JP4133540B2 - Substrate cleaning method and substrate cleaning apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate cleaning method and a substrate cleaning apparatus for supplying an aqueous cleaning solution to a substrate such as a semiconductor wafer, an FPD (flat panel display) substrate, or a photomask substrate and cleaning the substrate.
[0002]
[Prior art]
For example, in a semiconductor device manufacturing process, a resist liquid is formed on the surface of a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film, and the wafer after resist coating is exposed in accordance with a predetermined pattern. After the processing, a resist pattern is formed as a mask for forming a predetermined pattern by a so-called photolithography technique in which an exposure pattern formed on the resist film of the wafer is developed.
[0003]
In the development process in each process of such a photolithography technique, a developer is supplied to the wafer, a developer paddle is formed on the entire surface so as to have a thickness of, for example, 1 mm, and the developer is processed by natural convection for a predetermined time. Then, the developer is washed. In this cleaning, after the developer is shaken off, pure water is supplied as a cleaning solution to wash away the developer remaining on the wafer, and then the wafer is rotated at a high speed to shake off the developer and cleaning solution remaining on the wafer. Is performed by drying.
[0004]
After this development, a resist residue may be generated depending on the type of resist. Further, it is difficult to completely remove such resist residues even by the above-described cleaning process of supplying pure water, and the resist residues that are not removed by the cleaning process cause defects after development. .
[0005]
In order to prevent this, it has been proposed that a surfactant is added to the developer so as not to generate a resist residue itself (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP-A 61-177727
[0007]
[Problems to be solved by the invention]
However, even with the technique of the above-mentioned Patent Document 1, a resist residue remains to some extent, and it is desired to cope with the problem by improving the cleaning property of the cleaning process after development. Thus, improving the cleaning performance of a substrate such as a wafer is not limited to cleaning processing after development.
[0008]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate cleaning method and a substrate cleaning apparatus capable of sufficiently cleaning a substrate such as a semiconductor wafer with an aqueous cleaning liquid. It is another object of the present invention to provide a substrate cleaning method and a substrate cleaning apparatus that are highly effective in removing deposits and can reduce defects after development in cleaning a substrate after development with an aqueous cleaning solution.
[0009]
[Means for Solving the Problems]
  In order to solve the above-described problem, according to a first aspect of the present invention, there is provided a substrate cleaning method for cleaning a substrate to be processed by supplying an aqueous cleaning liquid from a nozzle to the substrate to be processed through the piping.Of the nozzle from the tip of the nozzle up to 3 m and / orAlternatively, the present invention provides a substrate cleaning method, wherein a magnetic field is applied to the aqueous cleaning liquid flowing through the nozzle, and the aqueous cleaning liquid is supplied to a substrate to be processed.
[0010]
  In the second aspect of the present invention, the resist film formed on the substrate to be processed is exposed to a predetermined pattern, and after developing the exposure pattern, an aqueous cleaning solution is supplied to the substrate to be processed from a nozzle via a pipe and developed. A substrate cleaning method for cleaning a substrate to be processed later, wherein the pipingOf the nozzle from the tip of the nozzle up to 3 m and / orAlternatively, a substrate cleaning method is provided, wherein a magnetic field is applied to the aqueous cleaning liquid flowing through the nozzle, and the aqueous cleaning liquid is supplied to the substrate to be processed after development.
[0011]
  In the third aspect of the present invention, a support member for supporting the substrate to be processed, a nozzle for supplying an aqueous cleaning liquid to the substrate to be processed, a pipe made of a nonmagnetic material connected to the nozzle, and an aqueous system connected to the pipe Cleaning liquid supply source and the pipingOf the nozzle from the tip of the nozzle up to 3 m and / orOr provided near the nozzle, the pipeOf the nozzle, and flow in the portion up to 3 m from the tip of the nozzle and / or in the nozzleThere is provided a substrate cleaning apparatus comprising magnetic field generating means for applying a magnetic field to an aqueous cleaning liquid.
[0012]
  According to the present invention, in cleaning the substrate to be processed by supplying the aqueous cleaning liquid from the nozzle to the substrate to be processed through the pipe,Of the nozzle from the tip of the nozzle up to 3 m and / orAlternatively, a magnetic field is applied to the aqueous cleaning liquid flowing through the nozzle, and the water molecule clusters are subdivided by the magnetic field, so that the aqueous cleaning liquid is activated and the surface tension is reduced, and the fine unevenness of the substrate to be processed is also reduced by the aqueous system. The cleaning liquid can enter, and the cleaning effect and cleaning efficiency can be dramatically increased. In particular, although the resist residue is likely to remain on the fine irregularities on the substrate to be processed after development, since the water molecule clusters thus subdivided easily enter the fine irregularities and are washed, the resist residues are extremely effective and It can be removed efficiently, and defects after development can be reduced. Further, since the cleaning effect and the cleaning efficiency are high as described above, the cleaning time can be shortened and the amount of the cleaning liquid used can be reduced. In the present invention, the water-based cleaning liquid refers to a liquid mainly composed of pure water and having other additives added as necessary.
[0013]
  In the present invention,WaterSystem cleaning solutionFlowing part ofBy applying a magnetic field of 0.08 T or more to water, the water molecule cluster can be effectively subdivided.
[0014]
  The magnetic field generating means is the pipeAmong these, the part from the tip of the nozzle to 3 m and / or the nozzleIt can be set as the structure which has a magnet element provided along. In this case, there are multiple magnet elements.DistributionMay be arranged, and the magnet element is the pipe.Among these, the part from the tip of the nozzle to 3 m and / or the nozzleMay be provided so as to face each other.
[0015]
  The magnetic field generating means may be configured to include a magnet element made of an electromagnet, a power source for supplying power to the magnet element, and a control mechanism for controlling the magnetic field strength of the magnet element. This allows pipingOf the nozzle from the tip of the nozzle up to 3 m and / orAlternatively, the magnetic field intensity acting on the aqueous cleaning liquid flowing through the nozzle can be controlled to a desired value. The magnet element comprising the electromagnet is the pipe.Of the nozzle from the tip of the nozzle up to 3 m and / orOr it can be set as the structure which is provided so that it may straddle the said nozzle, and has a core which has a pair of edge part used as a magnetic pole, and the connection part which connects these edge parts, and the coil wound around the connection part of the said core. .
[0016]
  The control mechanism isAboveThe magnetic field strength of the magnet element made of the electromagnet can be controlled according to the flow rate of the aqueous cleaning liquid. Also. When the magnetic field generation means has a plurality of magnet elements made of the electromagnet, the control mechanism isAboveDepending on the flow rate of the aqueous cleaning liquid, a part of the plurality of magnet elements can be controlled to be turned on / off. By controlling in this way, the magnetic field strength can be increased when the flow rate of the aqueous cleaning liquid is large, and the magnetic field strength can be decreased when the flow rate is small, and an appropriate magnetic field can be applied according to the flow rate.
[0017]
  AboveThe part where the magnetic field is applied to the aqueous cleaning liquid can be configured to have a coil shape. This, ThroughA magnetic field can be efficiently applied to the flowing aqueous cleaning liquid.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic plan view showing a resist coating / development processing system including a development processing unit for carrying out an embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof.
[0019]
This resist coating / development processing system 1 includes a cassette station 11 serving as a transfer station, a processing station 12 having a plurality of processing units, and an exposure apparatus 14 provided adjacent to the processing station 12 and the processing station 12. And an interface station 13 for delivering the wafer W.
[0020]
In the cassette station 11, a wafer cassette (CR) containing a plurality of (for example, 25) wafers W is loaded and unloaded, and as shown in FIG. A plurality of (five in FIG. 1) positioning protrusions 20a are formed in one row. The wafer cassette (CR) can be placed at the position of the positioning projection 20a with the wafer loading / unloading port facing the processing station 12 side.
[0021]
The cassette station 11 includes a wafer transfer mechanism having a wafer transfer pick 21a. The wafer transfer pick 21a can selectively access any one of the wafer cassettes (CR), and a third processing unit group G of the processing station 12 to be described later._ThreeTransition unit (TRS-G_Three) Can be accessed.
[0022]
In the processing station 12, the third processing unit group G is arranged in order from the cassette station 11 side on the rear side of the system (upper side in FIG. 1)._Three, Fourth processing unit group G_FourAnd the fifth processing unit group G_FiveIs arranged. The third processing unit group G_ThreeAnd the fourth processing unit group G_FourBetween the first main transport section A₁And a fourth processing unit group G_FourAnd the fifth processing unit group G_FiveBetween the second main transport section A₂Is provided. Further, on the front side of the system (lower side in FIG. 1), in order from the cassette station 11 side, the first processing unit group G₁And second processing unit group G₂Is provided.
[0023]
As shown in FIG. 3, the third processing unit group G_ThreeThen, an oven-type processing unit that performs predetermined processing by placing the wafer W on the mounting table, for example, a high-temperature heat treatment unit (BAKE) that heat-treats the wafer W, and a high-accuracy temperature that controls the temperature of the wafer W with high accuracy. Adjustment unit (CPL-G_Three), Temperature control unit (TCP), cassette station 11 and first main transport section A₁Transition unit (TRS-G) that serves as a transfer part of the wafer W between_Three) Are stacked, for example, in 10 steps.
[0024]
Fourth processing unit group G_FourThen, for example, a pre-bake unit (PAB) that heat-treats the wafer W after resist coating, a post-bake unit (POST) that heat-treats the wafer W after development, and a high-precision temperature control unit (CPL-G)_Four) Are stacked, for example, in 10 steps. Fifth processing unit group G_FiveThen, for example, a post-exposure bake unit (PEB) that heat-treats the wafer W after exposure and before development, a high-precision temperature control unit (CPL-G)_Five) Are stacked, for example, in 10 steps.
[0025]
As shown in FIGS. 1 and 3, the first main transport section A₁The sixth processing unit group G having an adhesion unit (AD) and a heating unit (HP) for heating the wafer W is provided on the back side of the substrate.₆Is provided.
[0026]
Second main transport section A₂On the back side of the wafer, a peripheral exposure device (WEE) that selectively exposes only the edge portion of the wafer W in order to remove excess resist at the peripheral portion of the wafer, and a film thickness measurement device (FTI) that measures the resist film thickness. ) Having a seventh processing unit group G₇Is provided.
[0027]
As shown in FIGS. 1 and 2, the first processing unit group G₁Then, five spinner type processing units, for example, three resist coating units (COT) as liquid supply units for performing predetermined processing by placing the wafer W on the spin chuck SP in the cup (CP), and at the time of exposure A bottom coating unit (BARC) for forming an antireflection film for preventing light reflection is stacked in a total of five stages. The second processing unit group G₂Then, spinner type processing units, for example, development units (DEV) are stacked in five stages.
[0028]
First main transport section A₁Is provided with a first main wafer transfer device 16, which is connected to the first processing unit group G.₁, Third processing unit group G_Three, Fourth processing unit group G_FourAnd the sixth processing unit group G₆Each unit can be selectively accessed. The second main transport section A₂Is provided with a second main wafer transfer device 17, which is connected to the second processing unit group G.₂, Fourth processing unit group G_Four, Fifth processing unit group G_Five, Seventh processing unit group G₇Each unit can be selectively accessed.
[0029]
FIG. 4 is a perspective view showing a schematic structure of the first main wafer transfer device 16. The first main wafer transfer device 16 includes three arms 7a, 7b, 7c that hold the wafer W, arm support plates 51 attached to the respective base ends of the arms 7a to 7c, and each arm support plate 51. A base 52 that is engaged, a support 53 that supports the base 52 and the like, a motor (not shown) built in the support 53, a rotating rod 54 that connects the base 52 and the motor, and a first And second processing unit group G₁, G₂A support column 55 provided on the side and having a sleeve 55a formed in the vertical direction, a flange member 56 slidably engaged with the sleeve 55a and connected to the support portion 53, and the flange member 56 being moved up and down (not shown) And a lifting mechanism.
[0030]
On the base 52, rails (not shown) are laid for each arm support plate 51 in parallel with the longitudinal direction of the base 52, and each arm support plate 51 is slidable along this rail. . Further, when the motor built in the support portion 53 is rotated, the rotating rod 54 is rotated, whereby the base 52 can be rotated in the XY plane. Furthermore, since the support portion 53 is attached to a flange member 56 that is movable in the Z direction, the base 52 is also movable in the Z direction.
[0031]
Vertical members 59a are attached to both sides of the distal end portion of the base 52, and a shielding plate 8 and a bridging member 59b for blocking radiant heat between the arms 7a and 7b are attached to the vertical members 59a. A pair of optical sensors (not shown) are provided at the center of the bridging member 59b and the tip of the base 52, thereby detecting the presence / absence of the wafer W in each of the arms 7a to 7c and the protrusion of the wafer W. It has come to be. The second main wafer transfer device 17 has the same structure as the first main wafer transfer device 16.
[0032]
The wall 57 shown in FIG. 4 is the first processing unit group G.₁Second main transport section A on the side₂Of the first processing unit group G.₁A window portion 57a is provided for transferring the wafer W to and from each unit provided in the. The second main transport section A₂Four fans 58 are provided at the bottom of the.
[0033]
First processing unit group G₁And the cassette station 11 and the second processing unit group G₂And the interface station 13 are respectively connected to the first and second processing unit groups G.₁, G₂Liquid temperature control pumps 24 and 25 for supplying a processing solution to the processing unit group G are further supplied to the processing unit group G.₁~ G_FiveDucts 28 and 29 are provided for supplying the inside.
[0034]
Panel on the back side of the processing station 12 and the first processing unit group G₁~ Seventh processing unit group G₇Can be removed for maintenance. The first and second processing unit groups G₁, G₂At the bottom of each, chemical units (CHM) 26 and 27 for supplying a chemical solution to these are provided. Further, a central control unit 19 for controlling the entire resist coating / development processing system 1 is provided below the cassette station 11.
[0035]
The interface station 13 includes a first interface station 13a on the processing station 12 side and a second interface station 13b on the exposure apparatus 14 side. The first interface station 13a includes a fifth processing unit group G._FiveThe first wafer transfer body 62 is arranged so as to face the opening of the second wafer station, and the second wafer transfer body 63 movable in the X direction is arranged at the second interface station 13b.
[0036]
On the back side of the first wafer transfer body 62, the peripheral exposure apparatus (WEE), the in-buffer cassette (INBR) for temporarily storing the wafer W transferred to the exposure apparatus 14, and the exposure apparatus 14 are sequentially carried out from the top. 8th processing unit group G in which out buffer cassettes (OUTBR) for temporarily storing the wafers W are stacked₈Is arranged. Further, on the front side of the first wafer transfer body 62, the transition units (TRS-G₉) And two-stage high-precision temperature control unit (CPL-G)₉) Are stacked in the ninth processing unit group G₉Is arranged.
[0037]
The first wafer transfer body 62 has a fork 62a for wafer transfer. The fork 62a is connected to the fifth processing unit group G._Five, Eighth processing unit group G₈, Ninth processing unit group G₉The units can be accessed, whereby the wafer W is transferred between the units.
[0038]
The second wafer transfer body 63 has a fork 63a for wafer transfer. This fork 63a is connected to the ninth processing unit group G₉These units and the in-stage 14a and out-stage 14b of the exposure apparatus 14 are accessible, and the wafer W is transferred between these units.
[0039]
In the resist coating / development processing system 1 configured as described above, one wafer W is taken out from the wafer cassette (CR) by the wafer transfer mechanism 21 and the transition unit (TRS-G) of the processing station 12 is taken._ThreeThen, the first and second main wafer transfer devices 16 and 17 sequentially transfer the wafer W to each unit according to the order of the recipe, and perform a series of processes on the wafer W.
[0040]
For example, after the temperature of the wafer W is adjusted, the adhesion process in the adhesion unit (AD) and / or the formation of the antireflection film in the bottom coating unit (BARC), the heat treatment in the heating unit (HP), the high temperature heat treatment Bake processing in the unit (BAKE), temperature control of the wafer W, resist liquid coating processing in the resist coating unit (COT), pre-baking processing in the pre-baking unit (PAB), and peripheral exposure processing in the peripheral exposure device (WEE) After sequentially adjusting the temperature of the wafer W, the wafer W is transferred into the exposure apparatus 14 by the second wafer transfer body 63. After exposure by the exposure apparatus 14, the wafer W is transferred by the second wafer transfer body 63 to the transition unit (TRS-G₉), The post-exposure bake process in the post-exposure bake unit (PEB), the development process in the development unit (DEV), and the post-bake process in the post-bake unit (POST) are sequentially performed to control the temperature of the wafer W. After processing, the transition unit (TRS-G_Three) To the wafer cassette (CR) of the cassette station 11. Such a series of operations is repeated by the number of cassette wafers.
[0041]
Next, a development processing unit (DEV) for carrying out one embodiment of the substrate cleaning method of the present invention will be described with reference to FIG. 5 and 6 are a cross-sectional view and a plan view showing the overall configuration of the development processing unit (DEV).
[0042]
The developing unit (DEV) has a housing 70, an annular cup CP is disposed at the center thereof, and a spin chuck 72 is disposed inside the cup CP. The spin chuck 72 is rotationally driven by a drive motor 74 in a state where the wafer W is fixedly held by vacuum suction. The drive motor 74 is disposed in the opening of the bottom plate 70a of the housing 70 so as to be movable up and down, and is coupled to a lift drive mechanism 78 and a lift guide 80 made of, for example, an air cylinder via a cap-like flange member 76 made of, for example, aluminum. ing. A cylindrical cooling jacket 82 made of, for example, stainless steel (SUS) is attached to the side surface of the drive motor 74, and the flange member 76 is attached so as to cover the upper half of the cooling jacket 82.
[0043]
When applying the developing solution, the lower end of the flange member 76 is in close contact with the bottom plate 70a in the vicinity of the outer periphery of the opening of the bottom plate 70a, thereby sealing the inside of the unit. When the wafer W is transferred between the spin chuck 72 and the second main wafer transfer mechanism 17, the elevating drive mechanism 78 lifts the drive motor 74 and the spin chuck 72 upward so that the lower end of the flange member 76 is in the housing. It rises from the bottom plate 70a of the body 70.
[0044]
To the bottom of the cup CP, an exhaust pipe 84 is connected to a portion near the center thereof, and a drainage pipe 86 is connected to a portion near the outside thereof. Then, the gas in the cup CP is exhausted from the exhaust pipe 84, and from the drain pipe 86, the developer scattered when the developer is shaken off and the cleaning liquid for washing away the developer are discharged. Note that an opening 88 through which any of the arms 7a to 7c enters is formed in the side wall of the housing 70 of the development processing unit (DEV).
[0045]
Above the cup CP, there are a developer supply nozzle 91 for supplying a developer to the surface of the wafer W, and an aqueous cleaning solution supply nozzle 94 for supplying an aqueous cleaning liquid such as pure water to the wafer W after development. It is provided to be movable between a supply position on the wafer W and a standby position outside the wafer W. The developer supply nozzle 91 is connected to a developer supply source 93 via a developer supply pipe 92, and the water-based cleaning liquid supply nozzle 94 is connected to a water-based cleaning liquid supply source 96 via a water-based cleaning liquid supply pipe 95. It is connected to the. The developer supply source 93 and the aqueous cleaning solution supply source 96 are accommodated outside the development unit (DEV), for example, in the chemical unit (CHM) 27.
[0046]
The developer supply nozzle 91 is detachably attached to the distal end portion of the first nozzle scan arm 97, and the aqueous cleaning solution supply nozzle 94 is detachably attached to the distal end portion of the second nozzle scan arm 98. The first and second nozzle scan arms 97 and 98 extend in a vertical direction from a guide rail 99 laid along the Y direction on the bottom plate 70a of the housing 70, and are arranged on the guide rail 99. Are attached to the upper end portions of the first vertical support member 100 and the second vertical support member 101 that can move horizontally, and the developer supply nozzle 91 and the aqueous cleaning solution supply nozzle 94 are the first and second vertical support members. Along with the support members 100 and 101, the Y-axis drive mechanism (not shown) moves along the Y direction. The first and second vertical support members 100 and 101 can be moved in the Z direction by a Z-axis drive mechanism (not shown), and the developer supply nozzle 91 and the aqueous cleaning liquid supply nozzle 94 correspond to the corresponding vertical support members. Is moved between a discharge position close to the wafer W and a non-discharge position above it. The developer supply nozzle 91 is placed on standby in the nozzle standby unit 102, and the nozzle standby unit 102 is provided with a nozzle cleaning mechanism 103 that cleans the developer supply nozzle 91.
[0047]
The developer supply nozzle 91 has a long shape and is arranged with its longitudinal direction horizontal. For example, the developer supply nozzle 91 has a plurality of discharge ports on the lower surface so that the discharged developer is formed in a strip shape as a whole. It has become. Then, when applying the developer, the wafer W is rotated 1/2 turn or more, for example, one turn while discharging the developer from the developer supply nozzle 91 located above the wafer W in a strip shape, or The developing solution supply nozzle 91 is scanned along the guide rail 94 without rotating the wafer W, and is applied to the entire surface. It should be noted that a slit nozzle in which the discharge port has a slit shape may be used, or a straight nozzle that is not long may be used.
[0048]
The aqueous cleaning liquid supply nozzle 94 is a straight nozzle, and after completion of the development process, the aqueous cleaning liquid supply nozzle 94 is moved onto the wafer W to form a nozzle on the resist film on which a development pattern is formed on the wafer W. An aqueous cleaning solution is supplied from 94 to perform cleaning. Thus, in the state where the aqueous cleaning liquid supply nozzle 94 is positioned on the wafer W, the developing unit (DEV) functions as a cleaning device.
[0049]
The supply of the developer and the aqueous cleaning liquid from the developer supply source 93 and the aqueous cleaning liquid supply source 96 is controlled by the liquid supply controller 104.
[0050]
Next, an example of a configuration when the developing unit (DEV) functions as a cleaning device will be described with reference to FIG.
An aqueous cleaning liquid supply nozzle 94 is disposed above the center of the wafer W supported by the spin chuck 72. A pipe 95 for supplying an aqueous cleaning liquid connected to the aqueous cleaning liquid supply nozzle 94 has a liquid draining portion 95 a that is continuously curved upward from the aqueous cleaning liquid supply nozzle 94. The pipe 95 is formed of a nonmagnetic material, for example, a resin such as PFA which is a fluororesin. In the middle of the pipe 95, a filter 105 and an electromagnetic valve 106 are interposed. Then, the aqueous cleaning liquid is supplied toward the wafer W from the aqueous cleaning liquid supply source 96 through the pipe 95 and the aqueous cleaning liquid supply nozzle 94 by a pumping mechanism (not shown) such as a pump.
[0051]
A magnetic field generation mechanism 110 is provided in the vicinity of the downstream side portion of the filter 105 of the pipe 95. In the example of FIG. 7, the magnetic field generation mechanism 110 has a magnet element 111 made of a permanent magnet. For example, the magnet element 111 has a triangular recess 111a as shown in FIGS. 8A and 8B, and a pipe 95 is fitted in the recess 111a. A magnetic field formed by the magnet element 111 made of a permanent magnet acts on the inside of the pipe 95. Specifically, the magnet element 111 made of a permanent magnet is arranged so that the magnetic force lines ML from the N pole to the S pole are substantially orthogonal to the flow direction of the aqueous cleaning liquid flowing through the pipe 95.
[0052]
Next, a processing operation in the developing unit (DEV) configured as described above will be described. First, the wafer W, on which a predetermined pattern is exposed and post-exposure bake processing and cooling processing, is transferred by the second main wafer transfer device 17 to a position directly above the cup CP in the development unit (DEV), and the spin chuck 72 is moved up and down. By being raised by the drive mechanism 78, it is vacuum-adsorbed on the spin chuck 72. Next, the developer supply nozzle 91 is moved substantially upward at the center of the wafer W, and the wafer W is rotated 1/2 turn or more, for example, 1 rotation while discharging the developer from the developer supply nozzle 91 in a strip shape. Alternatively, the developer is applied to the entire surface of the wafer W by discharging the developer while scanning the developer supply nozzle 91 along the guide rail 99 from one end of the wafer W to the other end. For example, a 1 mm developer paddle is formed and development is advanced by natural convection.
[0053]
While the development proceeds in this way, the developer supply nozzle 91 is moved to the standby position 102 and the aqueous cleaning liquid supply nozzle 94 is moved almost upward in the center of the wafer W, so that the cleaning apparatus is operated as shown in FIG. Constitute.
[0054]
After a predetermined time has elapsed, the spin chuck 72 is rotated at a predetermined rotation speed to shake off the developer from the wafer W, and at substantially the same time, the wafer W is rotated at the predetermined rotation speed while the water-based cleaning liquid supply nozzle 94 is moved onto the wafer W. An aqueous cleaning solution, for example, pure water, is supplied to the resist film on which the developing pattern is formed, and the developing solution present on the resist film is washed away. After the cleaning of the resist film on the wafer W is thus completed, the wafer W is rotated at a high speed, and the liquid agent remaining on the wafer W is shaken off to dry the wafer W. Thereby, a series of development processing is completed.
[0055]
When cleaning the wafer W, a resist residue is generated depending on the type of resist, and it is difficult to completely remove such a resist residue simply by supplying an aqueous cleaning solution such as pure water. Resist residues that are not removed by the cleaning process cause defects after development. Also, the cleaning efficiency is not sufficient. In other words, water molecules usually form a group called a cluster due to the electrical binding force acting between the molecules, and if this cluster is large, the surface tension is large and the activity is low. The cleaning power tends to be insufficient, and it is difficult to effectively remove the resist residue. This tendency is particularly great when the development pattern is fine.
[0056]
Therefore, in the present embodiment, a magnetic field generating mechanism 110 having a magnet element 111 made of, for example, a permanent magnet is provided in the vicinity of the pipe 95 for the aqueous cleaning liquid, and a magnetic field is applied to the aqueous cleaning liquid flowing through the pipe 95. Specifically, the magnet element 111 made of a permanent magnet is arranged so that the magnetic field lines ML from the N pole to the S pole are substantially orthogonal to the flow direction of the aqueous cleaning liquid flowing through the pipe 95. By forming such a magnetic field, the water molecule clusters of the aqueous cleaning liquid flowing through the pipe 95 are activated and fragmented, and the surface tension is reduced, so that the aqueous cleaning liquid is also applied to the fine development pattern of the wafer W. Intrusion can be achieved, and the cleaning effect and cleaning efficiency can be dramatically increased. Therefore, the resist residue can be effectively removed, and defects after development can be reduced. In particular, a great effect can be obtained in the case of an ultrafine pattern having a resist pattern width of 200 nm or less. Further, since the cleaning effect and the cleaning efficiency are high as described above, the cleaning time can be shortened and the amount of the cleaning liquid used can be reduced.
[0057]
In order to effectively subdivide the water molecule cluster and effectively exhibit the above effect, it is desirable to apply a magnetic field of 0.08 T or more to the flow site of the aqueous cleaning liquid. Furthermore, the diameter of the pipe 95 is preferably about 1 to 30 mm in order to efficiently apply a magnetic field to the flowing aqueous cleaning liquid. As a permanent magnet constituting the magnet element 111, a permanent magnet material that is normally used can be adopted as long as such an effect is obtained. For example, a neodymium magnet is preferable. A neodymium magnet is one of the materials that can form the largest magnetic field among magnet materials. For example, when the pipe 95 is made of resin and has an outer diameter of 6.35 mm and an inner diameter of 4.35 mm, if a 0.5 to 2.5 T neodymium magnet is used as the permanent magnet 111, the magnetic field inside the pipe 95 is 0. It becomes about 1-0.36T.
[0058]
Even if a large water molecule cluster is subdivided, if the distance until the aqueous cleaning liquid is discharged is long, the subdivided water molecule cluster may be recombined. Therefore, a magnetic field is applied to the aqueous cleaning liquid in the pipe 95. It is preferable that the position to act is closer to the tip of the nozzle 94, specifically, a position from the tip of the nozzle 94 to 3 m is preferable.
[0059]
Further, in order to activate the aqueous cleaning solution more effectively and further subdivide the water molecule cluster, it is preferable to increase the magnetic field. For this purpose, it is preferable to dispose the magnet element 111 as close to the piping 95 as possible. When only one magnet element is not sufficient, the magnet element 111 is arranged opposite to the both sides of the pipe 95 as shown in FIG. 9, or a plurality of (five in the figure) as shown in FIG. It is preferable to arrange the magnet elements 111 along the pipe 95. In this case, as shown in the drawing, it is preferable that the direction of the adjacent magnet element 111 is opposite to the pipe 95. Thereby, the magnet element 111 apparently covers the entire area of the pipe 95, and a stronger magnetic field can be exerted in the pipe 95.
[0060]
As shown in FIG. 11, the magnet element 111 can be arranged on the upstream side of the filter 105. In this case, a magnetic field can be applied to the aqueous cleaning liquid flowing in the pipe 95 upstream of the filter 105, and the water molecule cluster is subdivided and passes through the filter 105. And the removal efficiency of foreign substances can be increased.
[0061]
Note that the electromagnetic valve 106 malfunctions when the magnet is close to it, so it is desirable to avoid the vicinity of the electromagnetic valve 106 as the arrangement position of the magnet element 111.
[0062]
The shape of the magnet element is not limited to the triangular element as in the above-described magnet element 111. For example, a magnet element 111 'combining two semicircular shapes (arc shapes) as shown in FIG. Various forms can be adopted.
[0063]
In the above example, the magnetic field generating mechanism 110 has the magnet element 111 made of a permanent magnet. However, as shown in FIG. 13, a magnet element 112 made of an electromagnet may be used. The electromagnetic element 112 is configured by winding a coil 114 around a core 113 that is a magnetic member, and magnetizes the core 113 by passing a direct current from the power source 115 to the coil 114. The core 113 is provided so as to straddle the pipe 95, and has a pair of end portions 113a and 113b serving as magnetic poles and a connecting portion 113c that connects these end portions 113a and 113b, and the coil 114 is wound around the connecting portion 113c. Has been. When power is supplied from the power source 115, a current flows through the coil 114, and a magnetic field corresponding to the power supplied by magnetizing the core 113 is generated. The magnet element 112 made of this electromagnet is controlled by a controller 116. The controller 116 may control to energize the coil 114 in synchronism with the movement signal of the nozzle arm 98, or to energize the coil in synchronism with the discharge signal of the valve. You may control.
[0064]
Further, the controller 116 can control the voltage of the power source 115. Thereby, the magnetic field intensity acting on the aqueous cleaning liquid flowing through the pipe 95 can be controlled to a desired value. For example, as shown in FIG. 14, the controller 116 receives a signal from a flow rate adjustment valve 117 provided in the pipe 95, and controls the power source 115 based on the signal to control the magnetic field strength of the magnet element 112. Can be. That is, since the signal from the flow rate adjusting valve 117 corresponds to the flow rate of the aqueous cleaning liquid flowing through the pipe 95, the magnetic field intensity of the magnet element 112 made of an electromagnet is controlled according to the flow rate of the aqueous cleaning liquid flowing through the pipe 95. The intensity of the magnetic field applied to the aqueous cleaning liquid can be controlled. Thereby, when the flow rate of the aqueous cleaning liquid is large, the magnetic field strength can be increased, and when the flow rate is small, the magnetic field strength can be decreased and an appropriate magnetic field can be applied according to the flow rate.
[0065]
In addition, when a plurality of magnet elements 112 are provided as shown in FIG. 14 (two in the figure but three or more are the same), the controller 116 controls the flow rate of the aqueous cleaning liquid flowing through the pipe 95. Accordingly, the same effect can be obtained even if part of the plurality of magnet elements 112 is on / off controlled to control the entire magnetic field strength. Further, the current to be supplied may be controlled to periodically switch the NS magnetic pole.
[0066]
Also, from the viewpoint of efficiently applying a magnetic field to the aqueous cleaning liquid flowing through the pipe, as shown in FIG. 15, a part of the pipe 95 is a winding part 95a wound in a coil shape, and the winding part 95a. Is preferably sandwiched between, for example, the magnet element 112 of the magnetic field generation mechanism 110 so that the magnetic field acts. Accordingly, the aqueous cleaning liquid flowing through the winding portion 95a stays for a long time under the influence of the magnetic field, and is more susceptible to the action of the magnetic field. Such a winding portion 95a can be formed by processing a φ1 / 8 inch and φ1 / 2 inch tube made of PFA which is a fluororesin, for example.
[0067]
From the viewpoint of preventing recombination of water molecule clusters, as described above, the magnetic field generation mechanism 110 is preferably provided at a position relatively close to the tip of the nozzle 94 in the development unit (DEV), but is shown in FIG. As described above, by providing the magnetic field generating mechanism 110 in the common pipe 120 that supplies the aqueous cleaning liquid to the five-stage developing unit (DEV), the water molecule clusters can be subdivided collectively. Further, when a plurality of resist coating / development processing systems 1 are installed, as shown in FIG. 17, an aqueous cleaning liquid supply source 121 common to each system is arranged, and an aqueous system is provided to each resist coating / developing processing system 1 therefrom. The magnetic field generation mechanism 110 may be provided in the common pipe 122 that guides the cleaning liquid.
[0068]
Although the example in which the magnet elements of the magnetic field generation mechanism 110 are arranged along the pipe 95 has been described above, the magnet elements may be arranged along the nozzle 94. For example, as shown in FIG. 18A, a magnet element 111 made of a permanent magnet having a triangular recess may be provided along the nozzle 94, or as shown in FIG. A magnet element 111 ′ composed of a permanent magnet combining two circular shapes (arc shapes) may be provided, or an electromagnet 112 may be provided as shown in FIG. In this case, the distance from the tip of the nozzle 94 to the wafer W as the substrate to be processed is set to 20 mm, for example.
[0069]
When a plurality of magnet elements are used, a part of them may be provided along the nozzle 94 and the rest may be provided along the pipe 95.
[0070]
Next, an experiment for confirming the effect of the present invention will be described.
Here, when cleaning the wafer after development, defects after development were compared between the case where a magnetic element made of a permanent magnet was provided as a magnetic field generating mechanism at the position shown in FIG. Pure water was used as the cleaning liquid, and the pure water piping made of PFA having an outer diameter of 6.35 mm and an inner diameter of 4.35 mm was used. A bare wafer was used as the wafer. As the permanent magnet, a neodymium magnet having a shape of FIG. The cleaning time was 15 seconds for all. Defects after development were grasped by an inspection apparatus manufactured by KLA and determined by the number. As a result, when the permanent magnet as the magnetic field generating mechanism was not used, the number of defects was about 30000, whereas when the permanent magnet was used, it was about 9000, and the number of defects after development was reduced. It was confirmed that it can be reduced by 70%.
[0071]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, cleaning after development has been described as an example. However, the present invention is not limited to this, and can be applied to other substrate cleaning such as cleaning before resist coating. In the above embodiment, the case where a semiconductor wafer is used as the substrate to be processed has been described. However, the present invention is not limited to the semiconductor wafer, but may be another substrate to be processed such as an FPD (flat panel display) substrate or a mask reticle substrate. May be.
[0072]
【The invention's effect】
  As described above, according to the present invention, in cleaning the substrate to be processed by supplying the aqueous cleaning liquid from the nozzle to the substrate to be processed through the pipe,Of the nozzle from the tip of the nozzle up to 3 m and / orAlternatively, a magnetic field is applied to the aqueous cleaning liquid flowing through the nozzle, and the water molecule clusters are subdivided by the magnetic field, so that the aqueous cleaning liquid is activated and the surface tension is reduced, and the fine unevenness of the substrate to be processed is also reduced by the aqueous system. The cleaning liquid can enter, and the cleaning effect and cleaning efficiency can be dramatically increased. In particular, although the resist residue is likely to remain on the fine irregularities on the substrate to be processed after development, since the water molecule clusters thus subdivided easily enter the fine irregularities and are washed, the resist residues are extremely effective and It can be removed efficiently, and defects after development can be reduced. Further, since the cleaning effect and the cleaning efficiency are high as described above, the cleaning time can be shortened and the amount of the cleaning liquid used can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a resist coating / development processing system including a development processing unit for carrying out an embodiment of the present invention.
FIG. 2 is a front view of the resist coating and developing system shown in FIG.
3 is a rear view of the resist coating and developing treatment system shown in FIG. 1. FIG.
4 is a perspective view showing a schematic structure of a main wafer transfer device provided in the resist coating and developing treatment system of FIG. 1. FIG.
FIG. 5 is a cross-sectional view showing an overall configuration of a developing unit installed in the coating and developing treatment system shown in FIG. 1;
6 is a plan view of the developing unit shown in FIG.
7 is a schematic diagram showing a configuration when performing cleaning after development in the development unit of FIG. 5;
8 is a schematic view showing an example of a magnetic element of a magnetic field generation mechanism used in the configuration of FIG.
FIG. 9 is a schematic view showing another example of a magnetic element of a magnetic field generation mechanism.
FIG. 10 is a schematic view showing still another example of a magnet element of a magnetic field generation mechanism.
FIG. 11 is a diagram showing another example of the arrangement position of the magnetic field generation mechanism.
FIG. 12 is a schematic view showing still another example of the magnet element of the magnet generating mechanism.
FIG. 13 is a schematic view showing an example in which an electromagnet is used as a magnetic element of a magnetic field generation mechanism.
FIG. 14 is a schematic diagram showing a configuration of a mechanism that uses an electromagnet as a magnet element of the magnet generation mechanism and controls the magnetic field intensity according to the flow rate of the aqueous cleaning liquid.
FIG. 15 is a view showing another example of piping through which an aqueous cleaning liquid flows.
FIG. 16 is a diagram showing still another example of the arrangement position of the magnetic field generation mechanism.
FIG. 17 is a diagram showing still another example of the arrangement position of the magnetic field generation mechanism.
FIG. 18 is a perspective view showing an example in which the magnet elements of the magnet generating mechanism are arranged along the nozzle.
[Explanation of symbols]
72 …… Spin chuck
94 …… Water-based cleaning liquid supply nozzle
95 …… Piping
95a ...... winding part
96 …… Water-based cleaning liquid supply source
110 …… Magnetic field generation mechanism
111, 111 ′ …… Magnet element composed of permanent magnets
112 …… Magnet element made of electromagnet
113 …… Core
114 …… Coil
115 …… Power supply
116 …… Controller (control mechanism)
117 …… Flow adjustment valve
DEV …… Development processing unit
W …… Semiconductor wafer

Claims (14)

A substrate cleaning method for cleaning a substrate to be processed by supplying a water-based cleaning liquid from a nozzle to the substrate to be processed, wherein a portion of the piping from the tip of the nozzle to 3 m and / or the nozzle is passed. A substrate cleaning method, wherein a magnetic field is applied to a flowing aqueous cleaning liquid, and the aqueous cleaning liquid is supplied to a substrate to be processed. A substrate that exposes a resist film formed on a substrate to be processed to a predetermined pattern, develops the exposure pattern, and then supplies the aqueous cleaning liquid to the substrate to be processed from a nozzle through a pipe to clean the substrate to be processed after development. A cleaning method, wherein a magnetic field is applied to a portion of the pipe up to 3 m from the tip of the nozzle and / or an aqueous cleaning liquid flowing through the nozzle, and the aqueous cleaning liquid is supplied to a substrate to be processed after development. And a substrate cleaning method. The substrate cleaning method according to claim 1 or claim 2, characterized in that the action of the magnetic field of more than 0.08T in Tsuryu site before Kisui based cleaning fluid. The flow rate of the water-based cleaning solution, wherein one of the pipe, according to claim 1, characterized in that controlling the magnetic field intensity acting on the aqueous cleaning liquid in the partial and / or in the nozzle from the tip of the nozzle to 3m Item 4. The substrate cleaning method according to any one of Items 3 to 3. A support member for supporting the substrate to be processed;
A nozzle for supplying an aqueous cleaning liquid to the substrate to be processed;
A pipe made of a non-magnetic material connected to the nozzle;
An aqueous cleaning liquid supply source connected to the pipe;
The pipe is provided in a portion up to 3 m from the tip of the nozzle and / or in the vicinity of the nozzle, and flows in the portion of the pipe from the tip of the nozzle to 3 m and / or in the nozzle. A substrate cleaning apparatus, comprising: a magnetic field generating means for applying a magnetic field to the aqueous cleaning liquid. The magnetic field generating means, the substrate cleaning apparatus according to claim 5, characterized in that the action of the magnetic field of more than 0.08T in Tsuryu site before Kisui based cleaning fluid. The said magnetic field generation | occurrence | production means has a magnetic element provided along the part and / or 3 m from the front-end | tip of the said nozzle among the said piping. Substrate cleaning device. The substrate cleaning apparatus according to claim 7, wherein the magnet element is multiple array. 8. The substrate cleaning apparatus according to claim 7, wherein the magnet element is provided so as to be opposed to a portion of the pipe from a tip of the nozzle up to 3 m and / or the nozzle .   The magnetic field generating means comprises a magnet element made of an electromagnet, a power source for supplying power to the magnet element, and a control mechanism for controlling the magnetic field strength of the magnet element. A substrate cleaning apparatus according to claim 1. The magnet element made of the electromagnet includes a part of the pipe extending from the tip of the nozzle to 3 m and / or straddling the nozzle, and a pair of end portions serving as magnetic poles and a connecting portion connecting these end portions. The substrate cleaning apparatus according to claim 10 , further comprising: a core having a coil wound around a connecting portion of the core. The control mechanism according to the flow rate of the aqueous cleaning solution, the substrate cleaning apparatus according to claim 10 or claim 11, characterized in that controlling the magnetic field strength of the magnet element made of the electromagnet. The magnetic field generating means has a plurality of magnet device consisting of the electromagnet, the control mechanism, depending on the flow rate of the aqueous cleaning liquid, characterized by on-off control portions of said plurality of magnet device The substrate cleaning apparatus according to claim 10 or 11 . The substrate cleaning apparatus according to any one of claims 5 to 13 , wherein a portion to which a magnetic field is applied to the aqueous cleaning liquid has a coil shape.

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