JP3905784B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing apparatus for drying a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc. (hereinafter simply referred to as “substrate”) after being washed with pure water under reduced pressure, and The present invention relates to a substrate processing method.
[0002]
[Prior art]
Conventionally, in a substrate manufacturing process, a treatment with a chemical solution such as hydrofluoric acid and a cleaning treatment with pure water are sequentially performed, and then an organic material such as isopropyl alcohol (hereinafter referred to as “IPA”) is pulled out from the pure water. 2. Description of the Related Art Substrate processing apparatuses that perform drying by supplying solvent vapor to the periphery of a substrate are used. In particular, in recent years when the structure of the pattern formed on the substrate is becoming more complicated and finer, the substrate is lifted from pure water while supplying the IPA vapor, and then the atmosphere containing the IPA vapor is decompressed. Lifting and drying systems equipped with a decompression function are becoming mainstream.
[0003]
The lift-drying type substrate processing equipment equipped with a decompression function houses a treatment tank for cleaning with pure water inside the container. Conventionally, pure water adhered to the substrate is dried by the following procedure. Is called. First, after completion of the cleaning process in the processing tank, IPA vapor is supplied into the container to form an IPA atmosphere above the processing tank. Next, the substrate is lifted from the pure water stored in the treatment tank into the IPA atmosphere. In this process, IPA vapor condenses on the substrate. Subsequently, nitrogen gas is fed into the container to create a nitrogen atmosphere in the container. Then, the inside of the container is depressurized at once by a decompression pump to evaporate IPA on the substrate, and the substrate is dried.
[0004]
Here, the inside of the container is decompressed by the decompression pump because the IPA vapor remaining in a gaseous state in the container is forcibly exhausted from the container, and the IPA partial pressure in the container is determined by the temperature in the container. This is because the IPA adhering to the substrate is promoted to evaporate by performing the drying process quickly by lowering the saturation vapor pressure of the determined IPA.
[0005]
[Problems to be solved by the invention]
Incidentally, it is generally known that the density at which a substance can exist in a gaseous state is proportional to temperature. It is also known that when the inside of the container is depressurized without heat exchange, the atmosphere in the container is adiabatically expanded and the temperature inside the container is lowered. Therefore, compared with the amount of IPA discharged from the container by the decompression pump, the temperature drop due to adiabatic expansion is superior, and as a result, the density of the IPA vapor in the container is such that the IPA vapor is at the ambient temperature in the container. When the density exceeds the maximum density that can exist (hereinafter also referred to as “IPA saturation density”), fine IPA mist is generated in the container. When this mist adheres to a fine pattern such as a trench structure formed on the substrate, particles are generated on the substrate, causing a problem of poor drying.
[0006]
Such a problem is not limited to a drying process using IPA, and is a problem that occurs in general substrate processing using an organic solvent as a desiccant.
[0007]
Therefore, in the present invention, in the process of drying by reducing the atmosphere in the container, the organic solvent is prevented from becoming mist in the container, and the generation of fine particles is suppressed by preventing the generation of fine particles. It is an object of the present invention to provide a substrate processing apparatus and a substrate processing method that can suppress the above-described problem.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 is a substrate processing apparatus for performing a drying process on a substrate that has been cleaned with pure water. Accommodates the substrate A container, and an organic solvent discharge means that is provided in the container, discharges vapor of the organic solvent, and forms an atmosphere containing the organic solvent in the container; Pressure reducing means for reducing the pressure in the container, and inert gas discharge means for discharging an inert gas into the container, By controlling the environment adjusting means for adjusting the gas environment in the container and the environment adjusting means, the vapor of the organic solvent in the container is maintained in an unsaturated state, and the inside of the container And a control means for reducing pressure The control means stops the discharge of the inert gas by the inert gas discharge means, and starts the discharge of the organic solvent vapor by the organic solvent discharge means, thereby changing the substrate to the vapor of the organic solvent. Exposure, and subsequently, the discharge of the organic solvent vapor by the organic solvent discharge means is stopped, the discharge of the inert gas by the inert gas means is started, and then the inside of the container is reduced by the decompression means. By reducing the pressure, the pressure in the unsaturated state is reduced. It is characterized by that.
[0010]
Claim 2 The invention described in Claim 1 2. The substrate processing apparatus according to claim 1, wherein the control means decompresses the inside of the container after replacing part or all of the vapor of the organic solvent with the inert gas.
[0011]
Claim 3 The invention described in claim 1 provides Claim 2 A processing tank that is provided in the container, stores pure water, immerses the substrate in the pure water, and performs a cleaning process; and a pure water stored in the processing tank A discharge path for discharging water, wherein the organic solvent discharge means discharges the organic solvent after pure water stored in the treatment tank is discharged from the discharge path.
[0012]
Claim 4 The invention described in Claim 1 Or Claim 3 4. The substrate processing apparatus according to claim 1, further comprising a lifting unit that lifts the substrate from the processing tank into an atmosphere containing the vapor of the organic solvent.
[0013]
Claim 5 The invention described in Claim 1 Or Claim 4 The substrate processing apparatus according to any one of the above, wherein the organic solvent is isopropyl alcohol.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
<1. First Embodiment>
(1) Configuration of substrate processing equipment
First, a first embodiment of the present invention will be described. 1 and 3 are a front view of a substrate processing apparatus 1 according to a first embodiment of the present invention, FIG. 2 is a plan view of the substrate processing apparatus 1 shown in FIG. 1, FIG. 4 is a substrate shown in FIG. Side views of the processing apparatus 1 are shown. 1 and the subsequent drawings are attached with an XYZ orthogonal coordinate system in which the Z-axis direction is the vertical direction and the XY plane is the horizontal plane, as necessary, in order to clarify the directional relationship.
[0017]
As shown in FIG. 1, the substrate processing apparatus 1 is an apparatus that performs a substrate cleaning process with pure water and dries the substrate after the cleaning process with IPA. A mechanism 30 and a decompression pump 40 are provided.
[0018]
The container 10 is a housing that accommodates the processing tank 20, the lifting mechanism 30, the gas discharge nozzle 11, and the like therein. The upper part of the container 10 can be opened and closed by a sliding opening / closing mechanism (not shown). In a state where the upper portion of the container 10 is opened, the substrate can be carried in and out from the opened portion. On the other hand, in a state where the upper portion of the container 10 is closed, the inside thereof can be a sealed space.
[0019]
The treatment tank 20 is a tank that stores chemicals such as hydrofluoric acid or pure water (hereinafter collectively referred to as “treatment liquid”) and sequentially performs surface treatment on the substrate, and is accommodated in the container 10. Has been. Two treatment liquid discharge nozzles 21 are arranged near the bottom of the treatment tank 20. The treatment liquid discharge nozzle 21 is connected to a pure water supply source 63 via a pipe 13 (13a, 13b, 13c, 13d) and a valve 53. Therefore, the substrate 53 can be cleaned by opening the valve 53 and storing the pure water in the processing tank 20. Further, by supplying a processing liquid from a processing liquid supply source (not shown) to the processing tank 20 via the processing liquid discharge nozzle 21, it is possible to perform substrate processing other than the cleaning process using pure water.
[0020]
The processing liquid is supplied from the bottom of the processing tank 20 and overflows from the upper end of the processing tank 20. For this reason, the recovery unit 22 is disposed at the upper end of the processing tank 20, and the drainage of the processing liquid overflowing from the upper part of the processing tank 20 is recovered in the recovery unit 22, and the discharge path 42 (42b, 42c, 42d, 42e) and the factory line LE to be discharged to the outside of the substrate processing apparatus 1. By opening the valve 54 provided at the bottom of the processing tank 20, the waste of the used processing liquid stored in the processing tank 20 is also discharged to the discharge path 42 (42 a).
[0021]
Note that a quick drain mechanism may be provided in the processing tank 20 to forcibly and rapidly discharge the processing liquid stored in the processing tank 20 to the discharge path 42. In addition, the liquid supply path and the discharge path described below including the discharge path 42 are constituted by pipes.
[0022]
The elevating mechanism 30 is a mechanism for immersing a set of a plurality of substrates 100 (lots) in the processing liquid stored in the processing tank 20. As shown in FIG. 2, the elevating mechanism 30 includes a lifter 31, a lifter arm 32, and three holding bars 33, 34, and 35 that hold the substrate 100. Each of the three holding rods 33, 34, and 35 is provided with a plurality of holding grooves arranged in the X direction at predetermined intervals so that the outer edge portion of the substrate 100 fits in and holds the substrate 100 in a standing posture. Yes. Each holding groove is a notch-shaped groove. The three holding rods 33, 34, and 35 are fixed to the lifter arm 32, and the lifter arm 32 is provided so as to be lifted and lowered in the vertical direction (Z direction) by the lifter 31 (FIG. 3).
[0023]
With such a configuration, the elevating mechanism 30 converts the plurality of substrates 100 arranged and held parallel to each other in the X direction by the three holding rods 33, 34, and 35 into the processing liquid stored in the processing tank 20. It moves up and down between the position to be immersed (dotted line position in FIG. 3) and the position completely lifted from the processing liquid (solid line position in FIG. 3). Two gas discharge nozzles 11 are provided in the container 10 in the vicinity of the upper part of the container 10. As shown in FIG. 4, each of the gas discharge nozzles 11 is a hollow tubular member extending along the X direction, and includes a plurality of discharge holes 11 a arranged at equal intervals in the X direction. Each of the plurality of discharge holes 11a is formed so that the discharge direction is substantially horizontal.
[0024]
Further, the two gas discharge nozzles 11 are connected to the IPA vapor supply source 61 and the pipe 12 (12a, 12b, 12c, 12e, 12g) via the pipe 12 (12a, 12b, 12c, 12d, 12f) and the valve 51. And a nitrogen gas supply source 62 through a valve 52. Therefore, opening the valve 51 discharges IPA vapor from the gas discharge nozzle 11 to create an atmosphere containing IPA vapor, and opening the valve 52 discharges nitrogen gas from the gas discharge nozzle 11 to discharge nitrogen gas. Is formed in the container 10.
[0025]
The decompression pump 40 forcibly exhausts the atmosphere in the container 10 to reduce the pressure in the container 10. The gas in the exhausted atmosphere is discharged to the factory line LE via the pipe 41. The decompression pump 40 is configured to be able to start and stop according to a command from the control unit 70 to be described later, and to adjust the exhaust output, and the atmosphere in the container 10 can be adjusted by the exhaust amount corresponding to the exhaust output. Therefore, the pressure in the container 10 is reduced.
[0026]
Among the above elements, two systems, (1) a gas supply system having a nitrogen gas supply source 62 and a gas discharge nozzle 11, and (2) a decompression system having a decompression pump 40 and a pipe 41, are contained in the container 10. It is an element of environmental adjustment means for adjusting the gas environment inside.
[0027]
The control unit 70 includes a memory 71 that stores programs, variables, and the like, and a CPU 72 that executes control according to the programs stored in the memory 71. In accordance with a program stored in the memory 71, the CPU 72 controls the raising / lowering of the raising / lowering mechanism 30, the exhaust amount control of the decompression pump 40, and valve control for controlling the opening / closing of each valve and the flow rate of processing liquid or drainage flowing through each valve. Etc. are performed at a predetermined timing. Therefore, the control unit 70 controls each part including the environment adjusting means.
[0028]
(2) Substrate drying process
a) Drying sequence
Here, a substrate drying process sequence will be described. FIG. 5 is a timing chart showing an example of the open / close state of the valves of the supply / drainage unit, the output of the decompression pump, and the position of the lifting mechanism in the drying process in the period from time t0.
[0029]
As shown in FIG. 5, at time t <b> 0, the valve 52 communicating with the nitrogen gas supply source 62 is closed, the supply of nitrogen gas into the container 10 is stopped, and the valve 51 communicating with the IPA vapor supply source 61. Is opened, and IPA vapor begins to be ejected from the gas discharge nozzle 11 into the container 10. Therefore, an atmosphere containing IPA vapor is formed above the container 10. At time t0, pure water is stored in the treatment tank 20, and the valve 53 communicating with the pure water supply source 63 is opened. Therefore, the pure water overflowing from the upper part of the processing tank 20 is recovered by the recovery unit 22 and discharged to the factory line LE via the discharge path 42.
[0030]
Next, from time t1 to t2, the elevating mechanism 30 is raised from Z = Z0 (dotted line position) shown in FIG. 3 to Z = Z1 (solid line position). The plurality of substrates 100 immersed in the pure water stored in the processing tank 20 is lifted from the processing tank 20. At this time, since the substrate 100 is exposed to the IPA vapor discharged from the gas discharge nozzle 11, the IPA vapor is condensed on the surface of each substrate 100. Here, since IPA is an organic solvent having a surface tension smaller than that of pure water and a low latent heat of vaporization, the substrate can be efficiently dried.
[0031]
Subsequently, at time t2, the valve 53 is closed to stop the supply of pure water to the processing tank 20, and the valve 54 is opened to supply pure water stored in the processing tank 20 through the discharge path 42 to the factory line. It is discharged to LE. And when discharge | emission of the pure water from the processing tank 20 to the discharge path 42 is complete | finished, the valve | bulb 53 will be closed (time t3).
[0032]
Subsequently, at time t <b> 3, the valve 51 is closed and the supply of IPA vapor is stopped, and the valve 52 communicating with the nitrogen gas supply source 62 is opened to supply nitrogen gas from the gas discharge nozzle 11. As a result, the IPA vapor existing in the container 10 is replaced with nitrogen gas, and the concentration of the IPA vapor decreases, so that the partial pressure of the IPA vapor in the container 10 decreases.
[0033]
Subsequently, at time t4, the output W of the decompression pump 40 is set from 0 to the maximum output value W0, and the atmosphere in the container 10 is forcibly exhausted and decompressed. When the IPA partial pressure in the container 10 is lower than the saturated vapor pressure of IPA determined by the ambient temperature T in the container 10, the IPA condensed on the substrate 100 is rapidly evaporated and the substrate is dried. Done quickly. At this time, nitrogen gas is continuously supplied to increase the exhaust efficiency of the IPA vapor existing in the atmosphere in the container 10.
[0034]
Subsequently, at time t5, the valve 52 is closed and the supply of nitrogen gas to the container 10 is stopped. At this time, since the inside of the container 10 is continuously decompressed by the decompression pump 40, the IPA condensed on the substrate 100 is further evaporated.
[0035]
Subsequently, at time t6, the valve 52 is opened to restart the supply of nitrogen gas, and the output of the decompression pump 40 is set to zero at time t7 when the drying of the substrate 100 is completed. At this time, since the nitrogen gas is continuously supplied, the pressure in the container 10 is increased and recovered to the atmospheric pressure.
[0036]
By the above procedure, the drying process is performed by condensing the IPA vapor on the substrate 100 and further depressurizing the inside of the container 10 to evaporate the IPA on the substrate 100.
[0037]
b) Pressure change in the container
Here, using FIG. 6, per unit time discharged from the gas discharge nozzle 11 at time t7 when the output W of the decompression pump 40 becomes zero from time t3 when the supply of nitrogen gas shown in FIG. 5 is started. The relationship between the supply amount of nitrogen gas (supply rate), the output of the decompression pump 40 (decompression rate), and the pressure in the container 10 will be described in comparison with a conventional drying process.
[0038]
FIG. 6A shows a nitrogen gas supply amount V ′ per unit time by the conventional drying process from time t3 to time t7, a nitrogen gas supply amount V by unit time by the drying process in the first embodiment, and a reduced pressure. It is a figure which shows the timing chart which shows an example with the output W of the pump. FIG. 6B is a diagram showing the relationship between the pressure P in the container 10 and the time t when the nitrogen gas supply amount and the output of the decompression pump 40 are set as shown in FIG. 6A. . The dotted line in FIG. 6 (b) shows the pressure curve C1 in the container 10 by the conventional drying process, and the solid line shows the pressure curve C2 in the container 10 by the drying process according to the present invention.
[0039]
As shown in FIG. 6 (a), the configuration of the drying process according to the first embodiment is different from the conventional drying process only in the nitrogen gas supply amount per unit time from time t4 to t5. The configuration of is the same.
[0040]
In the conventional drying process, as shown in FIG. 6 (a), at time t3, the valve 52 is opened so that the maximum supply amount V0 is obtained from the nitrogen gas supply source 62, and nitrogen gas begins to be ejected into the container 10. . Here, since the atmosphere in the container 10 communicates with the outside of the container 10 through a pipe (not shown) except for forced exhaust by the decompression pump 40, the pressure P in the container 10 becomes a constant value P0. .
[0041]
Next, at time t4, the flow rate of the nitrogen gas passing through the valve 52 is decreased from the maximum supply amount V0 to V1, and the output W of the decompression pump 40 is increased from zero to the maximum output W0. Depressurize the atmosphere. Here, the supply amount V1 of the nitrogen gas is an amount sufficient to replace the IPA vapor and the nitrogen gas, but is sufficiently small as compared with the exhaust amount per unit time by the decompression pump 40. The IPA vapor in the atmosphere in the vessel 10 is quickly exhausted to shorten the drying time. At this time, the atmosphere in the container 10 is suddenly exhausted to the outside of the container 10 by the decompression pump 40, whereby the pressure of the atmosphere in the container 10 is rapidly reduced. Since the atmosphere is in the same state as when it is adiabatically expanded, the ambient temperature T decreases.
[0042]
Subsequently, at time t5, the valve 52 is closed and the supply of nitrogen gas is stopped. At this time, since the decompression pump 40 operates at the maximum output W0, the inside of the container 10 is further decompressed. Then, as the pressure P1 determined by the performance of the pressure reducing pump 40 approaches, the absolute value of the slope of the pressure curve C1 (tangent to the time t-axis, hereinafter the same) gradually decreases and the slope value gradually approaches zero.
[0043]
Subsequently, at time t6, the valve 52 is opened to reach the maximum supply amount V0, and nitrogen gas is supplied again to the atmosphere in the container 10, and at time t7, the output W of the decompression pump 40 is set to zero. And the drying process is complete | finished when the pressure P in the container 10 becomes P0.
[0044]
Thus, in the conventional drying process, the drying time is shortened by reducing the supply amount V ′ of nitrogen gas from V0 to V1 from time t4 to time t5. However, if the pressure in the container 10 is reduced at a stretch, the ambient temperature T in the container 10 rapidly decreases due to the influence of adiabatic expansion. When the concentration of the IPA vapor in the container 10 exceeds the saturation concentration of IPA vapor determined by the atmospheric temperature T in the container 10 (hereinafter also referred to as “IPA saturation concentration”), the IPA vapor in the atmosphere is condensed. As a result, a fine mist is generated, and the fine IPA mist adheres to a fine pattern such as a trench structure formed on the substrate, thereby generating fine particles on the substrate, resulting in a problem of poor drying. It was.
[0045]
On the other hand, in the drying process in the first embodiment, as shown in FIG. 6A, at the time t3, the supply amount of nitrogen gas is supplied to the atmosphere in the container 10 as the maximum supply amount V0 as in the conventional drying process. To do. At this time, the pressure P in the container 10 becomes a constant pressure P0 as in the conventional drying process.
[0046]
Next, at time t4, pressure reduction in the container 10 is started with the output W of the decompression pump 40 set to the maximum output W0 while the supply amount of nitrogen gas is kept constant at V0. At this time, the supply amount V of nitrogen gas into the container 10 is larger than the supply amount V ′ of nitrogen gas in the conventional drying process. Therefore, the absolute value of the slope of the pressure curve C2 in the container 10 from time t4 to t5 is smaller than the pressure curve C1 of the conventional drying process, and the pressure value is also higher than that of the conventional drying process. (FIG. 6 (b)). At this time, since the nitrogen gas is continuously supplied, the IPA vapor contained in the atmosphere in the container 10 is replaced with the nitrogen gas. Therefore, the drying time can be shortened by quickly exhausting the IPA vapor. it can.
[0047]
Subsequently, at time t5, the valve 52 is closed and the supply of nitrogen gas is stopped. At this time, since the atmosphere in the container 10 is continuously discharged by the decompression pump 40, the pressure value in the container 10 is depressurized at a stroke from P2. Then, as the pressure value approaches the pressure P1 determined by the performance of the decompression pump 40, the slope of the pressure curve C2 gradually becomes gentle.
[0048]
At time t6, the valve 52 is opened to the maximum supply amount V0 and the supply of nitrogen gas is resumed. At time t7, the output W of the decompression pump 40 is set to zero and the pressure P in the container 10 is increased. Is raised to P0 at once, and the drying process is completed.
[0049]
Here, when the pressure curve C2 of the drying process in the first embodiment is compared with the pressure curve C1 of the conventional drying process, the pressure values in the container 10 are equal in the range of P0 ≧ P> P2. The absolute value of the slope of the curve at a certain point (for example, P = P ′) is smaller in the pressure curve C2 than in C1. Therefore, at the same pressure, the drying process in the first embodiment is less susceptible to adiabatic expansion than the conventional drying process. Therefore, when the pressure P in the container 10 is in the range of P0 ≧ P> P2, the atmospheric temperature T in the container 10 at the same pressure value is higher in the drying process according to the first embodiment.
[0050]
Further, in the range where the pressure P in the container 10 is P2 ≧ P> P1 (a value determined by the performance of the pressure reducing pump 40), the absolute value of the slope of the curve at a position where the pressure values are equal (for example, P = P ″). Since the pressure curves C2 and C1 are substantially equal, the amount of decrease in the ambient temperature T in the container 10 due to the influence of adiabatic expansion is approximately equal, where the pressure P in the container 10 is P2 ≧ P>. In the range of P1, the relational expression between the pressure value P specified by the pressure curve C1 and the atmospheric temperature T in the container 10 at the pressure value P is the atmospheric temperature at T = T1 (P) and pressure P = P2. Is T12, and the relational expression between the pressure value P specified by the pressure curve C2 and the atmospheric temperature T at the pressure value P is T = T2 (P), and the atmospheric temperature at the pressure P = P2 is T22, Pressure The atmospheric temperature difference ΔT between the first embodiment and the conventional drying process when the value P is the same is almost the same as the decrease in the atmospheric temperature T due to the pressure drop between the drying process in the first embodiment and the conventional drying process. Therefore, ΔT = T1 (P) −T2 (P) = T12−T22 (constant) Therefore, in the range where the pressure P in the container 10 satisfies P2 ≧ P> P1, in the first embodiment. In the drying process, nitrogen gas is supplied by the maximum supply amount V0 from time t4 to t5, so that the atmospheric temperature T in the container 10 at the same pressure value is controlled to a temperature higher by ΔT than the conventional drying process. can do.
[0051]
(3) Advantages of the substrate processing apparatus of the first embodiment
As described above, in the drying process of the substrate processing apparatus according to the first embodiment, the supply amount of nitrogen gas into the container 10 is set to the maximum supply amount V0 from time t4 to t5 while controlling the ambient temperature T. The atmosphere in the container 10 can be decompressed. Therefore, in the conventional drying process, the atmosphere temperature T is rapidly reduced by reducing the atmosphere in the container 10 at once, the IPA concentration in the container 10 becomes equal to or higher than the IPA saturation density, and the IPA vapor is misted. Even with the atmospheric temperature T, in the apparatus of this embodiment, the unsaturated state of the IPA vapor can be continuously maintained from the start to the completion of the decompression, and as a result of performing the control according to the decompression pattern, the occurrence of mist generation Thus, the drying process can be performed while preventing the occurrence of poor drying.
[0052]
In addition, since the atmosphere in the container 10 can be reduced while preventing the IPA vapor from becoming mist, the atmosphere temperature T in the drying process can be set lower than that in the conventional drying process. As a result, the ambient temperature T can be made lower than the surface temperature of the substrate 100 to promote the condensation of the IPA vapor on the substrate 100, the drying efficiency can be improved, and the IPA consumption can be reduced.
[0053]
Further, water droplets inside the fine pattern formed on the substrate 100 having a trench structure or the like can be efficiently discharged, and the drying performance can be improved.
[0054]
Further, by reducing the pressure by controlling the atmospheric temperature T, it is possible to promote the condensation of the IPA vapor on the substrate 100 by making the atmospheric temperature T lower than the surface temperature of the substrate 100. Therefore, even if the concentration of the IPA vapor in the container 10 is lowered from the conventional substrate processing apparatus, the same drying performance and drying efficiency can be obtained, so that the amount of IPA used can be reduced. It can also be applied to a drying process in a process that has been difficult to use because of its reactivity with.
[0055]
<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. Since the mechanical configuration of the substrate processing apparatus of the second embodiment is exactly the same as that of the first embodiment, description thereof is omitted. The second embodiment is different from the first embodiment only in the timing at which the valve 51 is opened and the IPA vapor is supplied from the IPA vapor supply source 61 into the container 10.
[0056]
FIG. 7 shows a timing chart showing an example of the open / closed state of the valves of the supply / drainage section, the output of the decompression pump, and the position of the lifting mechanism in the second embodiment.
[0057]
In the second embodiment, at time t0, the valve 52 is closed and the supply of nitrogen gas is stopped. At this time, the valve 53 is opened, and pure water supplied from the pure water supply source 63 is continuously supplied to the treatment tank 20 to perform pure water treatment.
[0058]
Next, at the time t1 when the cleaning process using pure water is completed, the elevating mechanism 30 is raised from Z = Z0 (dotted line position) shown in FIG. 3 to Z = Z1 (solid line position) and stored in the processing tank 20. The plurality of substrates 100 immersed in the pure water are pulled up from the processing tank 20.
[0059]
Subsequently, at time t2, the valve 54 is closed to stop the supply of pure water to the treatment tank 20, and the valve 54 is opened to discharge the pure water stored in the treatment tank 20 to the discharge passage 42, It discharges outside the substrate processing apparatus 1 via the line LE. At the same time, the valve 51 is opened, and the IPA vapor is supplied from the IPA vapor supply source 61 to the atmosphere in the container 10 through the gas discharge nozzle 11. At this time, the plurality of substrates 100 fixed to the lifting mechanism 30 are exposed to the IPA vapor discharged from the gas discharge nozzle 11.
[0060]
And from time t3 to t7, a drying process is advanced by the procedure similar to 1st Embodiment. Here, the supply amount of the nitrogen gas from the time t3 to the time t4 is set to the maximum supply amount V0 as in the first embodiment.
[0061]
As described above, in the second embodiment, since the drying process of the substrate 100 described in the first embodiment is performed from the time t4 to the time t7, the pressure is reduced while the IPA vapor is maintained in the unsaturated state. The drying process of the embodiment has the same advantages as the first embodiment.
[0062]
In the second embodiment, the supply amount of IPA vapor is reduced by shortening the IPA supply time from time t2 to time t3 to reduce the IPA supply time. As described in the first embodiment, the shortening of the IPA vapor supply time is due to the fact that the drying process from the time t4 to the time t7 can improve the drying efficiency and reduce the amount of IPA used compared with the conventional drying process. Has been realized. As a result, the substrate processing apparatus of the second embodiment can shorten the time for the pure water stored in the processing tank 20 and the IPA vapor to contact each other, and the IPA vapor is added to the pure water stored in the processing tank 20. Since the amount to be dissolved can be reduced, the amount of IPA contained in the drainage discharged to the factory line LE via the discharge path 42 can be reduced to reduce the drainage treatment cost.
[0063]
<3. Third Embodiment>
Next, a third embodiment of the present invention will be described. Since the mechanical configuration of the substrate processing apparatus of the third embodiment is exactly the same as that of the first embodiment as in the second embodiment, the description thereof is omitted. The third embodiment differs from the first embodiment in the timing of opening the valve 52 and supplying nitrogen gas from the nitrogen gas supply source 62 into the container 10 and the output control of the decompression pump 40.
[0064]
FIG. 8 is a timing chart showing an example of the open / closed state of the valves of the supply / drainage section, the output of the decompression pump, and the position of the lifting mechanism in the third embodiment. 9 shows the supply amount of the nitrogen gas discharged from the gas discharge nozzle 11 and the pressure reducing pump at time t7 when the output W of the pressure reducing pump 40 becomes zero from the time t3 when the supply of nitrogen gas shown in FIG. 8 is started. It is a figure which shows the relationship between the output of 40, and the pressure in the container. Further, FIG. 9A shows a nitrogen gas supply amount V ′ per unit time by the conventional drying process from time t3 to time t7, and a nitrogen gas supply amount V by unit time by the drying process in the third embodiment. FIG. 10 is a timing chart showing an example of an output W of the decompression pump 40 by the conventional drying process and an output W ′ of the decompression pump 40 by the drying process in the third embodiment. FIG. 9B is a diagram showing the relationship between the pressure P in the container 10 and the time t when the nitrogen gas supply amount and the output of the decompression pump 40 are set as shown in FIG. 9A. . In addition, the dotted line of FIG.9 (b) shows the pressure curve C1 in the container 10 by the conventional drying process, and a continuous line shows the pressure curve C3 in the container 10 by the drying process in 3rd Embodiment, respectively.
[0065]
As shown in FIG. 8, in the third embodiment, the opening / closing control of the valves 51 to 54 is performed from time t0 to t3 by the same procedure as in the first embodiment, so that IPA vapor, nitrogen gas and pure water are controlled. Supply control, discharge control of pure water stored in the processing tank 20, and lift control of the lift mechanism 30 are performed.
[0066]
Subsequently, at time t <b> 3, the valve 51 is closed to stop the supply of IPA vapor, and the valve 52 communicating with the nitrogen gas supply source 62 is opened to supply nitrogen gas from the gas discharge nozzle 11. As a result, the IPA vapor existing in the container 10 is replaced with nitrogen gas, and the concentration of the IPA vapor decreases, so that the partial pressure of the IPA vapor in the container 10 decreases.
[0067]
Subsequently, at time t4, the valve 52 is closed and the supply of nitrogen gas is stopped, and the output of the decompression pump 40 is gradually increased from zero to reach the maximum output W0 at time t5. At this time, the discharge amount per unit time of the atmosphere in the container 10 gradually increases from the time t4 to the time t5, so that the pressure P in the container 10 becomes a pressure curve C3 shown in FIG. Here, as in the first embodiment, the absolute value of the slope of the pressure curve C3 in the container 10 from time t4 to t5 becomes smaller than the pressure curve C1 of the conventional drying process, and the pressure value Is higher than that of the conventional drying process (FIG. 9B).
[0068]
Subsequently, at time t5, since the atmosphere in the container 10 continues to be discharged by the decompression pump 40, the pressure value in the container 10 is depressurized all at once from P3. Then, as the pressure value approaches the pressure P1 determined by the performance of the decompression pump 40, the absolute value of the slope of the pressure curve C3 gradually approaches the zero value.
[0069]
At time t6, the valve 52 is opened to the maximum supply amount V0 and the supply of nitrogen gas is resumed. At time t7, the output W ′ of the decompression pump 40 is set to zero and the pressure in the container 10 is increased. P is raised to P0 at once, and the drying process is finished.
[0070]
Thus, in the third embodiment, by controlling the output W ′ of the decompression pump 40 and discharging the atmosphere in the container 10, the pressure in the container 10 is maintained while maintaining the IPA vapor in an unsaturated state. Since it can control, it becomes possible to control the atmospheric temperature T in the container 10 similarly to 1st Embodiment. As a result, it is possible to obtain the same advantages as the first embodiment, such as suppressing the occurrence of poor drying.
[0071]
<4. Modification>
The first to third embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.
[0072]
In each embodiment of the present invention, the substrate processing apparatus 1 is uniquely provided with an IPA supply source 61, a nitrogen gas supply source 62, and a pure water supply source 63, but from a supply source installed at a different location to factory piping. You may get through. In such a case, the “environment adjustment means” as an element of the substrate processing apparatus includes the gas discharge nozzle 11 as a gas discharge system, piping extending to the nozzle, and a decompression system.
[0073]
In the first embodiment, from time t4 to t5, the nitrogen gas is supplied at the maximum supply amount V0 per unit time. However, the supply amount is not limited to this, and the decompression pump is not limited to this. When the IPA vapor mist is not generated when the atmosphere in the container 10 is forcibly exhausted by 40, the supply amount of nitrogen gas per unit time may be reduced from the maximum supply amount V0. Further, the supply time of the nitrogen gas from the time t4 to the time t5 may be shortened if no IPA vapor mist is generated when the inside of the container 10 is decompressed. Furthermore, if IPA vapor mist is not generated when the inside of the container 10 is decompressed, the supply amount of nitrogen gas and the supply time of nitrogen gas may be reduced.
[0074]
Further, in the first embodiment, when the atmosphere in the container 10 is forcibly exhausted, the output W of the decompression pump 40 is set to the maximum value W0. However, the output W is not limited to this, and the storage The output value may be reduced according to the volume in the vessel 10 or the like.
[0075]
Furthermore, at the time t2 of the second embodiment, the valve 51 is opened and the supply of IPA vapor to the atmosphere in the container 10 is started. At the same time, the valve 53 is opened and the pure water stored in the treatment tank 20 is removed. However, the opening / closing timing of the valve 51 and the valve 53 is not limited to this. For example, the valve 53 is opened and the discharge of pure water stored in the processing tank 20 is completed. After the valve 53 is closed, the valve 51 may be opened to start supplying IPA vapor. By setting such valve opening / closing timing, the amount of IPA dissolved in the pure water stored in the treatment tank 20 can be further reduced, and the amount of IPA contained in the drainage can be further reduced.
[0076]
Further, from the time t4 to the time t5 of the third embodiment, the output curve indicating the relationship between the time t and the output W ′ of the pressure reducing pump 40 changes linearly from the output value zero toward the maximum output value W0. Although the output control of the decompression pump 40 is not limited to this, if the IPA vapor mist does not occur when decompressing the inside of the container 10, the output curve shape is, for example, a quadratic curve shape. Or an exponential function shape.
[0077]
【The invention's effect】
From claim 1 Claim 5 The organic solvent vapor contained in the atmosphere in the container can reduce the pressure in the container while maintaining the unsaturated state of the vapor of the organic solvent. Therefore, it is possible to prevent the generation of mist of the organic solvent at the time of decompression, and as a result, it is possible to suppress the generation of fine particles caused by this mist adhering to the substrate, thereby suppressing the drying failure of the substrate. it can.
[0078]
Moreover, even if the temperature in the container is lowered due to the influence of adiabatic expansion during decompression, the vapor of the organic solvent can be decompressed while maintaining a gaseous state, so the temperature of the container atmosphere can be lowered. Therefore, the temperature of the container atmosphere can be made lower than the substrate temperature, the condensation of the organic solvent on the substrate can be promoted, the water droplets inside the fine pattern such as the trench structure can be discharged efficiently, and the drying performance can be improved. Can be improved.
[0079]
Furthermore, the concentration of the organic solvent vapor in the container atmosphere can be reduced, and the amount of organic solvent used can be reduced.
[0080]
Furthermore, since the concentration of the organic solvent used for drying can be reduced, it can be applied to a drying process in a process that could not be used because of its reactivity with the organic solvent.
[0081]
Also , Claims 1 to 5 According to the invention described in the above, by reducing the pressure while controlling the pressure in the container while adjusting the discharge amount of the inert gas, the vapor of the organic solvent in the container is efficiently replaced with the inert gas. It can be discharged out of the container. As a result, since the organic solvent condensed on the substrate can be efficiently evaporated, the drying time can be shortened while improving the drying performance.
[0082]
In particular, Claim 2 According to the invention described in the above, after replacing part or all of the organic solvent vapor existing in the container with the inert gas, the inside of the container is decompressed to reduce the vapor of the organic solvent in the container. In the state where the partial pressure is lowered, the drying process can be started while reducing the pressure. As a result, since the organic solvent condensed on the substrate can be efficiently evaporated, the drying time can be shortened while improving the drying performance.
[0083]
In particular, Claim 3 According to the invention described in the above, the organic solvent is discharged into the container after the pure water stored in the treatment tank is discharged, thereby suppressing the organic solvent from being dissolved in the pure water in the treatment tank. Therefore, the amount of the organic solvent contained in the drainage can be reduced, and the drainage treatment cost can be reduced.
[0084]
In particular, Claim 4 According to the invention described in (1), the drying efficiency can be improved by exposing the substrate after cleaning to the atmosphere containing the vapor of the organic solvent while being lifted.
[0085]
In particular, Claim 5 According to the invention described in (1), since the organic solvent is isopropyl alcohol having a surface tension smaller than that of pure water and further having a low latent heat of vaporization, the substrate can be efficiently dried.
[Brief description of the drawings]
FIG. 1 is a front view of a substrate processing apparatus of the present invention.
FIG. 2 is a plan view of the substrate processing apparatus of FIG.
FIG. 3 is a view for explaining movement of a lifting mechanism of the substrate processing apparatus of FIG. 1;
4 is a side view of the substrate processing apparatus of FIG. 1. FIG.
FIG. 5 is a timing chart showing an example of the open / closed state of the valves of the supply / drainage unit, the output of the decompression pump, and the position of the lifting mechanism in the first embodiment of the present invention.
FIG. 6 is a diagram for explaining a comparison between the present invention and a conventional apparatus, using a timing chart showing an example of a nitrogen gas supply amount and a container internal pressure in the first embodiment.
FIG. 7 is a timing chart showing an example of the open / closed state of the valves of the supply / drainage section, the output of the decompression pump, and the position of the lifting mechanism in the second embodiment.
FIG. 8 is a timing chart showing an example of the open / close state of the valves of the supply / drainage section, the output of the decompression pump, and the position of the lifting mechanism in the third embodiment.
FIG. 9 is a timing chart showing an example of an output value of a pressure reducing pump and a container internal pressure in the third embodiment.
[Explanation of symbols]
1 Substrate processing equipment
10 Container
20 treatment tank
40 Pressure reducing pump
100 substrates
LE factory line

Claims (5)

A substrate processing apparatus for drying a substrate that has been cleaned with pure water,
A container for accommodating a substrate ;
An organic solvent discharging means provided in the container, for discharging an organic solvent vapor, and forming an atmosphere containing the organic solvent in the container;
A pressure reducing means for reducing the pressure in the container, and an inert gas discharging means for discharging an inert gas in the container, and an environment adjusting means for adjusting a gas environment in the container;
By controlling the environment adjusting means, a control means for reducing the pressure in the container while maintaining the vapor of the organic solvent in the container in an unsaturated state;
Equipped with a,
The control means includes
The substrate is exposed to the vapor of the organic solvent by stopping the discharge of the inert gas by the inert gas discharge unit and starting the discharge of the organic solvent vapor by the organic solvent discharge unit,
Subsequently, the discharge of the organic solvent vapor by the organic solvent discharge means is stopped, and the discharge of the inert gas by the inert gas means is started,
Then, by reducing the pressure in said container by said vacuum means, the substrate processing apparatus according to claim Rukoto to perform the decompression of the at unsaturated state. The substrate processing apparatus according to claim 1,
The substrate processing apparatus characterized in that the control means decompresses the inside of the container after replacing part or all of the vapor of the organic solvent with the inert gas . The substrate processing apparatus according to claim 1 or 2, wherein
A treatment tank provided in the container, storing pure water and immersing the substrate in the pure water to perform a cleaning process;
A discharge path for discharging pure water stored in the treatment tank;
With
The organic solvent discharge means, a substrate processing apparatus according to claim Rukoto the pure water stored in the processing bath is discharged to the organic solvent from being discharged from the discharge passage. A substrate processing apparatus according to any one of claims 1 to 3,
The substrate processing apparatus according to claim further comprising Rukoto hoisting means, which withdraw in an atmosphere containing the vapor of the organic solvent the substrate from the processing bath. The substrate processing apparatus according to claim 1, wherein:
The organic solvent the substrate processing apparatus according to claim Oh Rukoto with isopropyl alcohol.

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