JP2006319350A - Substrate treating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the finishing size of a pattern irrespective of fineness of the pattern. <P>SOLUTION: A substrate treating method comprises: a step of a chemical treatment of treating the nearly whole surface of a substrate with a first chemical by continuously discharging the first chemical on the substrate from a first chemical discharge port 261 disposed on the lower surface of a first chemical discharge/suction unit 260, and by continuously sucking a solution on the substrate through two suction mouths 262, 263 disposed so as to interpose the chemical discharge port while the first chemical discharge/suction unit is horizontally and linearly moved relatively to the substrate; and a step of a chemical treatment of the nearly whole surface of the substrate with a second chemical by continuously discharging the second chemical different from the first chemical on the substrate from a second chemical discharge port 271 disposed on the lower surface of a second chemical discharge/suction unit 270, and by continuously sucking a solution on the substrate through two suction mouths 272, 273 disposed so as to interpose the chemical discharge port while the second chemical discharge/suction unit is horizontally and linearly moved relatively to the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing method for performing chemical treatment on a substrate surface.

  In recent years, problems in the photolithography process used in the semiconductor manufacturing process are becoming more prominent. As the miniaturization of semiconductor devices progresses, the demand for miniaturization in the photolithography process is increasing. Already, the device design rule has been refined to 0.13 μm, and the pattern dimension accuracy that must be controlled is about 10 nm, and extremely strict accuracy is required. Under such circumstances, as a factor that hinders the high accuracy of the pattern formation process, there is a problem that the finished dimensions of the pattern to be formed differ due to the density difference of the patterns. For example, when a line pattern having a width of 130 nm is formed on a silicon wafer, the finished dimension of the line pattern of 130 nm is different depending on whether another large pattern exists around the line pattern or no pattern exists. It will be different.

  This occurs because the line width of the pattern having the same design dimension is different between a dense part and a sparse part in the pattern forming process, particularly in the developing process.

  As described above, there is a problem that the finished dimensions of the pattern differ depending on the density of the pattern.

  An object of the present invention is to provide a substrate processing method that can make the finished dimension of a pattern uniform regardless of the density of the pattern.

  The present invention is configured as follows to achieve the above object.

  In the substrate processing method according to the present invention, the first chemical liquid is continuously discharged from the first chemical liquid discharge port disposed on the lower surface of the first chemical liquid discharge / suction unit to the substrate, and the chemical liquid discharge port is provided. While continuously sucking the solution on the substrate from the two suction ports arranged on the lower surface of the first chemical solution discharge / suction part so as to sandwich the first chemical solution discharge / suction part and the substrate relatively A step of treating the substantially surface of the substrate with a first chemical solution while moving in a horizontal straight line, and a second chemical solution discharge disposed on a lower surface of a second chemical solution discharge / suction unit different from the first chemical solution discharge / suction unit A second chemical solution different from the first chemical solution is continuously discharged from the outlet to the substrate, and from two suction ports arranged on the lower surface of the second chemical solution discharge / suction unit so as to sandwich the chemical solution discharge port. While continuously sucking the solution on the substrate, the second chemical solution discharge / While relatively to horizontal linear movement between the substrate and 引部 and a step of chemical processing by the second liquid chemical to substantially the surface of the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the substrate processing method which can make the finishing dimension of a pattern uniform irrespective of the density of a pattern can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
First, a change in development rate (dissolution rate) when the resist was dissolved in the developer was tested for various resist dissolution concentrations. The developer used in the experiment is 2.38% TMAH. The result of the experiment is shown in FIG. FIG. 1 is a diagram showing the relationship between the resist dissolution concentration and the development speed according to the first embodiment of the present invention.

  FIG. 1 is a characteristic diagram showing the developing speed with respect to the resist penetration density. FIG. 1 shows the experimental results for the resist 1 and the resist 2. The developing speed of each resist is standardized by the developing speed with a developing solution having a resist dissolution concentration of 0%.

  Although resists 1 and 2 in FIG. 1 are resists having similar constituent elements, it can be seen that the development rate changes with respect to the resist dissolution concentration are greatly different. As shown in FIG. 1, in the case of the resist 1, when the dissolved concentration of the resist in the developer reaches about 0.001%, the development speed starts to decrease. On the other hand, in the case of the resist 2, when the dissolved concentration of the resist in the developing solution reaches about 0.1%, the developing speed starts to decrease. The resist dissolution concentration at which the resist development rate begins to decrease was defined as the “limit penetration concentration”.

  When the concentration of the dissolved resist in the developer is equal to or higher than the limit penetration concentration specific to each resist, the development speed is lowered. The limit penetration concentration is unique to each resist. Therefore, when developing a pattern-drawn resist, the development speed depends on the pattern density by performing development such that the dissolved resist concentration in the developer in all regions on the substrate is not more than the “limit penetration concentration”. However, the density-dependent dimensional difference becomes very small.

  In the present embodiment, a developing method when the developing device shown in FIG. 2 is used will be described. FIG. 2 is a diagram showing a schematic configuration of the developing device according to the first embodiment of the present invention.

  As shown in FIG. 2, a resist film 13 is formed on the substrate 11 with an antireflection film 12 interposed therebetween. A scan nozzle (chemical solution discharge / suction unit) 20 is disposed oppositely on the substrate 11. The scan nozzle 20 is provided with a developer discharge nozzle 21 that discharges the developer 31 from the developer discharge port 21a. The scanning nozzle 20 is provided with two suction nozzles 22 for sucking the solution on the substrate 11 from the suction port 22b. The two suction ports 22b are arranged so as to sandwich the developer discharge port 21a. A moving mechanism (not shown) for moving the scan nozzle is provided in the arrangement direction of the developer discharge port 21a and the suction port 22b. The developer discharge port 21 a and the suction port 22 b have a slit shape whose length in the direction orthogonal to the arrangement direction is longer than that of the substrate 11.

  The developer 31 is discharged from the developer discharge port 21a of the scan nozzle 20 disposed close to the substrate 11, and is sucked together with the rinse liquid 32 from the suction port 22b disposed adjacent to the developer discharge port 21a. At this time, the substrate 11 was covered with the rinse liquid 32. For this reason, the developer 31 exists only in the region surrounded by the surface of the substrate 11, the bottom surface of the scan nozzle 20, and the suction port 22b. In this embodiment, by adjusting the moving speed of the scan nozzle 20, the gap between the bottom surface of the scan nozzle 20 and the substrate 11, and the developer discharge speed, the resist dissolution concentration in the developer 31 on the substrate 11 is set to the “limit penetration concentration”. "Make sure that

  A method for performing development in which the dissolved resist concentration in the developer in all regions on the substrate is equal to or less than the “limit penetration concentration” will be described. FIG. 3 is a flowchart of the developing method according to the first embodiment of the present invention.

  First, the development rate change when the resist is dissolved in the developer is tested with respect to the resist dissolution concentration. From the experimental result, the resist limit penetration amount is examined (step S101).

  Next, the discharge speed of the developer discharged from the developer discharge port, in which the dissolved resist concentration in the developer in all regions is equal to or less than the “limit penetration concentration”, is obtained (step S102).

Next, the developer is discharged from the developer discharge port at the determined discharge speed (step S103).

  By performing development by the above method, the development speed depends on the pattern density by performing development such that the dissolved resist concentration in the developer in all regions on the substrate is not more than the “limit penetration concentration”. However, the density-dependent dimensional difference is very small.

  The developing solution discharge amount estimation method in step S102 will be described with reference to FIG.

In FIG. 4, the scan nozzle 20 has a moving speed of s (cm / sec), the distance between the center of the developer discharge port 21a and the center of the suction port 22b is 10 mm, and the gap between the substrate 11 and the bottom surface of the scan nozzle 20 is 50 μm. Think. At this time, consider a case where the uniformly exposed resist (film thickness 500 nm) is dissolved in the developer. Considering an elongated region (volume: vol = 75 × 10 ⁻⁴ [cm ³ ]) having a height of 50 μm, a width of 1 mm, and a depth of 150 mm, the developer in this region is surrounded by the upper surface of the substrate 11, the lower surface of the scan nozzle 20, and the suction port 22b. The developing solution discharge speed x (cm ³ / sec) is obtained so that the resist dissolution concentration becomes equal to or less than the “limit penetration concentration” when flowing in the region without being disturbed. Since there are two suction ports 22b, the speed of the developer supplied to one suction port 22b is x / 2 (cm ³ / sec).

である。 In the case of the above conditions, the developer flow velocity v (cm / sec) in the region is

It is.

Therefore, the time T (s) until the developer discharged from the discharge port 21a reaches the suction port 22b is
T = 0.15 / x (s)
It is.

である。 Since the developer is in contact with the exposed resist 42 only for T (s), the amount of resist dissolved in the volume vol = 75 × 10 ⁻⁴ (cm ³ ) during this period is calculated. Assuming that the residual film of the exposed resist becomes 0 at 1/4 of the time when the resist at a certain point starts to contact with the developing solution again (= development time), the film reduction rate per second v _red is

It is.

Therefore, the resist amount R _vol (cm ³ ) dissolved in the developing solution in T seconds from the resist film having a width of 1 mm and a depth of 150 mm is Rvol = 10 ⁻⁴ × s × T × 0.1 × 15 [cm ³ ].
It is.

From the above, the resist dissolution concentration C is obtained by the following equation.

In this embodiment, since s = 0.1 (cm / sec),
Resist dissolution concentration = 0.03 / x (%)
Is required.

From this result and the limit penetration concentration, for each of the resist 1 and the resist 2, a developer discharge amount x (cm ³ / sec) is obtained so that the resist dissolution concentration in the developer becomes equal to or less than the “limit penetration concentration”. .

  The resist 1 may satisfy the condition of 0.001 ≧ 0.03 / x. The resist 2 only needs to satisfy the condition of 0.1 ≧ 0.03 / x.

Therefore, it can be understood that when the developer discharge amount with respect to the resist 1 is 30 cm ³ / sec or more, the dissolution concentration of the resist 1 in the developer is equal to or less than the “limit penetration concentration”. Further, it can be seen that when the developer discharge amount with respect to the resist 2 is 0.3 cm ³ / sec or more, the dissolution concentration of the resist 2 in the developer is equal to or less than the “limit penetration concentration”.

  Hereinafter, an example in which the developing method of this embodiment is applied to a photomask manufacturing process will be described. FIG. 5 is a cross-sectional view showing a photomask manufacturing process according to the first embodiment of the present invention.

  First, two photomask substrates are prepared as substrates to be processed. As shown in FIG. 5A, the photomask substrate 50 is configured by forming a Cr light shielding film 52 on a quartz glass 51. A resist agent is applied on the two photomask substrates 50 and then baked to form a resist film 53. In this embodiment, a chemically amplified EB positive resist (resist 1) is used as the resist, and the film thickness is 500 nm. Next, pattern drawing is performed on the resist film 53 by an EB drawing apparatus. The exposure part 54 is formed by pattern drawing. Then, Post-Exposure-Bake (PEB) was performed. PEB was performed at 120 ° C. for 900 seconds.

Thereafter, as shown in FIG. 5B, the developing solution 55 is supplied to the surfaces of the two photomask substrates 50 to develop the resist film 53. One photomask substrate is developed using the developing device shown in FIG. Development was performed under the previously estimated developer discharge rate of 30 (cm ³ / sec) and nozzle scan speed of 0.1 (cm / sec). Development time was approximately 150 seconds. The other photomask substrate is developed by a developing device shown in FIG. As shown in FIG. 6A, the photomask substrate 50 is held by a chuck 72. Development is performed by spraying the developer 75 from the nozzle 74 on the photomask substrate 50 rotated by the rotation mechanism 73. Alternatively, a paddle method in which the developer 77 is dropped from the nozzle 76 onto the stopped photomask substrate 50 shown in FIG. 6B may be used. In these development methods (conventional methods), there is a region where the dissolution concentration of the resist 1 in the developer is equal to or higher than the “limit penetration concentration” depending on the density of the pattern.

  After the development, as shown in FIG. 5C, the photomask substrate 50 is sequentially cleaned and dried.

  Next, the Cr light-shielding film 52 was dry-etched with a plasma etching apparatus for both of the two photomask substrates. In this embodiment, an etching gas made of a mixed gas such as chlorine / oxygen is used. The etching time was approximately 360 seconds.

  Finally, the resist film 53 was peeled off by a process using a resist ashing device and a resist stripping cleaning device to complete a photomask. The formed pattern is shown in FIG. As shown in FIG. 7, a pad pattern is arranged adjacent to the line pattern. A region having a plurality of distances X between the line pattern and the pad pattern is formed. The target dimension of the line pattern is fixed at 600 nm.

  Thereafter, the dimension of the light-shielding film Cr having the same pattern on the two photomask substrates is measured by a dimension measuring device. An explanatory diagram of the measurement results and measurement patterns is shown in FIG. FIG. 8 is a characteristic diagram showing the line pattern dimension Y with respect to the distance X.

  In the case of the pattern formed by the conventional current increasing method, the dimensional error increases as the distance X increases. This is because as the distance X increases, the resist dissolution concentration in the developer increases and exceeds the “limit penetration concentration”, so that the loading effect of development becomes remarkable.

  On the other hand, in the case of the pattern formed by the developing method of this embodiment, the dimensional error can be kept within 5 nm even if the distance X changes. This is because the resist dissolution concentration is low and below the “limit penetration concentration”.

  In this embodiment, the discharge amount of the developer is a predetermined fixed amount. However, if the resist concentration dissolved in the developer is equal to or less than the “limit penetration concentration”, the aperture ratio in the pattern area to be developed is increased. Accordingly, the developer discharge amount and the nozzle scan speed may be changed.

  FIG. 9 is a diagram illustrating an example of a method for setting the resist aperture ratio and the developer discharge amount. In the figure, all of A, B, and C are set such that the resist concentration in the developer does not exceed the “limit penetration concentration”. 10 and 11 are diagrams showing a resist aperture ratio distribution and a developer discharge amount setting value in the development of an actual semiconductor wafer and exposure mask.

  FIG. 10A is a diagram showing a configuration of a semiconductor wafer. FIG. 10B is a diagram showing a resist aperture ratio distribution from I to I ′ in FIG. FIG. 10C is a diagram illustrating a developer discharge speed distribution from I to I ′. In FIG. 10, a plurality of chips 102 are formed on a wafer 101.

  FIG. 11A is a diagram showing the configuration of the exposure mask. FIG. 11B is a diagram showing a resist aperture ratio distribution from II to II ′ in FIG. FIG. 11C is a diagram showing a developer discharge speed distribution from II to II '.

  As shown in FIG. 10C and FIG. 11C, the usage amount of the developer can be further reduced by reducing the developer discharge speed in the region where the pattern aperture ratio is low.

  In this embodiment, a photomask substrate is used as the substrate, but the same effect can be obtained by using a semiconductor substrate, a mask substrate for next-generation lithography such as EB exposure, a flat panel display substrate, or the like.

(Second Embodiment)
First, FIGS. 12 to 14 will be described with respect to the configuration of a chemical solution discharge / suction unit (hereinafter referred to as a scan nozzle) of the developing device used in this embodiment. FIG. 12 is a plan view showing the configuration of the lower surface of the scan nozzle. FIG. 13 is a cross-sectional view showing the configuration of the scan nozzle. FIG. 14 is a view of the scan nozzle as viewed from the front side in the movement direction.

  The chemical liquid discharge / suction unit (hereinafter referred to as a scan nozzle) has a width of about 18 cm in a direction perpendicular to the movement direction with respect to the substrate and a depth of about 5 cm in a direction parallel to the movement direction. As shown in FIG. 12R> 2, there are five slit-shaped ports 121 to 125 on the surface of the scan nozzle facing the substrate. The developer is discharged from the central port (developer discharge slit) 121. The chemical solution on the substrate is sucked from the two adjacent ports (suction slits) 122 and 123. Further, prewetting liquid or rinsing liquid is discharged from two outer ports (prewetting liquid discharging slit / rinsing liquid discharging slit) 124 and 125. A prewetting liquid discharge slit 124 that discharges the prewetting liquid in front of the moving direction and a rinsing liquid discharge slit 125 that discharges the rinsing liquid are arranged in the rear of the moving direction. The developer discharge slit 121 has a length of 150 mm and a width of 1 mm. The suction slits 122 and 123 have a length of 155 mm and a width of 1 mm. The pre-wet liquid discharge slit 124 and the rinse liquid discharge slit 125 have a length of 155 mm and a width of 2 mm.

  As shown in FIG. 13, the developer supplied from the developer supply line 136 to the developer discharge nozzle 131 is discharged from the developer discharge slit 121 to the substrate 130. The chemical liquid sucked from the suction slits 122 and 123 is discharged to the outside of the scan nozzle 120 through the suction nozzles 132 and 133 and the suction lines 136 and 137. The prewetting liquid supplied from the prewetting liquid supply line 139 to the prewetting liquid discharge nozzle 134 is discharged from the prewetting liquid discharge slit 124 onto the substrate 130. The rinse liquid supplied from the rinse liquid supply line 140 to the rinse liquid discharge nozzle 135 is discharged to the substrate 130 from the rinse liquid discharge slit 125.

  Control is performed so that the developer discharged from the developer discharge slit 121 does not protrude outside the suction slits 122 and 123. This control is performed by adjusting the suction force from the suction slits 122 and 123 and the discharge speed from the developer discharge slit 121.

A developing solution, a prewetting solution, and a rinsing solution are supplied to each line from a pump connected to each line.

  A pH meter 151 for measuring the pH of the solution sucked from the suction port is provided. In this embodiment, the pH monitor 151 is not used, and will be described in another embodiment.

  As shown in FIG. 14, the developing device includes a substrate holder 141 on which the substrate 120 is placed, a gap measuring mechanism 142 provided in the scan nozzle 120, a gap adjusting mechanism 143 provided at both ends of the scan nozzle 120, A scan stage 144 is provided for moving the scan nozzle 120 and the substrate holder 141 relatively in a substantially horizontal direction.

  The gap measuring mechanism 142 is provided on the side surface of the scan nozzle 120. The gap measuring mechanism 142 measures the distance between the lower surface of the scan nozzle 120 and the upper surface of the substrate 130. The measurement is performed using laser light.

  The gap adjusting mechanism 143 is provided at both ends of the scan nozzle 120, and is attached to the scan nozzle 120 so as to be movable on the scan stage 144 in the horizontal linear direction.

  The gap adjusting mechanism 143 includes a piezo element, and based on the measurement result of the gap measuring mechanism 142, the gap between the lower surface of the scan nozzle 120 and the upper surface of the substrate 130 placed on the substrate holder 141 is a predetermined value. It is supposed to adjust to. For example, the gap can be adjusted in the range of 10 to 500 μm.

  FIG. 15 shows the relationship between the average aperture ratio after development in a 5 mm square area in a positive resist and the gap between the nozzle and the substrate for finishing to a desired resist dimension. It can be seen that the larger the aperture ratio, the smaller the optimum gap. This is because the volume of the resist that must be removed increases as the aperture ratio increases, so that it is necessary to flow the developer at a higher speed and replace it with a fresh developer earlier. By reducing the gap, the amount of the developer that passes through the unit volume region in contact with the substrate per unit time increases, and the developer on the resist can be replaced quickly.

  FIG. 16 shows the relationship between the nozzle and substrate surface gap and the resist dimensions after development. The developer speed was 0.2 l / min. From FIG. 16, it can be seen that when the gap is 0.5 mm or more, the dimensions change abruptly. This is because as the gap becomes larger, the flow rate of the developer on the resist surface becomes slower and the replacement efficiency of the developer is lowered. In other words, the gap between the substrate and the nozzle is preferably 0.5 mm or less, and even if it is too close, contact between the substrate and the nozzle is concerned due to nozzle processing accuracy, gap control accuracy, and the like. .5 mm or less is preferable.

  FIG. 17 shows the relationship between the average flow rate of the developer flowing through the gap between the nozzle and the substrate and the resist dimensions after development. The average flow rate of the developing solution is calculated from the gap and the discharging speed of the developing solution. As shown in FIG. 17, it can be seen that when the average flow velocity is less than 0.02 m / sec, the development changes abruptly. This is because the flow rate of the developing solution on the resist surface becomes slow and the replacement efficiency of the developing solution decreases. Therefore, the average flow rate of the developer is preferably 0.02 m / sec or more.

  An example in which a photomask is actually manufactured using these relationships will be described below. A layer having a system LSI device pattern is drawn on an Cr mask blank coated with a positive chemically amplified resist having a thickness of 400 nm by an electron beam drawing apparatus.

  FIG. 18 shows an outline of layers of the system LSI device pattern to be drawn. FIG. 18 is a plan view schematically showing a layer having a system LSI device pattern according to the second embodiment of the present invention. As shown in FIG. 18, half of the system LSI device pattern 170 is a logic device. The other half is a memory device area. The resist pattern has an aperture ratio of 45% in the memory device region 171 and 80% in the logic device region 172 after development. The memory device area 171 and the logic device area 172 are greatly different.

  Conventionally, when such a pattern is developed, the memory device region 171 deviates from the desired size under the condition that the logic device region 172 has a desired size. In order to finish both the regions 171 and 172 to a desired size at the same time, it is necessary to change the pattern size to be drawn. However, changing the drawing data depending on the location increases the time and cost of data conversion, and needs to be improved.

  After drawing, baking was performed at 110 degrees for 15 minutes. Next, the substrate 130 is placed on the substrate holder 141 of the developing device described above. Next, as shown in FIGS. 19A to 19C, the scanning nozzle 120 is linearly moved at a constant speed from one end A to the other end B opposite to the one end A, and development processing is performed. At this time, the gap between the lower surface of the scan nozzle 120 and the upper surface of the substrate 130 was controlled so as to have a desired dimension in accordance with the average aperture ratio of the pattern in the region between the two suction slits 122 and 123. FIG. 20 shows the relationship between the position of the scan nozzle and the gap. In other words, the logic device region 172 having a large aperture ratio has a small gap, and the memory device region 171 having a small aperture ratio has a large gap. The moving speed of the scan nozzle 20 is 1 mm / sec. The developer is a 0.27 normal alkaline developer. The discharge speed was 0.2 l / min. Since the interval between the developer discharge slit and the suction slit is 5 mm, which is on both sides of the developer discharge slit, and the width of the chemical discharge slit is 1 mm, the developer exists between the scan nozzle and the substrate surface. Is about 11 mm in a direction parallel to the moving direction. That is, when attention is paid to a certain point on the substrate surface, the time required for the developer to pass through the place is about 11 seconds, and the effective development time is about 11 seconds.

  With this development process, after the developer is discharged, the developer flows at high speed through the gap between the nozzle and the substrate surface and is immediately sucked and removed, so that fresh developer can always be supplied to the resist surface. As a result, a uniform development process can be realized over the entire surface of the photomask.

  Next, the Cr film is etched by reactive ion etching using the formed resist pattern as an etching mask. A mixed gas of chlorine gas and oxygen gas was used as the etching gas. Thereafter, the resist was peeled off with an ashing device and washed with a washing machine. And the formed Cr pattern dimension was measured with the dimension measuring apparatus. As a result, the difference between the average value of the pattern dimension and the target dimension was 2 nm, and the in-plane uniformity of the Cr pattern dimension was 6 nm (3σ) without distribution depending on the aperture ratio.

  Next, as an experiment for confirming the effectiveness of the developing method shown in the present embodiment, the wafer was exposed with an ArF scanner using the shipped mask, and the exposure tolerance was evaluated. The evaluation was performed by measuring the dimension of the resist pattern formed on the wafer by changing the defocus amount and the exposure amount by SEM. As a result, the defocus tolerance at which the variation amount of the resist pattern dimension formed on the wafer was 10% or less was 0.40 μm, and the exposure tolerance at that time was 12%.

  Although this embodiment is an example applied to a positive resist, it goes without saying that it can be similarly applied to a negative resist. Furthermore, this embodiment is an example of application to the development process of the mask manufacturing process, but is not limited to this. In the flat panel display manufacturing process, the wafer process, etc., resist peeling, surface natural oxide film removal, cleaning, etc. Applicable to any chemical treatment.

(Third embodiment)
In the second embodiment, the developing method has been described in which the gap is adjusted according to the ratio of the exposed portion to finish the pattern uniformly. In the present embodiment, a developing method will be described in which the scan speed of the scan nozzle is adjusted in accordance with the ratio of the exposed portion to finish the pattern uniformly.

  FIG. 21 shows the relationship between the average aperture ratio after development in each region of 5 mm in the positive resist and the scanning speed of the nozzle for finishing to a desired resist dimension. As shown in FIG. 21, it can be seen that as the aperture ratio increases, the optimum scanning speed decreases. This is because the volume of the resist that must be removed increases as the aperture ratio increases, and it is necessary to supply a larger amount of fresh developer by flowing the developer longer. An example in which a photomask is actually manufactured using this relationship will be described below.

  Since the resist coating conditions, the exposure pattern, the exposure conditions, and the PEB conditions are the same as those in the second embodiment, description thereof is omitted.

Next, as in the second embodiment, development is performed by scanning the scan nozzle from one end of the substrate toward the other end. During scanning, development processing is performed while changing the scanning speed according to the aperture ratio. Development processing was performed while controlling the scanning speed in accordance with the average aperture ratio of the pattern between the two suction ports. FIG. 22 shows the relationship between the position of the scan nozzle and the scan speed.

  As shown in FIG. 22, the scan speed is slow in the logic device region where the aperture ratio is large, and the scan speed is increased in the memory device region where the aperture ratio is small. The scan speed varies between 1.2 and 1.6 mm / sec depending on the aperture ratio. The developer used is a 0.27 normal alkaline developer. The discharge speed of the developer was set to 0.2 l / min.

  The distance between the developer discharge slit and the suction slit is 5 mm. There are two suction slits on both sides of the developer discharge slit, and their width is 1 mm. Therefore, the developer exists between the scan nozzle and the substrate surface in about 11 mm in the direction parallel to the moving direction. That is, when attention is paid to a certain point on the substrate surface, the time required for the developer to pass through the place is about 7 to 9 seconds, and the effective development time is about 7 to 9 seconds.

  With the development processing method shown in this embodiment, after the developer is discharged, the developer flows through the gap between the nozzle and the substrate surface at a high speed and is immediately removed by suction, and the necessary development corresponding to the aperture ratio is achieved. By ensuring the time, the effect of being able to always supply a fresh developer to the resist surface, it was possible to realize a uniform development process over the entire photomask.

  Next, the Cr film was etched by reactive ion etching using the formed resist pattern as an etching mask. A mixed gas of chlorine gas and oxygen gas was used as the etching gas. Thereafter, the resist was peeled off with an ashing device and washed with a washing machine. And the formed Cr pattern dimension was measured with the dimension measuring apparatus. As a result, the difference between the average value of the pattern dimension and the target dimension was 2 nm, and the in-plane uniformity of the Cr pattern dimension was 6 nm (3σ) without distribution depending on the aperture ratio.

  Next, as an experiment to confirm the effectiveness of this method, the wafer was exposed with an ArF scanner using the shipped mask, and the exposure latitude was evaluated. The evaluation was performed by measuring the dimension of the resist pattern formed on the wafer by changing the defocus amount and the exposure amount by SEM. As a result, the defocus tolerance at which the variation amount of the resist pattern dimension formed on the wafer was 10% or less was 0.40 μm, and the exposure tolerance at that time was 12%.

  Although this embodiment is an example applied to a positive resist, it goes without saying that it can be similarly applied to a negative resist. In the case of a negative resist, the scanning speed is increased when the aperture ratio is large, and the scanning speed is decreased when the aperture ratio is small.

  Furthermore, this embodiment is an example of application to the development process of the mask manufacturing process, but is not limited to this. In the flat panel display manufacturing process, the wafer process, etc., resist peeling, surface natural oxide film removal, cleaning, etc. Applicable to any chemical treatment.

(Fourth embodiment)
In the second and third embodiments, the developing method has been described in which the gap or the scanning speed is adjusted according to the ratio of the exposed portion to finish the pattern uniformly. In the present embodiment, a developing method for uniformly finishing a pattern by adjusting the developer discharge speed of the scan nozzle in accordance with the ratio of the exposed portion will be described.

  FIG. 23 shows the relationship between the average aperture ratio after development in each region of 5 mm in the positive resist and the developer discharge speed for finishing to a desired resist dimension.

  As shown in FIG. 23, it can be seen that the optimum developer discharge speed increases as the aperture ratio increases. This is because the volume of the resist that must be removed increases as the aperture ratio increases, and it is necessary to supply a larger amount of developer and supply fresh developer earlier. The average developer flow rate is a value obtained by dividing the cross-sectional area of the space in which the developer between the scan nozzle and the substrate flows by the supply speed of the developer flowing in the space.

In the present embodiment, since the gap between the scan nozzle and the substrate is 50 μm and the width of the discharge port and the suction port is 150 mm, the cross-sectional area of the space through which the developer flows is about 7.5 mm ² . When the developer is discharged there at a discharge speed of 5 ml / min, the flow rate is about 5.5 mm / sec.

  By the way, the moving speed of the scan nozzle was fixed at 1 mm / sec, and development processing was performed at various developer discharge speeds. As a result, it was found that when the developer flow rate became 1 mm / sec or less, the pattern dimensions changed rapidly. It has been found that this is because the developer flow speed and the scan speed from the developer discharge slit to the rinse slit side (the rear side in the scanning direction) are almost the same. This is because the replacement of the developer is not performed because the two speeds are equal. That is, it is desirable that the flow rate of the developer flowing through the gap between the substrate and the nozzle is faster than the nozzle scan speed. An example in which a photomask is actually manufactured using this relationship will be described below.

  Since the resist coating conditions, the exposure pattern, the exposure conditions, and the PEB conditions are the same as those in the second embodiment, description thereof is omitted.

  Next, as in the second embodiment, development is performed by scanning the scan nozzle from one end of the substrate toward the other end. During scanning, development processing is performed while changing the developer discharge speed in accordance with the aperture ratio. In accordance with the average aperture ratio of the pattern between the two suction ports, development processing was performed by controlling the discharge of the developer. FIG. 24 shows the relationship between the position of the scan nozzle and the scan speed.

  As shown in FIG. 24, the developer discharge speed was increased when the aperture ratio was large, and the developer discharge speed was decreased when the aperture ratio was small. The developer discharge speed was set to 0.18 to 0.26 l / min depending on the aperture ratio. The developer is a 0.27 normal alkaline developer. The distance between the developer discharge slit and the suction slit is 5 mm. Two suction slits are provided on both sides of the developer discharge slit. The width of the chemical solution discharge slit is 1 mm. Therefore, the developer exists between the scan nozzle and the substrate surface in about 11 mm in the direction parallel to the moving direction. That is, when attention is paid to a certain point on the substrate surface, the time required for the developer to pass through the spot is about 11 seconds. The effective development time is about 11 seconds.

  By this development processing, after the developer is discharged, the developer flows at high speed through the gap between the nozzle and the substrate surface and is immediately sucked and removed, and the necessary developer flow rate corresponding to the aperture ratio is secured. As a result, a uniform developing process can be realized over the entire photomask due to the effect that a fresh developer can always be supplied to the resist surface.

  Next, the Cr film was etched by reactive ion etching using the formed resist pattern as an etching mask. A mixed gas of chlorine gas and oxygen gas was used as the etching gas. Thereafter, the resist was peeled off with an ashing device and washed with a washing machine.

  The dimension of the formed Cr pattern was measured with a dimension measuring device. As a result, the difference between the average value of the pattern dimension and the target dimension was 2 nm, and the in-plane uniformity of the Cr pattern dimension was 6 nm (3σ) without distribution depending on the aperture ratio.

  Next, as an experiment to confirm the effectiveness of the development processing shown in the present embodiment, the wafer was exposed with an ArF scanner using the shipped mask, and the exposure tolerance was evaluated. The evaluation was performed by measuring the dimension of the resist pattern formed on the wafer by changing the defocus amount and the exposure amount by SEM. As a result, the defocus tolerance at which the variation amount of the resist pattern dimension formed on the wafer was 10% or less was 0.40 μm, and the exposure tolerance at that time was 12%.

  Although this embodiment is an example applied to a positive resist, it goes without saying that it can be similarly applied to a negative resist. In the case of a negative resist, the developer discharge speed is controlled to be small when the aperture ratio is large, and the developer discharge speed is increased when the aperture ratio is small. Furthermore, this embodiment is an example of application to the development process of the mask manufacturing process, but is not limited to this. In the flat panel display manufacturing process, the wafer process, etc., resist peeling, surface natural oxide film removal, cleaning, etc. Applicable to any chemical treatment.

(Fifth embodiment)
A method for performing development by controlling the scanning speed so as to obtain a desired pH value from a pH meter that constantly monitors the pH value of the sucked chemical solution will be described.

  An example of actually manufacturing a photomask will be described below. Since the resist coating conditions, the exposure pattern, the exposure conditions, and the PEB conditions are the same as those in the second embodiment, description thereof is omitted.

  Next, as in the second embodiment, development is performed by scanning the scan nozzle from one end of the substrate toward the other end. During scanning, development processing is performed while changing the scanning speed so that the measured value of the pH meter substantially maintains the value of the fresh developer.

  FIG. 25 shows the relationship between the scanning speed and the pattern aperture ratio on the lower surface of the nozzle. As a result, when the aperture ratio is large, the scan speed is slow, and when the aperture ratio is small, the scan speed is fast. The scanning speed varies between 1.2 and 1.6 mm / sec depending on the aperture ratio. The developer is a 0.27 normal alkaline developer. The developer discharge speed was 0.2 l / min.

  The distance between the developer discharge slit and the suction slit is 5 mm. There are two suction slits on both sides of the developer discharge slit. The width of the chemical solution discharge slit is 1 mm. Therefore, the developer exists between the scan nozzle and the substrate surface in about 11 mm in the direction parallel to the moving direction. That is, when attention is paid to a certain point on the substrate surface, the time required for the developer to pass through the spot is about 7 to 9 seconds. Therefore, the effective development time is about 7 to 9 seconds.

  By the above-described development processing, after the developer is discharged, the developer flows through the gap between the nozzle and the substrate surface at a high speed and is immediately sucked and removed, and a necessary development time corresponding to the aperture ratio is secured. As a result, a uniform developing process can be realized over the entire photomask due to the effect that a fresh developer can always be supplied to the resist surface.

  Next, the Cr film was etched by reactive ion etching using the formed resist pattern as an etching mask. A mixed gas of chlorine gas and oxygen gas was used as the etching gas. Thereafter, the resist was peeled off with an ashing device and washed with a washing machine. And the formed Cr pattern dimension was measured with the dimension measuring apparatus. As a result, the difference between the average value of the pattern dimension and the target dimension was 2 nm, and the in-plane uniformity of the Cr pattern dimension was 6 nm (3σ) without distribution depending on the aperture ratio.

  Next, as an experiment for confirming the effectiveness of the development method described above, the wafer was exposed with an ArF scanner using the shipped mask, and the exposure latitude was evaluated. The evaluation was performed by measuring the dimension of the resist pattern formed on the wafer by changing the defocus amount and the exposure amount by SEM. As a result, the defocus tolerance at which the variation amount of the resist pattern dimension formed on the wafer was 10% or less was 0.40 μm, and the exposure tolerance at that time was 12%.

  In this embodiment, the concentration of the suction developer is measured by a pH monitor, but it may be monitored by optical transmittance or electrical conductivity. In addition, this embodiment is an example of application to the development process of the mask manufacturing process, but is not limited to this, and in various processes such as resist stripping, surface natural oxide film removal, and cleaning in flat panel display manufacturing processes and wafer processes. Applicable to chemical treatment.

(Sixth embodiment)
In the present embodiment, a cleaning process for a photomask substrate after resist removal will be described. The cleaning device used is the same as the developing device used in the second embodiment. However, ozone water is discharged from the developer discharge port instead of the developer. A particle counter is provided instead of the pH counter. Since other configurations are the same, illustration and description are omitted.

  As a result of inspecting the mask after resist removal after the formation of the Cr pattern with a defect inspection apparatus, 280 foreign matters were confirmed. As a result of cleaning this mask with a conventional mask cleaning machine, the number of foreign matters could be reduced to 73. However, the number of foreign substances is still insufficient. Therefore, conventionally, the same cleaning apparatus was cleaned three times to reduce the number of foreign matters to zero. Thus, conventionally, the cleaning ability is not sufficient, and a lot of time has been spent to remove foreign substances.

  Similarly, a substrate on which 332 foreign substances have adhered after resist removal is placed on the above-described cleaning apparatus, and the measured value of the particle counter is 0.1 / min from one end A to the other end B opposite to the substrate. The ozone water treatment was performed while changing the scanning speed so as to be as follows. The ozone water discharge speed is set to 0.2 l / min. Note that. If the dirt is severe, the scanning speed may become zero until the particle counter becomes 0.1 particles / min or less.

  The interval between the ozone water discharge slit and the suction slit is 5 mm. There are two suction slits on both sides of the ozone water discharge slit. The width of the chemical solution discharge slit is 1 mm. Therefore, the ozone water is present between the scan nozzle and the substrate surface in about 11 mm in the direction parallel to the moving direction.

  With this cleaning, ozone water is discharged, and ozone water flows through the gap between the nozzle and the substrate surface at a high speed and is removed by suction immediately after removing foreign substances. Therefore, the most foreign matter is prevented from adhering to the mask.

  In addition, by performing ozone water treatment while changing the scan speed so that the particle counter value is 0.1 piece / min or less, the mask surface is always clean and uniform over the entire surface of the photomask substrate. Ozone water treatment was realized. As a result, the number of foreign matters on the mask after cleaning was zero, and stable cleaning according to the cleanliness of the mask could be realized.

  In this embodiment, the degree of cleaning is measured with a particle counter, but may be monitored with optical transmittance or electrical conductivity. In addition, this embodiment is an example applied to the development process of the mask manufacturing process. However, the present invention is not limited to this, and any chemical processing such as resist stripping and surface natural oxide film removal in the flat panel display manufacturing process, wafer process, etc. Can be applied to.

(Seventh embodiment)
Embodiments of the present invention will be described with reference to the drawings. First, the chemical solution discharge / suction unit of the substrate processing apparatus used in the present invention will be described.

  The developing device of this embodiment has two scan nozzles similar to the scan nozzles described with reference to FIGS. 12 to 14 in the second embodiment. The developing device will be described with reference to FIG. FIG. 26 is a plan view showing the configuration of the lower surface of the scan nozzle according to the seventh embodiment of the present invention.

  As shown in FIG. 26, there are two chemical liquid discharge / suction units (hereinafter referred to as scan nozzles) having the same structure, and each scan nozzle has a width of 35 cm in the direction perpendicular to the movement direction with respect to the substrate, The width is about 5 cm in the parallel direction. In addition, five slit-shaped openings are provided on the lower surface of each scan nozzle facing the substrate of the scan nozzle.

  First, the configuration of the first scan nozzle 260 will be described. The ozone water liquid is discharged from the central ozone water discharge slit 261. From the two first suction slits 262 and 263 adjacent to each other, the solution (ozone water, prewetting liquid, rinse liquid) on the substrate is sucked. Further, prewetting liquid or rinsing liquid is discharged from the two outer ports (first prewetting liquid discharge slit and second rinsing liquid discharge slit) 264 and 265. A prewetting liquid discharge slit 264 that discharges the prewetting liquid in the front in the movement direction and a rinsing liquid discharge slit 265 that discharges the rinsing liquid in the rear in the movement direction are arranged.

  First, the configuration of the second scan nozzle 270 will be described. The developer is discharged from the central developer discharge slit 271. From the two suction slits 272 and 273 on both sides, the solution (developer, prewetting liquid, rinse liquid) on the substrate is sucked. Further, prewetting liquid or rinsing liquid is discharged from the two outer ports (prewetting liquid discharging slit and rinsing liquid discharging slit) 274 and 275. A prewetting liquid discharge slit 274 that discharges the prewetting liquid in the front in the movement direction and a rinsing liquid discharge slit 275 that discharges the rinsing liquid in the rear in the movement direction are arranged.

  The ozone water discharge slit 261 and the developer discharge slit 271 have a length of 310 mm and a width of 1 mm. The first to fourth suction slits 262, 263, 272, and 273 have a length of 310 mm and a width of 3 mm. The first and second prewetting liquid discharge slits 264 and 274 have a length of 310 mm and a width of 3 mm. The suction force from the suction slits 262, 263, 272, and 273 and the discharge speed from the ozone water or developer discharge slits 261 and 271 are balanced, and the chemical solution (developer solution) discharged from the ozone water or developer discharge slits 261 and 271 is balanced. , Ozone water) prevents the chemical solution from protruding outside the suction slit. Both the prewetting liquid and the rinsing liquid are supplied from each liquid discharge slit with pure water by a pump.

  As shown in FIGS. 13 and 14, each of the scan nozzles 260 and 270 includes a gap measuring mechanism 142 provided in the scan nozzle 120, a gap adjusting mechanism 143 provided at both ends of the scan nozzle 120, and the scan nozzle 120. And a scan stage 144 for relatively moving the substrate holder 141 in a substantially horizontal direction.

  Next, an example of substrate processing will be described. A 0.1 μm rule line-and-space DRAM pattern was drawn on a Cr mask blank coated with a positive chemically amplified resist to a thickness of 500 nm by an electron beam lithography system having an acceleration voltage of 50 keV. . After drawing, baking was performed at 110 degrees for 15 minutes. In this baking process, the acid evaporated from the resist reattaches to the resist, and the state of the poorly soluble layer on the resist surface depends on the drawing area ratio, which changes the pattern size after development, resulting in dimensional uniformity. make worse.

  Next, a substrate is mounted on the developing device. As shown in FIGS. 27A to 27C, the first scan nozzle 260 that performs ozone water treatment is moved at a constant speed from one end A of the substrate 130 to the other end B opposite to the substrate 130 to thereby generate ozone water. Process. The moving speed of the first scan nozzle 260 is set to 20 mm / sec. The ozone concentration of the ozone water was 5 ppm, and the discharge speed was 1 l / min. Since the interval between the ozone water discharge slit 261 and the suction slits 262 and 263 is 10 mm and the width of the ozone water discharge slit 261 is 1 mm, the ozone water exists between the scan nozzle and the substrate surface in the moving direction. Is about 21 mm in the direction parallel to. That is, when attention is paid to a certain point on the substrate surface, the time for the ozone water to pass through the place is about 1 second, and the effective ozone water treatment time is about 1 second. By this short-time ozone water treatment, it becomes possible to remove only the extremely thin hardly soluble layer formed on the resist surface, and the dissolution of the resist in the next development processing step starts uniformly. By using this apparatus, it is possible to uniformly perform chemical treatment in such a short time in a plane.

  A conventional combination of spray and substrate rotation or a combination of paddle and spin drying has different in-plane processing times and cannot achieve uniform processing. FIG. 29 shows the relationship between the ozone water concentration, the resist etching amount, and the resist surface roughness. It has been found that the effect of etching the resist is small at 0.2 ppm or more, and the surface roughness increases sharply when the content exceeds 35 ppm. For this reason, the ozone concentration of ozone water needs to be used between 0.2 ppm and 35 ppm. More preferably, ozone water having an ozone concentration of 0.2 ppm or more and 5 ppm or less is used.

  Next, as shown in FIGS. 28D to 28F, the second scan nozzle 270 that performs the development process is moved at a constant speed from one end A of the substrate 130 to the other end B that faces the second scan nozzle 270. And developed. The moving speed is 1 mm / sec. The developer is a 0.27 normal alkaline developer. The discharge speed was 0.5 l / min. The distance between the developer discharge slit 271 and the suction slits 272 and 273 is 10 mm, and the width of the developer discharge slit 271 is 1 mm. Therefore, the developer exists between the second scan nozzle 270 and the substrate surface in about 21 mm in the direction parallel to the moving direction. That is, when attention is paid to a certain point on the substrate surface, the time required for the developer to pass through the place is about 21 seconds, and the effective development time is about 21 seconds. In addition to the resist dissolution starting uniformly by this development process, after the developer is discharged, the developer flows at a high speed through the gap between the nozzle and the substrate surface, and is immediately removed by suction. Due to the effect that it can always be supplied to the resist surface, a uniform development process can be realized over the entire surface of the photomask. In other words, it can be realized only by a combination of uniform ozone water treatment using a proximity scan nozzle and development treatment.

  Next, the Cr film was etched by reactive ion etching using the formed resist pattern as an etching mask. A mixed gas of chlorine gas and oxygen gas was used as the etching gas. Thereafter, the resist was peeled off with an ashing device and washed with a washing machine. And the formed Cr pattern dimension was measured with the dimension measuring apparatus. As a result, the difference between the average value of the pattern dimension and the target dimension was 2 nm, and the in-plane uniformity of the Cr pattern dimension was 6 nm (3σ).

  Next, as an experiment to confirm the effectiveness of this developing method, the wafer was exposed with an ArF scanner using the shipped mask, and the exposure latitude was evaluated. The evaluation was performed by measuring the dimension of the resist pattern formed on the wafer by changing the defocus amount and the exposure amount by SEM. As a result, the defocus tolerance at which the variation amount of the resist pattern dimension formed on the wafer was 10% or less was 0.40 μm, and the exposure tolerance at that time was 12%.

  In addition, the present embodiment is an application example of the photomask manufacturing process to the developing process, but is not limited to this. In the flat panel display manufacturing process, the wafer process, etc., resist peeling, surface natural oxide film removal, cleaning, etc. Applicable to any chemical treatment.

(Eighth embodiment)
Embodiment 1 of the present invention will be described in detail with reference to FIG. 1, taking as an example the case of developing a wafer.

  30, 31, and 32 are diagrams showing a schematic configuration of the developing device according to the eighth embodiment of the present invention.

  As shown in FIGS. 30A and 30B, the developing nozzle 310 of the developing device includes a developer discharge nozzle 313 and a suction nozzle 314. The developer discharge nozzle 313 has a developer discharge port 311 on the surface facing the substrate 300. The developer discharge nozzle 313 has a discharge port 312 on the surface facing the substrate 300. The suction port 312 is disposed so as to continuously surround the developer discharge port 311.

  The developer discharge nozzle 313 pressurizes a chemical canister (not shown) of the supply / suction system 317 so that the developer is supplied into the developer discharge nozzle 313 through the developer introduction pipe 315. The supplied developer is discharged from the developer discharge port 311. The suction nozzle 314 is connected to the pump of the supply / suction system 317 via the discharge pipe 316. The solution on the substrate 300 is sucked from the suction port by the suction force of the pump. By performing the discharge and suction simultaneously, the developer 301 exists only in the region between the developer discharge port 311 and the suction port 312.

  Further, as shown in FIG. 31, the substrate 300 is held by a vacuum chuck 321. An auxiliary plate 322 is provided around the substrate. The auxiliary plate 322 is provided with a drive mechanism that moves up and down. It is preferable that the surface of the auxiliary plate 322 has substantially the same wettability with the developer as the surface of the substrate 310. A rinse liquid supply nozzle 323 that supplies a rinse liquid to the substrate 310 is provided. The rinse liquid supply nozzle 323 continuously supplies the rinse liquid. The substrate 300 is in a state filled with the rinse liquid supplied from the rinse liquid supply nozzle 323. Therefore, the suction port 312 sucks the solution in which both the developer and the rinse liquid are mixed. The developer discharge, suction, and rinse liquid discharge continue to be performed simultaneously.

  As shown in FIG. 32, a moving mechanism 319 for moving the developing nozzle 310 relative to the substrate 300 is provided. The moving mechanism 319 moves the developing nozzle 310 in the horizontal direction and the vertical direction. The control system 318 controls the supply / suction system 317 and the moving mechanism 319. The control system 318 controls the developer discharge speed, the developer discharge time, the suction speed, the suction time, the rinse liquid discharge amount, the discharge time, the nozzle moving speed, and the like.

  As shown in FIG. 30B, the developer discharged from the developer discharge port 311 creates a flow toward the suction port 312 that surrounds the periphery and is sandwiched between the suction ports 312. Development is carried out only at. That is, the control system 318 balances the developer discharge pressure and the suction pressure so that the developer does not leak outside the suction port 312.

The treatment area with the developer is set to 4πmm ² . The distance between the lower surface of the nozzle 310 and the substrate 300 is set to about 100 μm. Next, a specific method for supplying the developer onto the wafer will be described. The pattern formed on the mask by a KrF excimer stepper is transferred to a wafer on which a photosensitive resin film such as a resist having a thickness of 0.4 μm is formed on the base film to be processed, and a pattern latent of 0.13 μm is transferred to the photosensitive thin film. Form an image. The wafer is held horizontally by a wafer holder. The developer used was TMAH (normality 0.27N), and the developer discharge speed and suction speed were adjusted.

  The developer discharge port diameter was 2 mm, the suction port inner diameter was 3.5 mm, the suction port outer diameter was 4.5 mm, the developer discharge speed was 100 cc / min, the suction speed was 100 cc / min, and the rinse liquid discharge speed was 300 cc / min.

  Next, a processing method will be described.

  First, the wafer substrate is held by the vacuum chuck 321. The developing nozzle 310 is moved above the edge on the wafer main surface. The upper surface of the auxiliary plate 322 is set to the same height as the wafer surface. The nozzle 310 is moved from the upper end of the wafer main surface to a position on the gap 100 μm and to the development start point.

  A procedure for determining processing conditions will be described. FIG. 33 shows the relationship between the pattern coverage and the nozzle scan speed in a 0.13 μm pattern. The pattern coverage is the area ratio of the resist that remains on the substrate without being dissolved in the developer by the development process.

  When the coverage is large, the resist pattern size is finished larger when a positive resist is used than when the coverage is small. Therefore, a desired dimension is obtained by changing the scanning speed according to the coverage. The rate of change is also indicated according to the coverage. As the method, the coverage in the processing area formed by the developer flowing from the developer discharge port to the suction port is calculated, and the scan speed of the nozzle finished to a desired pattern dimension is calculated from the value from the preliminary experiment data.

  FIG. 34 shows the coverage distribution of chips in the wafer to be processed this time. FIG. 34A is a plan view showing the configuration of the wafer. FIG. 34B is a diagram showing a coverage distribution in the chip. The coverage of the pattern in the chip 341 of the wafer 340 can be obtained from the design data. Further, a light source for irradiating the substrate with light and a reflected light intensity measurement system for measuring the reflected light intensity from the substrate are provided on the front side in the moving direction of the developing nozzle. In addition, it is preferable to use the line sensor longer than the width | variety of a process area for the intensity meter which measures reflected light intensity. And it can obtain | require from the change of the measurement result of a reflected light intensity measurement system, and a process area | region shape. Further, the transmitted light intensity can be measured instead of the reflected light intensity, and can be obtained from the change in the measurement result of the reflection intensity measurement system and the shape of the processing region.

  The developing nozzle 310 is moved over the scan start point of the chip 341. Then, the developer discharge, the developer suction, and the rinse liquid discharge are simultaneously performed, and scanning of the developing nozzle 310 is started. The locus of the developing nozzle 310 is shown in FIG. FIG. 36 shows the relationship between processing time and scan speed. After the start of scanning, the nozzle passes through an area with a coverage of 50%, but the scanning speed at that time is 1 mm / sec as shown in FIG. 3636, and then passes through an area with a coverage of 10%, but the scanning speed at that time is 1.3 mm. The processing is performed at a scanning speed corresponding to the coverage of the region through which the nozzle passes, such as / sec. The coverage of the boundary portion of the processing region was also obtained so that the nozzle scan speed was achieved to a desired pattern size.

  After the development processing was completed, the substrate was rotated, the liquid on the substrate was shaken off, the drying of the substrate was completed, and the resist pattern formation was completed.

  The relationship between the amount of deviation of the formed pattern from the target value and the coverage is shown in FIG. The pattern dimensions could be formed with a deviation amount of ± 5 nm or less from the target value in the entire region.

  In this embodiment, an example of application of resist development is shown, but the present invention is not limited to resist development. For example, it can be applied to the development of photosensitive films on substrates in wet etching of wafers and photomask manufacturing processes for semiconductor manufacturing, wet etching, cleaning, color filter manufacturing processes, and development in the processing of discs such as DVDs. It is.

  The size, shape, and processing conditions of the nozzle are not limited to the shapes shown in the examples. For example, a chemical solution discharge port may be arranged at the center, and the periphery thereof may be surrounded by a rectangular suction port. Further, the developing nozzle 380 shown in FIGS. 38A and 38B may be used. A rinse liquid discharge port 381 is provided outside the suction port 311. FIG. 38A is a plan view showing the configuration of the lower surface of the developing nozzle, and FIG. 38B is a plan view showing the configuration of the developing nozzle.

  Further, as shown in FIG. 39, a developer discharge port 311 may be disposed around the suction port 312. FIG. 39A is a plan view showing the configuration of the lower surface of the developing nozzle, and FIG. 39B is a plan view showing the configuration of the developing nozzle.

  Further, as shown in the present embodiment, the rinsing liquid does not necessarily have to be present outside the nozzle suction port. For example, there may be other liquid outside the nozzle suction port, or there may be no liquid. It may be in a gaseous state. In such a case, it is necessary to balance the developer discharge pressure and the developer suction pressure so that the developer does not leak to the outside of the developer suction port and the atmosphere such as external air is not sucked.

  The processing conditions may need to be changed depending on the surface condition of the material to be processed, the wettability of the processing liquid, the nozzle diameter and the material, etc. in order to obtain a desired flow rate, and are limited to the values shown in this embodiment. It is not something. In addition, even when the pattern sizes are different, it is of course included in the present method that the relationship between the coverage and the scanning speed is acquired in advance depending on the respective pattern sizes, and the optimum scanning speed for finishing to a desired dimension is selected. The processing region may be only a part of processing as well as the entire surface of the processing wafer.

(Ninth embodiment)
FIG. 40 is a diagram showing the configuration of the developing nozzle of the developing device according to the ninth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same site | part as 30, and the description is abbreviate | omitted.

  A reflective optical monitor 400 is attached to the side surface of the developing nozzle 310. The measured value of the reflective optical monitor 400 is taken into the control system 318. The control system 318 measures a gap between the upper surface of the substrate and the lower surface of the nozzle from the measured value. In this embodiment, the processing is performed by changing the flow rate of the developer by controlling the gap between the nozzle 310 and the substrate. Other configurations are the same as those in the eighth embodiment, and thus are omitted.

  Under the processing conditions of the eighth embodiment, the average flow velocity of the processing liquid is 0.1 (mm) × 4π × v (mm / sec) = 0.1 / 60 (L / sec). It is about 27 m / sec. FIG. 41 shows the relationship between the coverage and the developer flow rate.

  In order to finish pattern dimensions having different coverage ratios at a predetermined development time (scanning speed: 1 mm / sec), it is necessary to increase the flow rate when the coverage ratio is large. Conversely, where the coverage is small, the flow rate need not be so fast. The developing nozzle 310 was moved to the scan start point, and developer discharge, developer suction, and rinse liquid discharge were performed. The conditions were changed while changing the gap between the nozzle and the substrate so that the flow rate of the developing solution became the optimum flow rate according to the coverage of the substrate. FIG. 41 shows the relationship between the coverage and the optimum flow rate. More specifically, FIG. 42 shows the developer flow rate with respect to the processing time.

  Based on the relationship shown in FIG. 42, development processing is performed in the same manner as in the chip of the eighth embodiment and the coverage ratio.

  After the development processing was completed, the wafer was rotated, and the rinse solution on the wafer was shaken off and dried to complete the resist pattern formation.

  Further, the flow rate control is not limited to the gap. This can also be achieved by controlling the developer discharge speed and developer suction speed.

(Tenth embodiment)
The surface treatment before the development of the resist film will be described.

  After the exposure, an oxidation treatment is performed before developing the resist on the wafer subjected to a predetermined baking. Since the wettability with respect to the developer is different between the exposed portion and the unexposed portion, the flow rate of the developer is strictly different between the exposed portion and the unexposed portion when the development process is performed. The oxidation treatment is performed in order to improve the wettability of the resist surface with respect to the developer over the entire surface of the substrate. Ozone water was used for the oxidation treatment.

  FIG. 43 is a diagram showing the configuration of the processing nozzle of the substrate surface processing apparatus according to the tenth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the site | part same as FIG. 30, and the description is abbreviate | omitted. As shown in FIG. 43R> 3, the processing nozzle 430 includes an ozone water supply nozzle 432. The ozone water supply nozzle 432 has an ozone water discharge port 431 on the surface facing the substrate 300. Ozone water supplied from a supply / suction system (not shown) is discharged from the ozone water discharge port 431 to the substrate 300.

  Next, the oxidation treatment will be described. The concentration of ozone water used for the oxidation treatment of the resist surface was 3 ppm. An oxidation process is performed on a chip having the same coverage as that in the eighth embodiment. As in the eighth embodiment, processing is performed based on the relationship between the processing time and the scanning speed shown in FIG. During the oxidation process, processing is performed so that the gap between the lower surface of the processing nozzle 430 and the upper surface of the substrate 300 becomes a constant value according to the measurement value of the reflection optical monitor.

  After the oxidation treatment, development processing is performed on the resist film to be processed. Then, after rinsing is performed by supplying a rinsing liquid onto the substrate, the substrate is rotated and the liquid on the substrate is shaken off to dry the substrate. Thus, the formation of the resist pattern is completed.

  Before and after the ozone water treatment, the contact angle of the developer on the resist film was measured to evaluate the wettability. The contact angle was 60 ° before the treatment, but improved to 54 ° after the treatment. It was confirmed that the wettability of the resist film to the developer was improved by the ozone water treatment. Improved wettability allows the developer to flow on the substrate at a very high rate. As a result, the replacement effect of development inhibitors between patterns during development was improved, and the dimensional difference due to pattern density could be reduced to ± 4 nm.

  The means used for changing the processing time is not limited to the relative speed between the substrate and the nozzle. For example, the effective processing time can be changed by changing the concentration and temperature of the processing solution and the flow rate of the processing solution. Moreover, this method is not limited to performing the said process about all the area | regions on a board | substrate. There may be a case where only the exposed part or only the unexposed part is processed. The substrate surface treatment is not limited to the oxidizing liquid. The treatment with the reducing liquid may be performed after the treatment with the oxidizing liquid, or an acidic or alkaline liquid with a very low concentration may be used.

(Eleventh embodiment)
In the present embodiment, a case will be described in which the present invention is applied to cleaning that removes resist residue and attached dust on the mask.

  FIG. 44 is a diagram showing the configuration of the processing nozzle of the processing apparatus according to the eleventh embodiment of the present invention. Since the processing nozzle 430 used for processing is the same as the nozzle described in the tenth embodiment, detailed description thereof is omitted. Ozone water having a concentration of 20 ppm is used as the cleaning liquid.

  Next, actual processing will be described.

  Defect inspection is performed on the 6-inch mask substrate after the resist pattern is formed, and the position of the foreign matter 441 such as resist residue and attached dust on the mask is detected in advance.

  After the mask is set on the substrate support, the nozzle is moved above the defect coordinate position as shown in FIG. The gap between the lower surface of the processing nozzle 430 and the upper surface of the substrate 300 is set to 50 μm. Thereafter, ozone water is discharged from the ozone water discharge port 431 and simultaneously sucked from the suction port 312. After the position of the processing nozzle 430 is fixed and ozone water is discharged and sucked for 10 seconds, the discharge and suction operations of the ozone water are stopped. After the processing, the nozzle is retracted to the nozzle standby position.

  At the time of processing, the gap is controlled to 50 μm by the measurement value of the reflection optical monitor. By controlling the gap, the average flow rate of the cleaning liquid was set to 10 cm / sec or more.

  After the processing, a rinsing liquid is supplied onto the substrate 300 to perform a rinsing process, and then the substrate is rotated to shake off the liquid on the substrate and the cleaning of the substrate is completed.

All the organic deposits on the substrate were successfully removed using the method according to the present embodiment.

  According to the experiments by the inventors, it was confirmed that the organic matter adhesion was completely removed when the cleaning liquid flow rate was 10 cm / sec or more. Accordingly, the cleaning liquid flow rate is preferably 10 cm / sec or more. Needless to say, it is possible to arbitrarily select a gap, a cleaning liquid discharge speed, and a cleaning liquid suction speed at which the average cleaning liquid flow rate can achieve 10 cm / sec. Pressure may be applied to the liquid with a pump or the like, which may be applied intentionally.

  In addition, this treatment is effective not only for the resist pattern but also for adhesion of organic substances on the chromium mask and the halftone mask after the resist is removed.

(Twelfth embodiment)
In the present embodiment, a case will be described in which the present invention is applied to cleaning that removes resist residue and attached dust on the mask.

  FIG. 45 is a diagram showing the configuration of the developing nozzle of the developing device according to the twelfth embodiment of the present invention. In FIG. 45, the same parts as those in FIG. 30 are denoted by the same reference numerals, and the description thereof is omitted.

  The developing nozzle 450 includes an ultrasonic vibrator 451 on the lower surface. By operating the ultrasonic vibrator 451 during the development process, the developer 301 between the lower surface of the development nozzle 450 and the substrate 300 is vibrated. Due to the pulsation of the developing solution, as shown in FIG. 46, the replacement of the developing solution 301 between the resist patterns 462 on the wafer 461 is efficiently performed. As a result, a desired pattern dimension can be obtained.

  In the case where development processing is performed only with a developing solution having a specific flow rate with the development nozzle being brought close to the surface of the substrate, it is very difficult for the development processing to finish, for example, patterns having different coverage ratios to desired dimensions at the same time. This is considered to be caused by the poor efficiency of developer replacement between patterns. However, by applying ultrasonic vibration to the developer on the substrate, the replacement efficiency is improved, and patterns with different coverages can be finished to the desired dimensions at the same time.

  In addition, not only the method of applying ultrasonic vibration to the developer on the substrate, the replacement efficiency can be improved similarly even if the flow rate of the developer is changed with time. Further, the same effect can be obtained even when at least one of the relative movement speed between the developing nozzle and the substrate and the distance between the chemical solution discharge / suction unit and the substrate surface is varied with time.

  Further, an ultrasonic vibrator may be provided in the scan nozzle of the developing device shown in FIGS. 12 to 14 to give vibration to the developer on the substrate. Further, the same effect can be obtained even when at least one of the flow rate of the developing solution, the relative movement speed between the developing nozzle and the substrate, and the distance between the chemical solution discharge / suction unit and the substrate surface is varied over time.

  In addition, this invention is not limited to the said embodiment, In addition, this invention can be variously modified and implemented in the range which does not deviate from the summary.

  As described above, according to the present invention, the “limit solution concentration” is estimated, and the developer treatment is performed so that the resist solution concentration in the developer is equal to or less than the “limit solution concentration” when developing the patterned substrate. As a result, uniform development can be performed regardless of the density difference of the patterns, and a pattern with very high dimensional accuracy can be formed.

  By changing the amount of the first chemical liquid that passes through the unit volume area in contact with the substrate per unit time, it becomes possible to perform high-precision chemical liquid processing regardless of the density difference of the pattern, and the dimensional accuracy is very high. A high pattern can be formed.

  The flow rate of the chemical solution flowing between the substrate and the chemical solution discharge / suction unit is made faster than the relative movement speed of the chemical solution discharge / suction unit and the substrate, thereby suppressing a rapid change in pattern size. Can do.

  By setting the distance between the substrate and the lower surface of the chemical solution discharge / suction part to 0.01 mm or more and 0.5 mm or less, it is possible to suppress a decrease in the replacement efficiency of the chemical solution, and it is highly accurate regardless of the pattern density difference. It becomes possible to perform a proper chemical treatment.

  By making the average flow rate of the chemical solution flowing between the substrate and the chemical solution discharge / suction part 0.02 m / sec or more, the replacement efficiency of the chemical solution is improved, and high-precision chemical solution processing is performed regardless of the density difference of the pattern. Can be performed.

  By varying temporally the flow rate of the chemical solution flowing between the chemical solution discharge / suction unit and the substrate or the interval between the chemical solution discharge / suction unit and the substrate, high accuracy can be achieved regardless of the density difference of the pattern. It is possible to perform chemical treatment.

  By arranging the chemical solution suction port so as to surround the chemical solution discharge port, it is possible to form a chemical solution flow that flows radially from the center to the periphery, and to make each of the chemical solution discharge port and the chemical solution suction port have desired sizes. This makes it possible to perform chemical treatment only on the desired region. By performing processing at an optimum relative speed between the substrate and the chemical solution discharge / suction unit corresponding to the coverage of the pattern existing in the processing region formed by the chemical solution flow, it is uniform regardless of the density difference of the pattern. Chemical treatment can be performed.

The figure which shows the relationship between the resist melt | dissolution density | concentration and development speed concerning 1st Embodiment. 1 is a diagram illustrating a schematic configuration of a developing device according to a first embodiment. FIG. 3 is a flowchart illustrating a developing method according to the first embodiment. FIG. 4 is a diagram for explaining a developer discharge amount estimation method according to the first embodiment. Sectional drawing which shows the photomask manufacturing process concerning 1st Embodiment. The figure which shows the structure of the conventional image development apparatus. FIG. 3 is a plan view showing a pattern formed by development processing according to the first embodiment. The characteristic view which shows the line pattern dimension Y with respect to the distance X shown in FIG. The figure which shows an example of the setting method of a resist aperture ratio and a developing solution discharge amount. The figure which shows resist opening rate distribution and a developing solution discharge amount setting value. The figure which shows resist opening rate distribution and a developing solution discharge amount setting value. FIG. 4 is a diagram illustrating a schematic configuration of a developing device according to a second embodiment. FIG. 4 is a diagram illustrating a schematic configuration of a developing device according to a second embodiment. FIG. 4 is a diagram illustrating a schematic configuration of a developing device according to a second embodiment. The figure which shows the relationship between the average aperture ratio after image development of a 5 mm square area | region in a positive type resist, and the gap between the nozzle for finishing to a desired resist dimension, and a board | substrate. The figure which shows the relationship between the gap of a nozzle and a substrate surface, and the resist dimension after image development. The figure which shows the relationship between the average flow velocity of the developing solution which flows through the clearance gap between a nozzle and a board | substrate, and the resist dimension after image development. The top view which shows the aperture ratio of the layer of the system LSI device pattern drawn concerning 2nd Embodiment. FIG. 10 is a diagram illustrating a state of movement of a scan nozzle in development processing according to the second embodiment. The figure which shows the relationship between the position of the scan nozzle concerning 2nd Embodiment, and a gap. The figure which shows the relationship between the average aperture ratio after the development of each 5 mm area | region in the positive resist concerning 3rd Embodiment, and the scanning speed of the nozzle for finishing to a desired resist dimension. The figure which shows the relationship between the position of the scan nozzle concerning 3rd Embodiment, and a scanning speed. The figure which shows the relationship between the average aperture ratio after the development of each 5 mm area | region in the positive resist concerning 4th Embodiment, and the developing solution discharge speed for finishing to a desired resist dimension. The figure which shows the relationship between the position of the scan nozzle concerning 4th Embodiment, and a scanning speed. The figure which shows the relationship between the scanning speed concerning 4th Embodiment, and the pattern aperture ratio of a nozzle lower surface. FIG. 10 is a diagram illustrating a schematic configuration of a developing device according to a seventh embodiment. FIG. 10 is a diagram illustrating a state of movement of a scan nozzle in development processing according to a seventh embodiment. FIG. 10 is a diagram illustrating a state of movement of a scan nozzle in development processing according to a seventh embodiment. The figure which shows the relationship between ozone water concentration, the amount of resist etching, and the relationship of resist surface roughness. FIG. 10 is a diagram illustrating a schematic configuration of a developing device according to an eighth embodiment. FIG. 10 is a diagram illustrating a schematic configuration of a developing device according to an eighth embodiment. FIG. 10 is a diagram illustrating a schematic configuration of a developing device according to an eighth embodiment. The figure which shows the relationship between the pattern coverage in the pattern of 0.13 micrometer concerning 8th Embodiment, and a nozzle scan speed. The figure which shows the coverage distribution of the chip | tip in a wafer concerning 8th Embodiment. The top view which shows the locus | trajectory of the developing nozzle concerning 8th Embodiment. The figure which shows the relationship between the processing time and scan speed concerning 8th Embodiment. The figure which shows the relationship between the deviation | shift amount from the target value of the formed pattern concerning 8th Embodiment, and a coverage. The figure which shows the modification of the developing nozzle concerning 8th Embodiment. The figure which shows the modification of the developing nozzle concerning 8th Embodiment. The figure which shows the structure of the developing nozzle of the developing device concerning 9th Embodiment. The figure which shows the relationship between the coverage concerning 9th Embodiment, and the flow velocity of a developing solution. The figure which shows the developing solution flow rate with respect to the processing time concerning 9th Embodiment. The figure which shows the structure of the process nozzle of the substrate surface processing apparatus concerning 10th Embodiment. The figure which shows the structure of the process nozzle of the processing apparatus concerning 11th Embodiment. The figure which shows the structure of the developing nozzle of the developing device concerning 12th Embodiment. FIG. 20 is a diagram for explaining the operations and effects of a developing device according to a twelfth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Board | substrate, 20 ... Scan nozzle, 21a ... Developer discharge port, 21 ... Developer discharge nozzle,
21b ... Developer discharge port, 21a ... Discharge port, 22b ... Suction port, 22 ... Suction nozzle, 31 ... Developer, 32 ... Rinse solution

Claims (10)

The first chemical liquid is continuously discharged from the first chemical liquid discharge port disposed on the lower surface of the first chemical liquid discharge / suction unit to the substrate, and the first chemical liquid discharge / While the solution on the substrate is continuously sucked from the two suction ports arranged on the lower surface of the suction unit, the first chemical solution discharge / suction unit and the substrate are relatively horizontally linearly moved while the substrate is abbreviated. Treating the surface with a first chemical solution;
A second chemical liquid different from the first chemical liquid is continuously discharged to the substrate from a second chemical liquid discharge port disposed on the lower surface of the second chemical liquid discharge / suction section different from the first chemical liquid discharge / suction section. In addition, while continuously sucking the solution on the substrate from the two suction ports arranged on the lower surface of the second chemical solution discharge / suction unit so as to sandwich the chemical solution discharge port, And a step of performing chemical treatment on a substantially surface of the substrate with a second chemical solution while moving the substrate relatively horizontally and linearly. The first chemical solution discharge / suction unit includes two third and fourth chemical solution discharge ports arranged on the lower surface of the first chemical solution discharge / suction unit so as to sandwich the two first suction ports.
The second chemical solution discharge / suction unit includes two fifth and sixth chemical solution discharge ports arranged on the lower surface of the second chemical solution discharge / suction unit so as to sandwich the two second suction ports.
During the first chemical liquid treatment, the third and fourth chemical liquids are continuously discharged from the third and fourth chemical liquid discharge ports to the substrate,
2. The substrate processing method according to claim 1, wherein the fifth and sixth chemical liquids are continuously discharged from the fifth and sixth chemical liquid discharge ports to the substrate during the second chemical liquid processing. The first suction port, the first chemical solution discharge port, and the first suction port are arranged in this order with respect to the relative movement direction of the substrate and the first chemical solution discharge / suction unit. The substrate processing method according to claim 1. In the second chemical solution discharge / suction unit, the second suction port, the second chemical solution discharge port, and the second suction port are arranged in this order with respect to the relative movement direction of the substrate and the chemical solution discharge / suction unit. The substrate processing method according to claim 1, wherein the substrate processing method is provided. The substrate processing method according to claim 1, wherein the first chemical solution is ozone water, and the second chemical solution is a developer. A third chemical solution discharge port, a first suction port, a first chemical solution discharge port, a first suction port, a fourth, with respect to the relative movement direction of the substrate and the first chemical solution discharge / suction unit. The substrate processing method according to claim 2, wherein the chemical solution discharge ports are arranged in this order. A fifth chemical liquid discharge port, a second suction port, a second chemical liquid discharge port, a second suction port, a sixth liquid discharge port, a second chemical liquid discharge port, a second suction port, and a sixth chemical liquid discharge port. The substrate processing method according to claim 2, wherein the openings are arranged in the order of the chemical solution discharge openings. 8. The substrate processing method according to claim 2, wherein the first chemical liquid is ozone water, the second chemical liquid is a developer, and the third to sixth chemical liquids are pure water. The substrate processing method according to claim 5, wherein an ozone concentration in the ozone water is 0.2 ppm to 35 ppm. A method of manufacturing a semiconductor device, comprising: manufacturing a semiconductor device using the substrate processing method according to claim 1.

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