JP2004356379A - Substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing apparatus which can keep almost constant amount of vapor of the processing liquid supplied per unit period. <P>SOLUTION: A hydrofluoric acid vapor generator 43 supplies the aqueous solution of hydrofluoric acid by discharging the same from a pressure dispersion nozzle 61 at the time of supplying the aqueous solution of hydrofluoric acid to an internal space 35 in a reservoir tank 57. Accordingly, since liquid pressure of the aqueous solution of hydrofluoric acid supplied to the internal space 35 of the reservoir tank 57 can be lowered and amount of the hydrofluoric acid vapor can be kept almost constant. Therefore, it can be prevented that the aqueous solution of supplied hydrofluoric acid splashes and the drops thereof are adhered to the internal wall of the ceiling 43a or the like at the internal side of the reservoir tank 57. Therefore, the film removing process can be performed almost equivalently to each substrate W. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
In the present invention, a chemical solution such as a hydrofluoric acid aqueous solution (hereinafter, also referred to as a “treatment solution”) is applied to a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk (hereinafter, simply referred to as a “substrate”). The present invention relates to a substrate processing apparatus for removing a film formed on the surface of a substrate by supplying the vapor of the method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a manufacturing process of a semiconductor element, when a memory capacitor film is formed on a semiconductor substrate, BSG (Boron-Silicate Glass), PSG (Phosphor-Silicate Glass), BPSG (Boron-doped Phospho-Silicate Glass), or the like is used. An oxide film containing many impurities is used as a sacrificial oxide film. These sacrificial oxide films can have a high selectivity to a thermal oxide film or a CVD (chemical vapor deposition) oxide film in etching using hydrofluoric acid vapor, and the thermal oxide film or the CVD oxide film is etched. It can be selectively removed by using it as a stopper film (for example, Patent Document 1).
[0003]
In an etching process for removing a thermal oxide film or a CVD film, hydrofluoric acid vapor evaporated from a hydrofluoric acid aqueous solution is supplied to a substrate together with a carrier gas. As described above, a vaporizer for vaporizing an object to be supplied and supplying the vaporized object to a substrate has been conventionally known (for example, Patent Document 2).
[0004]
[Patent Document 1]
JP-A-2002-110627
[Patent Document 2]
JP-A-06-163417
[0005]
[Problems to be solved by the invention]
By the way, in the etching process for removing the thermal oxide film and the CVD film, the hydrofluoric acid aqueous solution stored in the storage tank inside the vaporizer evaporates and decreases as the processing proceeds. It will be necessary to replenish.
[0006]
However, when replenishing the storage tank with the hydrofluoric acid aqueous solution, the hydrofluoric acid aqueous solution jumps on the inner wall of the storage tank and drops of the hydrofluoric acid aqueous solution adhere to the inner wall of the storage tank. The hydrofluoric acid vapor evaporates from the attached droplets. In other words, until the droplets attached to the inner wall evaporate and disappear, the amount of hydrofluoric acid vapor generated in the vaporizer is the amount of hydrofluoric acid vaporized from the stored hydrofluoric acid aqueous solution and adhered to the inner wall. This is the sum of the amount of hydrofluoric acid vaporized from the droplets. Therefore, the amount of hydrofluoric acid vapor supplied to the substrate per unit time fluctuates until the liquid droplets attached to the inner wall evaporate and disappear, and as a result, the thermal oxide film or the CVD film per unit time changes. The amount of removal will vary.
[0007]
Therefore, an object of the present invention is to provide a substrate processing apparatus capable of making the amount of vapor of a processing liquid supplied by a processing liquid gas supply unit per unit time substantially constant.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a substrate processing apparatus for removing a film formed on a surface of a substrate, wherein the processing liquid is introduced into a storage tank and an inner space of the storage tank. A liquid pipe, a processing liquid gas supply unit for supplying a vapor of the processing liquid evaporated in the inner space to the substrate by supplying a carrier gas to the inner space, and the processing liquid pipe to the inner space. A pressure reducing unit configured to reduce the introduction pressure of the processing liquid and supply the processing liquid to the inside space when introducing the processing liquid.
[0009]
According to a second aspect of the present invention, in the substrate processing apparatus according to the first aspect, the pressure relaxation unit supplies the processing liquid to the inner space while dispersing the pressure of the processing liquid flowing through the processing liquid pipe. It is characterized by having a pressure dispersing nozzle.
[0010]
According to a third aspect of the present invention, in the substrate processing apparatus according to the second aspect, the pressure dispersion nozzle is fitted to an outer end of one end of the end of the processing liquid pipe provided in the inner space. A first cylindrical portion having a through-hole into which the processing liquid pipe is inserted, and a second cylindrical portion fitted to the outside of the first cylindrical portion; The processing liquid supplied to the pressure dispersing nozzle includes a first flow path interposed between the outer circumference of the processing liquid pipe and the inner circumference of the first cylindrical portion, and the outer circumference of the first cylindrical portion and the second flow path. And a second flow path interposed between the inner circumference of the cylindrical portion and the inner space.
[0011]
Further, the invention according to claim 4 is a substrate processing apparatus for removing a film formed on a surface of a substrate, a storage tank, a processing liquid pipe for introducing the processing liquid into an inner space of the storage tank, and By supplying a carrier gas to the inner space, processing liquid gas supply means for supplying the processing gas vapor evaporated in the inner space together with the carrier gas to the substrate, and removing a film formed on the surface of the substrate Before performing the processing, when the processing liquid is introduced into the inner space by the processing liquid pipe, a processing liquid removing unit that removes the processing liquid attached to the inner wall of the storage tank is provided. I do.
[0012]
Further, according to a fifth aspect of the present invention, in the substrate processing apparatus according to the fourth aspect, the processing liquid removing unit stores the storage solution for a predetermined time before performing a process of removing a film formed on the surface of the substrate. A carrier gas is supplied to an upper space above the processing liquid stored in the tank.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
<1. Configuration of Substrate Processing Apparatus>
FIG. 1 is an illustrative plan view for explaining the overall configuration of a substrate processing apparatus 1 according to the present invention. This apparatus is an apparatus for removing an oxide film formed on the surface of the substrate W. More specifically, for example, when a sacrificial oxide film (BPSG film or the like) used for forming a memory capacitor is formed on a thermal oxide film formed on substrate W, this sacrificial oxide film is This is a device for selective removal. In the substrate processing apparatus 1 of the present invention, the film removing step is performed by a hydrofluoric acid vapor phase etching process for supplying a hydrofluoric acid vapor to the surface of the substrate W.
[0015]
As shown in FIG. 1, the substrate processing apparatus 1 mainly performs a gas phase etching process using hydrofluoric acid vapor on a loader unit 10 in which a cassette CL containing a substrate W before processing is placed and on the surface of the substrate W. A gas-phase etching processing unit 40, a water-washing / drying processing unit 50 for rinsing the substrate W after the gas-phase etching process, and then performing a water-drying process, and a substrate W after the water-washing / drying processing unit 50 And an unloader section 60 on which a cassette CU for housing the cassette is placed.
[0016]
The loader unit 10 and the unloader unit 60 are arranged behind the front panel 77 of the substrate processing apparatus 1. The loader unit 10, the vapor phase etching unit 40, the washing / drying unit 50, and the unloader unit 60 are arranged in this order along a substantially U-shaped wafer transfer path 78 in plan view.
[0017]
Between the loader unit 10 and the vapor-phase etching processing unit 40, a loader transport robot that takes out the unprocessed substrates W one by one from the cassette CL placed in the loader unit 10 and carries the substrates W into the vapor-phase etching processing unit 40. 71 are arranged. Further, between the vapor-phase etching processing unit 40 and the water-washing / drying processing unit 50, an intermediate transport for taking out the substrate W after the gas-phase etching processing from the vapor-phase etching processing unit 40 and carrying the substrate W into the water-washing / drying processing unit 50 A robot 81 is arranged. An unloader is provided between the rinsing / drying unit 50 and the unloader unit 60 for taking out the substrate W after the rinsing / drying unit from the rinsing / drying unit 50 and storing the substrate W in the cassette CU placed in the unloader unit 60. A transfer robot 72 is provided.
[0018]
Each of the loader transfer robot 71, the intermediate transfer robot 81, and the unloader transfer robot 72 has a form of a bending and stretching robot having a lower arm LA and an upper arm UA. The lower arm LA is rotated along a horizontal plane by a rotation drive mechanism (not shown). At the tip of the lower arm LA, an upper arm UA is provided so as to be freely rotatable along a horizontal plane. When the lower arm LA rotates, the upper arm UA rotates in a direction opposite to the rotation direction of the lower arm LA by twice the rotation angle of the lower arm LA. As a result, the lower arm LA and the upper arm UA can assume a contracted state in which both arms are vertically overlapped, and an extended state in which both arms are deployed toward one side or the other side along the path 78. it can.
[0019]
In this way, the loader transfer robot 71, the intermediate transfer robot 81, and the unloader transfer robot 72 can transfer the substrate W along the path 78 between the processing units or between the cassette and the processing unit.
[0020]
The rinsing / drying processing unit 50 for rinsing and drying the substrate W after the vapor-phase etching processing includes, for example, a spin chuck that horizontally holds and rotates the substrate W, and a pure chuck for the substrate W held by the spin chuck. A pure water supply nozzle for supplying water is provided. With this configuration, pure water is supplied to the front surface and / or the back surface of the substrate W to wash the surface of the substrate W with water. After the completion of the water washing, the supply of pure water is stopped, and the spin chuck is rotated at a high speed to shake off and dry the surface of the substrate W.
[0021]
FIG. 2 is a schematic cross-sectional view for explaining the configuration of the vapor-phase etching processing section 40. The vapor-phase etching processing section 40 includes a hydrofluoric acid vapor generator 43 that stores a hydrofluoric acid aqueous solution 42, which is an example of a processing liquid containing an acid, in a sealed state in a housing 41 (the internal structure and the like are shown in FIG. 3). With reference to later). At the bottom of the hydrofluoric acid vapor generator 43, a disk-shaped punching plate 44 having a large number of through holes 44a is provided. The hydrofluoric acid vapor is supplied to the upper surface of the substrate W widely through each of the many through holes 44 a formed in the punching plate 44.
[0022]
Below the punching plate 44, a hot plate 45 for holding the substrate W to be processed horizontally while facing the punching plate 44 is disposed. Inside the hot plate 45, a heater for heating the substrate W at a predetermined temperature (for example, 40 ° C. to 80 ° C.) is provided. Further, the hot plate 45 is fixed to the upper end of a rotating shaft 47 which is rotated (rotated) around a vertical axis OW (hereinafter, referred to as a rotating axis OW) passing through the center of the substrate W by a rotation driving mechanism 46 including a motor and the like. I have.
[0023]
A bellows 48 that contracts up and down with respect to the bottom surface 41 a of the housing 41 is provided on the outer side of the hot plate 45 in plan view. The bellows 48 makes an annular contact portion 48 a provided on the upper end edge thereof come into contact with the periphery of the punching plate 44 (the lower surface of the hydrofluoric acid steam generator 43) to seal the space around the hot plate 45. A closed position (a position shown by a solid line in the figure) to form a processing chamber 85, and a retracted position (a position shown by a two-dot chain line in FIG. 2) in which the upper end edge is retracted below the upper surface 45a of the hot plate 45. In between, the drive mechanism is driven to extend / contract by a drive mechanism (not shown).
[0024]
The internal space of the bellows 48 is exhausted by exhaust means 55 via an exhaust pipe 49 connected to the bottom surface 41a of the housing 41. The exhaust means 55 may be a forced exhaust mechanism such as an exhaust blower or an ejector, or may be an exhaust facility provided in a clean room where the substrate surface treating apparatus is installed.
[0025]
On the side of the hot plate 45, a carry-in opening 21 for carrying in the substrate W and a carry-out opening 22 for discharging the substrate W are formed in the side wall of the housing 41. Shutters 38 and 39 are arranged in these openings 21 and 22, respectively. When the substrate W is loaded, the bellows 48 is lowered to the retracted position (the position indicated by the broken line in FIG. 2), the shutter 38 is opened, and the substrate W is received on the hot plate 45 by the loader transfer robot 71 (see FIG. 1). Passed. When the substrate W is carried out, the bellows 48 is set to the retracted position, the shutter 39 is opened, and the substrate W on the hot plate 45 is delivered to the intermediate transfer robot 81 and carried out. Note that the positional relationship between the carry-in opening 21 and the shutter 38 and the carry-out opening 22 and the shutter 39 is actually such that two line segments connecting these and the center of the substrate W are orthogonal to each other in plan view. However, in FIG. 2, for the sake of simplicity of illustration, these arrangement relations are such that two line segments connecting these and the center of the substrate W overlap in a plan view (substrate). (In substantially point-symmetrical relation with respect to the center of W).
[0026]
FIG. 3 is a sectional view showing the configuration of the hydrofluoric acid vapor generator 43 of the present invention. The hydrofluoric acid vapor generator 43 is a member that generates hydrofluoric acid vapor used for etching a thermal oxide film or a CVD oxide film formed on the substrate W. As shown in FIG. 3, the hydrofluoric acid vapor generator 43 mainly includes a storage tank 57 for storing the hydrofluoric acid aqueous solution, and a discharge unit for supplying the hydrofluoric acid aqueous solution to the inner space 35 of the storage tank 57. A nitrogen gas supply pipe 54 for introducing nitrogen gas into the upper space 35a of the storage tank 57 (that is, the space in which the hydrofluoric acid aqueous solution is not stored) 35a, and a storage tank The hydrofluoric acid vapor supply path 36 supplies the hydrofluoric acid vapor generated at 57 to a container 91 (see FIG. 2) described later.
[0027]
As shown in FIG. 3, a hydrofluoric acid aqueous solution 42 is stored in the inner space 35 of the storage tank 57, and the hydrofluoric acid aqueous solution 42 is introduced into the temperature control unit 25 through the pipe 26a to be at a constant temperature. Can be held. Further, the hydrofluoric acid aqueous solution introduced into the temperature control unit 25 is supplied with a valve 24a, a pipe 26b, a processing liquid pipe 28b for introducing the hydrofluoric acid aqueous solution from outside the storage tank 57 to the inner space 35 of the storage tank 57, and a pressure dispersion nozzle. The water is additionally supplied to the hydrofluoric acid aqueous solution 42 in the inner space 35 of the storage tank 57 via 61. Therefore, the hydrofluoric acid aqueous solution 42 stored in the inner space 35 of the storage tank 57 can be maintained at a constant temperature by opening the valve 24a and circulating the hydrofluoric acid aqueous solution 42 while introducing it into the temperature control unit 25. .
[0028]
The inner space 35 of the storage tank 57 is connected to the hydrofluoric acid water supply source 27 via a valve 24b, a pipe 28a, a processing liquid pipe 28b, and a pressure dispersion nozzle 61. Therefore, when the storage amount of the hydrofluoric acid aqueous solution 42 decreases due to evaporation, the hydrofluoric acid aqueous solution can be replenished to the inner space 35 of the storage tank 57.
[0029]
Here, the pressure dispersion nozzle 61 used as a discharge port of the hydrofluoric acid aqueous solution supplied to the inner space 35 of the storage tank 57 will be described. 4 shows a vertical cross section of the pressure distribution nozzle 61, and FIG. 5 shows a cross section of the pressure distribution nozzle 61 when viewed from the line VV of FIG. As shown in FIGS. 4 and 5, the pressure distribution nozzle 61 mainly includes an inner cylindrical portion 63 and an outer cylindrical portion 64.
[0030]
As shown in FIGS. 4 and 5, the inner cylindrical portion 63 is a cylindrical body having an opening at an upper portion, and is disposed substantially concentrically outside the processing liquid piping 28b. Further, the inner cylindrical portion 63 is disposed such that the lower end portion 28c of the processing liquid pipe 28b exists inside the inner cylindrical portion 63.
[0031]
Therefore, the hydrofluoric acid aqueous solution flowing in the inner space 62b of the processing liquid pipe 28b in the direction of the arrow AR1 reaches the inner portion of the inner cylindrical portion 63 from the lower end 28c of the processing liquid pipe 28b and is bounced off at the inner bottom surface 63a. The traveling direction of the acid aqueous solution changes from the direction of arrow AR1 to the direction of arrow AR2. Then, the repelled hydrofluoric acid aqueous solution flows into the internal space 63b sandwiched between the outer peripheral portion of the processing liquid pipe 28b and the inner peripheral portion of the inner cylindrical portion 63. That is, the internal space 63b is used as a flow path for the hydrofluoric acid aqueous solution.
[0032]
As shown in FIGS. 4 and 5, the outer cylindrical portion 64 is a cylindrical body having an opening at a lower portion, and is disposed substantially concentrically outside the inner cylindrical portion 63. Further, a through hole is provided near the center of the upper end portion 64c of the outer cylindrical portion 64, the processing liquid pipe 28b is inserted into the through hole, and the outer cylindrical portion 64 is mounted on the outer peripheral surface of the processing liquid pipe 28b. It is provided. Further, the outer peripheral portion of the inner cylindrical portion 63 is fixed to the inner peripheral portion of the outer cylindrical portion 64 by a plurality of (four in the present embodiment) support pieces 65. The position in the axial direction and the position in the Z-axis direction of the lower end 63d of the inner cylindrical portion 63 are set to be substantially the same. The processing liquid pipe 28b is connected to the ceiling 43a of the hydrofluoric acid vapor generator 43 by screws inside and outside, respectively, to form a pipe. With this configuration, the pressure dispersing nozzle 61 in the hydrofluoric acid vapor generator 43 can be attached and detached by releasing the screw between the processing liquid pipe 28b inside the hydrofluoric acid vapor generator 43 and the ceiling 43a.
[0033]
Therefore, the hydrofluoric acid aqueous solution flowing in the internal space 63b in the direction of the arrow AR3 reaches the inner portion of the outer cylindrical portion 64 and is rebounded on the inner upper surface 64a, and the traveling direction of the hydrofluoric acid aqueous solution changes from the arrow AR3 direction to the arrow AR4 direction. change. Then, the repelled hydrofluoric acid aqueous solution flows into the internal space 64b sandwiched between the outer peripheral portion of the inner cylindrical portion 63 and the inner peripheral portion of the inner cylindrical portion 63. That is, the internal space 64b is used as a flow path for the hydrofluoric acid aqueous solution.
[0034]
As described above, the hydrofluoric acid aqueous solution introduced into the pressure dispersing nozzle 61 from the hydrofluoric acid water supply source 27 or from the temperature control unit 25 via the processing liquid pipe 28 b is formed on the inner bottom surface 63 a of the inner cylindrical portion 63 and the outer side. It is rebounded by the inner upper surface 64a of the cylindrical portion 64. In other words, when the hydrofluoric acid aqueous solution flowing through the processing liquid piping 28b is rebounded at the inner bottom surface 63a of the inner cylindrical portion 63 and flows into the internal space 63b, the hydrofluoric acid aqueous solution is dispersed, and the pressure in the processing liquid piping 28b is reduced. The state becomes more relaxed. The liquid pressure (pressure) of the hydrofluoric acid aqueous solution in the internal space 63b decreases. Subsequently, when the hydrofluoric acid aqueous solution flowing through the internal space 63b is bounced off the inner upper surface 64a of the outer cylindrical portion 64 and flows into the internal space 64b, the hydrofluoric acid aqueous solution is further dispersed and the hydrofluoric acid aqueous solution flows through the internal space 64b. The hydraulic pressure of the water liquid is further reduced and reduced. Therefore, the liquid pressure (pressure) of the hydrofluoric acid aqueous solution supplied from the pressure dispersion nozzle 61 to the inner space 35 of the storage tank 57 can be reduced as compared with the liquid pressure of the hydrofluoric acid aqueous solution flowing through the processing liquid pipe 28b. .
[0035]
As shown in FIGS. 2 and 3, the upper space 35 a in the inner space 35 of the storage tank 57 and above the liquid surface of the hydrofluoric acid aqueous solution 42 has a nitrogen gas supply pipe 54, a valve 53, and a flow controller ( An MFC (MFC) 52 is connected to a nitrogen gas supply source 31 that supplies nitrogen gas as a carrier gas. The upper space 35a of the storage tank 57 is an internal space surrounded by the lower part of the hydrofluoric acid steam generator 43 and the punching plate 44 via the valve 37, the hydrofluoric acid vapor supply passage 36, and a plurality of discharge ports 36a described later. (See FIG. 2).
[0036]
Here, as shown in FIG. 2, the container 91 is provided with a punching plate 44 so as to close the opening 91b on the bottom surface of the container 91. Further, the internal space of the container 91 is a cylindrical space having the central axis OH (which coincides with the rotation axis OW of the substrate W in the present embodiment) as the central axis. Further, a plurality of (six in the present embodiment) discharge ports 36 a communicating with the hydrofluoric acid vapor supply passage 36 are opened in the inner peripheral surface 91 a of the container 91.
[0037]
Therefore, when the valve 53 and the valve 37 are opened, the hydrofluoric acid vapor evaporated from the hydrofluoric acid aqueous solution 42 stored inside the storage tank 57, together with the nitrogen gas used as the carrier gas, flows from the discharge port 36a to the internal space of the container 91. It is discharged toward. Then, the hydrofluoric acid vapor discharged into the internal space of the container 91 passes through each of the many through holes 44 a formed in the punching plate 44 and is widely supplied to the upper surface of the substrate W. That is, the nitrogen gas supply source 31, the valves 53 and 37, the nitrogen gas supply pipe 54, and the hydrofluoric acid vapor supply path 36 are used to supply hydrofluoric acid vapor toward the substrate W.
[0038]
Note that the hydrofluoric acid aqueous solution 42 stored in the inner space 35 of the storage tank 57 has a concentration (for example, about 39.6% under a pressure of 1 atm and room temperature (20 ° C.)) of a so-called pseudo-co-fluorine composition. Has been prepared. In the hydrofluoric acid aqueous solution 42 having the pseudo-cofluoric composition, the evaporation rates of water and hydrogen fluoride are equal, so that hydrofluoric acid vapor is led from the valve 37 to the punching plate 44 via the hydrofluoric acid vapor supply passage 36. Even if the amount of the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generator 43 decreases, the concentration of the hydrofluoric acid vapor guided to the hydrofluoric acid vapor supply passage 36 is kept unchanged. In FIG. 2, reference numeral 90 denotes a pipe through which temperature-regulated water flows to maintain the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generator 43 at a constant temperature.
[0039]
Further, valves 33 and 53 for switching supply / stop of the nitrogen gas and flow controllers 32 and 52 for changing the supply amount of the nitrogen gas are controlled by a controller 80.
[0040]
By the way, using a conventional hydrofluoric acid vapor generating container without the pressure dispersing nozzle 61, an etching process for removing an oxide film formed on the substrate by hydrofluoric acid vapor generated in the hydrofluoric acid vapor generating container is performed. In such a case, there has been a problem that the removal amount of the oxide film removed per unit time varies.
[0041]
Therefore, when the inventors investigated in detail,
(1) In the period from the start of the etching process to the lapse of a certain time, the removal amount of the oxide film per unit time decreases with the lapse of time,
(2) After a lapse of a certain time, the removal amount of the oxide film per unit time becomes substantially the same regardless of the lapse of time.
It turned out that.
[0042]
And the inventor conducted further research, and found that in the conventional hydrofluoric acid vapor generating vessel,
(1) When replenishing the hydrofluoric acid aqueous solution into the storage tank, the replenished hydrofluoric acid aqueous solution jumps and adheres as droplets to the inner wall such as the inner ceiling of the storage tank.
(2) Hydrofluoric acid vapor is generated from the hydrofluoric acid aqueous solution stored in the storage tank and the hydrofluoric acid aqueous solution adhering to the inner wall until the hydrofluoric acid aqueous solution droplets attached to the inner wall evaporate and disappear. Since the amount of hydrofluoric acid vapor fluctuates until a certain time has elapsed from the start of the etching process, the removal amount of the oxide film per unit time fluctuates with the elapse of time.
(3) When the hydrofluoric acid aqueous solution droplets adhered to the inner wall disappear, the etching process is performed by hydrofluoric acid vapor evaporated from the hydrofluoric acid aqueous solution stored in the storage tank, so that the hydrofluoric acid aqueous solution droplets disappear. After that, the removal amount of the oxide film per unit time should be substantially the same,
Ascertained.
[0043]
On the other hand, in the hydrofluoric acid vapor generator 43 of the present embodiment, the hydrofluoric acid aqueous solution is supplied to the inner space 35 of the storage tank 57 from the pressure dispersing nozzle 61 capable of reducing the liquid pressure (pressure) of the hydrofluoric acid aqueous solution. Is discharged and supplied. Thereby, when the hydrofluoric acid aqueous solution is supplied to the storage tank 57, it is possible to prevent the water hydrofluoric acid solution from jumping and attaching to the inner wall such as the ceiling 43 a inside the storage tank 57. Therefore, the amount of hydrofluoric acid supplied per unit time to the substrate W can be made substantially constant, and the oxide film formed on the substrate W can be removed satisfactorily.
[0044]
<2. Substrate processing procedure>
Here, a substrate processing procedure by the substrate processing apparatus 1 of the present embodiment will be described. In the substrate processing according to the present embodiment, first, one substrate W before processing is taken out from the cassette CL mounted on the loader unit 10 by the loader transfer robot 71. Subsequently, the bellows 48 of the vapor phase etching section 40 is lowered and the shutter 38 is opened. Then, the unprocessed substrate W is carried into the processing chamber 85 of the vapor phase etching processing section 40 through the carrying-in opening 21 by the loader carrying robot 71, and placed on the hot plate upper surface 45a.
[0045]
Subsequently, the processing operation of the substrate W in the processing chamber 85 of the vapor phase etching processing unit 40 will be described. When performing the film removing step of removing the film on the surface of the substrate W, the bellows 48 is raised to the close contact position (the position indicated by the solid line in FIG. 2) in close contact with the periphery of the punching plate 44, and the shutter 38 is closed. A sealed processing chamber 85 surrounding the plate 45 is formed. In this state, the controller 80 holds the valves 33, 37, and 53 in the open state. Thereby, the hydrofluoric acid vapor generated in the upper space 35 a in the hydrofluoric acid vapor generator 43 is pushed out to the hydrofluoric acid vapor supply passage 36 via the valve 37 by the nitrogen gas from the nitrogen gas supply pipe 54. The hydrofluoric acid vapor is further discharged into the container 91 from the six discharge ports 36a through the circular flow passage 36b by the nitrogen gas from the nitrogen gas supply pipe 34. Then, the hydrofluoric acid vapor in the container 91 is supplied to the surface of the substrate W through a through-hole 44a formed in the punching plate 44 closing the opening 91b on the bottom surface of the container 91. Then, on the surface of the substrate W, hydrofluoric acid vapor reacts with an oxide film (silicon oxide) on the surface of the substrate W under the participation of water molecules near the substrate W, thereby achieving removal of the oxide film. Is done.
[0046]
Here, in the film removing step of the present embodiment, the hydrofluoric acid vapor supplied to the surface of the substrate W is generated by the hydrofluoric acid vapor generator 43 having the pressure dispersion nozzle 61. Thus, even if the hydrofluoric acid aqueous solution is supplied to the storage tank 57 (FIG. 3) of the hydrofluoric acid vapor generator 43, it is possible to prevent the hydrofluoric acid aqueous solution from adhering to the inner wall of the storage tank 57. Therefore, the vapor amount of hydrofluoric acid supplied per unit time can be made substantially the same for each substrate W subjected to the film removal processing in the processing chamber 85, and the film removal amount of each substrate W can be made substantially the same. can do.
[0047]
After performing the film removing step for a predetermined period of time in this way, the controller 80 closes the valves 37 and 53 to stop the film removing step. At the same time, the controller 80 keeps the valve 33 open, controls the flow rate controller 32 to increase the flow rate of the nitrogen gas flowing through the nitrogen gas supply pipe 34, and removes the nitrogen gas from the punching plate. The liquid is supplied to the surface of the substrate W through the through hole 44a. As a result, water molecules and hydrofluoric acid molecules present near the surface of the substrate W are replaced and removed, and are carried out of the processing chamber 85 by exhausting the processing chamber 85 through the exhaust pipe 49. At this time, since the vortex flow S of the nitrogen gas is generated in the container 91, the replacement and removal of water molecules and hydrofluoric acid molecules near the surface of the substrate W are uniformly performed in the surface of the substrate W.
[0048]
Subsequently, immediately after the film removing step, by supplying nitrogen gas as an inert gas to the surface of the substrate W, water and hydrofluoric acid molecules near the surface of the substrate W are promptly removed. The vapor phase etching process stops immediately. Since the stop of the vapor phase etching process occurs almost simultaneously over the entire surface of the substrate W, uniform film removal processing can be performed on each part of the surface of the substrate W. In addition, it is possible to reduce a variation in processing for a plurality of substrates W. Then, the supply of the nitrogen gas after the film removing step is continued for a predetermined time (for example, 10 seconds or more, preferably about 20 seconds), and then the controller 80 closes the valve 33 to supply the nitrogen gas. Stop.
[0049]
When the film removing step in the vapor phase etching processing section 40 is completed, the bellows 48 is lowered and the shutter 39 is opened. Then, the substrate W subjected to the film removal processing is carried out of the processing chamber 85 of the vapor-phase etching processing unit 40 by the intermediate transfer robot 81, and the substrate W having been subjected to the film removal processing is transferred to the washing / drying processing unit 50. Carry in and subject to washing and drying.
[0050]
When the cleaning / drying processing is completed, the substrate W is unloaded by the unloader transfer robot 72 and is placed on the cassette CU of the unloader unit 60, thereby completing the substrate processing.
[0051]
<3. Advantages of substrate processing equipment>
As described above, the hydrofluoric acid vapor generator 43 of the substrate processing apparatus 1 according to the present embodiment discharges the hydrofluoric acid aqueous solution from the pressure dispersion nozzle 61 when supplying the hydrofluoric acid aqueous solution to the inner space 35 of the storage tank 57. By supplying the hydrofluoric acid, the hydrofluoric acid aqueous solution is introduced with the pressure reduced. Thereby, the liquid pressure (pressure) of the hydrofluoric acid aqueous solution supplied to the inner space 35 of the storage tank 57 can be reduced, and the supplied hydrofluoric acid aqueous solution jumps and is formed on the inner wall such as the ceiling 43 a inside the storage tank 57. The attachment of the hydrofluoric acid aqueous solution droplets can be prevented. Therefore, the film removal processing performed in the processing chamber 85 of the vapor phase etching processing unit 40 can be performed on each substrate W in substantially the same manner.
[0052]
<4. Modification>
The embodiments of the present invention have been described above, but the present invention is not limited to the above examples.
[0053]
In the present embodiment, the use of the pressure dispersing nozzle 61 prevents droplets of the hydrofluoric acid aqueous solution from adhering to the inner wall of the storage tank 57, and makes the vapor amount of hydrofluoric acid per unit time substantially constant. However, the present invention is not limited to this.
[0054]
For example, even if the hydrofluoric acid aqueous solution is replenished to the inner space 35 of the storage tank 57 without using the pressure dispersion nozzle 61, the hydrofluoric acid aqueous solution attached to the inner wall of the storage tank 57 is once removed and removed, and then the film removing process is performed. Is performed, the amount of hydrofluoric acid vapor per unit time can be made substantially constant.
[0055]
Specifically, the valve 33 is closed and the valves 53 and 37 are opened before the substrate W is loaded and placed on the hot plate 45 in the processing chamber 85 of the vapor phase etching processing unit 40. Then, a predetermined amount of nitrogen gas per unit time is supplied to the upper space 35a of the storage tank 57 per unit time into the upper space 35a (see FIGS. 2 and 3). Thus, the hydrofluoric acid aqueous solution droplets attached to the inner wall of the storage tank 57 continue to evaporate, and after a certain period of time, the hydrofluoric acid aqueous solution droplets attached to the inner wall of the storage tank 57 disappear. Then, after the droplets of the hydrofluoric acid aqueous solution attached to the inner wall of the storage tank 57 have disappeared, the substrate W is carried into the processing chamber 85 and placed on the hot plate 45 to perform the film removing process. By doing so, the amount of hydrofluoric acid vapor per unit time can be made substantially constant for each substrate W on which film removal processing is performed in the processing chamber 85, and the film removal amount of each substrate W is made substantially the same. be able to.
[0056]
In this modification, the supply amount of nitrogen gas per unit time is 30 to 50 (liter / min), and the supply time of nitrogen gas is 30 minutes or more.
[0057]
In the hydrofluoric acid vapor generator 43 of the present embodiment, the hydrofluoric acid aqueous solution 42 stored in the inner space 35 of the storage tank 57 is kept constant by introducing and circulating the hydrofluoric acid aqueous solution 42 into the temperature control unit 25. Keep at temperature. Therefore, when the hydrofluoric acid aqueous solution is re-supplied from the temperature control unit 25 to the inner space 35 of the storage tank 57 in this circulation, it is conceivable that droplets of the hydrofluoric acid aqueous solution adhere to the inner wall of the storage tank 57.
[0058]
However, if the amount V1 of the hydrofluoric acid aqueous solution adhering to the inner wall of the storage tank 57 is smaller than the amount V2 of the hydrofluoric acid aqueous solution evaporating per unit time, the unit time supplied to each substrate W The amount of hydrofluoric acid vapor per unit can be substantially constant. Therefore, even when the hydrofluoric acid aqueous solution liquid drops adhere to the inner wall of the storage tank 57, the film removal amount of each substrate W can be made substantially the same.
[0059]
【The invention's effect】
According to the first to third aspects of the present invention, since the processing liquid is introduced at a pressure lower than the pressure at which the processing liquid is supplied by the processing liquid pipe, the processing liquid introduced into the inner space of the storage tank. Can be prevented from adhering to the liquid in the storage tank. Accordingly, the vapor of the processing liquid supplied to the substrate does not include the evaporation of the processing liquid attached to the inner wall, but substantially only the evaporation of the processing liquid stored in the inner space. The amount of vapor of the processing liquid supplied to the apparatus can be made constant. Therefore, when removing the film formed on the surface of the substrate, the removal amount of the film per unit time can be made constant.
[0060]
In particular, according to the second aspect of the present invention, by using the pressure dispersion nozzle, the processing liquid can be supplied to the inner space of the storage tank while reducing the pressure of the processing liquid. Therefore, it is possible to prevent the processing liquid supplied to the inner space from splashing and adhering to the inner wall of the storage tank.
[0061]
In particular, according to the third aspect of the present invention, the processing liquid supplied from the processing liquid pipe to the pressure dispersion nozzle is dispersed through the first flow path and the second flow path, thereby dispersing the processing liquid pressure. Is done. Therefore, it is possible to prevent the processing liquid supplied to the inner space from splashing and adhering to the inner wall of the storage tank.
[0062]
According to the fourth and fifth aspects of the present invention, even when the processing liquid adheres to the inner wall of the storage tank when the processing liquid is introduced into the inner space of the storage tank, the processing liquid removing means can be used. The processing liquid attached to the internal liquid can be removed before the substrate processing. As a result, the vapor of the processing liquid supplied to the substrate does not include the vaporized processing liquid attached to the inner wall, but includes the vaporized processing liquid stored in the inner space. The amount of vapor of the processing liquid supplied to the apparatus can be made constant. Therefore, when removing the film formed on the surface of the substrate, the removal amount of the film per unit time can be made constant.
[0063]
In particular, according to the fifth aspect of the present invention, the carrier gas is supplied to the inner space of the storage tank by supplying the carrier gas to the upper space of the storage tank before performing the process of removing the film formed on the surface of the substrate. The processing liquid can be evaporated. Therefore, when performing the film removal processing, the processing liquid attached to the inner wall does not include the vapor of the processing liquid evaporated and the film removal processing is performed by the processing liquid vapor evaporated from the processing liquid stored in the inner space. It can be carried out.
[Brief description of the drawings]
FIG. 1 is a plan view showing an overall configuration of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view illustrating a configuration of a vapor phase etching processing unit according to an embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a configuration of a hydrofluoric acid vapor generating container according to an embodiment of the present invention.
FIG. 4 is a longitudinal sectional view showing a configuration of a pressure distribution nozzle according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view of the pressure dispersion nozzle of FIG. 4 as viewed from line VV.
[Explanation of symbols]
1 Substrate processing equipment
10 Loader section
31 Nitrogen gas supply source
34 Nitrogen gas supply piping
36 Hydrofluoric acid vapor supply path
40 Gas phase etching unit
43 Hydrofluoric acid steam generator
49 Exhaust piping
50 Washing / drying processing section
54 Nitrogen gas supply piping
55 exhaust means
60 Unloader section
61 Pressure dispersion nozzle
62 Inlet pipe
62b, 63b, 64b space
63 Inner cylindrical part
63a Inside bottom
64 Outer cylindrical part
64a Inside upper surface
65 Support strip
80 Controller

Claims (5)

A substrate processing apparatus for removing a film formed on a surface of a substrate,
(A) a storage tank;
(B) a processing liquid pipe for introducing the processing liquid into an inner space of the storage tank;
(C) a processing liquid gas supply unit that supplies a vapor of the processing liquid evaporated in the inner space to the substrate by supplying a carrier gas to the inner space;
(D) when introducing the processing liquid into the inner space through the processing liquid pipe, a pressure reducing unit configured to reduce the introduction pressure of the processing liquid and supply the processing liquid to the inner space;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The substrate processing apparatus according to claim 1, wherein the pressure reducing unit includes a pressure distribution nozzle that supplies the processing liquid to the inner space while dispersing the pressure of the processing liquid flowing through the processing liquid pipe. The substrate processing apparatus according to claim 2,
The pressure distribution nozzle,
A first cylindrical portion fitted to the outside of one end of the processing liquid pipe disposed in the inside space,
A second cylindrical portion having a through hole into which the treatment liquid pipe is inserted, and fitted to the outside of the first cylindrical portion;
Has,
The processing liquid supplied to the pressure dispersion nozzle from the processing liquid pipe includes a first flow path sandwiched between an outer circumference of the processing liquid pipe and an inner circumference of the first cylindrical section, and a first flow path of the first cylindrical section. The substrate processing apparatus is supplied to the inner space via a second flow path sandwiched between an outer periphery and an inner periphery of the second cylindrical portion. A substrate processing apparatus for removing a film formed on a surface of a substrate,
(A) a storage tank;
(B) a processing liquid pipe for introducing the processing liquid into an inner space of the storage tank;
(C) processing liquid gas supply means for supplying a vapor of the processing liquid evaporated in the inner space together with the carrier gas to the substrate by supplying a carrier gas to the inner space;
(D) before introducing the treatment liquid into the inner space by the treatment liquid pipe before performing the treatment for removing the film formed on the surface of the substrate, removing the treatment liquid attached to the inner wall of the storage tank; Processing liquid removing means for removing;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 4,
The processing liquid removing unit supplies a carrier gas to an upper space above the processing liquid stored in the storage tank for a certain period of time before performing a process of removing a film formed on the surface of the substrate. A substrate processing apparatus.

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