the semiconductor substrate, it is difficult to add a dopant to the side wall of the pattern. For example, when manufacturing a three-dimensional NAND (Not-AND) flash memory, tall patterns are formed at narrow intervals on the surface of the semiconductor substrate. When a dopant is implanted into such a semiconductor substrate by an ion implantation method, adjacent patterns become obstacles, and the ions of the dopant are unlikely to hit the side wall (particularly the lower part) of the pattern. Therefore, it is difficult to inject the dopant into the side wall (particularly the lower part) of the pattern.

In order to solve the above problem, a technique of applying an impurity diffusion composition to the surface of a semiconductor substrate to form a coating film on the surface of the semiconductor substrate and then performing a heat treatment to diffuse impurities to the semiconductor substrate is also used. (For example, Patent Documents 1 to 3). The impurity diffusion composition contains an impurity diffusion component, and the impurity diffusion component is, for example, a boron compound containing a nitrogen atom. In this case, the impurity (dopant) is boron. According to such a method, a coating film can be formed on the side wall of the pattern, and the dopant can be diffused on the side wall of the pattern.

Japanese Unexamined Patent Publication No. 2018-10734 Japanese Patent No. 6269760 JP-A-2017-174978

In order to diffuse a sufficient amount of dopant on the semiconductor substrate, it is desirable to increase the thickness of the coating film (hereinafter, also referred to as a dopant film) formed on the surface of the semiconductor substrate. This is because the amount of the dopant contained in the dopant film can be increased.

Therefore, an object of the present application is to provide a pretreatment method for dopant diffusion treatment and a substrate treatment apparatus capable of increasing the film thickness of the dopant film.

The first aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment, which comprises a mounting step of placing the substrate on the substrate holding portion and a coating containing a dopant after the pre-described placement step. The coating agent supply step of supplying the agent to the surface of the substrate and forming a liquid film of the coating agent on the surface of the substrate, and the humidity of the upper atmosphere of the surface of the substrate are applied to the coating agent. A humidity adjusting step for adjusting within a predetermined first humidity range corresponding to the above is provided, and the humidity of the upper atmosphere is maintained within the first humidity range for at least a part of the period of the coating agent supply step.

The second aspect of the pretreatment method of the dopant diffusion treatment is the pretreatment method of the dopant diffusion treatment according to the first aspect, which is executed between the pre-described step and the coating agent supply step, and is described above. The coating agent supply step further comprises a removal step of removing the natural oxide film on the surface of the substrate in a hypoxic state in which the oxygen concentration of the atmosphere is lower than the oxygen concentration of the upper atmosphere in the above-mentioned pre-described step. , Performed in the hypoxic state.

The third aspect of the pretreatment method of the dopant diffusion treatment is the pretreatment method of the dopant diffusion treatment according to the second aspect, which is executed between the pre-described step and the removal step to create the upper atmosphere. A blocking member arranging step of arranging the blocking member at a position facing the surface of the substrate is further provided, and in the removing step, the coating agent supply step, and the humidity adjusting step, the blocking member is arranged at the position. It is executed in the state of.

The fourth aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment according to the second or third aspect, and in the removal step, a chemical solution for removing the natural oxide film is applied to the substrate. After the first step of supplying the surface to the surface, a second step of supplying a rinsing solution for removing the chemical solution on the surface of the substrate, and after the second step, the substrate is provided. Includes a third step of drying.

The fifth aspect of the pretreatment method of the dopant diffusion treatment is the pretreatment method of the dopant diffusion treatment according to any one of the first to fourth aspects, and is to the coating agent supply step and the surface of the substrate. The present invention further includes a repetitive step of repeatedly executing a set of a stop step of stopping the supply of the treatment liquid of the above.

The sixth aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment according to any one of the first to fifth aspects, and the substrate is first rotated in the coating agent supply step. The pretreatment method of the dopant diffusion treatment, which is rotated at a speed, controls the rotation speed of the substrate to be lower than the first rotation speed, and holds the liquid film of the coating agent on the surface of the substrate. Further provided with a processing step.

The seventh aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment according to the sixth aspect, in which the rotation speed of the substrate is gradually reduced in the paddle treatment step.

The eighth aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment according to any one of the first to seventh aspects, and the substrate is dried after the coating agent supply step. Further provided with a drying step to allow.

A ninth aspect of the dopant diffusion treatment pretreatment method is the dopant diffusion treatment pretreatment method according to the eighth aspect, wherein the humidity of the upper atmosphere is the first aspect during at least a part of the drying step. It is maintained within a second humidity range lower than one humidity range.

The tenth aspect of the pretreatment method for the dopant diffusion treatment is the pretreatment method for the dopant diffusion treatment according to any one of the first to ninth aspects, wherein the liquid film is formed after the coating agent supply step. A flattening step of supplying a chemical solution for flattening to the surface of the substrate is further provided.

A mode of the substrate processing apparatus is a substrate processing apparatus, in which a substrate holding portion for holding a substrate and a coating agent containing a dopant are supplied to the surface of the substrate, and a liquid film of the coating agent is applied to the substrate. A coating agent supply unit formed on the surface, a humidity adjustment unit that adjusts the humidity of the upper atmosphere of the surface of the substrate within a predetermined first humidity range corresponding to the coating agent, and the coating agent on the substrate. The coating agent supply unit and the control unit that controls the humidity adjustment unit are provided so that the humidity of the upper atmosphere is maintained within the first humidity range for at least a part of the period during which the surface is supplied. ..

According to the first aspect of the pretreatment method for the dopant diffusion treatment and the aspect of the substrate processing apparatus, the film thickness of the coating film can be increased.

According to the second aspect of the pretreatment method of the dopant diffusion treatment, since the coating agent is supplied in a state where the natural oxide film is difficult to be formed, the coating film is easily formed on the surface of the substrate.

According to the third and fourth aspects of the pretreatment method for the dopant diffusion treatment, the volume of the upper atmosphere can be reduced, so that the humidity and oxygen concentration can be easily adjusted.

According to the fifth aspect of the pretreatment method of the dopant diffusion treatment, since the coating film can be laminated, the film thickness of the coating film as a whole can be further increased.

According to the sixth aspect of the pretreatment method of the dopant diffusion treatment, the fluidity of the liquid film of the coating agent can be reduced in the paddle treatment step. Therefore, the dopant in the coating agent is easily exposed. Therefore, the film thickness of the coating film can be further increased.

According to the seventh aspect of the pretreatment method of the dopant diffusion treatment, the thickness of the liquid film of the coating agent can be easily adjusted.

According to the eighth aspect of the pretreatment method of the dopant diffusion treatment, a substrate on which a coating film is formed can be produced.

According to the ninth aspect of the pretreatment method of the dopant diffusion treatment, since the water content in the upper atmosphere is reduced, the amount of water mixed in the coating agent from the upper atmosphere can be reduced. Therefore, the drying time can be shortened.

According to the tenth aspect of the pretreatment method of the dopant diffusion treatment, the surface of the coating film can be flattened.

It is a figure which shows a schematic example of the structure of the substrate processing apparatus. It is a figure which shows an example of the structure inside the chamber schematicly. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a figure which shows a schematic example of the structure of the humidity adjustment part. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a graph which shows an example of the change of the rotation speed.

Hereinafter, embodiments will be described with reference to the attached drawings. It should be noted that the drawings are shown schematically, and for convenience of explanation, the configuration is omitted or the configuration is simplified as appropriate. Further, the interrelationship between the sizes and positions of the configurations shown in the drawings is not always accurately described and can be changed as appropriate.

Further, in the description shown below, similar components are illustrated with the same reference numerals, and their names and functions are also the same. Therefore, detailed description of them may be omitted to avoid duplication.

The first embodiment.
<Outline of board processing equipment>
FIG. 1 is a diagram schematically showing an example of the configuration of the substrate processing apparatus 1. The substrate processing apparatus 1 is an apparatus that supplies a liquid coating agent containing a dopant to the surface of a semiconductor substrate W1 (hereinafter, substrate W1) to form a coating film (hereinafter, dopant film) on the surface of the substrate W1. The substrate W1 on which the dopant film is formed is carried out from the substrate processing apparatus 1 and appropriately conveyed to an annealing processing apparatus (not shown). The annealing treatment apparatus appropriately anneals the substrate W1 on which the dopant film is formed, thereby diffusing the dopant into the substrate W1. As a result, a semiconductor layer having a predetermined conductive type can be formed on the substrate W1.

By the way, a fine three-dimensional structure (pattern) may be formed on the upper surface of the substrate W1 by the processing before being carried into the substrate processing apparatus 1. That is, the substrate W1 may be carried into the substrate processing device 1 in a state where a three-dimensional fine structure is formed on the upper surface thereof. For example, in the case of manufacturing a three-dimensional NAND flash memory as a semiconductor device, tall patterns are formed at narrow intervals on the upper surface of the substrate W1, and the substrate W1 is carried into the substrate processing device 1 in that state. The minimum value of the spacing between the patterns formed on the upper surface of the substrate W1 is, for example, 100 [nm] or less, and the maximum value of the aspect ratio of the patterns is, for example, 40 or more.

The substrate processing apparatus 1 supplies a liquid coating agent to the upper surface of the substrate W1 to form a dopant film on the upper surface of the substrate W1. According to this, the dopant film can be appropriately formed on the side wall of the pattern of the substrate W1. Further, by the annealing treatment, the dopant can be appropriately diffused also on the side wall of the pattern. Therefore, this substrate processing apparatus 1 is particularly effective for the substrate W1 on which the three-dimensional fine structure is formed.

<Details of board processing equipment>
With reference to FIG. 1, the substrate processing apparatus 1 includes a chamber 2, a substrate holding unit 3, a coating agent supply unit 4, a humidity adjusting unit 5, and a control unit 10. The chamber 2 is, for example, a hollow member having a substantially rectangular parallelepiped outer shape. In the example of FIG. 1, a fan filter unit 21 is provided above the chamber 2. The fan filter unit 21 sends clean air downward from the ceiling of the chamber 2 into the chamber 2. As a result, a downflow that flows downward in the chamber 2 is formed. The substrate W1 is processed in a state where a downflow is formed in the chamber 2.

A shutter (not shown) for loading / unloading the substrate W1 is provided on the side wall of the chamber 2. A substrate transfer robot (not shown) is provided outside the substrate processing device 1, and the substrate transfer robot transfers the substrate processing device 1 and the substrate W1 with the shutter open.

The substrate holding portion 3 is provided in the chamber 2 and holds the substrate W1 carried in from the substrate transfer robot. The substrate holding portion 3 holds the substrate W1 in a horizontal posture in which the thickness direction of the substrate W1 is along the vertical direction. The substrate holding portion 3 also includes a rotation mechanism 33 for rotating the substrate W1. The rotation mechanism 33 rotates the substrate W1 around a substantially vertical rotation axis A1 passing through the central portion of the substrate W1. The rotation mechanism 33 is controlled by the control unit 10.

In the example of FIG. 1, the substrate holding portion 3 includes a base 31, a plurality of chuck pins 32, and a rotation mechanism 33. The base 31 has a substantially disk-shaped outer shape, and its upper surface is provided so as to face the lower surface of the substrate W1. In the example of FIG. 1, the outer diameter of the base 31 is larger than the diameter of the substrate W1. The plurality of chuck pins 32 are erected on the upper surface of the base 31. These plurality of chuck pins 32 are arranged in an annular shape at intervals along the peripheral edge of the substrate W1. The plurality of chuck pins 32 hold the peripheral edge of the substrate W1.

In the example of FIG. 1, the rotation mechanism 33 is provided on the floor plate of the chamber 2 below the base 31. The rotation mechanism 33 includes a motor (not shown). In the example of FIG. 1, one end below the shaft 331 is connected to the motor, and the other end above the shaft 331 is connected to the lower surface of the base 31. The motor rotates the shaft 331 to rotate the base 31 around the rotation axis A1. As a result, the substrate W1 rotates around the rotation axis A1.

The coating agent supply unit 4 supplies the coating agent to the surface of the substrate W1 held by the substrate holding unit 3. This coating agent contains a dopant. As the dopant, for example, boron can be adopted. As a more specific example, the coating agent contains a compound having a dopant (hereinafter, also referred to as a dopant compound) and an organic solvent. As the dopant compound, for example, an organic boron compound can be adopted. As the organic solvent, for example, PGMEA (propylene glycol monomethyl ether acetate) or PGME (propylene glycol monomethyl ether) can be adopted.

The coating agent supply unit 4 includes a nozzle 41, a supply pipe 42, a supply valve 43, and a coating agent supply source 44. The nozzle 41 is connected to the coating agent supply source 44 via the supply pipe 42. The coating agent supply source 44 supplies the coating agent to the supply pipe 42. The supply valve 43 is provided in the middle of the supply pipe 42, and switches the opening and closing of the flow path in the supply pipe 42. The supply valve 43 is controlled by the control unit 10. The supply valve 43 may be a valve capable of adjusting the flow rate of the coating agent.

In the example of FIG. 1, the nozzle 41 is provided in the chamber 2 above the substrate holding portion 3. When the supply valve 43 is opened, the nozzle 41 discharges the coating agent onto the upper surface of the substrate W1 held by the substrate holding portion 3.

In the example of FIG. 1, the nozzle 41 is provided at a position facing the central portion of the upper surface of the substrate W1 in the vertical direction. Therefore, the coating agent discharged from the nozzle 41 lands on the central portion. When the coating agent supply unit 4 supplies the coating agent while the substrate holding unit 3 rotates the substrate W1, the coating agent on the upper surface of the substrate W1 spreads over the entire surface of the substrate W1 due to centrifugal force, and the peripheral edge of the substrate W1 is spread. Scatter from.

In the supply treatment of the coating agent, the compound contained in the coating agent reacts with the moisture in the air (hydrolysis), and as a result, a dopant film containing a dopant is formed on the upper surface of the substrate W1. The dopant film can also be called a molecular film.

When the viscosity of the coating agent is high, irregularities may be formed on the surface of the dopant film formed on the upper surface of the substrate W1. That is, the variation in the film thickness of the dopant film may become large. In this case, the substrate processing apparatus 1 may perform a flattening step of flattening the surface of the dopant film. In the example of FIG. 1, the substrate processing apparatus 1 further includes a first chemical solution supply unit 6 for performing a flattening step. The first chemical solution supply unit 6 supplies the first chemical solution for flattening the dopant film to the upper surface of the substrate W1. The first chemical solution is, for example, a solvent for a dopant film, and for example, PGMEA can be adopted. The first chemical solution supply unit 6 supplies the first chemical solution to the surface of the rotating substrate W1. The first chemical solution receives the centrifugal force of the substrate W1 and spreads on the upper surface of the substrate W1 and scatters from the peripheral edge of the substrate W1. In this flattening step, the first chemical solution acts on the entire surface of the dopant film on the substrate W1 to flatten the surface thereof.

The first chemical solution supply unit 6 includes a nozzle 61, a supply pipe 62, a supply valve 63, and a chemical solution supply source 64. The nozzle 61 is connected to the chemical solution supply source 64 via the supply pipe 62. The chemical solution supply source 64 supplies the first chemical solution to the supply pipe 62. The supply valve 63 is provided in the middle of the supply pipe 62, and switches the opening and closing of the flow path in the supply pipe 62. The supply valve 63 is controlled by the control unit 10. The supply valve 63 may be a valve capable of adjusting the flow rate of the first chemical solution.

In the example of FIG. 1, both the nozzle 41 and the nozzle 61 are provided at positions facing the central portion of the substrate W1. More specifically, the nozzle 41 and the nozzle 61 have, for example, a substantially cylindrical shape, one of which is concentrically provided inside the other (see also FIG. 2). For example, the nozzle 41 is provided inside the nozzle 61. That is, the outer diameter of the nozzle 41 is set smaller than the inner diameter of the nozzle 61. The nozzle 41 and the nozzle 61 are provided so that their central axes are along the vertical direction. In this case, the coating agent flows inside the nozzle 41, and the first chemical solution flows between the inner peripheral surface of the nozzle 61 and the outer peripheral surface of the nozzle 41. The first chemical solution is applied to the central portion of the substrate W1 in the same manner as the coating agent.

In the example of FIG. 1, a cup 9 is also provided in the chamber 2. The cup 9 surrounds the substrate holding portion 3 around the rotation axis A1. The cup 9 receives the treatment liquid (including the chemical liquid, the coating agent, and the rinse liquid described later) scattered from the peripheral edge of the substrate W1 and discharges the treatment liquid to a drainage portion (not shown). Further, the gas inside the cup 9 is sucked into the exhaust unit 91 and discharged to the exhaust unit 91.

The cup 9 can be raised and lowered by the raising and lowering mechanism 92. The elevating mechanism 92 has, for example, a ball screw mechanism and is controlled by the control unit 10. The elevating mechanism 92 elevates the cup 9 between the upper position and the lower position. The lower position (position shown in FIG. 1) is a standby position in which the upper end of the cup 9 is located below the upper surface of the base 31. The upper position (the position shown in FIG. 2 described later) is a position above the lower position. The elevating mechanism 92 is controlled by the control unit 10.

The humidity adjusting unit 5 adjusts the humidity of the space in the chamber 2. More specifically, the humidity adjusting unit 5 adjusts the humidity of the processing space (upper atmosphere) H1 in contact with the upper surface of the substrate W1. In the example of FIG. 1, the humidity adjusting unit 5 includes a first gas supply unit 50. The first gas supply unit 50 supplies the inert gas to the processing space H1. As the inert gas, for example, nitrogen or argon can be adopted. By supplying this inert gas, at least a part of the air in the processing space H1 is pushed out of the processing space H1 and exhausted to, for example, the exhaust unit 91. That is, at least a part of the air in the processing space H1 can be replaced with an inert gas. Since the water content of the inert gas is very small, the humidity of the treatment space H1 can be lowered by the substitution.

The first gas supply unit 50 includes a nozzle 51, a supply pipe 52, a supply valve 53, and a gas supply source 54. The nozzle 51 is connected to the gas supply source 54 via the supply pipe 52. The gas supply source 54 supplies the inert gas to the supply pipe 52. The supply valve 53 is provided in the middle of the supply pipe 52, and switches the opening and closing of the flow path in the supply pipe 52. The supply valve 53 is controlled by the control unit 10. The supply valve 53 may be a valve capable of adjusting the flow rate of the inert gas.

In the example of FIG. 1, the nozzle 51 is provided above the substrate W1 at a position facing the central portion of the substrate W1 in the vertical direction. Specifically, the nozzle 41 and the nozzle 61 are provided inside the nozzle 51. The inner peripheral surface of the nozzle 51 has a substantially cylindrical shape, and the central axis thereof is arranged in a vertical direction. The nozzle 41 and the nozzle 61 are provided inside the nozzle 51 concentrically with each other.

In the example of FIG. 1, the substrate processing device 1 further includes a blocking member 7. The blocking member 7 is provided in the chamber 2. Specifically, the blocking member 7 is provided at a position above the substrate W1 held by the substrate holding portion 3 and facing the substrate W1 with the processing space H1 facing each other. The space between the blocking member 7 and the substrate W1 corresponds to the processing space H1.

The blocking member 7 can be raised and lowered by the raising and lowering mechanism 75. The elevating mechanism 75 has, for example, a ball screw mechanism and is controlled by the control unit 10. The elevating mechanism 75 elevates the blocking member 7 between the standby position and the processing position. The processing position is the position of the blocking member 7 when the processing for the substrate W1 is performed, and is a position below the standby position. Therefore, when the blocking member 7 is located at the processing position, the spacing between the blocking member 7 and the substrate W1 (the spacing along the vertical direction) is relatively narrow, and the spacing is set to, for example, about several [mm]. To. According to this, the volume of the processing space H1 can be reduced. Therefore, the humidity adjusting unit 5 can adjust the humidity of the processing space H1 with less inert gas.

The standby position is a position above the processing position, and is a position where the blocking member 7 does not hinder the transfer of the substrate W1 between the external substrate transfer robot and the substrate holding portion 3.

FIG. 2 is a diagram schematically showing an example of the configuration of the blocking member 7. In the example of FIG. 2, a part of the substrate W1, the substrate holding portion 3, and the cup 9 is also shown. FIG. 2 shows a state in which the blocking member 7 is located at the processing position.

In the example of FIG. 2, the blocking member 7 includes a disk portion 71 and a cylindrical portion 72. The disk portion 71 is provided so that its thickness direction is along the vertical direction. The lower surface of the disk portion 71 faces the upper surface of the substrate W1 and is substantially parallel to the upper surface of the substrate W1. The space between the disk portion 71 and the substrate W1 corresponds to the processing space H1. At the processing position, the distance between the disk portion 71 and the substrate W1 is set to, for example, several [mm]. The lower surface of the disk portion 71 is, for example, at least half the area of the upper surface of the substrate W1 and faces the substrate W1. In other words, the area of the region of the lower surface of the disk portion 71 facing the substrate W1 is, for example, half or more of the area of the upper surface of the substrate W1. Thereby, the volume of the processing space H1 can be effectively reduced. Further, in the example of FIG. 1, the outer peripheral edge of the blocking member 7 (disk portion 71) is located outside the peripheral edge of the substrate W1. According to this, the substrate W1 and the blocking member 7 can more effectively reduce the volume of the processing space H1.

The cylindrical portion 72 projects downward from the outer peripheral edge of the disc portion 71. In the example of FIG. 2, the outer diameter of the disk portion 71 is larger than the diameter of the substrate W1 and the outer diameter of the substrate holding portion 3, and the cylindrical portion 72 is located radially outside the substrate holding portion 3. The lower end of the cylindrical portion 72 is located below the upper surface of the base 31 when the blocking member 7 is stopped at the processing position. A gap is formed between the cylindrical portion 72 and the base 31, and the treatment liquid flows out to the cup 9 through the gap. The upper end of the cup 9 is located radially outside the blocking member 7. At the processing position, the upper end of the cup 9 is located above the lower end of the cylindrical portion 72.

A through hole is formed in the central portion of the disk portion 71. In the example of FIG. 2, this through hole forms an internal space on the tip end side of the nozzle 51. That is, the disk portion 71 constitutes the tip portion of the nozzle 51, and the nozzle 51 is integrally formed with the blocking member 7. In the example of FIG. 1, the nozzles 41 and 61 are connected to the blocking member 7. In this case, the nozzles 41, 51, 61 and the blocking member 7 move up and down integrally.

In the example of FIG. 1, the substrate processing apparatus 1 further includes a second gas supply unit 500. The second gas supply unit 500 supplies an inert gas (for example, nitrogen) to the lower surface of the substrate W1 held by the substrate holding unit 3. The second gas supply unit 500 includes a nozzle 511, a supply pipe 521, a supply valve 531 and a gas supply source 541. The nozzle 511 penetrates the central portion of the base 31 along the vertical direction, and its discharge port faces the central portion of the lower surface of the substrate W1. The nozzle 511 is connected to the gas supply source 541 via the supply pipe 521. The gas supply source 541 supplies the inert gas to the supply pipe 521. In the example of FIG. 1, the shaft 331 is a hollow shaft, and a part of the supply pipe 521 is provided in the internal space of the shaft 331.

The supply valve 531 is provided in the middle of the supply pipe 521, and switches the opening and closing of the flow path in the supply pipe 521. The supply valve 531 is controlled by the control unit 10. The supply valve 531 may be a valve capable of adjusting the flow rate of the inert gas.

When the supply valve 531 is opened, the inert gas is supplied from the nozzle 511 to the lower surface side of the substrate W1. The inert gas flows in the space between the lower surface of the substrate W1 and the upper surface of the base 31, and blows out from the opening between the peripheral edge of the substrate W1 and the peripheral edge of the base 31. According to this, the processing liquid wrapping around from the upper surface to the side surface of the substrate W1 can be blown outward by the gas. Therefore, it is possible to prevent the processing liquid from wrapping around to the lower surface of the substrate W1.

By the way, when the substrate W1 is carried into the substrate processing apparatus 1, a natural oxide film may be formed on the upper surface of the substrate W1. When a natural oxide film is present on the upper surface of the substrate W1, the natural oxide film can inhibit the formation of the coating film. Therefore, in such a case, it is desirable to first remove this natural oxide film.

In the example of FIG. 1, the substrate processing apparatus 1 further includes a removal processing unit 80 for removing the natural oxide film of the substrate W1. The removal processing unit 80 includes a second chemical solution supply unit 81, a first rinse liquid supply unit 82, and a second rinse liquid supply unit 83.

The second chemical solution supply unit 81 supplies the second chemical solution for removing the natural oxide film to the surface of the substrate W1. As the second chemical solution, for example, dilute hydrofluoric acid (DHF) can be adopted. The second chemical supply unit 81 includes a nozzle 811, a supply pipe 821, a supply valve 831, and a chemical liquid supply source 841. In the example of FIG. 1, the nozzle 811 is provided above the substrate W1 at a position facing the central portion of the substrate W1 in the vertical direction. More specifically, the nozzles 811 are also provided concentrically with the nozzles 41, 51, and 61. The nozzle 811 is connected to the chemical supply source 841 via the supply pipe 821. The chemical supply source 841 supplies the second chemical solution to the supply pipe 821. The supply valve 831 is provided in the middle of the supply pipe 821, and switches the opening and closing of the flow path in the supply pipe 821. The supply valve 831 is controlled by the control unit 10. The supply valve 831 may be a valve capable of adjusting the flow rate of the second chemical solution.

The first rinse liquid supply unit 82 supplies the first rinse liquid to the upper surface of the substrate W1 and removes (washes out) the second chemical liquid on the substrate W1. That is, the second chemical solution on the upper surface of the substrate W1 is replaced with the first rinse solution. As the first rinsing liquid, for example, pure water can be adopted. The first rinse liquid supply unit 82 includes a nozzle 811, a supply pipe 822, a supply valve 832, and a rinse liquid supply source 842. Here, the nozzle 811 is also used as the first chemical solution and the first rinse solution. The nozzle 811 is also connected to the rinse liquid supply source 842 via the supply pipe 822. The rinse liquid supply source 842 supplies the first rinse liquid to the supply pipe 822. The supply valve 832 is provided in the middle of the supply pipe 822, and switches the opening and closing of the flow path in the supply pipe 822. The supply valve 832 is controlled by the control unit 10. The supply valve 832 may be a valve capable of adjusting the flow rate of the first rinse liquid.

The supply valves 831, 832 are controlled to open and close exclusively with each other. When the supply valve 831 is open and the supply valve 832 is closed, the second chemical solution is discharged from the nozzle 811, and when the supply valve 831 is closed and the supply valve 832 is open, the first rinse solution is discharged from the nozzle 811. It is discharged.

The second rinse liquid supply unit 83 supplies the second rinse liquid to the upper surface of the substrate W1 and removes (washes out) the first rinse liquid on the substrate W1. That is, the first rinse liquid on the upper surface of the substrate W1 is replaced with the second rinse liquid. The second rinse liquid is a liquid having higher volatility than the first rinse liquid. As the second rinsing solution, for example, IPA (isopropyl alcohol) can be adopted. The second rinse liquid supply unit 83 includes a nozzle 813, a supply pipe 823, a supply valve 833, and a rinse liquid supply source 843. In the example of FIG. 1, the nozzle 813 is provided above the substrate W1 at a position facing the central portion of the substrate W1 in the vertical direction. More specifically, the nozzle 813 is also provided concentrically with the nozzles 41, 51, 61, 811. The nozzle 813 is connected to the rinse liquid supply source 843 via the supply pipe 823. The rinse liquid supply source 843 supplies the second rinse liquid to the supply pipe 823. The supply valve 833 is provided in the middle of the supply pipe 823, and switches the opening and closing of the flow path in the supply pipe 823. The supply valve 833 is controlled by the control unit 10. The supply valve 833 may be a valve capable of adjusting the flow rate of the second rinse liquid.

<Board processing method>
Next, an example of the operation of the substrate processing device 1 will be described. The substrate processing apparatus 1 illustrated in FIG. 1 includes a removal processing unit 80 as described above. Therefore, here, an embodiment in which the natural oxide film is removed will be described. Further, the substrate processing apparatus 1 illustrated in FIG. 1 includes a first chemical solution supply unit 6 as described above. Therefore, here, an embodiment in which the dopant film flattening step is performed will be described.

FIG. 3 is a flowchart showing an example of the operation of the substrate processing device 1. First, in step S1 (mounting step), the substrate W1 is carried into the substrate processing device 1. Specifically, the control unit 10 opens the shutter of the chamber 2, and the substrate transfer robot places the substrate W1 on the substrate holding unit 3 in the chamber 2 through the opening of the shutter. The substrate holding unit 3 holds the substrate W1. After that, the control unit 10 closes the shutter of the chamber 2.

Next, in step S2 (blocking member arranging step), the blocking member 7 is arranged at the processing position. Specifically, the control unit 10 controls the elevating mechanism 75 to lower the blocking member 7 from the standby position to the processing position. As a result, the volume of the processing space H1 can be reduced. The steps described below are executed with the blocking member 7 arranged at the processing position.

Next, in step S3, the substrate holding portion 3 rotates the substrate W1. Specifically, the control unit 10 controls the rotation mechanism 33 to rotate the substrate W1 at a predetermined rotation speed.

Next, in step S4 (removal step), the natural oxide film is removed. FIG. 4 is a flowchart showing an example of a specific operation of the removal process of the natural oxide film. First, in step S41, the first gas supply unit 50 lowers the oxygen concentration and humidity of the processing space H1. Specifically, the control unit 10 supplies the inert gas (for example, nitrogen) from the nozzle 51 to the processing space H1 by opening the supply valve 53. As a result, at least a part of the air in the processing space H1 is pushed out of the processing space H1 by the inert gas. That is, at least a part of the air in the processing space H1 is replaced with the inert gas. As a result, the oxygen concentration in the processing space H1 becomes lower than the oxygen concentration (initial concentration value) in the chamber 2 in step S1. It can be said that the first gas supply unit 50 is an oxygen concentration adjusting unit that adjusts the oxygen concentration of the processing space H1.

As a more specific example, the oxygen concentration is reduced to about 1 [%] or less (for example, 0.1 [%]). By this treatment, the humidity of the treatment space H1 is also lower than the humidity (initial value of humidity) in the chamber 2 in step S1. As a more specific example, the humidity is reduced to about several [%] or less (for example, about 3 [%] or less). The steps described below are performed in a state where the oxygen concentration in the treatment space H1 is lower than the initial concentration value and the humidity in the treatment space H1 is lower than the initial humidity value.

In the example of FIG. 1, the substrate processing apparatus 1 includes the second gas supply unit 500 as described above. In step S41, the control unit 10 also opens the supply valve 531 of the second gas supply unit 500 to supply the inert gas to the lower surface of the substrate W1.

When the oxygen concentration and humidity of the processing space H1 are sufficiently lowered, in step S42, the second chemical solution supply unit 81 supplies the second chemical solution to the upper surface of the substrate W1. Specifically, when the first predetermined time has elapsed from the start of step S41, the control unit 10 opens the supply valve 831 in step S42. As a result, the second chemical solution is discharged from the nozzle 811 onto the upper surface of the substrate W1. The second chemical solution deposited on the upper surface of the substrate W1 spreads on the upper surface of the substrate W1 due to the centrifugal force accompanying the rotation of the substrate W1 and scatters outward from the peripheral edge of the substrate W1. Since the second chemical solution acts on the entire upper surface of the substrate W1, the natural oxide film can be removed on the entire upper surface of the substrate W1. When the natural oxide film is sufficiently removed, the control unit 10 closes the supply valve 831 and ends the discharge of the second chemical solution. For example, when the second predetermined time has elapsed from the start of step S42, the control unit 10 closes the supply valve 831.

Next, in step S43, the first rinse liquid supply unit 82 supplies the first rinse liquid to the upper surface of the substrate W1. Specifically, the control unit 10 opens the supply valve 832 to discharge the first rinse liquid from the nozzle 811 onto the upper surface of the substrate W1. As a result, the second chemical solution on the upper surface of the substrate W1 is replaced with the first rinse solution. When the second chemical solution is sufficiently replaced with the first rinse solution, the control unit 10 closes the supply valve 832 and ends the discharge of the first rinse solution. For example, when a third predetermined time has elapsed from the start of step S43, the control unit 10 closes the supply valve 832.

Next, in step S44, the second rinse liquid supply unit 83 supplies the second rinse liquid to the upper surface of the substrate W1. Specifically, the control unit 10 opens the supply valve 833 to discharge the second rinse liquid from the nozzle 813 onto the upper surface of the substrate W1. As a result, the first rinse liquid on the upper surface of the substrate W1 is replaced with the second rinse liquid having high volatility. When the first rinse liquid is sufficiently replaced with the second rinse liquid, the control unit 10 closes the supply valve 833 and ends the discharge of the second rinse liquid. For example, when the fourth predetermined time has elapsed from the start of step S44, the control unit 10 closes the supply valve 833.

Next, in step S45 (drying step), the control unit 10 performs a drying process for drying the substrate W1. As a specific example, the control unit 10 controls the rotation mechanism 33 to increase the rotation speed of the substrate W1 (so-called spin dry). Due to this increase in the rotation speed, the amount of the second rinse liquid scattered from the peripheral edge of the substrate W1 increases, and the second rinse liquid easily volatilizes. Further, since the volatility of the second rinse liquid is higher than that of the first rinse liquid, the substrate W1 is easy to dry. When the substrate W1 is sufficiently dried, the control unit 10 controls the rotation mechanism 33 to reduce the rotation speed of the substrate W1. For example, when the fifth predetermined time elapses from the start of step S45, the control unit 10 reduces the rotation speed of the substrate W1.

With reference to FIG. 1, the coating film forming process is then executed in step S5. FIG. 5 is a flowchart showing an example of a specific operation of the coating film forming process. First, in step S51 (humidity adjusting step), the humidity adjusting unit 5 adjusts the humidity of the processing space H1 so that the humidity is within a predetermined first humidity range according to the coating agent. The first humidity range depending on the coating agent is, for example, 20 to 40 [%]. The control unit 10 controls the supply valve 53 to reduce the flow rate of the inert gas supplied to the processing space H1 to be lower than the flow rate in step S4. When the flow rate of the inert gas decreases, the amount of air entering the processing space H1 from the outside of the processing space H1 increases. Since the humidity (initial value of humidity) of the air outside the processing space H1 is high (for example, 40 [%] or more), the humidity of the processing space H1 increases. As a specific example, the control unit 10 controls the humidity of the processing space H1 to, for example, 25 [%]. The flow rate of the inert gas may be preset, for example, so that the humidity falls within the first humidity range.

For example, after the sixth predetermined time has elapsed from the start of step S51, in step S52 (coating agent supply step), the coating agent supply unit 4 supplies the coating agent to the upper surface of the substrate W1 and applies the coating agent liquid film to the substrate W1. It is formed on the upper surface of. Specifically, the control unit 10 opens the supply valve 43 to discharge the coating agent from the nozzle 41 onto the upper surface of the substrate W1. In this step S52, the coating agent is supplied while the humidity is maintained within the first humidity range. The humidity does not necessarily have to be maintained within the first humidity range during the entire period of step S52, and the humidity may be maintained within the first humidity range for at least a part of the period. The flow rate of the coating agent in step S52 is set to, for example, several hundreds (for example, 300) [mL / min], and the rotation speed of the substrate W1 is set to, for example, several hundreds [rpm].

The coating agent that has landed on the upper surface of the substrate W1 spreads on the upper surface of the substrate W1 due to the centrifugal force accompanying the rotation of the substrate W1 and scatters outward from the peripheral edge of the substrate W1. The dopant compound (for example, an organoboron compound) in the coating agent is hydrolyzed with water in the treatment space H1, and as a result, a dopant film is formed on the upper surface of the substrate W1. When a dopant film having a sufficient film thickness is formed on the upper surface of the substrate W1, the control unit 10 closes the supply valve 43 and ends the discharge of the coating agent. For example, when a seventh predetermined time (for example, about several seconds to several tens of seconds) has elapsed from the start of step S52, the control unit 10 closes the supply valve 43.

Next, in step S53 (flattening step), the first chemical solution supply unit 6 supplies the first chemical solution to the upper surface of the substrate W1. Specifically, the control unit 10 opens the supply valve 63 to discharge the first chemical solution from the nozzle 61 onto the upper surface of the substrate W1. The first chemical solution that has landed on the upper surface of the substrate W1 spreads on the upper surface of the substrate W1 due to the centrifugal force accompanying the rotation of the substrate W1 and scatters outward from the peripheral edge of the substrate W1. As a result, the surface of the dopant film is more flattened. In other words, variations in the film thickness of the dopant film can be reduced. When the variation in the film thickness of the dopant film is sufficiently reduced, the control unit 10 closes the supply valve 63 and ends the discharge of the first chemical solution. For example, when the eighth predetermined time has elapsed from the start of step S53, the control unit 10 closes the supply valve 63.

Next, in step S54, the humidity adjusting unit 5 adjusts the humidity of the processing space H1 so that the humidity is within the second humidity range lower than the first humidity range. The second humidity range lower than the first humidity range means that the upper limit of the second humidity range is lower than the lower limit of the first humidity range. Specifically, the control unit 10 controls the supply valve 53 to increase the flow rate of the inert gas supplied to the processing space H1. When the flow rate of the inert gas increases, more air in the processing space H1 is pushed out and replaced with the low humidity inert gas. As a result, the humidity of the processing space H1 decreases. The second humidity range is, for example, a range of 3 [%] or less. The flow rate of the inert gas in step S54 may be preset, for example, so that the humidity falls within the second humidity range.

For example, after the ninth predetermined time has elapsed from the start of step S54, in step S55 (drying step), the control unit 10 performs a drying process for drying the substrate W1. Specifically, the control unit 10 controls the rotation mechanism 33 to improve the rotation speed of the substrate W1 (so-called spin dry). In this step S55, the drying process is performed while the humidity is maintained within the second humidity range. The humidity does not necessarily have to be maintained within the second humidity range during the entire period of step S55, and the humidity may be maintained within the second humidity range for at least a part of the period.

With reference to FIG. 1, when the substrate W1 is sufficiently dried, in step S6, the control unit 10 controls the rotation mechanism 33 to end the rotation of the substrate W1. Further, the control unit 10 controls the supply valves 53 and 531 to end the discharge of the inert gas from the nozzles 51 and 511.

Next, in step S7, the substrate W1 is carried out from the substrate processing device 1. Specifically, the control unit 10 opens the shutter, and the substrate transfer robot takes out the substrate W1 from the substrate holding unit 3 via the shutter. The substrate transfer robot transfers the substrate W1 to the processing device in the next process.

Next, in step S8, the substrate W1 is baked. Specifically, the processing apparatus heats the substrate W1 (baking process). Next, in step S9, the substrate W1 is annealed. As the annealing treatment, for example, a flash lamp annealing treatment can be adopted. In this flash lamp annealing process, the flash lamp irradiates the upper surface of the substrate W1 with flash light. As a result, the substrate W1 is heated, and the dopant on the upper surface thereof is diffused to the substrate W1. As a result, a desired conductive semiconductor layer can be formed on the substrate W1.

It can be said that the processes of steps S1 to S7 are pretreatments for the dopant diffusion process, which is executed before the dopant diffusion process (annealing process).

By the way, as described above, according to the substrate processing apparatus 1, the humidity of the processing space H1 is higher than the second humidity range in the first humidity range during at least a part of the period of step S52 in which the coating agent is supplied. Maintained within. This first humidity range is a range in which the reactivity of the coating agent increases, and is set in advance according to the type of the coating agent. This first humidity range can be set, for example, by simulation or experiment. By adopting a first humidity range in which the coating agent has high reactivity, the film thickness of the dopant film formed on the upper surface of the substrate W1 can be increased. This makes it possible to increase the amount of dopant in the dopant film. It can also be considered that this is because the reactivity of hydrolysis of the coating agent can be increased by increasing the humidity. According to the experiment, the film thickness of the dopant film could be doubled or more as compared with the case where the humidity is lower than the lower limit of the first humidity range (for example, 2 to 3 [%]).

By the way, in order to increase the film thickness of the coating film, it is conceivable to increase the supply time of the coating agent (the period of step S52). However, even if this supply time was increased, no significant increase in film thickness was observed. The applicant of the present application has discovered that the humidity of the processing space H1 affects the film thickness of the coating film rather than the supply time, and based on the new knowledge, the substrate processing apparatus 1 has the humidity of the processing space H1. The coating agent is supplied in a state of being within the first humidity range.

Further, according to the substrate processing apparatus 1 described above, the humidity of the processing space H1 is maintained in a second humidity range lower than the first humidity range during at least a part of the period of step S55 (drying step). According to this, since the amount of water in the treatment space H1 is reduced, the amount of water mixed in the coating agent from the treatment space H1 can be reduced. Therefore, the time required for drying the substrate W1 (drying time) can be shortened.

Further, if the humidity of the treatment space H1 during the drying treatment is high, the moisture in the treatment space H1 may condense as the temperature drops due to the heat of vaporization of the coating agent. In this case, drying can be adversely affected. On the other hand, in the above-mentioned substrate processing apparatus 1, since the humidity is adjusted to be low during at least a part of the drying process, such an adverse effect can be suppressed. Such adverse effects can be avoided by adjusting the humidity within the second humidity range during the entire period of the drying process.

By the way, here, an organic solvent is adopted as the solvent of the coating agent, and the coating agent contains almost no water. Therefore, the humidity of the treatment space H1 is irrelevant to the vaporization of the coating agent, considering only the ease of vaporization of the coating agent based on the saturated vapor pressure. Therefore, this point of view alone does not motivate the drying process to reduce the humidity. However, the applicant has come to the conclusion that moisture can be mixed into the coating agent and that the heat of vaporization can cause condensation of moisture in the treatment space, and based on this finding, during at least a part of the drying process. It reduces the humidity.

Further, according to the substrate processing apparatus 1 described above, the natural oxide film is removed in a state where the oxygen concentration in the processing space H1 is lower than the initial value of the concentration (steps S42 to S45). That is, the natural oxide film is removed in a state where a new natural oxide film is unlikely to be formed on the substrate W1. Therefore, it is easy to appropriately remove the natural oxide film from the substrate W1. Further, when the humidity of the treatment space H1 is high, a natural oxide film is likely to be formed, whereas in the above example, the humidity of the treatment space H1 is maintained within the third humidity range lower than the first humidity range. , The natural oxide film is removed (step S5). This also makes it easy to appropriately remove the natural oxide film from the substrate W1.

Further, according to the substrate processing device 1 described above, the volume of the processing space H1 is reduced by lowering the blocking member 7. According to this, the humidity of the treatment space H1 can be greatly adjusted with a small amount of the inert gas. Therefore, the consumption of the inert gas can be reduced. In addition, the rate of change in humidity can be improved. Therefore, the processing time can be shortened.

Further, according to the substrate processing apparatus 1 described above, in steps S42 to S45 and S51 to S55, the inert gas is continuously supplied to the processing space H1 with the blocking member 7 stopped at the processing position. That is, the substrate processing apparatus 1 executes steps S42 to S45 and S51 to S55 while maintaining a hypoxic state in which the oxygen concentration in the processing space H1 is smaller than the initial value of the concentration. In other words, the coating agent is applied to the upper surface of the substrate W1 while maintaining a state in which the natural oxide film is difficult to be formed. Therefore, the dopant film can be easily formed on the upper surface of the substrate W1.

In the above example, step S51 (humidity adjustment step) is executed prior to step S52 (coating agent supply step). However, this is not always the case. Humidity adjustment may be started after the supply of the coating agent is started. In short, the humidity may be maintained within the first humidity range for at least a part of the period during which the coating agent is supplied.

Further, in the above example, by reducing the flow rate of the inert gas in step S51 (humidity adjustment step), the air outside the processing space H1 (air with high humidity) is allowed to flow into the processing space H1. The humidity of the treatment space H1 was increased. Since the air outside the processing space H1 contains more oxygen, the oxygen concentration in the processing space H1 becomes higher than the concentration value in step S4 (removal step) due to the inflow of the air. Since a natural oxide film is likely to be formed when the oxygen concentration is high, from the viewpoint of more strictly suppressing the natural oxidation of the upper surface of the substrate W1, after the start of step S52 (coating agent supply step), step S51 (humidity adjustment step) ) May be started. That is, the flow rate of the inert gas may be started to be reduced after the supply of the coating agent is started. According to this, it is possible to start supplying the coating agent to the upper surface of the substrate W1 in a state where the oxygen concentration in the processing space H1 is lower. After that, even if the oxygen concentration in the treatment space H1 is slightly increased, the upper surface of the substrate W1 is covered with the coating agent, so that a natural oxide film is unlikely to be formed. That is, this operation can further reduce the possibility that a natural oxide film is formed on the upper surface of the substrate W1.

Further, in the above example, step S54 (humidity adjusting step) is executed prior to step S55 (drying step). However, this is not always the case. After the start of drying, the humidity may start to decrease. In short, the humidity need only be maintained within the second humidity range for at least a part of the drying period.

Further, in the above example, step S54 (humidity adjustment step) is executed after step S53 (flattening step). However, since it is not always necessary to accelerate the reaction of the coating agent in this flattening step, step S54 (that is, reduction in humidity) is started prior to or during the flattening step. May be good.

Further, for example, when the substrate W1 is carried into the substrate processing apparatus 1 with the natural oxide film removed, it is not necessary to execute step S4 (removal step). In this case, the removal processing unit 80 is also unnecessary.

Further, for example, when the viscosity of the coating agent is low or the variation in the film thickness of the coating film does not matter, it is not necessary to execute step S53 (flattening step). In this case, the first chemical supply unit 6 is also unnecessary.

Further, in the above example, although the blocking member 7 is provided, the present invention is not necessarily limited to this. The substrate processing device 1 may adjust the humidity and oxygen concentration of the entire internal space of the chamber 2, or discharge gas into the space (upper atmosphere) directly above the substrate W1 in the internal space of the chamber 2 to obtain the said. Humidity and oxygen concentration in the space may be adjusted.

Further, in the above example, the nozzles 41, 51, 61, 811 and 813 are arranged concentrically with each other, but the nozzles are not necessarily limited to this. For example, at least two or more nozzles are provided so as to be movable separately, and each of them may move directly above the substrate W1 when discharging the treatment liquid. In this case, each nozzle may be formed separately from the blocking member 7.

<Humidity adjustment unit>
Further, in the above example, the humidity adjusting unit 5 is composed of the first gas supply unit 50. However, this is not always the case. FIG. 6 is a diagram schematically showing the configuration of the humidity adjusting unit 5A, which is another example of the humidity adjusting unit 5. The humidity adjusting unit 5A includes a first gas supply unit 50 and a third gas supply unit 50A. The third gas supply unit 50A supplies a high humidity gas (for example, steam) having a higher humidity than the gas (inert gas) supplied by the first gas supply unit 50 to the processing space H1. The humidity of this high-humidity gas (humidity before being supplied to the processing space H1) may be higher than the humidity (initial humidity) in the chamber 2 in step S1.

The third gas supply unit 50A includes a nozzle 51, a supply pipe 52A, a supply valve 53A, and a gas supply source 54A. In the example of FIG. 6, the nozzle 51 is also used by the first gas supply unit 50 and the third gas supply unit 50A. The nozzle 51 is connected to the gas supply source 54 via the supply pipe 52, and is also connected to the gas supply source 54A via the supply pipe 52A. The supply valve 53A is provided in the middle of the supply pipe 52A, and switches the opening and closing of the flow path in the supply pipe 52A. The supply valve 53A is controlled by the control unit 10. The supply valve 53A may be a valve capable of adjusting the flow rate of the high humidity gas.

When the supply valve 53 is open and the supply valve 53A is closed, inert gas is discharged from the nozzle 51, and when the supply valve 53 is closed and the supply valve 53A is open, steam is discharged from the nozzle 51 and the supply valve. When both the 53 and the supply valve 53A are open, a mixed gas of the inert gas and the high humidity gas is discharged from the nozzle 51. The humidity of the mixed gas is adjusted based on the ratio of the flow rate of the inert gas to the flow rate of the high humidity gas.

Such a humidity adjusting unit 5 can supply a gas containing a high humidity gas to the processing space H1 in step S51, for example. As a result, in step S51, the humidity of the processing space H1 can be rapidly increased. Therefore, the time required for step S51 can be shortened. Therefore, the throughput of the substrate processing apparatus 1 can be improved.

The second embodiment.
The configuration of the substrate processing apparatus 1 according to the second embodiment is the same as that of the first embodiment. In the second embodiment, the coating film forming treatment is different from that in the first embodiment. In the second embodiment, the control unit 10 repeatedly executes a set of a coating agent supply step and a stop step of stopping the supply of the treatment liquid to the upper surface of the substrate W1 in the coating film forming process. Hereinafter, a specific description will be given.

FIG. 7 is a flowchart showing an example of the operation of the substrate processing device 1. FIG. 7 shows an example of the coating film forming treatment. First, in step S51A (humidity adjusting step), the humidity adjusting unit 5 adjusts the humidity of the processing space H1 within the first humidity range. This step S51A is the same as step S51. Next, in step S52A (coating agent supply step), the coating agent supply unit 4 supplies the coating agent to the upper surface of the substrate W1. This step S52A is the same as step S52. Next, in step S53A (flattening step), the first chemical solution supply unit 6 supplies the first chemical solution to the upper surface of the substrate W1. This step S53A is the same as step S53. Next, in step S54A, the humidity adjusting unit 5 adjusts the humidity of the processing space H1 within the second humidity range. This step S54A is the same as step S54.

Next, in step S55A (stop step), the supply of the processing liquid to the upper surface of the substrate W1 is stopped. Specifically, the control unit 10 closes the supply valve 63. Since the other supply valves 43, 831 to 833 are also closed, the processing liquid is not supplied to the upper surface of the substrate W1 in step S55A. As a result, the treatment liquid (here, the first chemical liquid) on the upper surface of the substrate W1 is scattered and vaporized from the peripheral edge thereof to the outside. That is, the treatment liquid on the coating film of the substrate W1 is vaporized and the substrate W1 is slightly dried. Therefore, step S55A can also be regarded as a kind of drying process. In this step S55A, since the humidity is maintained within the second humidity range, the drying time of the substrate W1 can be shortened. It is not necessary that the humidity be maintained within the second humidity range during the entire period of step S55A, and the humidity may be maintained within the second humidity range during at least a part of the period.

When the degree of drying of the substrate W1 reaches a predetermined level, specifically, when the tenth predetermined time has elapsed from the start of step S55A, in step S56A, the control unit 10 performs a series of steps S51A to S55A. Judges whether or not the number of times of execution of the process of The predetermined number of times is set in advance and is stored in, for example, the storage medium of the control unit 10.

When it is determined in step S56A that the number of executions is less than a predetermined number, the control unit 10 executes step S51A (repetition step). That is, the control unit 10 determines that the series of processes of steps S51A to S55A has not yet been executed a predetermined number of times, and repeats the series of processes.

On the other hand, when it is determined in step S56A that the number of executions is equal to or greater than a predetermined number of times, in step S57A (drying step), the control unit 10 executes a drying process for drying the substrate W1. Step S57A is the same as step S55.

In the process in step S55A, the substrate W1 does not need to be completely dried. That is, the degree of drying of the substrate W1 at the end of step S55A may be smaller than the degree of drying of the substrate W1 at the end of step S57A.

As described above, also in the second embodiment, the humidity is adjusted within the first humidity range during at least a part of the period of step S52A (coating agent supply step). Therefore, the film thickness of the coating film formed by one step S52A can be increased as in the first embodiment.

Moreover, in the second embodiment, a set of steps S52A (coating agent supply step) and step S55A (stop step: which can be said to be a kind of drying step) is repeatedly executed. According to this, a new coating film is formed on the coating film under the coating agent every time the coating agent is supplied. Therefore, the layers of the coating film are sequentially laminated, and the film thickness of the coating film as a whole increases. Therefore, the film thickness of the coating film on the substrate W1 can be further increased.

Further, in the above example, step S53A (flattening step) is executed for each step S52A (coating agent supply step). According to this, each layer of the coating film can be flattened, and each layer of the coating film can be easily laminated. As a result, the coating film can be formed flat as a whole.

The flattening step does not necessarily have to be performed for each coating agent supply step. For example, the flattening step may be performed each time the coating agent supply step is executed a plurality of times. That is, the flattening step may be performed for each of a plurality of layers of the coating film. For example, a flat coating film can be formed as a whole by performing a flattening step for each of the two layers.

A third embodiment.
The configuration of the substrate processing device 1 according to the third embodiment is the same as that of the first embodiment. In the third embodiment, the coating film forming treatment is different from that in the first embodiment. In the third embodiment, the substrate processing apparatus 1 controls the rotation speed of the substrate W1 so that the liquid film of the coating agent is held on the upper surface of the substrate W1 in the coating film forming process. The retention of the liquid film of the coating agent referred to here means a state in which the coating agent hardly scatters from the peripheral edge of the substrate W1 and the liquid film exists on the upper surface of the substrate W1.

FIG. 8 is a flowchart showing an example of the operation of the substrate processing device 1. FIG. 8 shows an example of the operation of the coating film forming process. First, in step S51B (humidity adjustment step), the humidity adjustment unit 5 adjusts the humidity of the processing space H1 within the first humidity range. This step S51B is the same as step S51. Next, in step S52B (coating agent supply step), the coating agent supply unit 4 supplies the coating agent to the upper surface of the substrate W1. This step S52B is the same as step S52.

For example, after the eleventh predetermined time has elapsed from the start of step S52B, the liquid film of the coating agent is held on the upper surface of the substrate W1 in step S53B (paddle treatment step). Specifically, the control unit 10 closes the supply valve 43 to stop the supply of the coating agent, and further controls the rotation mechanism 33 to control the rotation speed of the substrate W1. The control unit 10 controls the rotation speed of the substrate W1 to be lower than the rotation speed in step S52A, and holds the liquid film of the coating agent on the upper surface of the substrate W1. According to this, the fluidity of the liquid film of the coating agent is lowered on the upper surface of the substrate W1. As a more specific example, the control unit 10 may control the rotation speed of the substrate W1 to zero. That is, the control unit 10 may stop the rotation of the substrate W1. In this case, the liquid film of the coating agent is substantially stationary on the upper surface of the substrate W1.

Also in this step S53B (paddle processing step), the humidity of the processing space H1 is maintained within the first humidity range. The humidity does not have to be maintained within the first humidity range during the entire period of step S53B (paddle processing step), and may be maintained within the first humidity range during at least a part of the period.

The dopant compound in the coating agent reacts with the moisture in the treatment space H1 not only in step S52B (coating agent supply step) but also in step S53B (paddle treatment step), and as a result, a dopant film is formed on the upper surface of the substrate W1. Will be done. That is, not only in step S52B (coating agent supply step) but also in step S53B (paddle treatment step), the coating agent reacts to form a coating film.

When a dopant film having a sufficient film thickness is formed on the upper surface of the substrate W1, the control unit 10 executes steps S54B to S56B in this order. For example, when the twelfth predetermined time (for example, several tens of seconds) has elapsed from the start of step S53B, the control unit 10 executes steps S54B to S56B in this order. Steps S54B to S56B are the same as steps S53 to S55, respectively.

According to this substrate processing apparatus 1, the coating agent is substantially stationary on the upper surface of the substrate W1 in step S53B (paddle processing step) as described above. According to this, the dopant is more likely to appear on the upper surface of the substrate W1 than when the coating agent flows on the upper surface of the substrate W1. As a result, the film thickness of the coating film formed on the upper surface of the substrate W1 can be increased. According to the experiment, the film thickness of the coating agent could be increased to several to several tens of times as compared with the film thickness when step S53B (paddle treatment step) was not executed.

In the above example, in step S53B (paddle processing step), the control unit 10 controlled the rotation speed of the substrate W1 to zero. However, the control unit 10 may increase the rotation speed of the substrate W1 to more than zero as long as the liquid film of the coating agent is held on the upper surface of the substrate W1. Even in this state, the degree of flow of the liquid film of the coating agent is smaller than the degree of flow in step S52B (coating agent supply step), so that the dopant is easily exposed and the film thickness of the dopant film can be increased. ..

Further, the control unit 10 may gradually reduce the rotation speed of the substrate W1 in step S53B (paddle processing step). FIG. 9 is a graph showing an example of a change in rotation speed. In the example of FIG. 9, the rotation speed of the substrate W1 decreases stepwise with the passage of time. Thereby, the thickness of the liquid film of the coating agent in step S53B (paddle treatment step) can be controlled with higher accuracy.

Modification example.
In the above example, the organoboron compound has been exemplified as the dopant compound, but the dopant compound is not necessarily limited to this. For example, any dopant compound capable of forming a dopant film on the upper surface of the substrate W1 by hydrolysis can be adopted.

Further, in the above example, although the coating agent is supplied to the upper surface of the substrate W1, the coating agent may be supplied to the lower surface of the substrate W1. In this case, the humidity of the processing space on the lower surface side of the substrate W1 may be adjusted.

Further, a rotation mechanism may be provided in the chamber 2 so that the blocking member 7 rotates around the rotation axis A1. The blocking member 7 may rotate at substantially the same rotation speed as the substrate W1 along the same direction as the rotation direction of the substrate W1.

Although the substrate processing apparatus and the pretreatment method for the dopant diffusion treatment have been shown and described in detail, the above description is exemplary and not limited in all embodiments. Therefore, the present embodiment can be appropriately modified or omitted within the scope of the disclosure. Further, the above-described embodiments can be combined as appropriate. For example, even if step S43B (paddle processing step) according to the third embodiment is executed between step S52A (coating agent supply step) and step S53A (flattening step) in the second embodiment. Good.

3 Substrate holding part 4 Coating agent supply part 5 Humidity adjustment part 7 Blocking member 10 Control part S1 Mounting process (step)
S2 Breaking member placement process (step)
S4 removal process (step)
S42 1st step (step)
S43, S44 Second step (step)
S45 3rd step (step)
S51, S51A, S51B Humidity adjustment process (step)
S52, S52A, S52B Coating agent supply process (step)
S55A Stop process (step)
S53B paddle processing process (step)
W1 board

Claims (11)

It is a pretreatment method for dopant diffusion treatment.
The mounting process of mounting the board on the board holding part,
After the above-mentioned setting step, a coating agent containing a dopant is supplied to the surface of the substrate, and a coating agent supply step of forming a liquid film of the coating agent on the surface of the substrate.
A humidity adjusting step of adjusting the humidity of the upper atmosphere of the surface of the substrate within a predetermined first humidity range according to the coating agent is provided.
A pretreatment method for a dopant diffusion treatment, in which the humidity of the upper atmosphere is maintained within the first humidity range during at least a part of the coating agent supply step. The pretreatment method for the dopant diffusion treatment according to claim 1.
The surface of the substrate is in a low oxygen state, which is carried out between the pre-described step and the coating agent supply step and the oxygen concentration in the upper atmosphere is lower than the oxygen concentration in the upper atmosphere in the pre-described step. Further equipped with a removal process to remove the natural oxide film of
The coating agent supply step is a pretreatment method for dopant diffusion treatment, which is carried out in the hypoxic state. The pretreatment method for the dopant diffusion treatment according to claim 2.
A blocking member arranging step, which is executed between the above-described setting step and the removing step, and arranges the blocking member at a position facing the surface of the substrate across the upper atmosphere, is further provided.
A pretreatment method for a dopant diffusion treatment, wherein the removal step, the coating agent supply step, and the humidity adjustment step are carried out with the blocking member arranged at the position. The pretreatment method for the dopant diffusion treatment according to claim 2 or 3.
The removal step is
The first step of supplying the chemical solution for removing the natural oxide film to the surface of the substrate, and
After the first step, a second step of supplying a rinse solution for removing the chemical solution on the surface of the substrate, and a second step.
A pretreatment method for a dopant diffusion treatment, which comprises a third step of drying the substrate after the second step. The pretreatment method for the dopant diffusion treatment according to any one of claims 1 to 4.
The coating agent supply process and
A pretreatment method for a dopant diffusion treatment, further comprising a repetitive step of repeatedly executing a set of a stop step of stopping the supply of the treatment liquid to the surface of the substrate a plurality of times. The pretreatment method for the dopant diffusion treatment according to any one of claims 1 to 5.
In the coating agent supply step, the substrate is rotated at the first rotation speed.
The pretreatment method for the dopant diffusion treatment is
A pretreatment method for a dopant diffusion treatment, further comprising a paddle treatment step of controlling the rotation speed of the substrate to be lower than the first rotation speed to hold the liquid film of the coating agent on the surface of the substrate. The pretreatment method for the dopant diffusion treatment according to claim 6.
In the paddle processing step
A pretreatment method for dopant diffusion treatment that gradually reduces the rotation speed of the substrate. The pretreatment method for the dopant diffusion treatment according to any one of claims 1 to 7.
A pretreatment method for a dopant diffusion treatment, further comprising a drying step of drying the substrate after the coating agent supply step. The pretreatment method for the dopant diffusion treatment according to claim 8.
A pretreatment method for dopant diffusion treatment, in which the humidity of the upper atmosphere is maintained within a second humidity range lower than the first humidity range during at least a part of the drying step. The pretreatment method for the dopant diffusion treatment according to any one of claims 1 to 9.
A pretreatment method for a dopant diffusion treatment, further comprising a flattening step of supplying a chemical solution for flattening the liquid film to the surface of the substrate after the coating agent supply step. It is a board processing device
The board holding part that holds the board and
A coating agent supply unit that supplies a coating agent containing a dopant to the surface of the substrate and forms a liquid film of the coating agent on the surface of the substrate.
A humidity adjusting unit that adjusts the humidity of the upper atmosphere of the surface of the substrate within a predetermined first humidity range according to the coating agent.
The coating agent supply unit and the humidity adjustment unit are controlled so that the humidity of the upper atmosphere is maintained within the first humidity range for at least a part of the period during which the coating agent is supplied to the surface of the substrate. A substrate processing device including a control unit for processing.

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