JP4054284B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a chemical solution such as a hydrofluoric acid solution (hereinafter also referred to as “treatment liquid”) is used for a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, an optical disk substrate or the like (hereinafter simply referred to as “substrate”). The substrate processing apparatus removes the film formed on the surface of the substrate by supplying the vapor.
[0002]
[Prior art]
Conventionally, when manufacturing a memory capacitor film on a semiconductor substrate in a semiconductor device manufacturing process, BSG (Boron-Silicate Glass), PSG (Phosphor-Silicate Glass), BPSG (Boron-doped Phosphor-Silicate Glass), etc. An oxide film containing a large amount of impurities is used as a sacrificial oxide film. These sacrificial oxide films can take a large selection ratio with respect to a thermal oxide film or a CVD (chemical vapor deposition) oxide film in etching using hydrofluoric acid vapor, and etch the thermal oxide film or the CVD oxide film. It can be selectively removed by using it as a stopper film (for example, Patent Document 1).
[0003]
In the etching process for removing the thermal oxide film and the CVD film, hydrofluoric acid vapor evaporated from the hydrofluoric acid aqueous solution is supplied to the substrate together with the carrier gas. Thus, the vaporizer which vaporizes a supply target object and supplies it to a board | substrate is also known conventionally (for example, patent document 2).
[0004]
[Patent Document 1]
JP 2002-110627 A
[Patent Document 2]
Japanese Patent Laid-Open No. 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 is evaporated and reduced as the process proceeds. It will be necessary to replenish.
[0006]
However, when the hydrofluoric acid aqueous solution is replenished to the storage tank, if the hydrofluoric acid aqueous solution jumps on the inner wall of the storage tank and droplets of the hydrofluoric acid aqueous solution adhere to the storage tank, the hydrofluoric acid aqueous solution stored in the storage tank and the inner wall of the storage tank The hydrofluoric acid vapor evaporates from the attached droplets. That is, until the droplets adhering to the inner wall evaporate and disappear, the amount of vapor of hydrofluoric acid generated in the vaporizer adhered to the inner wall and the amount of hydrofluoric acid evaporated from the stored hydrofluoric acid aqueous solution. It is the sum of the amount of hydrofluoric acid vapor evaporated from the droplets. Therefore, the amount of hydrofluoric acid vapor supplied to the substrate fluctuates until the droplets adhering to the inner wall evaporate and disappear. As a result, the thermal oxide film and the CVD film per unit time Variations in the removal amount will occur.
[0007]
Accordingly, an object of the present invention is to provide a substrate processing apparatus that can make the amount of vapor of the processing liquid supplied by the processing liquid gas supply means substantially constant per unit time.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is a substrate processing apparatus for removing a film formed on the 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 means for supplying 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. And pressure relaxation means for relaxing the introduction pressure of the treatment liquid and supplying the treatment liquid to the inner space when introducing the treatment liquid.
[0009]
Further, the invention of claim 2 is the substrate processing apparatus according to claim 1, wherein the pressure relaxation means supplies the processing liquid to the inner space while dispersing the pressure of the processing liquid flowing through the processing liquid piping. It has the pressure distribution nozzle which carries out.
[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 side of one end portion disposed in the inner space of the end portion of the processing liquid pipe. A first cylindrical portion, and a second cylindrical portion having a through-hole into which the processing liquid pipe is inserted and fitted to the outside of the first cylindrical portion, and from the processing liquid piping The processing liquid supplied to the pressure dispersion nozzle includes a first flow path sandwiched between an outer periphery of the processing liquid pipe and an inner periphery of the first cylindrical portion, an outer periphery of the first cylindrical portion, and the second It supplies to the said inner space through the 2nd flow path pinched | interposed into the inner periphery of the cylindrical part of this.
[0011]
The invention of claim 4 is a substrate processing apparatus for removing a film formed on the surface of a substrate, wherein a storage tank, a processing liquid pipe for introducing the processing liquid into an inner space of the storage tank, By supplying the carrier gas to the inner space, the processing liquid gas supply means for supplying the substrate with vapor of the processing liquid evaporated in the inner space together with the carrier gas, and the film formed on the surface of the substrate are removed. And a treatment liquid removing means for removing the treatment liquid adhering to the inner wall of the storage tank when the treatment liquid is introduced into the inner space by the treatment liquid piping before performing the treatment to be performed. To do.
[0012]
Further, the invention according to claim 5 is the substrate processing apparatus according to claim 4, wherein the processing liquid removing means performs the storage for a predetermined time before performing the process of removing the film formed on the surface of the substrate. A carrier gas is supplied toward an upper space above the processing liquid stored in the tank.
[0013]
DETAILED DESCRIPTION OF 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 the substrate W, this sacrificial oxide film is used. It is a device that selectively removes. In the substrate processing apparatus 1 of the present invention, the film removal step is performed by hydrofluoric acid vapor-phase etching processing for supplying hydrofluoric acid vapor to the surface of the substrate W.
[0015]
As shown in FIG. 1, the substrate processing apparatus 1 mainly performs a vapor-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 the surface of the substrate W. The vapor-phase etching processing unit 40 to be performed and the substrate W after the vapor-phase etching processing are washed with water, and then the water-washing / drying processing unit 50 for performing draining and drying, and the substrate W after being processed by the water-washing / drying processing unit 50. And an unloader unit 60 on which a cassette CU for storing the card is placed.
[0016]
The loader unit 10 and the unloader unit 60 are disposed behind the front panel 77 of the substrate processing apparatus 1. The loader unit 10, the vapor phase etching processing unit 40, the water washing / drying processing 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 substrates W before processing from the cassette CL placed on the loader unit 10 one by one and loads them into the vapor-phase etching processing unit 40. 71 is 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 vapor phase etching process from the vapor phase etching processing unit 40 and carrying it into the water washing / drying processing unit 50. A robot 81 is arranged. Between the water washing / drying processing unit 50 and the unloader unit 60, an unloader for taking out the substrate W after the water washing / drying processing from the water washing / drying processing unit 50 and storing it in the cassette CU placed in the unloader unit 60. A transfer robot 72 is arranged.
[0018]
Each of the loader transfer robot 71, the intermediate transfer robot 81, and the unloader transfer robot 72 has a bending-extension-type robot shape 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, the 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 an opposite direction to the rotation direction of the lower arm LA by an angle that is twice the rotation angle of the lower arm LA. As a result, the lower arm LA and the upper arm UA can take a contracted state in which both arms overlap each other vertically 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 manner, 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 water washing / drying processing unit 50 that rinses and dries the substrate W after the vapor phase etching process includes, for example, a spin chuck that rotates the substrate W while holding the substrate W horizontally, and a 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 back surface of the substrate W to wash the surface of the substrate W with water. After the rinsing is completed, the supply of pure water is stopped, and the spin chuck is rotated at a high speed to shake off the moisture on the surface of the substrate W and dry.
[0021]
FIG. 2 is a schematic cross-sectional view for explaining the configuration of the vapor-phase etching processing unit 40. The vapor-phase etching processing unit 40 includes a hydrofluoric acid vapor generator 43 that stores a hydrofluoric acid aqueous solution 42, which is an example of an acid-containing processing liquid, in a sealed state in a housing 41 (the internal structure thereof is shown in FIG. 3). To be described later). A disc-shaped punching plate 44 having a large number of through holes 44 a is provided at the bottom of the hydrofluoric acid vapor generator 43. The hydrofluoric acid vapor passes through each of a large number of through holes 44 a formed in the punching plate 44 and is widely supplied to the upper surface of the substrate W.
[0022]
Below the punching plate 44, a hot plate 45 that holds the substrate W to be processed horizontally with the substrate W facing the punching plate 44 is disposed. A heater for heating the substrate W at a predetermined temperature (for example, 40 ° C. to 80 ° C.) is provided inside the hot plate 45. Further, the hot plate 45 is fixed to the upper end of a rotating shaft 47 that is rotated (spinned) around a vertical axis OW (hereinafter referred to as a rotating shaft OW) passing through the center of the substrate W by a rotation driving mechanism 46 including a motor and the like. Yes.
[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 seals the space around the periphery of the hot plate 45 by bringing an annular contact portion 48a provided at the upper edge into contact with the periphery of the punching plate 44 (the lower surface of the hydrofluoric acid vapor generator 43). Then, a sealed position (a position indicated by a solid line in the drawing) that forms the processing chamber 85, and a retreat position (a position indicated by a two-dot chain line in FIG. 2) whose upper edge is retracted downward from the upper surface 45a of the hot plate 45. In between, it is extended / contracted by a drive mechanism (not shown).
[0024]
The internal space of the bellows 48 is exhausted by the exhaust means 55 via the exhaust pipe 49 connected to the bottom surface 41 a 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 exhaust equipment provided in a clean room where the substrate surface treatment apparatus is installed.
[0025]
On the side of the hot plate 45, a loading opening 21 for loading the substrate W and a loading opening 22 for discharging the substrate W are formed on the side wall of the housing 41. Shutters 38 and 39 are disposed in these openings 21 and 22, respectively. When the substrate W is carried in, 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 by the hot plate 45 by the loader transport robot 71 (see FIG. 1). Passed. When the substrate W is unloaded, the bellows 48 is set to the retracted position and the shutter 39 is opened, and the substrate W on the hot plate 45 is transferred to the intermediate transfer robot 81 and unloaded. 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 simplification of illustration, these arrangement relations are such that two line segments connecting these and the center of the substrate W overlap each other in a straight line (substrate It is drawn in a substantially point-symmetrical positional relationship with respect to the center of W).
[0026]
FIG. 3 is a cross-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 that stores the hydrofluoric acid aqueous solution, and a discharge section for the hydrofluoric acid aqueous solution when supplying the hydrofluoric acid aqueous solution to the inner space 35 of the storage tank 57. A pressure distribution nozzle 61 used as a storage tank, 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 aqueous hydrofluoric acid solution is not stored) 35a, and a storage tank The hydrofluoric acid vapor | steam supply path 36 which supplies the hydrofluoric acid vapor | steam generate | occur | produced in 57 to the container 91 (refer FIG. 2) mentioned later is comprised.
[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 adjustment unit 25 through a pipe 26 a to maintain a constant temperature. Can be held. Further, the hydrofluoric acid aqueous solution introduced into the temperature control unit 25 includes a valve 24a, a pipe 26b, a treatment liquid pipe 28b for introducing the hydrofluoric acid aqueous solution from the outside of the storage tank 57 into the inner space 35 of the storage tank 57, and a pressure dispersion nozzle. Via 61, it is additionally supplied to the hydrofluoric acid aqueous solution 42 in the inner space 35 of the storage tank 57. 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 24 a and circulating the hydrofluoric acid aqueous solution 42 while introducing it into the temperature control unit 25. .
[0028]
Further, the inner space 35 of the storage tank 57 is connected to the hydrofluoric acid water supply source 27 through 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 supplemented to the inner space 35 of the storage tank 57.
[0029]
Here, the pressure dispersion nozzle 61 used as a discharge port for the hydrofluoric acid aqueous solution supplied to the inner space 35 of the storage tank 57 will be described. 4 shows a longitudinal section of the pressure dispersion nozzle 61, and FIG. 5 shows a section of the pressure dispersion nozzle 61 when viewed from the line VV of FIG. As shown in FIGS. 4 and 5, the pressure dispersion 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 in the upper portion, and is disposed substantially concentrically outside the processing liquid pipe 28 b. Further, the inner cylindrical portion 63 is disposed so that the lower end portion 28 c of the processing liquid pipe 28 b exists inside the inner cylindrical portion 63.
[0031]
Accordingly, the hydrofluoric acid aqueous solution flowing in the direction of the arrow AR1 in the inner space 62b of the processing liquid pipe 28b reaches the inner portion of the inner cylindrical portion 63 from the lower end portion 28c of the processing liquid pipe 28b and is bounced back at the inner bottom surface 63a. The traveling direction of the acid aqueous solution changes from the arrow AR1 direction to the arrow AR2 direction. Then, the boiled hydrofluoric acid aqueous solution flows into the internal space 63 b sandwiched between the outer peripheral portion of the processing liquid pipe 28 b 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 in the lower portion, and is arranged on a substantially concentric circle outside the inner cylindrical portion 63. A through hole is provided in the vicinity of the substantially 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 attached to the outer peripheral surface of the processing liquid pipe 28b. 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 this embodiment) support pieces 65, and the Z of the lower end portion 64 d of the outer cylindrical portion 64 is fixed. 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 treatment liquid pipe 28 b is screwed to the ceiling 43 a of the hydrofluoric acid vapor generator 43 on the inner side and the outer side to form a pipe. With this configuration, the pressure distribution nozzle 61 in the hydrofluoric acid vapor generator 43 can be attached and detached by releasing the screwing between the processing liquid pipe 28b inside the hydrofluoric acid vapor generator 43 and the ceiling 43a.
[0033]
Accordingly, the hydrofluoric acid aqueous solution flowing in the direction of the arrow AR3 in the internal space 63b reaches the inner portion of the outer cylindrical portion 64 and rebounds at 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 boiled hydrofluoric acid aqueous solution flows into the internal space 64 b 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 dispersion nozzle 61 from the hydrofluoric acid water supply source 27 or from the temperature control unit 25 through the treatment liquid pipe 28b is formed on the inner bottom surface 63a of the inner cylindrical portion 63 and the outer side. It rebounds from the inner upper surface 64a of the cylindrical portion 64. That is, when the hydrofluoric acid aqueous solution flowing through the treatment liquid pipe 28b is bounced off 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 treatment liquid pipe 28b is increased. More relaxed. The hydraulic pressure (pressure) of the hydrofluoric acid aqueous solution in the internal space 63b decreases. Subsequently, when the aqueous hydrofluoric acid solution flowing in the internal space 63b is bounced off from the inner upper surface 64a of the outer cylindrical portion 64 and flows into the internal space 64b, the aqueous hydrofluoric acid solution is further dispersed and the hydrofluoric acid flowing in the internal space 64b. The hydraulic pressure of the water solution is further relaxed and reduced. Therefore, the hydraulic 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 hydraulic pressure of the hydrofluoric acid aqueous solution flowing through the processing liquid piping 28b. .
[0035]
Further, as shown in FIGS. 2 and 3, the upper space 35a, which is 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 rate controller ( An MFC) 52 is connected to a nitrogen gas supply source 31 that supplies nitrogen gas as a carrier gas. Further, the upper space 35a of the storage tank 57 is an internal space surrounded by the lower portion of the hydrofluoric acid vapor generator 43 and the punching plate 44 through the valve 37, the hydrofluoric acid vapor supply path 36, and a plurality of discharge ports 36a described later. The container 91 is connected in communication (see FIG. 2).
[0036]
Here, as shown in FIG. 2, the punching plate 44 is provided in the container 91 so as to close the opening 91 b on the bottom surface of the container 91. Further, the internal space of the container 91 is a cylindrical space having a central axis as a central axis OH (in the present embodiment, coincides with the rotation axis OW of the substrate W). Furthermore, a plurality (six in this embodiment) of discharge ports 36 a communicating with the hydrofluoric acid vapor supply path 36 are opened on 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, from the discharge port 36a to the internal space of the container 91. It is discharged toward. The hydrofluoric acid vapor discharged into the internal space of the container 91 passes through each of a large number of 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 the hydrofluoric acid vapor toward the substrate W.
[0038]
In addition, 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 1 atm and room temperature (20 ° C.)) that is a so-called pseudo eutectic composition. Has been prepared. In the hydrofluoric acid aqueous solution 42 having the pseudo-azeotropic composition, the evaporation rates of water and hydrogen fluoride are equal, and therefore, the hydrofluoric acid vapor is guided from the valve 37 to the punching plate 44 through the hydrofluoric acid vapor supply path 36. Even if the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generator 43 decreases, the concentration of the hydrofluoric acid vapor led to the hydrofluoric acid vapor supply path 36 is maintained unchanged. In FIG. 2, reference numeral 90 indicates a pipe through which temperature-controlled water for maintaining the hydrofluoric acid aqueous solution 42 in the hydrofluoric acid vapor generator 43 at a constant temperature flows.
[0039]
The valves 33 and 53 for switching supply / stop of nitrogen gas and the flow rate controllers 32 and 52 for changing the supply amount of nitrogen gas are controlled by a controller 80.
[0040]
By the way, using a conventional hydrofluoric acid vapor generating container that does not have the pressure dispersion nozzle 61, an etching process is performed to remove the oxide film formed on the substrate by the hydrofluoric acid vapor generated in the hydrofluoric acid vapor generating container. In some cases, there has been a problem that the removal amount of the oxide film removed per unit time varies.
[0041]
Therefore, when the inventor investigated in detail,
(1) The amount of oxide film removed per unit time decreases with the passage of time in the period from the start of the etching process until a certain period of time elapses.
(2) After a certain period of time, the amount of oxide film removed per unit time is substantially the same regardless of the passage of time.
I understood that.
[0042]
And when the inventor further studied earnestly, in the conventional hydrofluoric acid vapor generating container,
(1) When replenishing the hydrofluoric acid aqueous solution to the storage tank, the replenished hydrofluoric acid aqueous solution jumps and adheres to the inner wall such as the inner ceiling of the storage tank as a droplet,
(2) By generating hydrofluoric acid vapor from the hydrofluoric acid aqueous solution stored in the storage tank and the hydrofluoric acid aqueous solution adhering to the inner wall until the droplets of the hydrofluoric acid aqueous solution attached to the inner wall evaporate and disappear. The amount of hydrofluoric acid vapor varies until a certain time has elapsed from the start of the etching process, so that the amount of oxide film removed per unit time varies with the passage of time,
(3) When the droplets of hydrofluoric acid solution attached to the inner wall disappear, the etching process is performed with the hydrofluoric acid vapor evaporated from the hydrofluoric acid solution stored in the storage tank. After that, the removal amount of the oxide film per unit time becomes substantially the same,
I found out.
[0043]
On the other hand, in the hydrofluoric acid vapor generator 43 of the present embodiment, the hydrofluoric acid aqueous solution from the pressure dispersion nozzle 61 that can reduce the hydraulic pressure (pressure) of the hydrofluoric acid aqueous solution with respect to the inner space 35 of the storage tank 57. Is discharged and supplied. Thereby, when the hydrofluoric acid aqueous solution is supplied to the storage tank 57, it is possible to prevent the hydrofluoric acid aqueous solution from adhering to the inner wall such as the ceiling 43a inside the storage tank 57 by jumping. Therefore, the amount of hydrofluoric acid vapor supplied to the substrate W per unit time can be made substantially constant, and the oxide film removal process formed on the substrate W can be performed 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 of the present embodiment, first, one substrate W before processing is taken out from the cassette CL placed on the loader unit 10 by the loader transport robot 71. Subsequently, the bellows 48 of the vapor phase etching processing unit 40 is lowered and the shutter 38 is opened. Then, the substrate W before processing is loaded into the processing chamber 85 of the vapor-phase etching processing unit 40 through the loading opening 21 by the loader transport robot 71 and placed on the hot plate upper surface 45a.
[0045]
Next, 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 a film removal process for removing the film on the surface of the substrate W, the bellows 48 is raised to a close contact position (position indicated by a solid line in FIG. 2) in close contact with the peripheral edge 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 opened state. As a result, 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 path 36 through the valve 37 by the nitrogen gas from the nitrogen gas supply pipe 54. The hydrofluoric acid vapor is further discharged by the nitrogen gas from the nitrogen gas supply pipe 34 into the container 91 from the six discharge ports 36a through the circular flow passage 36b. The hydrofluoric acid vapor in the container 91 is supplied to the surface of the substrate W through a through hole 44 a formed in the punching plate 44 that closes the opening 91 b on the bottom surface of the container 91. 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 involvement of water molecules in the vicinity of the substrate W, thereby achieving removal of the oxide film. Is done.
[0046]
Here, in the film removal process 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. Thereby, even if a 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 droplets of 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 process in the processing chamber 85, and the film removal amount of each substrate W can be made substantially the same. can do.
[0047]
In this way, after the film removal process is performed for a predetermined time, the controller 80 closes the valves 37 and 53 to stop the film removal process. At the same time, the controller 80 keeps the valve 33 in an open state, and controls the flow rate controller 32 to increase the flow rate of nitrogen gas flowing through the nitrogen gas supply pipe 34. It is supplied to the surface of the substrate W through the through holes 44 a of 44. Thereby, water molecules and hydrofluoric acid molecules existing near the surface of the substrate W are replaced and removed, and are carried out of the processing chamber 85 by the exhaust of the processing chamber 85 via the exhaust pipe 49. At this time, the vortex flow S of the nitrogen gas is generated in the container 91, so that the water molecules and hydrofluoric acid molecules in the vicinity of the surface of the substrate W are uniformly removed within the surface of the substrate W.
[0048]
Subsequently, immediately after the film removal step, the surface of the substrate W is supplied with nitrogen gas as an inert gas, so that water and hydrofluoric acid molecules near the surface of the substrate W are immediately removed. The vapor phase etching process stops immediately. Since the stop of the vapor phase etching process occurs almost simultaneously in the entire surface of the substrate W, a uniform film removal process can be performed on each part of the surface of the substrate W. In addition, processing variations for a plurality of substrates W can be reduced. The supply of nitrogen gas after the film removal step is continued for a certain 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 removal process in the vapor phase etching processing unit 40 is completed, the bellows 48 is lowered and the shutter 39 is opened. Then, the substrate W on which the film removal process has been performed is carried out from the inside of the processing chamber 85 of the vapor phase etching processing unit 40 by the intermediate transfer robot 81, and the substrate W on which the film removal process has been completed is transferred to the water washing / drying processing unit 50. Carry in and wash and dry.
[0050]
When the cleaning / drying process is completed, the substrate W is unloaded by the unloader transport robot 72 and placed on the cassette CU of the unloader unit 60, thereby completing the substrate process.
[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. Thus, the hydrofluoric acid aqueous solution is introduced in a state where the pressure is relaxed. Thereby, the hydraulic 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 to the inner wall such as the ceiling 43 a inside the storage tank 57. It is possible to prevent droplets of hydrofluoric acid aqueous solution from adhering. 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>
While the embodiments of the present invention have been described above, the present invention is not limited to the above examples.
[0053]
In the present embodiment, the use of the pressure dispersion nozzle 61 prevents droplets of the hydrofluoric acid aqueous solution from adhering to the inner wall of the storage tank 57 and makes the amount of hydrofluoric acid vapor per unit time substantially constant. However, it 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 film removal process is performed after the hydrofluoric acid aqueous solution adhering to the inner wall of the storage tank 57 is once lost and removed. , 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 of the processing chamber 85 of the vapor phase etching processing unit 40. Then, a predetermined amount of nitrogen gas per unit time is supplied for a predetermined time to the upper space 35a of the storage tank 57 as a carrier gas (see FIGS. 2 and 3). As a result, the droplets of the hydrofluoric acid aqueous solution adhering to the inner wall of the storage tank 57 continue to evaporate, and after a certain time has passed, the liquid droplets of the hydrofluoric acid aqueous solution adhering to the inner wall of the storage tank 57 disappear. Then, after the droplets of the hydrofluoric acid aqueous solution adhering to the inner wall of the storage tank 57 disappear, the substrate W is carried into the processing chamber 85 and placed on the hot plate 45 to perform the film removal process. By doing so, the vapor amount of hydrofluoric acid 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 is 30 to 50 (liters / min) per unit time, and the supply time of nitrogen gas is 30 minutes or more.
[0057]
Further, 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. Hold 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 also conceivable that droplets of the hydrofluoric acid aqueous solution adhere to the inner wall of the storage tank 57.
[0058]
However, when the amount V1 of the aqueous solution of hydrofluoric acid adhering to the inner wall of the storage tank 57 is smaller than the amount of evaporation V2 of the aqueous solution of hydrofluoric acid evaporated per unit time, the unit time supplied to each substrate W. The amount of vapor of hydrofluoric acid per hit can be made almost constant. Therefore, even when droplets of the hydrofluoric acid aqueous solution adhere to the inner wall of the storage tank 57 in this way, 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 that is less than the pressure supplied by the processing liquid piping, the processing liquid introduced into the inner space of the storage tank Can be prevented from adhering to the internal liquid of the storage tank. As a result, 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 the vapor of the processing liquid supplied to 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, the processing liquid can be supplied to the inner space of the storage tank while reducing the pressure of the processing liquid by using the pressure dispersion nozzle. Therefore, it is possible to prevent the processing liquid supplied to the inner space from rebounding 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 piping to the pressure dispersion nozzle is dispersed in the pressure of the processing liquid through the first flow path and the second flow path. Is done. Therefore, it is possible to prevent the processing liquid supplied to the inner space from rebounding and adhering to the inner wall of the storage tank.
[0062]
Further, according to the invention described in claim 4 and claim 5, 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 The processing liquid adhering 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 evaporation of the processing liquid attached to the inner wall, but includes the evaporation of the processing liquid stored in the inner space. The amount of the vapor of the processing liquid supplied to 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 upper space of the storage tank before performing the process of removing the film formed on the surface of the substrate, thereby attaching to the inner wall of the storage tank. The treatment liquid can be evaporated. Therefore, when the film removal process is performed, the process liquid vapor evaporated from the process liquid attached to the inner wall is not included, and the film removal process is performed by the process liquid vapor evaporated from the process 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 showing 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 dispersion nozzle according to an embodiment of the present invention.
5 is a cross-sectional view of the pressure distribution nozzle of FIG. 4 as seen 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 Vapor phase etching process
43 Fluoric acid vapor generator
49 Exhaust piping
50 Washing and drying section
54 Nitrogen gas supply piping
55 Exhaust means
60 Unloader section
61 Pressure dispersion nozzle
62 Introduction pipe
62b, 63b, 64b space
63 Inner cylindrical part
63a Inside bottom
64 Outer cylindrical part
64a inner top 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 treatment liquid pipe for introducing the treatment liquid into the inner space of the storage tank;
(c) processing liquid gas supply means for supplying 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 by the processing liquid piping, pressure reducing means for reducing the introduction pressure of the processing liquid and supplying it to the inner space;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the pressure relaxation means includes a pressure dispersion nozzle that supplies the processing liquid to the inner space while dispersing the pressure of the processing liquid flowing through the processing liquid piping. The substrate processing apparatus according to claim 2,
The pressure distribution nozzle is
A first cylindrical portion fitted to the outside of one end portion disposed in the inner space of the end portion of the treatment liquid pipe;
A second cylindrical portion having a through-hole into which the processing liquid pipe is inserted and fitted to the outside of the first cylindrical portion;
Have
The treatment liquid supplied from the treatment liquid pipe to the pressure dispersion nozzle is a first flow path sandwiched between an outer circumference of the treatment liquid pipe and an inner circumference of the first cylindrical portion, and the first cylindrical portion. The substrate processing apparatus, wherein the substrate processing apparatus is supplied to the inner space through 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 treatment liquid pipe for introducing the treatment liquid into the inner space of the storage tank;
(c) processing liquid gas supply means for supplying the substrate with vapor of the processing liquid evaporated in the inner space together with the carrier gas by supplying a carrier gas to the inner space;
(d) Before performing the process of removing the film formed on the surface of the substrate, when the processing liquid is introduced into the inner space by the processing liquid piping, the processing liquid attached to the inner wall of the storage tank is removed. A treatment liquid removing means to be removed;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 4,
The processing liquid removing means supplies a carrier gas toward the upper space above the processing liquid stored in the storage tank for a certain period of time before performing the process of removing the film formed on the surface of the substrate. A substrate processing apparatus.

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