JP2005064482A - Method and device for treating substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for treating substrate by which high-quality surface treatment is realized by using an organic solvent mist having an extremely small size, and, in addition, the substrate treating time is also shortened. <P>SOLUTION: The substrate treating device 10 is provided with: a vapor generator 37<SB>1</SB>which generates a mixed gas of the organic solvent mist and an inert gas by bubbling the inert gas in an organic solvent; a supporting means which supports a plurality of substrates to be treated in a state where the substrates are vertically arranged in parallel with each other at equivalent intervals; and a treating vessel 15 which houses the assemblage of the substrates supported by the supporting means. The device is also provided with: a cap body 30 which covers the top opening of the treating vessel 15; an injection nozzle 33 installed to the cap body 30; and first pipelines 37<SB>12</SB>, 34<SB>2</SB>, 34<SB>21</SB>, and 34<SB>22</SB>which communicate the vapor generator 37<SB>1</SB>and injection nozzle 33 with each other. Heaters are respectively installed to the first pipelines 37<SB>12</SB>, 34<SB>2</SB>, 34<SB>21</SB>, and 34<SB>22</SB>and injection nozzle 33 and controlled so that the submicron-sized organic solvent mist may be contained in a dry gas injected from the injection nozzle 33. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for drying, for example, a semiconductor wafer, a liquid crystal display substrate, a recording disk substrate, a mask substrate, and other substrate surfaces with high quality and efficiency.

  Among various substrates, for example, in order to clean the surface of a semiconductor wafer (hereinafter referred to as a wafer), the wafer surface is washed with a chemical solution, then washed with a treatment solution such as pure water, and further an organic solvent such as isopropyl A process of drying a wafer using an organic solvent such as alcohol (hereinafter referred to as “IPA”) is performed. More specifically, in this process, after the wafer is washed with a chemical solution and pure water, it is exposed to the vapor of IPA to condense the IPA on the surface of the wafer. The pure water is replaced with IPA, and as the pure water flows down from the surface of the wafer, the process includes a step of washing away contaminants such as particles, and then a drying step of evaporating IPA to dry the wafer surface. If even a small amount of water droplets remain on the surface of the wafer in this drying process, a water mark is formed on the wafer surface, and this water mark causes the quality of the wafer to deteriorate as well as particles. For this reason, in the semiconductor manufacturing process, it is necessary to prevent these contaminants from adhering to the wafer. A number of substrate surface processing methods and processing apparatuses for wafers and the like that have taken such measures have been devised and put into practical use, and many are introduced in patent literature. (For example, see Patent Documents 1 and 2 below)

  Therefore, a substrate processing apparatus disclosed in the following Patent Document 1 will be described below with reference to FIGS. FIG. 10 is a cross-sectional view of the substrate processing apparatus described in Patent Document 1 below. The substrate processing apparatus 1 includes a processing tank 2 that accommodates a substrate to be processed (for example, a wafer), a processing liquid introduction pipe 3 that supplies a processing liquid (for example, pure water) to the inside of the processing tank 2, and an organic solvent liquid ( For example, a steam generation tank 4 that stores (IPA), a processing liquid discharge unit 5 that discharges the processing liquid from the processing tank 2, and a heating solvent supply device 6 for supplying a heated organic solvent into the steam generation tank 4. 6 ', and a plurality of the substrates are conveyed into the processing tank 2 in a state where they are erected in parallel and vertically at an equal pitch, and the surface treatment of each substrate is performed.

In the substrate processing apparatus 1, various substrates, for example, semiconductor wafers W (hereinafter referred to as “wafers W”) are surface-treated by the following steps.
1), the lid 2 _first treatment tank 2 in which pure water is stored in the processing device 1 in the loading step the standby state of the wafer is opened, a plurality of wafers W are conveyed into the inner tank 2 ₂ of the processing tank 2 the lid 2 ₁ is turned-immersed in pure water J is closed Te. Thereafter, inert gas into the processing vessel 2 from the inert gas supply pipe 8 _1, for example, nitrogen gas is supplied, air in the processing tank 2 is replaced by the nitrogen gas.

2) Drying process After the wafer W is washed or rinsed, nitrogen gas N ₂ for bubbling is supplied into the steam generation tank 4 to generate an organic solvent liquid, for example, IPA vapor, and generate it. steam is filled in the space above the pure water J is introduced into the processing tank 2 from the vapor discharge port 4 _1.
Then the inner tub drain pipe 5 ₁ on-off valve is opened, purified water J of the inner tank 2 in ₂ is discharged little by little through the flow control valve, down the liquid level of the pure water J, the wafer W is It is gradually exposed on the liquid level from its upper end.

When the surface of the wafer W is exposed on the liquid level, the IPA vapor in the processing tank 2 touches the surface of the wafer W on the liquid level. At this time, since the pure water J in the processing tank 2 is set to approximately room temperature, the temperature of the wafer W is also approximately room temperature. For this reason, the IPA vapor touches the wafer W and is rapidly cooled, and the IPA vapor condenses on the surface of the wafer W on the liquid surface. The condensed IPA lowers the surface tension of pure water and adheres to the wafer W until then. The pure water that was stored is replaced with this IPA. After draining all pure water J, the surface of the wafer W to the IPA evaporates by supplying the inert gas into the processing vessel 2 from the inert gas supply pipe 8 ₁ is dried.

3), wafer unloading step Then, after the pure water J of the inner tank 2 in ₂ is discharged, via the exhaust process to terminate the substrate processing, the lid 2 ₁ is opened, the wafer W is taken out from the processing bath 2 It is.

According to this substrate processing apparatus, since a series of processing steps are performed in one sealed processing tank, the wafer can be processed efficiently without being exposed to the atmosphere at all, and particles and watermarks can be processed on the wafer surface. It can suppress that contaminants, such as, adhere.
However, in recent years, in order to increase the processing efficiency, it is necessary to insert as many wafers as possible into the processing tank in order to increase the processing efficiency. In some cases, lots of 50 to 100 wafers are processed. Since the wafers are processed simultaneously in the processing tank, the gap between the wafers tends to be further narrowed, and the diameter of the wafer is increased from 200 mm to 300 mm. For this reason, the generation of watermarks can be suppressed with a relatively small wafer having a diameter of 200 mm or less, but a water mark is generated with a large-diameter wafer having a diameter of 300 mm, which is a limit to the processing in the conventional apparatus. There is.

  Therefore, the present inventors examined the cause of such a watermark remaining from various angles, and the cause was obtained by bubbling an inert gas in the IPA for the IPA vapor in the dry gas. Therefore, in addition to the IPA gas less than the saturation concentration, a large amount of fine IPA liquid particles (hereinafter referred to as “mist”) is contained, but the size (size) and mass of this mist are nitrogen gas. Since it is larger and heavier than that, it is difficult to pass through gaps between narrow wafers, and when the diameter of the wafer reaches 300 mm, it becomes difficult to supply IPA mist to the wafer surface far from the IPA mist supply port. Found that there is not enough to do. That is, if the total amount of IPA contained in the dry gas is the same, the number of mists decreases when the size of the IPA mist is large, and conversely, the number of mists increases when the size of the IPA mist is small. In addition, if the size of the IPA mist is large, the mass is heavier and the movement speed is slow. Therefore, in the drying step 2), even if the drying gas is supplied between a plurality of wafers in the processing tank, the number of water droplets of the cleaning liquid adhering to the wafer surface and the number of IPA mist grains are not balanced. If the number of mist grains is less than the number of water droplets, some water droplets remain without being replaced by IPA, which causes the generation of watermarks.

  In addition, since the size of the IPA mist is large and heavy, it becomes difficult to pass through the gaps between the narrow wafers. For wafers with a large diameter of 300 mm, the IPA mist adheres to nearby surfaces before reaching the wafer surface far from the supply port. There will be more things to do. Therefore, the number of IPA mists supplied on the surface of the wafer far away is reduced, and the IPA mists are not supplied uniformly. That is, a sufficient amount of IPA mist is supplied to the wafer surface near the IPA mist supply port, but not enough IPA mist is supplied to the wafer surface far from the supply port, so that the wafer surface far from the IPA mist supply port The cleaning liquid adhering to the wafer surface is not sufficiently replaced with IPA, which causes the generation of watermarks.

A situation where the water droplet is replaced by IPA will be described with reference to FIG. FIG. 11 is a cross-sectional view schematically showing the relationship between the IPA mist and the water droplets (hereinafter referred to as DIW) of the cleaning liquid adhering to the wafer W during the drying process. In the drying step of the above 2), as shown in FIG. 11A, a mixed gas of IPA vapor containing a large IPA mist (liquid) and nitrogen gas N ₂ (gas) is supplied into the treatment tank, Supply between wafers W. Then, as shown in FIG. 11 (b), DIW is replaced by IPA vapor, but the movement speed is slow due to the large size of the IPA mist. Furthermore, a large number of 300 mm wafers (50-100) Since the number of IPA mists is limited because they are simultaneously processed in the processing tank, there are cases where not all DIWs are reached. For these reasons, the IPA mist adheres to a nearby surface before reaching the wafer surface far from the dry gas supply port, and the IPA mist is not supplied to the far surface. Therefore, as shown in FIG. 11C, DIW remains, which causes the generation of watermarks.

  On the other hand, in Patent Document 2 below, without mixing an inert gas in an organic solvent, the organic solvent is heated and evaporated in an evaporation tank to generate a mixed gas of an organic solvent vapor and an inert gas. A substrate processing apparatus is disclosed in which a gas is separately diluted with an inert gas in a pipe, heated and kept warm, and jetted from a jet nozzle. In this substrate processing apparatus, the organic solvent vapor in the gas ejected from the pipe and the nozzle is completely a gas, and if such an organic solvent vapor that is completely gas is used, Since the size of the solvent molecule is much smaller than the size of the mist, there is no problem when the organic solvent mist as described above is used.

  However, even if substrate processing is performed using organic solvent vapor that is completely gaseous, the organic solvent vapor concentration in the dry gas does not exceed the saturation concentration, so the absolute amount of organic solvent in the dry gas is Few. Therefore, in the substrate processing apparatus disclosed in the following Patent Document 2, it takes a very long time to disperse the organic solvent vapor to every corner of a large substrate and replace the moisture on the substrate surface. However, the present invention has not yet achieved the problem of providing a substrate processing method and apparatus with a small number of watermarks, almost zero and no adhesion of particles, and a high drying processing speed.

  In general, “vapor” means “gas”, but in the technical field of substrate processing, those containing “fine liquid particles (mist)” in addition to “gas”, such as the above-mentioned dry gas, are also commonly used. Since it is expressed as “vapor” or “vapor” in the present specification and claims, what includes “fine liquid particles (mist)” in addition to “gas” is also expressed as “vapor”. And

JP 2001-271188 A (FIG. 1, left column on page 5 to left column on page 6) JP 11-191549 A (claims, paragraphs [0018] to [0024], FIG. 1)

  Therefore, the present inventors have made various studies based on the above examination results, and as a result, if the size of the mist constituting the vapor of the organic solvent is extremely small, the organic solvent can be used without increasing the amount of the organic solvent used. The number of solvent mist particles can be increased, and the surface area of each mist is reduced, while the total surface area represented by the sum of the individual mists is increased by the increase in the number of mists. In addition, if the vapor of the organic solvent having an increased surface area of the total mist is sprayed onto the substrate surface, it can be uniformly adhered to the water droplets adhering to the substrate. The present inventors have found that they can be replaced and have realized the present invention.

  That is, the first object of the present invention is to provide a substrate processing method that realizes high-quality surface treatment and shortens the processing time by including an extremely small organic solvent mist in the dry gas ejected from the spray nozzle. It is to provide.

  A second object of the present invention is to provide a substrate processing apparatus that realizes a high-quality surface treatment and shortens the processing time by including an extremely small organic solvent mist in the dry gas ejected from the ejection nozzle. There is to do.

  In order to solve the above-mentioned problem, the substrate processing method according to claim 1 of the present application injects a dry gas comprising a mixed gas of an organic solvent vapor and an inert gas from a plurality of injection nozzles onto a substrate. In the substrate processing method for drying the substrate surface, the dry gas ejected from the spray nozzle includes a mist of an organic solvent having a submicron size.

  The invention according to claim 2 of the present application is the substrate processing method according to claim 1, wherein a plurality of the substrates are arranged in parallel with each other at an equal pitch and vertically, and the aggregate of the plurality of substrates. The dry gas is jetted from the plurality of jet nozzles provided on the outer peripheral edge side of the nozzle.

  The invention according to claim 3 of the present application is the substrate processing method according to claim 2, wherein the plurality of injection nozzles provided at equal distances from the outer periphery of the aggregate of the plurality of substrates are A dry gas is ejected.

  The invention according to claim 4 of the present application is the substrate processing method according to claim 3, wherein the spray regions of the dry gas ejected from the spray nozzles adjacent to the plurality of spray nozzles are the plurality of sheets. It is characterized by overlapping at the outer peripheral edge of the substrate assembly.

  The invention according to claim 5 of the present application is the substrate processing method according to any one of claims 1 to 4, wherein the organic solvent is isopropyl alcohol, diacetone alcohol, 1-methoxy-2-propanol, ethyl. -It is at least one selected from the group consisting of glycol, 1-propanol, 2-propanol, and tetrahydrofuran, and the inert gas is at least one selected from the group consisting of nitrogen, argon, and helium. And

Furthermore, the invention of the substrate processing apparatus according to claim 6 of the present application is as follows:
A vapor generating section that generates a dry gas composed of a mixed gas of an organic solvent vapor and an inert gas by bubbling an inert gas into the organic solvent;
Support means for supporting a plurality of substrates to be processed in a parallel and vertical posture at equal pitches;
A cleaning tank for containing an assembly of substrates supported by the support means;
A lid covering the upper opening of the cleaning tank;
A plurality of injection nozzles provided at substantially equal distances from the outer peripheral edges of the plurality of substrates on the lid;
A first pipe communicating the steam generation unit and the injection nozzle;
In the substrate processing apparatus, the heater is attached to each of the first pipe and the injection nozzle, and the heater is controlled so that the temperature of the dry gas from the steam generation unit to the nozzle does not decrease. By controlling, the dry gas sprayed from the spray nozzle includes an organic solvent mist of submicron size.

  The invention according to claim 7 of the present application is the substrate processing apparatus according to claim 6, wherein the plurality of spray nozzles each include the plurality of dry gas spray regions ejected from the adjacent spray nozzles. It is provided in the position which overlaps with the outer periphery of this board | substrate.

  According to the substrate processing method of claim 1 of the present application, since the organic solvent in the dry gas ejected from the spray nozzle includes the mist of the organic solvent of submicron size, without increasing the amount of the organic solvent used. The number of grains of the organic solvent mist can be increased, so that the surface area of each mist is reduced, while the total surface area, which is the sum of the surface areas of the individual mists, is increased by the increase in the number of grains. The Therefore, a large amount of submicron mist can be sprayed onto the substrate surface, so that the cleaning liquid adhering to the substrate is efficiently replaced by the large amount of submicron organic solvent mist. As a result, even if a large number of large-diameter substrates are inserted into the processing tank, submicron-sized mist can rapidly infiltrate between the substrates, improving the drying processing efficiency and shortening the processing time. There is very little or no water mark generation. Furthermore, there is no adhesion of particles, and the speed of the drying process is increased, so that reattachment of particles can be prevented.

  In the substrate processing method according to claim 2, since the mist of the organic solvent of submicron size is included in the dry gas ejected from the ejection nozzle, a large number of substrates are arranged in parallel with each other at a narrow interval. However, mist of organic solvent of submicron size can easily enter between the substrates, and even if a fine pattern is provided on the substrate, mist of organic solvent of submicron size can easily enter between the patterns. In addition, the drying processing efficiency can be improved and the processing time can be shortened, and the generation of watermarks on the surface of the substrate can be very little or almost zero.

  Further, in the substrate processing method according to claim 3, since the drying gas ejected from the ejection nozzle can reach the outer peripheral edge of the aggregate of the plurality of substrates uniformly, the drying unevenness of the substrate is reduced and the substrate is homogeneous. A good drying effect.

  According to the substrate processing method of claim 4, the spray region of the dry gas ejected from the spray nozzle adjacent to each of the plurality of spray nozzles overlaps with the outer peripheral edge of the aggregate of the plurality of substrates. As a result, the dry gas ejected from the nozzle comes into contact with the entire outer peripheral edge of the substrate, so that the drying unevenness of the substrate is reduced and a uniform drying effect is obtained.

  Further, according to the substrate processing method of the fifth aspect, the selection range between the organic solvent and the inert gas is widened, and it can be adapted to various substrate processings by arbitrary combinations.

  Furthermore, according to the substrate processing apparatus according to claim 6 of the present application, by controlling the heaters provided at various locations, the organic solvent mist of submicron size is included in the dry gas that is easily sprayed from the spray nozzle. Thus, a substrate processing apparatus capable of easily carrying out the substrate processing method according to claim 1 is obtained.

  Moreover, according to the substrate processing apparatus of Claim 7, the substrate processing apparatus which can implement the substrate processing method of the said Claim 4 easily can be obtained.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a substrate processing method and a substrate processing apparatus for embodying the technical idea of the present invention, and is not intended to limit the present invention to these. Other embodiments within the scope of the claims are equally applicable. FIG. 1 is a sectional view showing a substrate processing apparatus according to an embodiment of the present invention, FIG. 2 is a side view from one side of the processing tank, FIG. 3 is a side view from the other side of the processing tank, and FIG. FIG. 5 is a side view of the lid shown in FIG. 4. FIG. 5 is a plan view of the lid shown in FIG.

  Referring to FIG. 1, this substrate processing apparatus 10 is an apparatus for processing a semiconductor wafer as an example of a substrate. The treatment referred to here is a step of etching the wafer W with a chemical solution, a step of hydrofluoric acid treatment of the surface of the wafer W, a rinse treatment step of washing the wafer W with water, and a drying treatment of drying the wafer W after washing with an organic solvent. Including processes. A series of these processes is continuously performed in one processing tank 15.

  As shown in FIGS. 2 to 5, the processing tank 15 is installed in a storage chamber 11 having a volume that can be stored together with the accessory device. The accessory device includes an air conditioner that performs air conditioning in the accommodation chamber, a supply source that supplies various processing liquids to the processing tank, a wafer transfer mechanism, and the like, which are omitted in the drawing. The processing tank 15 includes a bottomed box-shaped inner tank 20 having an open upper surface, an outer tank 25 that surrounds the upper outer periphery of the inner tank 20, and a lid body 30 that covers the opening of the inner tank 20. The tanks 20 and 25 are accommodated in the sink 29. The inner and outer tanks 20 and 25 are formed of a material that is not easily corroded by an organic solvent such as hydrofluoric acid or IPA, such as polyvinylidene fluoride.

  The inner tank 20 has a depth that allows a large number of large-diameter wafers W, for example, about 300 mm in diameter, to be held by the substrate holder 62 (see FIG. 3) and immersed in the processing liquid for processing. A processing liquid discharge unit 21 and a processing liquid supply unit 22 are provided at the bottom. The substrate holder 62 holds, for example, a plurality of wafers W in a state of standing upright in parallel with each other at an equal pitch by a cassette guide, for example. The substrate holder 62 is connected to an elevating mechanism 60, and the elevating mechanism 60 is provided with an elevating means 61. The elevating means 61 moves the substrate holder 62 in the vertical and vertical directions so that it can be taken in and out of the inner tank 20. Is done. “Dry Position” in FIG. 2 represents the position of the drying process, and “Rinse Position” represents the position of the cleaning process. For the elevating means 61, for example, an air cylinder mechanism is used.

The wafer assembly is taken out from the substrate holder 62 by the moving mechanism 50 as shown in FIG. The moving mechanism 50 includes a plurality of gripping claws 50 ₁ and 50 ₂ connected to a robot mechanism (not shown), and the wafer aggregate is gripped by the gripping claws 50 ₁ and 50 ₂ so that a predetermined location is obtained. Moved to. The processing fluid discharge section 21, as shown in FIG. 2, consists small diameter discharge ports 21 ₁ and the large diameter of the outlet 21 ₂ which, the outlet 21 ₂ of large diameter, the processing solution in the processing tank It functions as a drain mechanism that discharges quickly. Discharge ports 21 ₁ of small diameter is to discharge the process liquid stored in the bottom portion and the tube of the inner tank 20. The outer tank 25 functions as an overflow tank for receiving the processing liquid overflowing from the upper part of the inner tank 20. Outlet 25 ₁ is provided at a lower position of the outer tank 25.

  As shown in FIG. 5, the lid 30 is composed of a box-shaped container 31 having a size that can accommodate a wafer assembly W ′ in which a lower portion is opened and an upper portion is closed and a large number of wafers W are collected therein. The box-shaped container 31 is formed of a material that is not easily corroded by an organic solvent such as hydrofluoric acid or IPA. The lid 30 can be moved in the horizontal direction by a moving means 55 (see FIG. 3). The moving means 55 closes or opens the opening of the inner tank 20 by moving the lid 30 in the horizontal direction to the upper part of the inner tank 20 as indicated by an arrow in FIG. That is, the lid body 30 positioned on the inner tub 20 is lifted by a predetermined distance in the vertical direction, moved in the horizontal direction, and then lowered downward in the vertical direction to be held in a standby state. The movement of the lid 30 is performed when the wafer assembly W ′ is carried into the inner tank 20 and the processed wafer aggregate is taken out from the inner tank 20.

Further, as shown in FIG. 5, the box-shaped container 31 has a substantially arch-shaped ceiling surface 32 formed thereon, and a plurality of injection nozzles 33 _{1 to} 33 ₇ that inject inert gas onto the ceiling surface 32. Are arranged in four directions at almost equal intervals. As shown in FIG. 4, the plurality of nozzles 33 are above the wafer assembly W ′, and the plurality of nozzles 33 _{1 to} 33 ₇ arranged in the row direction at almost equal intervals are also arranged in the column direction. A plurality of rows are arranged at approximately equal intervals. 4 In those seven sequences in the row direction and six columns, a total of 42 pieces of injection nozzles 33 _to 333 ₇₆ is disposed on the upper outer peripheral edge of the wafer assembly W '. Seven jet nozzles ₃₃ to 333 ₇ in the row direction, the wafer assembly W 'relationship with, as shown in FIG. 5, the injection nozzle ₃₃ to 333 ₇ and the wafer assembly W' and the outer peripheral edge of the Are arranged on the ceiling surface 32 so as to be substantially equal to each other. By forming the ceiling surface 32 in an arch shape, the wafer W has a substantially disk shape, so that the above distances can be easily equalized. The shape of the ceiling surface is preferably changed in accordance with the shape of the wafer W, and the above distance is preferably made substantially equal.

Injection nozzle 33, as shown in FIG. 5, is connected a gas supply pipe 34 ₂ is, the supply pipe 34 ₂ is branched, or number of these branch pipes ₃₄ 21, _{34 22} respectively the injection nozzle 33 is the same, Alternatively, approximately equal numbers are combined. Thereby, gas can be distributed to each injection nozzle almost evenly. These injection nozzles 33 each use that in which an injection gas is diffused at a predetermined angle. When gas is injected from each injection nozzle 33 to the outer peripheral edge of the wafer assembly W ′, adjacent injection nozzles, for example, it is preferred that the propellant gas between the injection nozzle 33 ₂ and the injection nozzle 33 ₃ is set so as to overlap with the outer periphery b of the wafer assembly W '. By arranging the plurality of injection nozzles 33 in alignment with the ceiling surface 32 as described above, gas can be supplied to the wafer assembly W ′ almost uniformly.

The injection nozzle 33 has a conical shape as a whole, and an opening is formed at a tapered tip, and dry gas is injected from the opening. Each spray nozzle 33 is provided with a heater (not shown). Since the injection nozzle itself is already known, detailed description thereof is omitted. Furthermore, the branch pipes 34 _21, 34 ₂₂ which is branched from the gas supply pipe 34 ₂ and the tube, a heater (not shown) to the outer peripheral wall surface of the tubular body is attached. As this heater, for example, a belt heater is used. These heaters are connected to and controlled by the CPU 12.

As shown in FIGS. 2, 3, and 5, an intermediate connecting member 26 and a perforated plate insertion mechanism 27 are disposed between the inner and outer tanks 20 and 25 and the lid body 30. The intermediate connecting member 26 is formed of a cylindrical body having an opening having the same size as the lower opening of the lid 30. This cylindrical body is formed of a material that is not easily corroded by an organic solvent such as hydrofluoric acid or IPA. The intermediate connecting member 26 is provided above the perforated plate insertion mechanism 27, the opening 26 ₂ in the lower is positioned to be substantially brought into contact with the upper surface of the frame 27 ₁ housing the porous plate, above the opening 26 ₁ is fitted to the lower opening 31 ₁ of the box-shaped container 31. It is also possible to omit the intermediate connecting member 26 so as to fit the lid 30 directly frame 27 _1.

The porous plate 28 is composed of a flat plate inserted between the inner and outer tanks 20 and 25 and the intermediate connecting member 26 in the step of drying the wafer aggregate W ′ after the predetermined processing, and has a plate-like surface. Has a plurality of small holes. This perforated plate is formed of a material that is not easily corroded by an organic solvent such as hydrofluoric acid or IPA. The porous plate 28 is housed in the frame 27 ₁ is connected to a moving mechanism (not shown), as shown in FIG. 2, it is slid in the horizontal direction. Frame 27 ₁ for housing the porous plate 28 has a predetermined vertical width (vertical direction), when the porous plate 28 is housed in the frame body 27 _1, a frame body 27 ₁ and the porous plate 28 A gap 272 is formed between the _two .

The gap 27 _2, for example about 2mm gap, in the drying process, a portion of the dry gas is set to be released into the sink 29. Accordingly, a gap 27 ₂ (in FIG. 7, this gap is represented by x) is formed between the inner tank 20 and the lid body 30, so that the gap x causes the gap between the inner tank 20 and the lid body 30. It is semi-sealed without being sealed, that is, a semi-sealed state is formed between the drying processing unit and the cleaning processing unit and the sink 29. The perforated plate 28 is inserted between the inner and outer tanks 20 and 25 and the intermediate connecting member 26, and functions as a shutter that separates the inner tank 20 and the lid 30 from each other, that is, partitions the cleaning processing unit and the drying processing unit. .

Next, piping connection between the processing tank 15 and the accessory device will be described with reference to FIG. A processing liquid supply pipe 22 ₁ is connected to the processing liquid supply section 22 provided at the bottom of the inner tank 20, and this introduction pipe 22 ₁ is connected to a pure water supply source 38 via a flow rate control valve and a pump. Yes. The treatment liquid introduction pipe 22 _1, without the function of the processing liquid supply piping, the cleaning liquid supply means is constituted by this pipe and the flow control valve and the pump. Also, this treatment liquid introduction pipe 22 _1, is also connected to the chemical liquid supply source 39 via a likewise flow control valve. The chemical liquid supply source 39 includes chemical liquid preparation means (not shown) for preparing a desired chemical liquid at a predetermined concentration and a predetermined temperature. Depending on the purpose of the treatment (eg, cleaning, etching, oxidation, etc.), the chemical solution may be, for example, hydrofluoric acid, hydrochloric acid, hydrogen peroxide solution, sulfuric acid, ozone water, ammonia water, surfactant, amine organic solvent, fluorine Selected from organic organic solvents, electrolytic ionic water, etc., a mixture of these plural chemicals is used as necessary.

Further, as shown in FIG. 2, the treatment liquid discharge portion 21 provided at the bottom of the inner tank 20 includes a small-diameter discharge port 21 ₁ and a large-diameter discharge port 21 _{2. 1,} is connected to the 23 _2, these drainage pipes 23 ₁ off valve, the pump, and is connected to the drainage processing facility 40 via a flow control valve. Furthermore, drain pipe 23 ₂ is likewise off valves, pumps, is connected to an exhaust processing facility 41 through the flow control valve. Moreover, the sink 29 is also connected to an exhaust processing facility 41 _1. A lower position of the outer tank 25, the drain pipe 25 ₁ is connected, the drain pipe 25 ₁ is connected to the drain pipe 23 _1.

A steam supply mechanism 37 is provided in the vicinity of the processing tank 15. The vapor supply mechanism 37 stores an organic solvent made of, for example, an isopropyl alcohol (IPA) solvent, which is easy to mix with adhering water remaining on the surface of the wafer W and has an extremely small surface tension. and a steam generating tank 37 ₁ to generate the vaporization and mist by bubbling an inert gas while heating the. The vapor generation tank 37 ₁ is dipped in hot water heating tank 37 _2, the organic solvent is heated to a predetermined temperature. The vapor generating bath 37 ₁ and an organic solvent supply source 36 is connected by a pipe 36 _1, IPA is supplied to the steam generating tank 37 _1. In addition to IPA, the organic solvent is appropriately selected from the group consisting of organic compounds such as diacetone alcohol, 1-methoxy-2-propanol, ethyl glycol, 1-propanol, 2-propanol, and tetrahydrofuran.

The second inert gas supply source 35 through the pipe 35 ₁ and _{35 12,} are connected to the steam generating tank 37 _1, nitrogen gas _{N 2} is supplied to the bottom of the steam generating tank 37 _1, steam generator generating bubbles in IPA reserved in the tank 37 ₁ is (bubbling) to generate IPA vapor consisting IPA gas and mist. Further, the pipe _{37 12} derived from the vapor generating bath 37 ₁ is connected to a gas supply pipe 34 ₂ through the static mixer M, from the vapor generating bath 37 ₁ to the injection nozzle 33 of the carrier gas _{N 2} and the IPA vapor A mixed gas is supplied. The outer peripheral wall surface of the pipe _{35 12, 37} 12, 34 ₂ of the tubular body is attached a belt heater (not shown), these heaters are temperature controlled by CPU 12. The static mixer M is provided to promote and homogenize the degree of mixing of the mixed gas composed of the carrier gas N ₂ and the IPA vapor.

From the first inert gas supply source 34, the nitrogen gas _{N 2} is supplied as the inert gas in the pipe _{37 12} through the pipe 34 _1. Is controlled to a predetermined temperature by the pipe 34 ₁ is also belt heater. The nitrogen gas N ₂ is not only dilution of the mixed gas of an inert gas and an organic solvent vapor from the vapor generation tank 37 ₁ is also used to purge or finishing drying of the treatment vessel 15. As the inert gas, in addition to the nitrogen gas N _2, argon, helium appropriately selected and can be used.

  Next, a series of processes using this substrate processing apparatus will be described with reference to FIGS. 6 shows a time chart of a series of processes, FIG. 7 shows a cleaning / drying process, FIG. 7 (a) shows a cleaning process, FIG. 7 (b) shows a drying process 1, and FIG. 7 (c) shows a drying process. Step 2 and FIG. 7D are cross-sectional views illustrating the drying step 3.

Referring to FIGS. 1 and 6, first, lid 30 of processing tank 15 is opened, and wafer assembly W ′ is accommodated in inner tank 20. In the tank 20 at this time, is the reservoir is supplied to a desired chemical, for example, the inner tub 20 hydrofluoric acid (HF) is passed through the processing liquid supply unit 22 and the treatment liquid introduction pipe 22 ₁ from the chemical liquid supply source 39 . Therefore, the wafer assembly W ′ is immersed in this processing solution, whereby processing corresponding to the chemical solution (for example, etching, hydrofluoric acid processing, cleaning, etc.) is performed.

After this chemical processing is completed, as shown in FIG. 7 (a), pure water DIW is supplied to the inner bath 20 through the pure water supply source 38 and the treatment liquid introduction pipe 22 ₁ from the processing liquid supply unit 22. This pure water supply is performed while overflowing from the upper part of the inner tank 20. Pure water DIW overflowing from the inner tank 20 flows into the outer tank 25, and is discharged through the drain pipe from the drain pipe 25 _1. This supply of pure water is performed over a relatively long time, and the chemical liquid HF remaining in the inner tank 20 is pushed out.

  After the cleaning process is completed, in the drying process 1 shown in FIG. 7B, the continuous supply of pure water DIW is stopped, and a small amount of pure water is supplied (DIW water saving) while the wafer assembly W ′ is removed. The inner tank 20 is slowly pulled up (Slow up Speed). A small amount of IPA vapor can be supplied into the processing tank 15 simultaneously with the pulling of the wafer assembly W ′.

Then, the horizontal movement in FIG. 7 In the drying step 2 (c), the processing tank 15 bottom outlet 21 ₂ of the by operating the drain mechanism valve treatment solution quickly discharge the frame body 27 in _one of the perforated plate 28 And inserted between the inner and outer tubs 20 and 25 and the intermediate connecting member 26. Further, a dry gas made of a mixed gas of nitrogen gas N ₂ and IPA vapor warmed in the inner tank 20 is supplied. These operations are performed simultaneously as shown in the chart. The drying gas is heated in the pipe 34 ₂ and the nozzle 33. In this step, the vapor of the organic solvent in the processing tank 15 touches the surface of each wafer W, and the IPA mist is condensed on the surface of the wafer W to form an IPA film. When a film of an organic solvent is formed on the surface of the wafer W, the pure water that has adhered to the wafer W is replaced with IPA, so that the surface tension decreases and flows down from the surface of the wafer W. The IPA adhering to evaporates. In the drying step 3 of FIG. 7D, nitrogen gas N ₂ is supplied to dry the substituted IPA, and when the drying step 3 is completed, the wafer aggregate W ′ is taken out from the processing tank 15.

  In the above process, the pressure in the lid 30 (drying process unit) is higher than the pressure in the sink and its exhaust source pressure, and higher than the pressure in the inner tank 20 (cleaning process unit) and its exhaust source pressure. It will be lost. For this reason, the flow of the drying gas in the drying processing section becomes a laminar flow and is smoothly exhausted from the exhaust pipe to the outside of the tank. In this process, the drying gas is uniformly supplied to individual wafers, and water is applied to the surface of the substrate. No mark is formed, and removal and adhesion of particles can be prevented. In addition, since the dry gas does not recirculate in the treatment tank, reattachment of particles can be prevented.

At this time, the relationship between the temperatures T ₁ , T ₂ ′, T ₄ , T ₂ ″, and T ₃ at each location in FIG. 1 is controlled by the CPU 12 so that the following relationship is satisfied. Is set.
T ₁ ≦ T ₂ ′ ≦ T ₄ ≦ T ₂ ″ ≦ T ₃ ≦ Boiling point of organic solvent (1)
here,
Temperature in the steam generation tank 37 ₁ : T ₁ ,
Temperature in pipe 37 ₁₂ : T ₂ ',
The temperature in the pipe 34 ₁ : T ₄ ,
Temperature in the pipe 34 _{2: T 2} ",
Temperature in the injection nozzle: T ₃ ,

Thus, by setting the temperatures T ₁ , T ₂ ′, T ₄ , T ₂ ″ and T ₃ so as to satisfy the above equation (1), the size of the IPA mist injected from the injection nozzle 33 is More specifically, it is a mist with a very small particle size that is not observed by the Tyndall phenomenon, that is, a submicron mist, that is, a mist of several microns is confirmed by the Tyndall phenomenon. However, if it becomes submicron size, it cannot be confirmed even by the Tyndall phenomenon, and a special measuring device is required.In this embodiment, the size of the IPA mist cannot be confirmed by the Tyndall phenomenon, so it is submicron size. However, this submicron mist is not completely gasified and exists in a liquid state. And those are. Incidentally, _{T 3} has a boiling point of IPA as mist IPA does would provide an completely vaporized (82.4 ° C.) is controlled below.

  By making the size of the mist constituting the vapor of the organic solvent sub-micron, the number of grains of the organic solvent mist is increased without increasing the amount of the organic solvent used, and the surface area of each mist is reduced. The total surface area increases as the amount of increases. As a result, the specific surface area of the vapor of the organic solvent can be increased and sprayed onto the substrate, so that the replacement efficiency with the cleaning liquid is improved.

Moreover, in the temperature setting of said Formula (1), it is preferable that each temperature is the same or it becomes high gradually. That is, in the vapor generating bath 37 _1, although a mixed gas of an inert gas containing a IPA vapor comprising the IPA mist and IPA gas below the saturation concentration by bubbling inert gas into the IPA is obtained, this mixture Since the gas is maintained at the same temperature or gradually increased until it is discharged from the injection nozzle, the organic solvent mist in the mixed gas is prevented from condensing the vapor of the organic solvent in the piping and the injection nozzle. In addition, since the IPA vaporizes gradually from the surface of the IPA mist while moving in the piping and the nozzle, the particle size of the mist is reduced, so that it is easy as a dry gas ejected from the injection nozzle. A dry gas containing submicron sized IPA mist can be obtained.

Furthermore, a mixed gas composed of an inert gas containing IPA vapor comprising the IPA mist generated by the steam generating unit 37 ₁ and the IPA gas below the saturation concentration, is diluted with an inert gas supplied separately from the pipe 34 ₁ Therefore, since the IPA gas concentration in the mixed gas is reduced, the vaporization of IPA from the IPA mist is further promoted, and a dry gas containing many submicron-sized IPA mists together with a large amount of inert gas is treated. The tank 15 can be supplied. In this case, as newly supplied nitrogen gas N ₂ is mixed efficiently IPA vapor, etc., it is preferably stirred by a mixer M is provided in the middle of the pipe 34 _2. This mixer is preferably a static mixer.

  Thus, when many submicron-sized IPA mists are contained in the dry gas, even if a large number of large-diameter substrates are inserted into the processing tank 15, the submicron-sized mists are rapidly transferred between the substrates. Since the cleaning solution adhering to the substrate is rapidly replaced by the vapor of the submicron organic solvent that is continuously supplied in large quantities, the drying processing efficiency can be improved and the processing time can be shortened. , Drying process is extremely fast. Therefore, without increasing the amount of organic solvent used, the drying processing efficiency can be improved and the processing time can be shortened, the generation of watermarks on the substrate surface can be made extremely small or almost zero, and There is no adhesion, and the speed of the drying process is increased, so that re-adhesion of particles can be prevented.

In the manner described above, showed that from the pipe 34 ₁ adapted to supply diluting inert gas, the dilution inert gas is a necessarily to obtain the IPA mist submicron need It is not a thing. In this case, the temperature of the pipe _{37 12,} 34 2, _{34 21} and _{34 22} connecting the steam generating tank 37 ₁ and the nozzle 33 may be temperature controlled to satisfy all the different above (1) or by keeping all the same temperature T _2,
The temperature may be controlled so that T ₁ ≦ T ₂ ≦ T ₃ ≦ boiling point of the organic solvent.

Further, the temperature T ₃ of the piping and the injection nozzle or the same as the temperature T ₂ of the temperature T ₁ and an inert gas of the organic solvent to be supplied to the steam generating unit, or is set high. As a result, the vapor of the organic solvent does not condense in the piping and the injection nozzle, so the diameter of the organic solvent mist in the dry gas does not increase, and in addition, the surface of the organic solvent mist is ejected before being ejected from the nozzle. Furthermore, since a part of the organic solvent is vaporized, the size of the organic solvent mist in the dry gas ejected from the ejection nozzle can be easily made a submicron size. Further, since the organic solvent vapor does not condense in the pipe and the injection nozzle, there is no fear that the IPA droplets will fall from the nozzle.

  In this embodiment, in order to prevent the collision between organic solvent mists and the collision of the organic solvent mist to the wall of the device, the increase in the diameter of the organic solvent mist and the condensation of the mist are prevented. Is preferably configured as follows. In other words, the bubbling tank of the steam generating part has a conical or arc shape at the top. In addition, the dry gas supply piping has few steps so that the diameter does not change greatly. Furthermore, the bubbling nozzle of the steam generating part uses a nozzle having a small ejection diameter and a high ejection speed.

Further, a situation will be described in which the cleaning liquid attached to the substrate is replaced by the mist using the dry gas containing the IPA mist of the submicron size. 8 and 9 are cross-sectional views schematically showing the relationship between the IPA vapor and the substrate during the drying process, and FIG. 8 shows that the dry gas contains IPA mist of submicron size but is diluted with an inert gas. FIG. 9 shows the case where the dry gas contains IPA mist of submicron size and is diluted with an inert gas. FIGS. 8A, 8B, 9A, and 9B correspond to the “drying 2” process of FIG. 6, and FIGS. 8C and 9C correspond to FIG. This corresponds to the process of “drying 3”. As shown in FIG. 8A, when a dry gas composed of a mixed gas of submicron size IPA mist (liquid) and nitrogen gas N ₂ (gas) is sent into the processing tank 15 and supplied between the wafers W, By supplying this dry gas, as shown in FIG. 8B, DIW adhering to the wafer W is replaced by IPA. However, since a large amount of IPA mist is atomized and supplied, one DIW is supplied. On the other hand, since a plurality of IPA grains adhere to the DIW, the DIW is efficiently replaced. Next, as shown in FIG. 8C, IPA is evaporated by sending only N ₂ gas into the treatment tank 15. In this case, in the “drying 2” step (FIGS. 8A and 8B), since the supply amount of the nitrogen gas N ₂ is small, the carry effect of the IPA mist is not sufficient, and the submicron-sized mist is used. Although a good drying effect can be obtained by using it, a residual DIW watermark may remain slightly when used for drying large-diameter wafers.

  In addition, when the dry gas contains IPA mist of submicron size and is further diluted with an inert gas, the concentration of IPA vapor in the dry gas is reduced, but the carry effect of the IPA mist is sufficient. As shown in FIG. 9, the submicron size IPA mist can be continuously and uniformly supplied to the back of the wafer W by a large amount of carrier gas. Due to the dry gas containing a large amount of carrier gas, the IPA mist of submicron size is quickly attached to the DIW, so that the DIW is efficiently replaced. As a result, even when used for drying large-diameter wafers, the drying processing efficiency is increased and the processing speed is improved, so that the processing time can be shortened. As shown in FIG. DIW is zero, that is, the generation of watermarks can be completely eliminated. 9 is the same as that in FIG. 8 except that new nitrogen gas is mixed, and therefore detailed description thereof is omitted.

It is sectional drawing which shows the substrate processing apparatus of one Embodiment of this invention. It is a side view which shows the processing tank of one Embodiment of this invention. It is the side view which looked at the processing tank of Drawing 2 from the other side. It is the top view seen through from the upper part of the lid in the processing tub of one embodiment of the present invention. It is a side view of the cover body shown in FIG. It is a figure which shows the time chart of a series of processes. FIG. 7 (a) is a cleaning process, FIG. 7 (b) is a drying process 1, FIG. 7 (c) is a drying process 2, and FIG. 7 (d) is a cross-sectional view illustrating the drying process 3. It is. It is sectional drawing which showed typically the relationship between the IPA vapor | steam and a board | substrate in a drying process. FIG. 9 is a cross-sectional view schematically showing the relationship between the IPA vapor and the substrate in the drying step when nitrogen gas for dilution is used, as in FIG. 8. It is sectional drawing which shows the substrate processing apparatus of a prior art. It is sectional drawing which showed typically the relationship between the IPA vapor | steam and a board | substrate in the drying process of the substrate processing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 10 Substrate processing apparatus 11 Accommodating chamber 15 Processing tank 20 Inner tank 21 Processing liquid discharge part 22 Processing liquid supply part 25 Outer tank 26 Intermediate connection member 27 Perforated plate insertion mechanism 28 Perforated plate 29 Sink 30 Lid 31 Box-shaped container 33 Injection nozzle 37 Steam supply mechanism 37 ₁ Steam generation tank

Claims (7)

  In a substrate processing method of drying a substrate surface by spraying a dry gas composed of a mixed gas of an organic solvent vapor and an inert gas onto a substrate from a plurality of spray nozzles, a sub gas is submerged in the dry gas ejected from the spray nozzle. A substrate processing method comprising a mist of an organic solvent of micron size.   A plurality of the substrates are arranged in parallel with each other at an equal pitch and vertically, and the dry gas is ejected from the plurality of ejection nozzles provided on the outer peripheral edge side of the aggregate of the plurality of substrates. The substrate processing method according to claim 1.   The substrate processing method according to claim 2, wherein the dry gas is ejected from the plurality of spray nozzles provided at equal distances from an outer peripheral edge of the aggregate of the plurality of substrates.   4. The substrate according to claim 3, wherein a spray region of the dry gas ejected from a spray nozzle adjacent to each of the plurality of spray nozzles overlaps with an outer peripheral edge of the aggregate of the plurality of substrates. Processing method.   The organic solvent is at least one selected from the group consisting of isopropyl alcohol, diacetone alcohol, 1-methoxy-2-propanol, ethyl glycol, 1-propanol, 2-propanol, tetrahydrofuran, and the inert gas. The substrate processing method according to claim 1, wherein is at least one selected from the group consisting of nitrogen, argon, and helium. A vapor generating section that generates a dry gas composed of a mixed gas of an organic solvent vapor and an inert gas by bubbling an inert gas into the organic solvent;
Support means for supporting a plurality of substrates to be processed in a parallel and vertical posture at equal pitches;
A cleaning tank for containing an assembly of substrates supported by the support means;
A lid covering the upper opening of the cleaning tank;
A plurality of injection nozzles provided at substantially equal distances from the outer peripheral edges of the plurality of substrates on the lid;
A first pipe communicating the steam generation unit and the injection nozzle;
In the substrate processing apparatus, the heater is attached to each of the first pipe and the injection nozzle, and the heater is controlled so that the temperature of the dry gas from the steam generation unit to the nozzle does not decrease. A substrate processing apparatus characterized in that a submicron-sized organic solvent mist is contained in the dry gas sprayed from the spray nozzle by controlling.   The plurality of spray nozzles are provided at positions where dry gas spray regions ejected from adjacent spray nozzles overlap each other at outer peripheral edges of the plurality of substrates. Substrate processing equipment.

Images