Patent Description:
In the manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device, various types of wet processing using liquids are performed on a substrate, and thereafter drying treatment for removing the liquids adhered to the substrate in the wet processing is performed on the substrate.

As the wet processing, washing treatment which removes contaminants on the surface of the substrate can be considered. For example, on the surface of a substrate in which a fine pattern having recesses and projections is formed after a dry etching step, a reaction byproduct (etching residue) is present. In addition to the etching residue, a metal impurity, an organic contaminant and the like may be adhered to the surface of the substrate, and in order to remove these substances, washing treatment of for example, supplying a washing liquid to the substrate is performed.

After the washing treatment, rinsing treatment to remove the washing liquid using a rinse liquid and drying treatment to dry the rinse liquid are performed. Such rinsing treatment includes, as an example, rinsing to supply a rinse liquid such as deionized water (DIW) to the substrate surface to which the washing liquid is adhered, so as to remove the washing liquid from the substrate surface. Thereafter, the drying treatment is performed to remove the rinse liquid so as to dry the substrate.

In recent years, as a finer pattern has been formed on a substrate, the aspect ratio of a projection in a pattern having recesses and projections (the ratio between the height and the width of the projection in the pattern) has been increased. Hence, there is a problem of a so-called pattern collapse in which, at the time of drying treatment, surface tension that acts on a boundary surface between a liquid such as a washing liquid or a rinse liquid in recesses in the pattern and a gas in contact with the liquid pulls and collapses the adjacent projections in the pattern.

As a drying technology for preventing such a collapse of the pattern caused by surface tension, for example, <CIT> discloses a method wherein a solution is brought into contact with a substrate where a structure (pattern) is formed so as to change the solution into a solid form, the solid is then used as a support member for the pattern and the support member is removed by being changed from a solid phase to a gas phase without an intermediate phase of liquid. This patent literature also discloses that, at least any of a methacrylic resin material, a styrene resin material and a fluorocarbon material is used for the support member.

<CIT> and <CIT> disclose drying technologies in which the solution of a sublimable substance is supplied onto a substrate, in which a solvent in the solution is dried so that the substrate surface is filled with the sublimable substance in a solid phase and thus the sublimable substance is sublimed. According to these patent literatures, it is assumed that, since surface tension does not apply to the boundary surface between the solid and a gas in contact with the solid, it is possible to reduce the collapse of a pattern caused by surface tension.

<CIT> discloses a drying technology in which the melt of tertiary butanol (t-butanol) is supplied to a substrate to which a liquid is adhered, t-butanol is then solidified on the substrate so as to form a solidified body, and t-butanol is thereafter removed by sublimation.

In the drying technologies disclosed in the patent literatures described above, as compared with previous drying technologies, pattern collapse reduction can be expected to be more effective. However, in the case of a pattern which is finer and has a higher aspect ratio (in which, that is, the height of a projection in the pattern is greater than the width of the projection itself), even when the drying technologies disclosed in these patent literatures are used, the collapse of the pattern still occurs. Among a variety of causes for the occurrence of the collapse of the pattern, a force which applies between the sublimable substance and the surface of the pattern can be considered as an example.

Specifically, in a freeze drying (or sublimation drying) method utilizing sublimation, in a dry process on the surface of the substrate, the sublimable substance is changed from a solid state to a gas state without an intermediate phase of liquid. Then, on an interface between the pattern surface and the sublimable substance, forces such as an ionic bond, a hydrogen bond and a van der Waals' force act. Hence, in the sublimation drying, an uneven phase change (the solidification or the sublimation of the sublimable substance) occurs in the sublimable substance, and thus stress is applied to the pattern, with the result of the collapse of the pattern. These forces significantly depend on the physical properties of the sublimable substance. Hence, in order to reduce the occurrence of the collapse of a fine pattern caused by sublimation drying, it is necessary to select a sublimable substance suitable for the fine pattern.

<NPL>) disclose that on a substrate on which a fine pattern having recesses and projections is formed, a substrate treating liquid consisted of cyclohexane is supplied, that then the substrate treating liquid is solidified at - <NUM> and that the solidified substrate treating liquid is thereafter sublimed.

However, this prior art literature discloses that when cyclohexane is used as the substrate treating liquid, the collapse of a pattern cannot sufficiently be reduced.

The article "<NPL>, refers to molecular crystals, and specifically plastic crystals.

<CIT> discloses an apparatus for freeze drying a substrate. A chamber for receiving a substrate is provided. An electrostatic chuck for supporting and electrostatically clamping the substrate is within the chamber. A temperature controller controls the temperature of the electrostatic chuck. A condenser is connected to the chamber. A vacuum pump is in fluid connection with the chamber.

<CIT> discloses a substrate drier that can reduce process gas consumed to remove a solid and energy consumption in a process where only a solvent in a liquid on a substrate is dried and thus a solid is precipitated on the substrate before the solid is removed, when the substrate whose surface is formed by an irregularity pattern is dried by removing a liquid thereon.

The present invention is made in view of the foregoing problem, and has an object to provide a substrate treating apparatus and a substrate treating method which can remove a liquid adhered to the surface of a substrate while preventing the collapse of a pattern formed on the surface of the substrate.

In order to solve the above-mentioned problems, the substrate treating method according to the present invention is a substrate treating method of performing drying treatment on a pattern-formed surface of a substrate according to claim <NUM>.

In the configuration described above, at least the plastic crystalline material in the molten state is contained in the substrate treating liquid, and thus the substrate processing can be performed with a method different from the conventional freeze drying (or sublimation drying) using a sublimable substance. Specifically, in the conventional substrate treating method, for example, when a liquid is present on the pattern-formed surface of the substrate, the substrate treating liquid containing the sublimable substance is supplied to the pattern-formed surface, thereafter at least the sublimable substance is solidified into a solid state so as to form a solidified body and the solidified body is further sublimed, with the result that the liquid is removed. However, when the substrate treating liquid is solidified so as to form the solidified body, if an organic substance or the like serving as impurity is present in the substrate treating liquid containing the sublimable substance, the organic substance can serve as a crystal nucleus when the organic substance solidifies the substrate treating liquid containing the sublimable substance. In this way, the individual impurities serve as crystal nuclei such that crystal grains are grown, then the grown crystal grains collide with each other and thus crystal grain boundaries are generated in boundaries. By the generation of the crystal grain boundaries, stress is applied to the pattern, and thus the collapse of the pattern occurs.

By contrast, in the substrate treating method configured as described above, as the substrate treating liquid, the liquid is first used which contains the plastic crystalline material in the molten state. Moreover, instead of a conventional solidifying step, the plastic crystalline layer forming step is performed, bringing the plastic crystalline material into a state of the plastic crystal so as to form the plastic crystalline layer. Furthermore, the plastic crystalline material in the state of the plastic crystal is changed into the gas state without an intermediate phase of liquid so as to remove the plastic crystalline layer (removing step). Here, the state of the plastic crystal is an intermediate state between the liquid state and the solid state, which has fluidity. Hence, the plastic crystalline layer described above is formed on the pattern-formed surface, and thus it is possible to reduce the generation and growth of crystal grain boundaries. Consequently, in the configuration described above, the applying a stress caused by the generation and growth of crystal grain boundaries on the pattern is reduced, and thus it is possible to reduce the occurrence of the collapse of even a pattern which is finer and has a higher aspect ratio.

In the configuration described above, as compared with the case of the solidified body in which the substrate treating liquid containing the conventional sublimable substance is solidified, it is possible to reduce the stress exerted on the pattern. Consequently, it is possible to further reduce the occurrence of the collapse of the pattern.

In the plastic crystalline layer forming step, under atmospheric pressure, the substrate treating liquid is cooled in a temperature range which is equal to or higher than a temperature <NUM> lower than a freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material.

The substrate treating liquid containing the plastic crystalline material in the molten state is cooled in the temperature range described above, and thus the plastic crystalline material is brought into the state of the plastic crystal, so that it is possible to form, on the pattern-formed surface, the plastic crystalline layer having fluidity.

In the configuration described above, in at least any one of the plastic crystalline layer forming step and the removing step, a coolant may be supplied toward a back surface on the side opposite to the pattern-formed surface of the substrate at the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material.

In the configuration described above, in the plastic crystalline layer forming step, the coolant at the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material is supplied toward the back surface on the side opposite to the pattern-formed surface, and thus it is possible to form the plastic crystalline layer on the pattern-formed surface. In the removing step, the coolant is supplied to the back surface, and thus it is possible to change the plastic crystalline layer into the gas state while preventing the plastic crystalline layer from being brought into the liquid state.

In the configuration described above, in at least any one of the plastic crystalline layer forming step and the removing step, a gas inert to at least the plastic crystalline material may be supplied toward the pattern-formed surface at a temperature which is equal to or higher than a temperature <NUM> lower than a freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material.

In the configuration described above, in the plastic crystalline layer forming step, the inert gas at the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material is supplied toward the pattern-formed surface, and thus it is possible to cool the plastic crystalline material so as to bring it into the state of the plastic crystal. In the removing step, the inert gas is also supplied to the plastic crystalline layer formed on the pattern-formed surface, and thus it is possible to change the plastic crystalline layer into the gas state without an intermediate phase of liquid. Since the inert gas is inert to the plastic crystalline material, the plastic crystalline material is prevented from being denatured.

In the configuration described above, in the removing step, a gas inert to at least the plastic crystalline material may be supplied toward the pattern-formed surface at a temperature which is equal to or higher than a temperature <NUM> lower than a freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material, and a coolant may be supplied toward a back surface on a side opposite to the pattern-formed surface of the substrate at the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material.

In the configuration described above, the inert gas is supplied to the plastic crystalline layer formed on the pattern-formed surface at the temperature which is equal to or higher than the temperature <NUM> C lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material, and thus it is possible to change the plastic crystalline layer into the gas state without an intermediate phase of liquid. The coolant is supplied to the back surface on the side opposite to the pattern-formed surface at the temperature which is equal to or lower than the freezing point of the plastic crystalline material, and thus it is possible to change the plastic crystalline layer into the gas state while preventing the plastic crystalline layer from being brought into the liquid state. Since the inert gas is inert to the sublimable substance and the solvent, the sublimable substance and the solvent are prevented from being denatured.

In the configuration described above, in at least any one of the plastic crystalline layer forming step and the removing step, the pattern-formed surface to which the substrate treating liquid is supplied or the pattern-formed surface on which the plastic crystalline layer is formed may be reduced in pressure to an environment that is lower than atmospheric pressure.

In the configuration described above, in the plastic crystalline layer forming step, the pattern-formed surface to which the substrate treating liquid is supplied is reduced in pressure to the environment that is lower than atmospheric pressure, and thus it is possible to bring the plastic crystalline material into the state of the plastic crystal so as to form the plastic crystalline layer. In the removing step, the pattern-formed surface on which the plastic crystalline layer is formed is likewise reduced in pressure to the environment that is lower than atmospheric pressure, and thus it is possible to change the plastic crystalline layer into the gas state without an intermediate phase of liquid so as to remove the plastic crystalline layer.

In this configuration, it is preferred that the plastic crystalline material is cyclohexane.

In order to solve the above-mentioned problems, the substrate treating liquid according to the present invention, which is used in processing of a substrate with a pattern-formed surface, wherein the substrate treating liquid contains a plastic crystalline material in a molten state, and the substrate treating liquid is used in a state of a plastic crystal without being solidified under a condition of a temperature which is equal to or higher than a temperature <NUM> lower than a freezing point of the plastic crystalline material and is equal to or lower than the freezing point.

In the configuration described above, at least the plastic crystalline material in the molten state is contained in the substrate treating liquid, and thus the substrate processing can be performed with a method different from the conventional freeze drying (or sublimation drying) using a sublimable substance. Specifically, the plastic crystalline material is contained in the substrate treating liquid, and is used under a condition of the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point, and thus the substrate processing can be performed, without the substrate treating liquid being solidified, with the substrate treating liquid in the state of the plastic crystal. Here, the state of the plastic crystal is an intermediate state between the liquid state and the solid state so as to have fluidity. Hence, the plastic crystalline material is brought into the state of the plastic crystal instead of the solid state, and thus it is possible to reduce crystal grain boundaries generated when the conventional sublimable substance is used so as to perform the solidification and the growth thereof. Consequently, in the configuration described above, stress caused by the generation and growth of crystal grain boundaries is prevented from being applied to the pattern, and thus it is possible to prevent the collapse of even a pattern which is fine and has a high aspect ratio. In the configuration described above, it is possible to remove the stress itself exerted on the pattern by the solidification of the substrate treating liquid, and thus it is possible to further reduce the occurrence of the collapse of the pattern.

In order to solve the above-mentioned problems, the substrate treating apparatus according to the present invention defined in claim <NUM> is a substrate treating apparatus that is used in the substrate treating method.

In the configuration described above, at least the plastic crystalline material in the molten state is contained in the substrate treating liquid, and thus it is possible to provide a substrate treating apparatus which can perform the substrate processing with a method different from the conventional freeze drying (or sublimation drying) using a sublimable substance. Specifically, in the conventional substrate treating apparatus, for example, when a liquid is present on the pattern-formed surface of the substrate, the substrate treating liquid containing the sublimable substance is supplied with a supplying unit to the pattern-formed surface, thereafter at least the sublimable substance is solidified with a solidifying unit into a solid state so as to form a solidified body and the solidified body is further sublimed with a subliming unit, with the result that the liquid is removed. However, when the substrate treating liquid is solidified so as to form the solidified body, if an organic substance the like serving as impurity is present in the substrate treating liquid containing the sublimable substance, the organic substance can serve as a crystal nucleus when the organic substance solidifies the substrate treating liquid containing the sublimable substance. In this way, the individual impurities serve as crystal nuclei such that crystal grains are grown, then the grown crystal grains collide with each other and thus crystal grain boundaries are generated in boundaries. By the generation of the crystal grain boundaries, stress is applied to the pattern, and thus the collapse of the pattern occurs.

By contrast, in the substrate treating apparatus configured as described above, as the substrate treating liquid, the liquid is first used which contains the plastic crystalline material in the molten state. Moreover, instead of a conventional solidifying unit, the plastic crystalline layer forming unit for bringing the plastic crystalline material into state of the plastic crystal so as to form the plastic crystalline layer is included. Furthermore, a removing unit is included which changes the plastic crystalline material in the state of the plastic crystal into the gas state without an intermediate phase of liquid so as to remove the plastic crystalline layer. Here, the state of the plastic crystal is an intermediate state between the liquid state and the solid state so as to have fluidity. Hence, the plastic crystalline layer described above is formed on the pattern-formed surface, and thus it is possible to reduce the generation and growth of crystal grain boundaries. Consequently, in the configuration described above, the act of stress caused by the generation and growth of crystal grain boundaries on the pattern is reduced, and thus it is possible to reduce the occurrence of the collapse of even a pattern which is fine and has a high aspect ratio.

The present invention has effects which will be described below by the units described above.

Specifically, in the present invention, for example, when a liquid is present on the pattern-formed surface of the substrate, the liquid is replaced by the substrate treating liquid containing the plastic crystalline material, thereafter the plastic crystalline material is brought into the state of the plastic crystal so as to form the plastic crystalline layer and then the plastic crystalline layer is changed into the gas state without an intermediate phase of liquid. Hence, it is possible to reduce the collapse of the pattern caused by the generation of crystal grain boundaries. Since the plastic crystalline layer in which the plastic crystalline material is brought into the state of the plastic crystal has fluidity, as compared with the case where the sublimable substance is formed into the solidified body, it is possible to reduce the application of stress to the pattern. Consequently, in the present invention, it is possible to provide the substrate treating method, the substrate treating liquid and the substrate treating apparatus which can further reduce the collapse of the pattern with a method different from the conventional freeze drying (or sublimation drying) using a sublimable substance.

A first embodiment of the present invention will be described below.

A substrate treating apparatus according to the present embodiment can be used, for example, for processing on various types of substrates. The "substrates" described above refer to various types of substrates such as a semiconductor substrate, a substrate for a photomask glass, a substrate for a liquid crystal display glass, a substrate for a plasma display glass, a FED (Field Emission Display) substrate, a substrate for an optical disc, a substrate for a magnetic disc and a substrate for a magneto-optical disc. In the present embodiment, a description will be given using, as an example, a case where the substrate treating apparatus <NUM> is used for processing on a semiconductor substrate (hereinafter referred to as a "substrate").

A substrate is considered here, as an example of the substrate, in which a circuit pattern and the like (hereinafter referred to as a "pattern") are formed on only one main surface. Here, a pattern-formed surface (main surface) on which the pattern is formed is referred to as a "front surface", and a main surface on the opposite side on which the pattern is not formed is referred to as a "back surface". The surface of the substrate which is directed downward is referred to as a "lower surface", and the surface of the substrate which is directed upward is referred to as an "upper surface". A description will be given below with the assumption that the upper surface is the front surface. In the present specification, the "pattern-formed surface" means a surface in which a concave-convex pattern is formed in an arbitrary region in the substrate regardless of the surface with a planar shape, a curved shape or a concave-convex shape.

The substrate treating apparatus is a single-wafer type substrate treating apparatus which is used in washing treatment (including rinsing treatment) for removing contaminants such as particles adhered to the substrate and drying treatment after the washing treatment.

The configuration of the substrate treating apparatus according to the present embodiment will first be described with reference to <FIG>.

<FIG> is an illustrative diagram schematically showing the substrate treating apparatus according to the present embodiment. <FIG> is a schematic plan view showing the internal configuration of the substrate treating apparatus. <FIG> is a schematic cross-sectional view schematically showing a substrate holder in the substrate treating apparatus. In individual figures, in order to clarify the relationship of directions shown in the figures, XYZ orthogonal coordinate axes are shown as necessary. In <FIG>, an XY plane indicates a horizontal plane, and a + Z direction indicates a vertically upward direction.

As shown in <FIG>, the substrate treating apparatus <NUM> includes at least a chamber <NUM> which is a container for storing the substrate W, a substrate holder <NUM> which holds the substrate W, a control unit <NUM> which controls the individual portions of the substrate treating apparatus <NUM>, a substrate treating liquid supplying unit (supplying unit) <NUM> which supplies a substrate treating liquid to the front surface Wa of the substrate W, an IPA supplying unit <NUM> which supplies IPA to the front surface Wa of the substrate W, a plastic crystalline layer forming unit (gas unit) <NUM> which supplies preferably a gas to the front surface Wa of the substrate W, a scattering prevention cup <NUM> which collects the IPA, the substrate treating liquid and the like, a revolvingly driving part <NUM> which individually and independently turns and drives arms to be described later, a pressure reducing unit <NUM> which reduces the pressure within the chamber <NUM> and a coolant supplying unit (plastic crystalline layer forming unit, removing unit) <NUM> which supplies a coolant to the back surface Wb of the substrate W. The substrate treating apparatus <NUM> also includes a substrate carrying-in/out unit, a chuck pin opening/closing mechanism and a wet washing unit (all of which are not illustrated). The individual portions of the substrate treating apparatus <NUM> will be described below. Although in <FIG>, only portions used in the drying treatment are shown and a washing nozzle and the like used in the washing treatment are not shown, the substrate treating apparatus <NUM> may include the nozzle and the like.

The substrate holder <NUM> is a unit which holds the substrate W, and, as shown in <FIG>, holds the substrate W in a substantially horizontal posture in a state where the front surface Wa of the substrate is directed upward and rotates the substrate W. The substrate holder <NUM> includes a spin chuck <NUM> in which a spin base <NUM> and a rotation support shaft <NUM> are integrally coupled. The spin base <NUM> is formed substantially in the shape of a circle in plan view, and the hollow rotation support shaft <NUM> which is extended in a substantially vertical direction is fixed to the center portion thereof. The rotation support shaft <NUM> is coupled to the rotation shaft of a chuck rotation mechanism <NUM> which includes a motor. The chuck rotation mechanism <NUM> is stored within a cylindrical casing <NUM>, and the rotation support shaft <NUM> is supported by the casing <NUM> so as to be freely rotated about the rotation shaft in the vertical direction.

The chuck rotation mechanism <NUM> rotates the rotation support shaft <NUM> about the rotation shaft by drive from a chuck drive portion (unillustrated) in the control unit <NUM>. In this way, the spin base <NUM> attached to an upper end portion of the rotation support shaft <NUM> is rotated about the rotation shaft. The control unit <NUM> controls the chuck rotation mechanism <NUM> through the check drive portion, and thereby can adjust the rotation speed of the spin base <NUM>.

In the vicinity of the peripheral portion of the spin base <NUM>, a plurality of chuck pins <NUM> for grasping the peripheral end portion of the substrate W are provided so as to stand. Although the number of chuck pins <NUM> installed is not particularly limited, at least three or more chuck pins <NUM> are preferably provided in order to reliably hold the circular substrate W. In the present embodiment, along the peripheral portion of the spin base <NUM>, three chuck pins <NUM> are arranged at equal intervals (see <FIG>). Each of the chuck pins <NUM> includes a substrate support pin which supports the peripheral portion of the substrate W from below and a substrate hold pin which presses the outer circumferential end surface of the substrate W supported by the substrate support pin so as to hold the substrate W.

Each of the chuck pins <NUM> can be switched between a pressed state where the substrate hold pin presses the outer circumferential end surface of the substrate W and a released state where the substrate hold pin is separated from the outer circumferential end surface of the substrate W, and the switching of the states is performed according to an operation instruction from the control unit <NUM> which controls the entire device. More specifically, when the substrate W is loaded or unloaded with respect to the spin base <NUM>, the individual chuck pins <NUM> are brought into the released state whereas when substrate processing to be described later from the washing treatment to the removal treatment is performed on the substrate W, the individual chuck pins <NUM> are brought into the pressed state. When the chuck pin <NUM> is brought into the pressed state, the chuck pin <NUM> grasps the peripheral portion of the substrate W such that the substrate W is held in a horizontal posture (XY plane) a predetermined distance apart from the spin base <NUM>. In this way, the substrate W is held horizontally in a state where its front surface Wa is directed upward. A method of holding the substrate W is not limited to this method, and for example, the back surface Wb of the substrate W may be held by an adsorption method with a spin chuck or the like.

In a state where the substrate W is held by the spin chuck <NUM>, more specifically, in a state where the peripheral portion of the substrate W is held by the chuck pins <NUM> provided on the spin base <NUM>, the chuck rotation mechanism <NUM> is operated, and thus the substrate W is rotated about the rotation shaft A1 in the vertical direction.

The process liquid supplying unit, supplying unit <NUM> is a unit which supplies the substrate treating liquid to the pattern-formed surface of the substrate W held in the substrate holder <NUM>, and includes, as shown in <FIG>, at least a nozzle <NUM>, an arm <NUM>, a turning shaft <NUM>, a pipe <NUM>, a valve <NUM> and a substrate treating liquid storing part <NUM>.

As shown in <FIG>, the substrate treating liquid storing part <NUM> includes at least a substrate treating liquid storing tank <NUM>, an agitation part <NUM> which agitates the substrate treating liquid within the substrate treating liquid storing tank <NUM>, a pressurization part <NUM> which pressurizes the substrate treating liquid storing tank <NUM> so as to feed out the substrate treating liquid and a temperature adjusting part <NUM> which heats the substrate treating liquid within the substrate treating liquid storing tank <NUM>. <FIG> is a block diagram showing a schematic configuration of the substrate treating liquid storing part <NUM>, and <FIG> is an illustrative diagram showing a specific configuration of the substrate treating liquid storing part <NUM>.

The agitation part <NUM> includes a rotation part <NUM> which agitates the substrate treating liquid within the substrate treating liquid storing tank <NUM> and an agitation control part <NUM> which controls the rotation of the rotation part <NUM>. The agitation control part <NUM> is electrically connected to the control unit <NUM>. The rotation part <NUM> has a propeller-shaped agitation blade at a tip end of the rotation shaft (the lower end of the rotation part <NUM> in <FIG>), the control unit <NUM> provides an operation instruction to the agitation control part <NUM> such that the rotation part <NUM> is rotated, and thus the substrate treating liquid is agitated by the agitation blade, with the result that the concentration and temperature of a plastic crystalline material (details of which will be described later) and the like in the substrate treating liquid are made uniform.

The method of making the concentration and temperature of the substrate treating liquid within the substrate treating liquid storing tank <NUM> uniform is not limited to the method described above, and a known method such as a method of additionally providing a circulation pump to circulate the substrate treating liquid can be used.

The pressurization part <NUM> is formed with a nitrogen gas tank <NUM> which is the supply source of a gas for pressurizing the interior of the substrate treating liquid storing tank <NUM>, a pump <NUM> which pressurizes nitrogen gas and a pipe <NUM>. The nitrogen gas tank <NUM> is connected through the pipe <NUM> with the pipeline to the substrate treating liquid storing tank <NUM>, and the pump <NUM> is interposed in the pipe <NUM>.

The temperature adjusting part <NUM> is electrically connected to the control unit <NUM>, and heats, by the operation instruction of the control unit <NUM>, the substrate treating liquid stored in the substrate treating liquid storing tank <NUM> so as to perform temperature adjustment. The temperature adjustment is preferably performed such that the temperature of the substrate treating liquid is equal to or above the melting point of the plastic crystalline material contained in the substrate treating liquid. In this way, when the substrate treating liquid contains the plastic crystalline material in a molten state, it is possible to maintain the molten state of the plastic crystalline material. The upper limit of the temperature adjustment is preferably a temperature which is lower than the boiling point. The temperature adjusting part <NUM> is not particularly limited, and for example, a known temperature adjustment mechanism can be used such as a resistance heater, a Peltier element or a pipe through which water whose temperature is adjusted is passed. In the present embodiment, the configuration of the temperature adjusting part <NUM> is arbitrary. For example, when the substrate treating liquid contains the plastic crystalline material in the molten state, and an environment in which the substrate treating apparatus <NUM> is installed is an environment whose temperature is higher than the melting point of the plastic crystalline material, since it is possible to maintain the molten state of the plastic crystalline material, it is not necessary to heat the substrate treating liquid. Consequently, the temperature adjusting part <NUM> can be omitted.

The substrate treating liquid storing part <NUM> (more specifically, the substrate treating liquid storing tank <NUM>) is connected through the pipe <NUM> with the pipeline to the nozzle <NUM>, and the valve <NUM> is interposed partway through the path of the pipe <NUM>.

An air pressure sensor (unillustrated) is provided within the substrate treating liquid storing tank <NUM>, and is electrically connected to the control unit <NUM>. The control unit <NUM> controls, based on a value detected by the air pressure sensor, the operation of the pump <NUM> so as to keep the air pressure within the substrate treating liquid storing tank <NUM> at a predetermined air pressure higher than atmospheric pressure. On the other hand, the valve <NUM> is also electrically connected to the control unit <NUM>, and is normally closed. The opening and closing of the valve <NUM> is also controlled by the operation instruction of the control unit <NUM>. When the control unit <NUM> provides the operation instruction to the substrate treating liquid supplying unit <NUM> so as to open the valve <NUM>, the substrate treating liquid is fed by pressure from the interior of the substrate treating liquid storing tank <NUM> which is pressurized, and is discharged through the pipe <NUM> from the nozzle <NUM>. In this way, it is possible to supply the substrate treating liquid to the front surface Wa of the substrate W. Since the substrate treating liquid storing tank <NUM> uses, as described above, the pressure caused by the nitrogen gas to feed the substrate treating liquid, the substrate treating liquid storing tank <NUM> is preferably configured so as to be airtight.

The nozzle <NUM> is attached to the tip end portion of the arm <NUM> which is provided so as to be extended horizontally, and is arranged above the spin base <NUM>. The back end portion of the arm <NUM> is supported by the turning shaft <NUM> provided so as to be extended in the Z direction such that back end portion of the arm <NUM> is freely rotated about an axis J1, and the turning shaft <NUM> is provided so as to be fixed within the chamber <NUM>. The arm <NUM> is coupled through the turning shaft <NUM> to the revolvingly driving part <NUM>. The revolvingly driving part <NUM> is electrically connected to the control unit <NUM>, and turns the arm <NUM> about the axis J1 by the operation instruction from the control unit <NUM>. As the arm <NUM> is turned, the nozzle <NUM> is also moved.

As indicated by solid lines in <FIG>, the nozzle <NUM> is normally located outside the peripheral portion of the substrate W, and is arranged in a retraction position Pl outside the scattering prevention cup <NUM>. When the arm <NUM> is turned by the operation instruction of the control unit <NUM>, the nozzle <NUM> is moved along the path of an arrow AR1 so as to be arranged in a position above the center portion (the axis A1 or the vicinity thereof) of the front surface Wa of the substrate W.

As shown in <FIG>, the IPA supplying unit <NUM> is a unit which supplies the IPA (isopropyl alcohol) to the substrate W held in the substrate holder <NUM>, and includes a nozzle <NUM>, an arm <NUM>, a turning shaft <NUM>, a pipe <NUM>, a valve <NUM> and an IPA tank <NUM>.

The IPA tank <NUM> is connected through the pipe <NUM> with the pipeline to the nozzle <NUM>, and the valve <NUM> is interposed partway through the path of the pipe <NUM>. In the IPA tank <NUM>, the IPA is stored, the IPA within the IPA tank <NUM> is pressurized by an unillustrated pressurization unit and thus the IPA is fed from the pipe <NUM> in the direction of the nozzle <NUM>.

The valve <NUM> is electrically connected to the control unit <NUM>, and is normally closed. The opening and closing of the valve <NUM> is controlled by the operation instruction of the control unit <NUM>. When the valve <NUM> is opened by the operation instruction of the control unit <NUM>, the IPA is passed through the pipe <NUM> and is supplied from the nozzle <NUM> to the front surface Wa of the substrate W.

The nozzle <NUM> is attached to the tip end portion of the arm <NUM> which is provided so as to be extended horizontally, and is arranged above the spin base <NUM>. The back end portion of the arm <NUM> is supported by the turning shaft <NUM> provided so as to be extended in the Z direction such that the back end portion of the arm <NUM> is freely rotated about an axis J2, and the turning shaft <NUM> is provided so as to be fixed within the chamber <NUM>. The arm <NUM> is coupled through the turning shaft <NUM> to the revolvingly driving part <NUM>. The revolvingly driving part <NUM> is electrically connected to the control unit <NUM>, and turns the arm <NUM> about the axis J2 by the operation instruction from the control unit <NUM>. As the arm <NUM> is turned, the nozzle <NUM> is also moved.

As indicated by solid lines in <FIG>, the nozzle <NUM> is normally located outside the peripheral portion of the substrate W, and is arranged in a retraction position P2 outside the scattering prevention cup <NUM>. When the arm <NUM> is turned by the operation instruction of the control unit <NUM>, the nozzle <NUM> is moved along the path of an arrow AR2 so as to be arranged in a position above the center portion (the axis Al of the vicinity thereof) of the front surface Wa of the substrate W.

Although in the present embodiment, IPA is used in the IPA supplying unit <NUM>, as long as a liquid is used which is soluble in the plastic crystalline material and deionized water (DIW), in the present invention, there is no limitation to IPA. Examples of a replacement of the IPA in the present embodiment include methanol, ethanol, acetone, benzene, carbon tetrachloride, chloroform, hexane, decalin, tetralin, acetic acid, cyclohexanol, ether and hydrofluoroether.

As shown in <FIG>, the gas supplying unit <NUM> is a unit which supplies a gas to the substrate W held in the substrate holder <NUM>, and includes a nozzle <NUM>, an arm <NUM>, a turning shaft <NUM>, a pipe <NUM>, a valve <NUM> and a gas storing part <NUM>.

As shown in <FIG>, the gas storing part <NUM> includes a gas tank <NUM> which stores a gas and a gas temperature adjusting part <NUM> which adjusts the temperature of the gas stored in the gas tank <NUM>. This figure is a block diagram showing a schematic configuration of the gas storing part <NUM>. The gas temperature adjusting part <NUM> is electrically connected to the control unit <NUM>, and heats or cools the gas stored in the gas tank <NUM> by the operation instruction of the control unit <NUM> so as to perform temperature adjustment. The temperature adjustment is preferably performed such that the gas stored in the gas tank <NUM> has a low temperature which is equal to or higher than a temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material. The gas temperature adjusting part <NUM> is not particularly limited, and for example, a known temperature adjustment mechanism can be used such as a Peltier element or a pipe through which water whose temperature is adjusted is passed.

As shown in <FIG>, the gas storing part <NUM> (more specifically, the gas tank <NUM>) is connected through the pipe <NUM> with the pipeline to the nozzle <NUM>, and the valve <NUM> is interposed partway through the path of the pipe <NUM>. The gas within the gas storing part <NUM> is pressurized by an unillustrated pressurization unit so as to be fed to the pipe <NUM>. Since the pressurization unit can be realized by pressurization with a pump or the like or by compressing and storing the gas into the gas storing part <NUM>, any pressurization unit may be used.

The valve <NUM> is electrically connected to the control unit <NUM>, and is normally closed. The opening and closing of the valve <NUM> is controlled by the operation instruction of the control unit <NUM>. When the valve <NUM> is opened by the operation instruction of the control unit <NUM>, the gas is passed through the pipe <NUM> and is supplied from the nozzle <NUM> to the front surface Wa of the substrate W.

The nozzle <NUM> is attached to the tip end portion of the arm <NUM> which is provided so as to be extended horizontally, and is arranged above the spin base <NUM>. The back end portion of the arm <NUM> is supported by the turning shaft <NUM> provided so as to be extended in the Z direction such that the back end portion of the arm <NUM> is freely rotated about an axis J3, and the turning shaft <NUM> is provided so as to be fixed within the chamber <NUM>. The arm <NUM> is coupled through the turning shaft <NUM> to the revolvingly driving part <NUM>. The revolvingly driving part <NUM> is electrically connected to the control unit <NUM>, and turns the arm <NUM> about the axis J3 by the operation instruction from the control unit <NUM>. As the arm <NUM> is turned, the nozzle <NUM> is also moved.

As indicated by solid lines in <FIG>, the nozzle <NUM> is normally located outside the peripheral portion of the substrate W, and is arranged in a retraction position P3 outside the scattering prevention cup <NUM>. When the arm <NUM> is turned by the operation instruction of the control unit <NUM>, the nozzle <NUM> is moved along the path of an arrow AR3 so as to be arranged in a position above the center portion (the axis A1 or the vicinity thereof) of the front surface Wa of the substrate W. How the nozzle <NUM> is arranged in the position above the center portion of the front surface Wa is indicated by dotted lines in <FIG>.

In the gas tank <NUM>, an inert gas which is inert to at least the plastic crystalline material, more specifically, nitrogen gas, is stored. The nitrogen gas stored is adjusted in the gas temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material.

The nitrogen gas used in the present embodiment is preferably a dry gas whose dew point is equal to or lower than the freezing point of the plastic crystalline material. When the nitrogen gas is sprayed to a plastic crystalline layer (details of which will be described later) under an atmospheric pressure environment, the plastic crystalline material in the plastic crystalline layer is changed into a gas state in the nitrogen gas without an intermediate phase of liquid. Since the nitrogen gas is continuously supplied to the plastic crystalline layer, the partial pressure of the plastic crystalline material in the gas state produced in the nitrogen gas is kept lower than the saturated vapor pressure of the plastic crystalline material in the gas state at the temperature of the nitrogen gas, and thus at least the surface of the plastic crystalline layer is filled under an atmosphere in which the plastic crystalline material is present in the gas state at or below the saturated vapor pressure.

Although in the present embodiment, as the gas supplied by the gas supplying unit <NUM>, nitrogen gas is used, as long as the gas is inert to the plastic crystalline material, there is no limitation to the gas in the practice of the present invention. Examples of a replacement of the nitrogen gas in the first embodiment include argon gas, helium gas and air (a mixture gas of <NUM>% of nitrogen and <NUM>% of oxygen). Alternatively, a mixture gas obtained by mixing a plurality of types of gases described above may be used.

As shown in <FIG>, the pressure reducing unit <NUM> is a unit which reduces the interior of the chamber <NUM> in pressure to an environment lower than atmospheric pressure, and includes an exhaust pump <NUM>, a pipe <NUM> and a valve <NUM>. The exhaust pump <NUM> is a known pump which is connected through the pipe <NUM> with the pipeline to the chamber <NUM> and which applies pressure to the gas. The exhaust pump <NUM> is electrically connected to the control unit <NUM>, and is normally in a stop state. The drive of the exhaust pump <NUM> is controlled by the operation instruction of the control unit <NUM>. The valve <NUM> is interposed in the pipe <NUM>. The valve <NUM> is electrically connected to the control unit <NUM>, and is normally closed. The opening and closing of the valve <NUM> is controlled by the operation instruction of the control unit <NUM>.

When the exhaust pump <NUM> is driven by the operation instruction of the control unit <NUM>, and the valve <NUM> is opened, the gas present within the chamber <NUM> is exhausted by the exhaust pump <NUM> through the pipe <NUM> to the outside of the chamber <NUM>.

The scattering prevention cup <NUM> is provided so as to surround the spin base <NUM>. The scattering prevention cup <NUM> is connected to an unillustrated raising/lowering mechanism so as to be able to be raised and lowered in the Z direction. When the substrate treating liquid and the IPA are supplied to the pattern-formed surface of the substrate W, the scattering prevention cup <NUM> is located by the raising/lowering mechanism in a predetermined position as shown in <FIG> so as to surround, from lateral positions, the substrate W held by the chuck pins <NUM>. In this way, it is possible to collect liquids such as the substrate treating liquid and the IPA scattered from the substrate W and the spin base <NUM>.

A coolant supplying unit <NUM> is a unit which supplies the coolant to the back surface Wb of the substrate W and which forms part of the plastic crystalline layer forming unit and the removing unit in the present invention. More specifically, the coolant supplying unit <NUM> includes, as shown in <FIG> and <FIG>, at least a coolant storing part <NUM>, a pipe <NUM>, a valve <NUM> and a coolant supply part <NUM>.

As shown in <FIG>, the coolant storing part <NUM> includes a coolant tank <NUM> which stores the coolant and a coolant temperature adjusting part <NUM> which adjusts the temperature of the coolant stored in the coolant tank <NUM>. <FIG> is a block diagram showing a schematic configuration of the coolant storing part <NUM>.

The coolant temperature adjusting part <NUM> is electrically connected to the control unit <NUM>, and heats or cools the coolant stored in the coolant tank <NUM> by the operation instruction of the control unit <NUM> so as to perform temperature adjustment. The temperature adjustment is preferably performed such that the coolant stored in the coolant tank <NUM> has a low temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material. The coolant temperature adjusting part <NUM> is not particularly limited, and for example, a known temperature adjustment mechanism can be used such as a chiller using a Peltier element or a pipe through which water whose temperature is adjusted is passed.

The coolant storing part <NUM> is connected through the pipe <NUM> to the coolant supply part <NUM>, and the valve <NUM> is interposed partway through the path of the pipe <NUM>. The coolant within the coolant storing part <NUM> is pressurized by an unillustrated pressurization unit so as to be fed to the pipe <NUM>. Since the pressurization unit can be realized by pressurization with a pump or the like or by compressing and storing the gas into the coolant storing part <NUM>, any pressurization unit may be used.

The valve <NUM> is electrically connected to the control unit <NUM>, and is normally closed. The opening and closing of the valve <NUM> is controlled by the operation instruction of the control unit <NUM>. When the valve <NUM> is opened by the operation instruction of the control unit <NUM>, the coolant is passed through the pipe <NUM> and is supplied through the coolant supply part <NUM> to the back surface Wb of the substrate W.

The coolant supply part <NUM> is provided below the substrate W supported by the spin chuck <NUM> in a horizontal posture. As shown in <FIG>, the coolant supply part <NUM> includes at least an opposite member <NUM> whose horizontal upper surface is arranged opposite the back surface Wb of the substrate W, the supply pipe <NUM> which is attached to the center portion of the opposite member <NUM> and which is extended downward in the vertical direction and a discharge portion <NUM> which discharges the coolant in a fluid state toward the back surface Wb of the substrate W.

The opposite member <NUM> has a disc-shaped external form whose area is lower than the substrate W. The opposite member <NUM> is provided so as to be separated only an arbitrary distance apart from the substrate W. The separation distance between the opposite member <NUM> and the substrate W is not particularly limited, and is preferably set as necessary so as to be filled with the coolant.

The supply pipe <NUM> is inserted through the center portion of the hollow rotation support shaft <NUM>. The discharge portion <NUM> is opened, in the supply pipe <NUM>, toward the center portion Cb of the back surface Wb of the substrate W, and discharges the coolant supplied from the coolant storing part <NUM> toward the back surface Wb of the substrate W. The area of the opening of the discharge portion <NUM> is not particularly limited, and can be set as necessary with consideration given to the discharged amount and the like. The supply pipe <NUM> is not connected to the rotation support shaft <NUM>, and thus even when the spin chuck <NUM> is rotated, the discharge portion <NUM> is prevented from being rotated.

As the coolant, a liquid or a gas can be utilized whose temperature is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material. Furthermore, as the liquid, there is no particular limitation, and for example, cold water or the like at a predetermined temperature can be utilized. As the gas, there is no particular limitation, and a gas which is inert to the plastic crystalline material, and more specifically, nitrogen gas or the like at a predetermined temperature can be utilized.

The control unit <NUM> is electrically connected to the individual portions of the substrate treating apparatus <NUM> (see <FIG>), and controls the operations of the individual portions. <FIG> is a schematic view showing the configuration of the control unit <NUM>. As shown in <FIG>, the control unit <NUM> is formed with a computer which includes a computation processing part <NUM> and a memory <NUM>. As the computation processing part <NUM>, a CPU which performs various types of computation processing is used. The memory <NUM> includes a ROM which is a read-only memory for storing basic programs, a RAM which is a readable and writable memory for storing various types of information and a magnetic disc for storing control software, data and the like. In the magnetic disc, substrate processing conditions (recipes) corresponding to the substrate W are previously stored. The CPU reads the substrate processing conditions on the RAM so as to control the individual portions of the substrate treating apparatus <NUM> according to the details thereof.

The process liquid used in the present embodiment will then be described below.

The substrate treating liquid of the present embodiment contains the plastic crystalline material in a molten state, and, in drying treatment for removing the liquid present on the pattern-formed surface of the substrate, functions as a substrate treating liquid for assisting the drying treatment.

Here, in the present specification, the "molten state" means that the plastic crystalline material is molten either completely or partially so as to have fluidity and that thus the plastic crystalline material is in a liquid state. The "plastic crystal" means a substance which is formed with a regularly arranged three-dimensional crystal lattice but in which its molecular orientation is in a liquid state, in which the gravity center position of molecules is in a crystalline state and in which furthermore, an orientational and rotational disorder is present. The "plastic crystalline material" means a material which can from a state of the plastic crystal in a process where the state is changed from a liquid state to a solid state or from a solid state to a liquid state. Hence, in the present specification, the "state of the plastic crystal" means one of intermediate phases between a liquid state and a solid state.

In the present embodiment, the plastic crystalline material may have the properties of the sublimable substance. Here, the "sublimable" means that a single substance, a compound or a mixture has the property of changing its phase from a solid phase to a gas phase or from a gas phase to a solid phase without the intervention of a liquid phase, and the "sublimable substance" means a substance which has the sublimable property described above.

The vapor pressure of the plastic crystalline material is preferably <NUM> KPa to <NUM> MPa at room temperature, and is more preferably <NUM> KPa to <NUM> MPa. In the present specification, the "room temperature" means a temperature range of <NUM> to <NUM>.

The freezing point of the plastic crystalline material is preferably <NUM> to <NUM> at room temperature, and is more preferably <NUM> to <NUM>. When the freezing point of the plastic crystalline material is equal to or higher than <NUM>, the plastic crystalline material can be solidified by cold water, and thus it is possible to reduce the cost of the cooling function. On the other hand, when the freezing point of the plastic crystalline material is equal to or lower than <NUM>, the plastic crystalline material can be liquefied by hot water, and thus it is possible to reduce the cost of the temperature raising mechanism.

Although as the plastic crystalline material contained in the substrate treating liquid, the plastic crystalline material in a molten state is contained therein, the substrate treating liquid is consisted of only the plastic crystalline material in a molten state.

The plastic crystalline material is not particularly limited, and for example, cyclohexane and the like can be utilized.

When the plastic crystalline material and a solvent are mixed, the solvent is preferably compatible with the plastic crystalline material. Specifically, as an example of the solvent, at least one sort can be utilized which is selected from a group consisting of pure water, DIW, aliphatic hydrocarbon, aromatic hydrocarbon, ester, alcohol and ether. More specifically, at least one sort can be utilized which is selected from a group consisting of pure water, DIW, methanol, ethanol, IPA, butanol, ethylene glycol, propylene glycol, NMP, DMF, DMA, DMSO, hexane, toluene, PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), POPE (propylene glycol monopropyl ether), PGEE (propylene glycol monoethyl ether), GBL, acetyl acetone, <NUM>-pentanone, <NUM>-heptanone, ethyl lactate, cyclohexanone, dibutyl ether, HFE (hydrofluoroether), ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether and m-xylene hexafluoride.

The content of the plastic crystalline material in the substrate treating liquid is not particularly limited, and can be set as necessary.

A substrate treating method using the substrate treating apparatus <NUM> of the present embodiment will then be described below with reference to <FIG> and <FIG>. <FIG> is a flowchart showing the operation of the substrate treating apparatus <NUM> according to the first embodiment. <FIG> is a schematic view showing the state of the substrate W in individual steps of <FIG>. On the substrate W, a concave/convex pattern Wp is formed in the preceding step. The pattern Wp includes projections Wp1 and recesses Wp2. In the present embodiment, the height of the projection Wp1 falls within a range of <NUM> to <NUM>, and the width thereof falls within a range of <NUM> to <NUM>. The shortest distance between two adjacent projections Wp1 (the shortest width of the recesses Wp2) falls within a range of <NUM> to <NUM>. The aspect ratio of the projection Wp1, that is, a value (height/width) obtained by dividing the height by the width falls within a range of <NUM> to <NUM>.

The individual steps shown in (a) to (e) shown in <FIG> are processed under the atmospheric pressure environment unless otherwise explicitly indicated. Here, the atmospheric pressure environment refers to an environment under a pressure equal to or higher than <NUM> atmospheres and equal to or lower than <NUM> atmospheres with the standard atmospheric pressure (<NUM> atmosphere, <NUM> hPa) in the center. In particular, when the substrate treating apparatus <NUM> is arranged within a clean room under a positive pressure, the environment of the front surface Wa of the substrate W is higher than <NUM> atmosphere.

An operator first provides an instruction to perform a substrate processing program <NUM> corresponding to a predetermined substrate W. Thereafter, as a preparation for loading the substrate W into the substrate treating apparatus <NUM>, the operation instruction is provided by the control unit <NUM> so as to perform the following operation. Specifically, the rotation of the chuck rotation mechanism <NUM> is stopped, and the chuck pins <NUM> are located in positions suitable for receiving and delivering the substrate W. The valves <NUM>, <NUM>, <NUM> and <NUM> are closed, and the nozzles <NUM>, <NUM> and <NUM> are respectively located in the retraction positions P1, P2 and P3. Then, the chuck pins <NUM> are brought into an opened state by an unillustrated opening/closing mechanism.

When the unprocessed substrate W is loaded into the substrate treating apparatus <NUM> by an unillustrated substrate loading/unloading mechanism and is placed on the chuck pins <NUM>, the chuck pins <NUM> are brought into a closed state by the unillustrated opening/closing mechanism.

After the unprocessed substrate W is held by the substrate holder <NUM>, a washing step S11 is performed on the substrate by an unillustrated wet washing unit. The washing step S11 includes rinsing treatment for supplying a washing liquid to the front surface Wa of the substrate W so as to perform washing and then removing the washing liquid. The supply of the washing liquid (in the case of the rinsing treatment, a rinse liquid) is performed, by the operation instruction to the chuck rotation mechanism <NUM> provided by the control unit <NUM>, on the front surface Wf of the substrate W which is rotated about the rotation shaft A1 at a constant speed. The washing liquid is not particularly limited, and for example, a liquid containing ammonia, a hydrogen peroxide solution and water (designated SC-<NUM>), a liquid containing hydrochloric acid, a hydrogen peroxide solution and water (designated SC-<NUM>) and the like can be utilized. The rinse liquid is not particularly limited, and for example, DIW and the like can be utilized. The amounts of washing liquid and rinse liquid supplied are not particularly limited, and can be set as necessary according to the range which is washed and the like. The washing time is not particularly limited, and can be set as necessary.

In the present embodiment, the wet washing unit is used, thus the SC-<NUM> is supplied to the front surface Wa of the substrate W so as to wash the front surface Wa and thereafter the DIW is further supplied to the front surface Wa so as to remove the SC-<NUM>.

(a) shown <FIG> shows a state of the substrate W when the washing step S11 is completed. As shown in the figure, on the front surface Wa of the substrate W on which the pattern Wp is formed, the DIW (represented by "<NUM>" in the figure) supplied in the washing step S11 is adhered.

An IPA rinsing step S12 of supplying the IPA to the front surface Wa of the substrate W on which the DIW <NUM> is adhered is performed (see <FIG>). The control unit <NUM> first provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis A1 at a constant speed.

Then, the control unit <NUM> provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the center portion of the front surface Wa of the substrate W. Then, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the IPA is supplied from the IPA tank <NUM> through the pipe <NUM> and the nozzle <NUM> to the front surface Wa of the substrate W.

The IPA supplied to the front surface Wa of the substrate W is made to flow from around the center of the front surface Wa of the substrate W toward the peripheral portion of the substrate W by centrifugal force generated by the rotation of the substrate W so as to be diffused over the entire front surface Wa of the substrate W. In this way, the DIW adhered to the front surface Wa of the substrate W is removed by the supply of the IPA, and thus the entire front surface Wa of the substrate W is covered with the IPA. The rotation speed of the substrate W is preferably set such that the thickness of the film formed of the IPA is higher than the height of the projections Wpl on the entire front surface Wa. The amount of IPA supplied is not particularly limited, and can be set as necessary.

After the completion of the IPA rinsing step S12, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is closed. The control unit <NUM> also provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the retraction position P2.

(b) shown in <FIG> shows a state of the substrate W when the IPA rinsing step S12 is completed. As shown in the figure, on the front surface Wa of the substrate W on which the pattern Wp is formed, the IPA (represented by "<NUM>" in the figure) supplied in the IPA rinsing step S12 is adhered, and the DIW <NUM> is replaced by the IPA <NUM> so as to be removed from the front surface Wa of the substrate W.

A substrate treating liquid supplying step (supplying step) S13 of supplying the substrate treating liquid that contains the plastic crystalline material in a molten state to the front surface Wa of the substrate W to which the IPA <NUM> is adhered (see <FIG>). Specifically, the control unit <NUM> provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis A1 at a constant speed. Here, the rotation speed of the substrate W is preferably set such that the thickness of the liquid film formed of the substrate treating liquid is higher than the height of the projections Wp1 on the entire front surface Wa.

Then, the control unit <NUM> provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the center portion of the front surface Wa of the substrate W. The control unit <NUM> then provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the substrate treating liquid is supplied from the substrate treating liquid storing tank <NUM> through the pipe <NUM> and the nozzle <NUM> to the front surface Wa of the substrate W. The substrate treating liquid supplied to the front surface Wa of the substrate W is made to flow from around the center of the front surface Wa of the substrate W toward the peripheral portion of the substrate W by centrifugal force generated by the rotation of the substrate W so as to be diffused over the entire front surface Wa of the substrate W. In this way, the IPA adhered to the front surface Wa of the substrate W is removed by the supply of the substrate treating liquid such that the entire front surface Wa of the substrate W is covered with the substrate treating liquid (see (c) shown in <FIG>).

The temperature of the supplied substrate treating liquid is set within a range equal to or above the melting point of the plastic crystalline material and below the boiling point thereof at least after the substrate treating liquid is supplied to the front surface Wa of the substrate W. For example, when, cyclohexane (having a melting point of <NUM> to <NUM> and a boiling point of <NUM>) described above is used as the plastic crystalline material, the temperature is preferably set within a range equal to or higher than <NUM> and lower than <NUM>. In this way, it is possible to form, on the front surface Wa of the substrate W, the liquid film made of the substrate treating liquid <NUM>. The amount of substrate treating liquid supplied is not particularly limited, and can be set as necessary.

For example, when the temperature of the substrate W and the temperature of an atmosphere within the chamber <NUM> are equal to or lower than the melting point of the plastic crystalline material, the temperature of the substrate treating liquid <NUM> immediately before being supplied in the substrate treating liquid supplying step S13 is preferably adjusted at a temperature sufficiently higher than the melting point in order to prevent the substrate treating liquid <NUM> from being brought into the state of the plastic crystal or into a solid state on the substrate W after the supply.

When the substrate treating liquid supplying step S13 is completed, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is closed. The control unit <NUM> also provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the retraction position P1.

As shown in <FIG>, a plastic crystalline layer forming step S14 of cooling the substrate treating liquid <NUM> supplied to the front surface Wa of the substrate W so as to form a plastic crystalline layer is then performed. The control unit <NUM> first provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis Al at a constant speed. Here, the rotation speed of the substrate W is set such that the substrate treating liquid <NUM> can form a predetermined film thickness higher than the projections Wp1 on the entire front surface Wa.

Then, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the coolant (for example, cold water at a predetermined temperature) <NUM> stored in the coolant tank <NUM> is discharged through the pipe <NUM> and the supply pipe <NUM> from the discharge portion <NUM> toward the back surface Wb of the substrate W.

The coolant <NUM> supplied toward the back surface Wb of the substrate W is made to flow from around the center of the back surface Wb of the substrate W toward the direction of the peripheral portion of the substrate W by centrifugal force generated by the rotation of the substrate W so as to be diffused over the entire back surface Wb of the substrate W. In this way, the liquid film of the substrate treating liquid <NUM> formed on the front surface Wa of the substrate W is cooled to a low temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material, with the result that a plastic crystalline layer <NUM> is formed (see (d) shown in <FIG>).

(d) shown in <FIG> shows a state of the substrate W when the plastic crystalline layer forming step S14 is completed. As shown in the figure, the substrate treating liquid <NUM> supplied in the substrate treating liquid supplying step S13 is cooled by the supply of the coolant <NUM> to the back surface Wb of the substrate W, and thus the plastic crystalline material is brought into the state of the plastic crystal, with the result that the plastic crystalline layer <NUM> is formed.

Although the plastic crystalline layer <NUM> contains at least the plastic crystalline material present in the state of the plastic crystal such that in the plastic crystalline material in the state of the plastic crystal, intermolecular bonds are mutually weakened, the relative position relationship of individual molecules is not changed, and thus they are easily rotated in the positions thereof. Hence, for example, as compared with a solidified body formed of a conventional sublimable substance, the plastic crystalline layer <NUM> is so soft as to have fluidity. In this way, it is possible to reduce the generation and growth of crystal grain boundaries, and thus it is possible to reduce the act of stress caused by the generation and growth of crystal grain boundaries on a pattern, with the result that it is possible to reduce the occurrence of the collapse of even a pattern which is fine and has a high aspect ratio. As compared with the case of the solidified body, it is possible to reduce the stress exerted on the pattern, and thus it is possible to further reduce the occurrence of the collapse of the pattern. When the plastic crystalline layer <NUM> is formed in a state where a liquid and the like are present on the substrate W and where the substrate treating liquid <NUM> is mixed with the liquid, the plastic crystalline layer <NUM> can contain the liquid and the like.

As shown in <FIG>, a removing step S15 of bringing the plastic crystalline layer <NUM> formed on the front surface Wa of the substrate W into a gas state without an intermediate phase of liquid so as to remove the plastic crystalline layer <NUM> from the front surface Wa of the substrate W is then performed. In the removing step S15, the removal is performed while the supply of cold water (for example, cold water of <NUM> when cyclohexane is used as the plastic crystalline material) to the back surface Wb of the substrate W with the coolant supplying unit <NUM> is being continued. In this way, it is possible to cool the plastic crystalline layer <NUM> at a temperature equal to or lower than the freezing point of the plastic crystalline material, and thus it is possible to prevent the plastic crystalline material from being melted from the side of the back surface Wb of the substrate W.

In the removing step S15, the control unit <NUM> first provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis A1 at a constant speed. Here, the rotation speed of the substrate W is set such that nitrogen gas is sufficiently supplied by the rotation of the substrate W to the peripheral portion of the substrate W.

Then, the control unit <NUM> provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the center portion of the front surface Wa of the substrate W. Then, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the gas (for example, nitrogen gas of <NUM> when cyclohexane is used as the plastic crystalline material) is supplied from the gas tank <NUM> through the pipe <NUM> and the nozzle <NUM> toward the front surface Wa of the substrate W.

Here, the partial pressure of the vapor of the plastic crystalline material in the nitrogen gas is set lower than the saturated vapor pressure of the plastic crystalline material at a temperature when the nitrogen gas is supplied. Hence, the nitrogen gas described above is supplied to the front surface Wa of the substrate W so as to make contact with the plastic crystalline layer <NUM>, and thus the plastic crystalline material in the state of the plastic crystal contained in the plastic crystalline layer <NUM> is brought into a gas state. Since the nitrogen gas has a temperature lower than the melting point of the plastic crystalline material, it is possible to bring the plastic crystalline material into a gas state while preventing the plastic crystalline material in the state of the plastic crystal from being brought into a liquid state.

The plastic crystalline material in the state of the plastic crystal is changed into a gas state without an intermediate phase of liquid, and thus when the substance such as the IPA present on the front surface Wa of the substrate W is removed, it is possible to satisfactorily dry the front surface Wa of the substrate W while preventing surface tension from acting on the pattern Wp so as to reduce the occurrence of the collapse of the pattern.

(e) shown in <FIG> shows a state of the substrate W when the removing step S15 is completed. As shown in the figure, the plastic crystalline layer <NUM> in which the plastic crystalline material formed in the plastic crystalline layer forming step S14 is present in the state of the plastic crystal is brought into a gas state by the supply of the nitrogen gas at a predetermined temperature so as to be removed from the front surface Wa, with the result that the drying of the front surface Wa of the substrate W is completed.

After the completion of the removing step S15, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is closed. The control unit <NUM> also provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the retraction position P3.

In this way, a series of substrate drying treatment steps are completed. After the substrate drying treatment as described above, the substrate W on which the drying treatment has been performed is unloaded from the chamber <NUM> by the unillustrated substrate loading/unloading mechanism.

As described above, in the present embodiment, the substrate treating liquid containing the plastic crystalline material in a molten state is supplied to the front surface Wa of the substrate W to which the IPA is adhered, and thus the plastic crystalline layer in which the plastic crystalline material is present in the state of the plastic crystal is formed on the front surface Wa of the substrate W. Thereafter, the plastic crystalline material present in the state of the plastic crystal is changed into a gas state without the intermediate phase of liquid, and thus the plastic crystalline layer is removed from the front surface Wa of the substrate W, with the result that the drying treatment on the substrate W is performed. In this way, in the present embodiment, as compared with a conventional substrate drying treatment technology, it is possible to reliably reduce the collapse of even a pattern which is fine and has a high aspect.

A second embodiment according to the present invention will be described below.

The present embodiment differs from the first embodiment in that in the plastic crystalline layer forming step S14, instead of the supply of the coolant with the coolant supplying unit <NUM>, the supply of nitrogen gas with the gas supplying unit <NUM> is performed and that in the removing step S15, the supply of the coolant to the back surface Wb of the substrate W is not performed and only the supply of the nitrogen gas is performed. In the configuration described above, it is also possible to satisfactorily dry the front surface Wa of the substrate W while reducing the collapse of the pattern.

A substrate treating apparatus and a control unit according to the second embodiment basically have the same configurations as the substrate treating apparatus <NUM> and the control unit <NUM> according to the first embodiment (see <FIG>). Hence, they are identified with the same symbols, and the description thereof will be omitted. The substrate treating liquid used in the present embodiment is also the same as that according to the first embodiment, and thus the description thereof will be omitted.

A substrate treating method according to the second embodiment using the substrate treating apparatus <NUM> having the same configuration as in the first embodiment will then be described.

The steps of the substrate treating will be described below with reference to <FIG> and <FIG> as necessary. <FIG> is a schematic view showing the state of the substrate W in the individual steps of <FIG> in the second embodiment. In the second embodiment, the washing step S11, the IPA rinsing step S12 and the substrate treating liquid supplying step S13 shown in (a) to (c) shown in <FIG> are the same as in the first embodiment, and thus the description thereof will be omitted.

With reference to <FIG>, after the washing step S11, the IPA rinsing step S12, the substrate treating liquid supplying step S13 are performed, the plastic crystalline layer forming step S14 is performed in which the film of the substrate treating liquid <NUM> supplied to the front surface Wa of the substrate W is cooled, and in which thus the plastic crystalline material is changed into the state of the plastic crystal so as to form the plastic crystalline layer. Specifically, the control unit <NUM> provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis A11 at a constant speed. Here, the rotation speed of the substrate W is preferably set such that the thickness of the liquid film formed of the substrate treating liquid is higher than the height of the projections Wp1 on the entire front surface Wa.

Then, the control unit <NUM> provides the operation instruction to the revolvingly driving part <NUM> such that the nozzle <NUM> is located in the center portion of the front surface Wa of the substrate W. Then, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the gas (in the present embodiment, nitrogen gas of <NUM>) is supplied from the gas storing part <NUM> through the pipe <NUM> and the nozzle <NUM> toward the front surface Wa of the substrate W.

The nitrogen gas supplied toward the front surface Wa of the substrate W is made to flow from around the center of the front surface Wa of the substrate W toward the direction of the peripheral portion of the substrate W by centrifugal force generated by the rotation of the substrate W so as to be diffused over the entire front surface Wa of the substrate W covered with the liquid film of the substrate treating liquid <NUM>. In this way, the liquid film of the substrate treating liquid <NUM> formed on the front surface Wa of the substrate W is cooled to a temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point of the plastic crystalline material. In this way, for the same reason as described in the first embodiment, the plastic crystalline layer <NUM> is formed on the front surface Wa of the substrate W.

Although in the second embodiment, the nitrogen gas is used so as to cool the substrate treating liquid, as long as the gas is inert to the plastic crystalline material, there is no limitation to the nitrogen gas. Specific examples of the gas inert to the plastic crystalline material include helium gas, neon gas, argon gas and air (a mixture gas of <NUM>% of nitrogen and <NUM>% of oxygen in volume). Alternatively, a mixture gas obtained by mixing a plurality of types of gases described above may be used.

The removing step S15 of changing the plastic crystalline layer <NUM> formed on the front surface Wa of the substrate W into a gas state without the an intermediate phase of liquid so as to remove the plastic crystalline layer <NUM> from the front surface Wa of the substrate W is then performed. Even in the removing step S15, the supply of the nitrogen gas from the nozzle <NUM> is continued from the plastic crystalline layer forming step S14.

Here, the partial pressure of the vapor of the plastic crystalline material in the nitrogen gas is set lower than the saturated vapor pressure of the plastic crystalline material at a temperature when the nitrogen gas is supplied. Hence, the nitrogen gas described above makes contact with the plastic crystalline layer <NUM>, and thus the plastic crystalline material in the state of the plastic crystal contained in the plastic crystalline layer <NUM> is brought into a gas state. Since the nitrogen gas has a temperature lower than the melting point of the plastic crystalline material, it is possible to bring the plastic crystalline material into a gas state while preventing the plastic crystalline material in the state of the plastic crystal from being brought into a liquid state.

The plastic crystalline material in the state of the plastic crystal is changed into a gas state without the an intermediate phase of liquid, and thus when the substance such as the IPA present on the front surface Wa of the substrate W is removed, it is possible to satisfactorily dry the front surface Wa of the substrate W while preventing surface tension from acting on the pattern Wp so as to reduce the occurrence of the collapse of the pattern.

In the second embodiment, in the plastic crystalline layer forming step S14 and the removing step S15, the common gas supplying unit <NUM> is used so as to supply the nitrogen gas inert to the plastic crystalline material at the temperature which is equal to or higher than the temperature <NUM> lower than the freezing point of the plastic crystalline material and is equal to or lower than the freezing point. In this way, immediately after the plastic crystalline layer forming step S14, the removing step S15 can be started, the processing time necessary for operating the individual portions of the substrate treating apparatus <NUM> and the amount of memory in the substrate processing program <NUM> of the control unit <NUM> to be operated can be reduced and the number of components used in the processing can be reduced, with the result that it is possible to reduce the cost of the apparatus. In particular, in the present embodiment, the pressure reducing unit <NUM> is not used, and thus the pressure reducing unit <NUM> can be omitted.

A third embodiment according to the present invention will be described below. The present embodiment differs from the second embodiment in that in the plastic crystalline layer forming step S14 and the removing step S15, instead of the supply of the nitrogen gas, the interior of the chamber is reduced in pressure. Even in the configuration described above, it is possible to satisfactorily dry the surface of the substrate W while reducing the collapse of the pattern.

A substrate treating apparatus and a control unit according to the third embodiment basically have the same configurations as the substrate treating apparatus <NUM> and the control unit <NUM> according to the first embodiment (see <FIG>), and thus they are identified with the same symbols, and the description thereof will be omitted. The substrate treating liquid used in the present embodiment is also the same as that according to the first embodiment, and thus the description thereof will be omitted.

Next, a substrate treating method according to the third embodiment using the substrate treating apparatus <NUM> having the same configuration as in the first embodiment will be described.

The steps of substrate processing will be described below with reference to <FIG> and <FIG> as necessary. <FIG> is a schematic view showing the state of the substrate W in each step of <FIG> in the third embodiment. In the third embodiment, the washing step S11, the IPA rinsing step S12 and the substrate treating liquid supplying step S13 shown in <FIG> and (a) to (c) shown in <FIG> are the same as in the first embodiment, and thus the description thereof will be omitted.

Here, (a) shown in <FIG> shows a state of the substrate W in which the front surface Wa is covered by the liquid film of the DIW <NUM> when the washing step S11 in the third embodiment is completed, (b) shown in <FIG> shows a state of the substrate W in which the front surface Wa is covered by the liquid film of the IPA <NUM> when the IPA rinsing step S12 in the third embodiment is completed and (c) shown in <FIG> shows a state of the substrate W in which the front surface Wa is covered by the liquid film of the substrate treating liquid <NUM> melting the plastic crystalline material when the substrate treating liquid supplying step S13 in the third embodiment is completed.

The individual processing steps shown in (a) to (c) shown in <FIG> are processed under an atmospheric pressure environment unless otherwise indicated. Here, the atmospheric pressure environment refers to an environment under a pressure equal to or higher than <NUM> atmospheres but equal to or lower than <NUM> atmospheres with the standard atmospheric pressure (<NUM> atmosphere, <NUM> hPa) in the center. In particular, when the substrate treating apparatus <NUM> is arranged within a clean room under a positive pressure, the environment of the front surface Wa of the substrate W is higher than <NUM> atmosphere. The processing steps (details of which will be described later) shown in (d) and (e) shown in <FIG> are performed under a reduced pressure environment of <NUM> Pa (<NUM> × <NUM>-<NUM> atmospheres).

With reference back to <FIG>, after the washing step S11, the IPA rinsing step S12 and the substrate treating liquid supplying step S13 are performed, the plastic crystalline layer forming step S14 is performed in which the liquid film of the substrate treating liquid <NUM> supplied to the front surface Wa of the substrate W is cooled and thus the plastic crystalline material is changed into the state of the plastic crystal so as to form the plastic crystalline layer. Specifically, the control unit <NUM> first provides the operation instruction to the chuck rotation mechanism <NUM> such that the substrate W is rotated about the axis A1 at a constant speed. Here, the rotation speed of the substrate W is preferably set such that the thickness of the liquid film formed of the substrate treating liquid is higher than the height of the projections Wpl on the entire front surface Wa.

Then, the control unit <NUM> provides the operation instruction to the exhaust pump <NUM> such that the drive of the exhaust pump <NUM> is started. The control unit <NUM> then provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. In this way, the gas within the chamber <NUM> is exhausted through the pipe <NUM> to the outside of the chamber <NUM>. The interior of the chamber <NUM> is brought into a sealed state except the pipe <NUM>, and thus the internal environment of the chamber <NUM> is reduced in pressure from atmospheric pressure.

The pressure reduction is performed from atmospheric pressure (about <NUM> atmosphere, about <NUM> hPa) to about <NUM> atmospheres (about <NUM> hPa). There is no limitation to the gas pressure described above in the practice of the invention of the present application, and the gas pressure within the chamber <NUM> after the pressure reduction may be set as necessary according to the pressure resistance and the like of the chamber <NUM> and the like. The interior of the chamber <NUM> is reduced in pressure, and thus the substrate treating liquid <NUM> supplied to the front surface Wa of the substrate W is evaporated, with the result that the substrate treating liquid <NUM> is cooled by the heat of the vaporization such that the plastic crystalline material is brought into the state of the plastic crystal.

(d) shown in <FIG> shows a state of the substrate W when the plastic crystalline layer forming step S14 is completed. As shown in the figure, the substrate treating liquid <NUM> supplied in the substrate treating liquid supplying step S13 is cooled by the evaporation of the substrate treating liquid <NUM> caused by the pressure reduction within the chamber <NUM>, and thus the plastic crystalline material is brought into the state of the plastic crystal, with the result that the plastic crystalline layer <NUM> is formed.

Here, the layer thickness of the plastic crystalline layer <NUM> is reduced only by the amount of substrate treating liquid <NUM> that has evaporated. Hence, in the substrate treating liquid supplying step S13 in the present embodiment, with consideration given to the amount of substrate treating liquid <NUM> evaporated in the plastic crystalline layer forming step S14, the rotation speed of the substrate W and the like are preferably adjusted such that the substrate treating liquid <NUM> becomes a liquid film with a predetermined thickness or more.

With reference back to <FIG>, the removing step S15 of changing the plastic crystalline layer <NUM> formed on the front surface Wa of the substrate W into a gas state without the intermediate phase of liquid so as to remove the plastic crystalline layer <NUM> from the front surface Wa of the substrate W is then performed. Even in the removing step S15, the pressure reduction processing within the chamber <NUM> by the pressure reducing unit <NUM> is continued from the plastic crystalline layer forming step S14.

By the pressure reduction processing, the pressure of the environment within the chamber <NUM> is lower than the saturated vapor pressure of the plastic crystalline material. Hence, the pressure reduction environment as described above is maintained, and thus the plastic crystalline material in the state of the plastic crystal in the plastic crystalline layer <NUM> is brought into a gas state.

When the plastic crystalline material in the state of the plastic crystal in the plastic crystalline layer <NUM> is brought into a gas state, the plastic crystalline layer <NUM> is deprived of heat, and thus the plastic crystalline layer <NUM> is cooled. Hence, in the third embodiment, in the removing step S15, even when the temperature of the environment within the chamber <NUM> is slightly higher (normal temperature environment) than the melting point of the plastic crystalline material, the plastic crystalline layer <NUM> can be maintained at a temperature lower than the melting point of the plastic crystalline material without being additionally cooled, with the result that it is possible to remove the plastic crystalline layer <NUM> while preventing the plastic crystalline material in the plastic crystalline layer <NUM> from being brought into a liquid state. Consequently, it is not necessary to additionally provide a cooling mechanism, and thus it is possible to reduce the costs of the apparatus and the processing.

As described above, the plastic crystalline material in the state of the plastic crystal is changed into a gas state without the intermediate phase of liquid, and thus when the substance such as the IPA present on the front surface Wa of the substrate W is removed, it is possible to satisfactorily dry the front surface Wa of the substrate W while the surface tension is prevented from acting on the pattern Wp so as to reduce the occurrence of the collapse of the pattern.

(e) shown in <FIG> shows a state of the substrate W when the removing step S15 is completed. As shown in the figure, the plastic crystalline layer <NUM> of the plastic crystalline material formed in the plastic crystalline layer forming step S14 is brought into a gas state by the formation of the pressure reduction environment with the chamber <NUM> so as to be removed from the front surface Wa, with the result that the drying of the front surface Wa of the substrate W is completed.

After the completion of the removing step S15, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened. The control unit <NUM> also provides the operation instruction to the exhaust pump <NUM> such that the operation of the exhaust pump <NUM> is stopped. Then, the control unit <NUM> provides the operation instruction to the valve <NUM> such that the valve <NUM> is opened, and thus the gas (nitrogen gas) is introduced into the chamber <NUM> from the gas tank <NUM> through the pipe <NUM> and the nozzle <NUM>, with the result that the interior of the chamber <NUM> is returned from the pressure reduction environment to the atmospheric pressure environment. Here, the nozzle <NUM> may be located in the retraction position P3 or may be located in the center portion of the front surface Wa of the substrate W.

The method of returning the interior of the chamber <NUM> to the atmospheric pressure environment after the completion of the removing step S15 is not limited to the method described above, and various types of known methods may be adopted.

As described above, in the present embodiment, the substrate treating liquid melting the plastic crystalline material is supplied to the front surface Wa of the substrate W to which the IPA is adhered so as to replace the IPA. Thereafter, the plastic crystalline material is brought into the state of the plastic crystal, thus the plastic crystalline layer is formed on the front surface Wa of the substrate W and then the plastic crystalline material in the state of the plastic crystal is changed into a gas state without the intermediate phase of liquid so as to be removed from the front surface Wa of the substrate W. In this way, the drying treatment on the substrate W is performed.

As in the present embodiment, even when the plastic crystalline layer of the gas process liquid is formed by pressure reduction so as to remove the plastic crystal, it is possible to satisfactorily dry the substrate W while preventing the collapse of the pattern. Specific pattern reduction effects will be described later in examples.

In the present embodiment, in the plastic crystalline layer forming step S14 and the removing step S15, the common pressure reducing unit <NUM> is used, and thus the interior of the chamber <NUM> is reduced in pressure. In this way, immediately after the plastic crystalline layer forming step S14, the removing step S15 can be started, and thus the processing time necessary for operating the individual portions of the substrate treating apparatus <NUM>, the amount of memory in the substrate processing program <NUM> of the control unit <NUM> to be operated can be reduced and the number of components used in the processing can be reduced, with the result that it is possible to reduce the cost of the apparatus. In particular, in the third embodiment, low-temperature nitrogen gas is not used, and thus the temperature adjusting part <NUM> in the gas supplying unit <NUM> can be omitted. When the interior of the chamber <NUM> is returned from the pressure reduction environment to the atmospheric pressure environment, and a unit other than the gas supplying unit <NUM> is used, the gas supplying unit <NUM> may be omitted. The pressure reduction may be any one of the plastic crystalline layer forming step S14 and the removing step S15.

In the above discussion, the preferred embodiments of the present invention are described. However, the present invention is not limited to these embodiments, and can be practiced in other various forms. The major ones of the other various forms will be illustrated below.

In the first to third embodiments, within the one chamber <NUM>, the individual steps are performed on the substrate W. However, there is no limitation to this configuration in the practice of the present invention, and a chamber may be prepared for each of the steps.

For example, in each of the embodiments, the following configuration may be adopted in which the steps up to the plastic crystalline layer forming step S14 are performed in a first chamber, in which after the plastic crystalline material is formed on the front surface Wa of the substrate W, the substrate W is unloaded from the first chamber, in which the substrate W where the plastic crystalline material is formed is loaded into a separate second chamber and in which the removing step S15 is performed in the second chamber.

Preferred examples of this invention will be illustratively described in detail below. However, unless otherwise restrictively described, materials, mixed amounts and the like described in the examples are not intended to limit the scope of this invention.

As a substrate, a silicon substrate in which a model pattern was formed on its front surface was prepared. <FIG> shows an SEM (Scanning Electron Microscope) image showing the surface of the silicon substrate on which the model pattern is formed (magnification: <NUM>,<NUM> times). As the model pattern, a pattern was adopted in which cylinders (whose aspect ratio is <NUM>) having a diameter of <NUM> and a height of <NUM> were aligned at intervals of about <NUM>. In <FIG>, portions shown in white are the head portions of the cylinder portions (that is, the projections of the pattern), and the portions shown in black are the recesses of the pattern. As shown in <FIG>, it was confirmed that on the pattern-formed surface, white circles which were substantially equal in size to each other were aligned regularly.

In the present example, by procedures described below, drying treatment was performed on the silicon substrate, and the effect of reducing the collapse of the pattern was evaluated. In the processing of the silicon substrate, the substrate treating apparatus described in the first embodiment was used.

Initially, ultraviolet rays were radiated onto the front surface of the silicon substrate to make the front surface property thereof hydrophilic. In this way, liquid was made to easily enter the recesses of the pattern, and thus after the supply of the liquid, an environment in which the collapse of a pattern easily occurred was artificially formed.

Then, within the chamber <NUM> under atmospheric pressure, a substrate treating liquid (whose temperature was <NUM>) consisting of melting a plastic crystalline material was directly supplied to the dried pattern-formed surface of the silicon substrate. In this way, on the pattern-formed surface of the silicon substrate, a liquid film made of the substrate treating liquid was formed. As the plastic crystalline material, cyclohexane (product name: cyclohexane made by Wako Pure Chemical. ) was used. In the compound described above, its surface tension was <NUM> mN/m under an environment of <NUM>, and its vapor pressure was <NUM> kPa (<NUM> mmHg) under an environment of <NUM>. The compound was a substance whose melting point and freezing point were <NUM> to <NUM>, whose boiling point was <NUM> and whose specific gravity was <NUM>/ml under an environment of <NUM>.

Then, under the atmospheric pressure environment, cold water of <NUM> was supplied to the back surface of the silicon substrate on which the liquid film formed of the substrate treating liquid was formed so as to cool the substrate treating liquid through the silicon substrate, and thus a plastic crystalline layer was formed.

Then, the interior of the chamber <NUM> in which the silicon substrate was stored was reduced in pressure with the pressure reducing unit <NUM>, and the plastic crystalline material in the state of the plastic crystal was changed into a gas state while preventing the plastic crystalline layer from being brought into a liquid state, with the result that the plastic crystalline layer was removed from the pattern-formed surface of the silicon substrate.

<FIG> is an SEM image of the silicon substrate after the procedures <NUM>-<NUM> to <NUM>-<NUM> described above were performed (magnification: <NUM>,<NUM> times). As compared with the pattern-formed surface (see <FIG>) of the silicon substrate before the drying treatment, the collapse of the pattern was hardly found, and the collapse rate in the displayed region was <NUM>%. In this way, it is found that when cyclohexane is used as the plastic crystalline material, it is possible to extremely satisfactorily reduce the collapse of the pattern, and that thus the plastic crystalline material is effective for the drying of the substrate.

The collapse rate of the pattern was a value which was calculated by the formula below.

In the present comparative example, as the substrate treating liquid, instead of cyclohexane serving as the plastic crystalline material, t-butanol serving as a sublimable substance was used. Except for that, as in example <NUM>, the drying treatment on the silicon substrate was performed.

<FIG> is an SEM image of a region where the average collapse rate of the pattern was indicated in the silicon substrate after the procedures described above were performed (magnification: <NUM>,<NUM> times). It was confirmed that as compared with the pattern-formed surface (see <FIG>) of the silicon substrate before the drying treatment, parts of a white spotted pattern were observed in a large number of places, and that the collapse of the pattern caused by the generation and growth of crystal grain boundaries occurred. The collapse rate was about <NUM>%.

In the present comparative example, as the substrate treating liquid, instead of cyclohexane serving as the plastic crystalline material, acetic acid serving as a sublimable substance was used. Except for that, as in example <NUM>, the drying treatment on the silicon substrate was performed.

<FIG> is an SEM image of a region where the average collapse rate of the pattern was indicated in the silicon substrate after the procedures described above were performed (magnification: <NUM>,<NUM> times). It was confirmed that as compared with the pattern-formed surface (see <FIG>) of the silicon substrate before the drying treatment, parts where white circles were enlarged were observed in a large number of places, and that the collapse of the pattern was not reduced. The collapse rate was about <NUM>%.

In the present comparative example, as the substrate treating liquid, instead of cyclohexane serving as the plastic crystalline material, p-xylene serving as a sublimable substance was used. Except for that, as in example <NUM>, the drying treatment on the silicon substrate was performed.

<FIG> is an SEM image of a region where the average collapse rate of the pattern was indicated in the silicon substrate after the procedures described above were performed (magnification: <NUM>,<NUM> times). It was confirmed that as compared with the pattern-formed surface (see <FIG>) of the silicon substrate before the drying treatment, parts of a white spotted pattern were observed, and that the collapse of the pattern caused by the generation and growth of crystal grain boundaries occurred. The collapse rate was about <NUM>%.

In the present comparative example, as the substrate treating liquid, instead of cyclohexane serving as the plastic crystalline material, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>-heptafluorocyclopentane serving as a sublimable substance was used. Except for that, as in example <NUM>, the drying treatment on the silicon substrate was performed.

<FIG> is an SEM image of a region where the average collapse rate of the pattern was indicated in the silicon substrate after the procedures described above were performed (magnification: <NUM>,<NUM> times). It was confirmed that as compared with the pattern-formed surface (see <FIG>) of the silicon substrate before the drying treatment, parts of white circles were partially observed, and that the collapse of the pattern occurred. The collapse rate was about <NUM>%.

As shown in <FIG> and table <NUM>, it is confirmed that in example <NUM> in which as the plastic crystalline material, cyclohexane was used, as compared with comparative examples <NUM> to <NUM> in which the conventional sublimable substance was used, it is possible to reduce the occurrence of the collapse of the pattern.

Claim 1:
A substrate treating method of performing drying treatment on a pattern-formed surface (Wa) of a substrate (W),
the substrate treating method comprising the following steps:
a supplying step of supplying a substrate treating liquid containing a plastic crystalline material in a molten state to the pattern-formed surface (Wa) of the substrate (W);
forming a plastic crystalline layer without bringing the substrate treating liquid into a solid state by cooling, under atmospheric pressure, the substrate treating liquid to a temperature equal to or higher than a temperature that is <NUM> lower than a freezing point of the plastic crystalline material in the molten state and is equal to or lower than the freezing point of the plastic crystalline material in the molten state and thereby forming a plastic crystalline layer by bringing, on the pattern-formed surface (Wa), the plastic crystalline material into a state of a plastic crystal being an intermediate phase between a solid state and a liquid state, being softer than the solid state and having fluidity; and
a removing step of removing the plastic crystalline layer from the pattern-formed surface (Wa) by changing, under the atmospheric pressure, the plastic crystalline layer in the state of the plastic crystal into a gas state without passing through the solid state and the liquid state,
wherein, in the removing step, while the cooling in the forming of a plastic crystalline layer is being performed, the plastic crystalline layer is removed from the pattern-formed surface (Wa) with the state of the plastic crystal maintained at the temperature equal to or higher than the temperature that is <NUM> lower than the freezing point of the plastic crystalline material in the molten state and is equal to or lower than the freezing point of the plastic crystalline material in the molten state.