JP2003109897A - Method and device for processing development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing processing method which hardly produces pattern deterioration in final drying in developing processing for developing an exposure pattern. SOLUTION: Developing processing is performed by developing processes (ST2 and ST3) for feeding a developer to a resist film after exposure on a substrate W and developing an exposure pattern, a process (ST6) for feeding a water-based washing liquid to the resist film forming the developing pattern, a process (ST7) for feeding a chemical whose surface tension is smaller than water without substantially dissolving a resist on the resist film feeding the water-based washing liquid, and a process (ST8) for rotating and drying the substrate W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a development processing method and a development processing apparatus for developing an exposure pattern of a resist film after exposure on a substrate such as a semiconductor wafer.

[0002]

2. Description of the Related Art For example, in a semiconductor device manufacturing process, a resist solution is supplied to the surface of a semiconductor wafer (hereinafter referred to as "wafer") to form a resist film, and a predetermined pattern is formed on the wafer after the resist is applied. A resist pattern is formed as a mask for forming a predetermined pattern by a so-called photolithography technique in which the exposure pattern formed on the resist film of the wafer is developed after performing the exposure process corresponding to.

In the developing process among the respective steps of the photolithography technique, a developing solution is supplied to the wafer, a developing solution paddle is formed on the entire surface of the wafer so that the thickness thereof is, for example, 1 mm, and natural convection is performed for a predetermined time. After the development processing is advanced by, the developing solution is shaken off, and then pure water is supplied as a cleaning solution to wash away the developing solution remaining on the wafer.
After that, the wafer is rotated at a high speed to shake off the developing solution and the cleaning solution remaining on the wafer to dry the wafer.

[0004]

By the way, in recent years, the miniaturization of semiconductor devices has been further advanced due to the progress of exposure technology and the like, and a fine resist pattern having a high aspect ratio has appeared. A "pattern collapse", which is a problem that such a fine resist pattern having a high aspect ratio collapses during the final shake-off drying in the developing step, is a serious problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a development processing method and a development processing apparatus in which pattern collapse is less likely to occur during final drying in the development processing for developing an exposed pattern. To do.

[0006]

In order to solve the above problems, in a first aspect of the present invention, a developing step of supplying a developing solution to a resist film after exposure on a substrate to develop an exposure pattern, A step of supplying an aqueous cleaning solution to the resist film having a development pattern formed thereon, and a step of supplying a liquid agent having a surface tension smaller than water, which does not substantially dissolve the resist, in the resist film supplied with the aqueous cleaning solution. And a step of drying the substrate by rotating the substrate.

According to a second aspect of the present invention, a developing step of supplying a developing solution to the exposed resist film on the substrate to develop the exposed pattern, and a resist film on which the developed pattern is formed while rotating the substrate. Supplying an aqueous cleaning solution, and replacing the aqueous cleaning solution by supplying a liquid agent that does not substantially dissolve the resist in the resist film to which the aqueous cleaning solution is supplied while rotating the substrate and has a surface tension smaller than that of water And a step of rotating and drying the substrate.

According to a third aspect of the present invention, there is provided a development processing device for supplying a developing solution to a resist film after exposure on a substrate to develop an exposure pattern, the substrate holding device holding the substrate substantially horizontally. A member, a rotation mechanism for rotating the substrate holding member, a developing solution supply mechanism for supplying a developing solution to the substrate on the substrate holding member, and an aqueous cleaning solution supply mechanism for supplying an aqueous cleaning solution to the resist film on which the development pattern is formed. And a liquid agent supply mechanism that supplies a liquid agent having a surface tension smaller than that of water, which does not substantially dissolve the resist, to the resist film supplied with the aqueous cleaning solution, and the liquid agent is supplied from the liquid agent supply mechanism. After that, a development processing apparatus is provided in which the substrate is rotated by the rotation mechanism and dried.

In the present invention, after cleaning the developing solution on the substrate with an aqueous cleaning solution, a liquid agent having a smaller surface tension than water is supplied, so that an aqueous cleaning solution having a large surface tension is replaced with a liquid agent having a small surface tension. It is possible to reduce the stress exerted on the resist pattern during the dry-off.
Therefore, the resist pattern collapse can be suppressed. Further, since the liquid agent that does not dissolve the resist is used, the resist pattern is not adversely affected.

In the present invention, the liquid agent is preferably an organic solvent. Generally, organic solvents have low surface tension,
It is suitable for this purpose. The organic solvent is preferably hydrophobic. By using the hydrophobic organic solvent as described above, the organic solvent can be easily separated from the aqueous cleaning liquid, and the organic solvent can be reused by adding a step of recovering the organic solvent. Moreover, as such a hydrophobic organic solvent, at least one kind of hydrofluoroethers, xylene, and hexamethyldisilazane can be used. Further, among such hydrophobic organic solvents, those having a specific gravity larger than that of an aqueous cleaning liquid such as hydrofluoroethers are preferable. As a result, the organic solvent exists in the lower part of the recovery tank, and the organic solvent can be recovered more easily.
Dilute hydrofluoric acid can also be used as the liquid agent. The contact angle between the resist pattern corresponding to the development pattern and the liquid agent is preferably 60 to 120 °.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing a resist coating and developing treatment system equipped with a developing treatment unit for carrying out the developing treatment method of the present invention,
2 is a front view thereof, and FIG. 3 is a rear view thereof. In these figures, the directions orthogonal to each other in the plane are X-
Y and the vertical direction are indicated by Z.

The resist coating and developing system 1 is
A cassette station 10, which is a transfer station,
A processing station 11 having a plurality of processing units;
An interface unit 12 for transferring the wafer W between the processing station 11 and an exposure device (not shown) provided adjacent to the processing station 11.

In the cassette station 10, a plurality of wafers W to be processed are loaded into the wafer cassette CR in units of, for example, 25 wafers, and loaded into or unloaded from another system. Wafer cassette CR and processing station 1
This is for carrying the wafer W to and from 1.

In this cassette station 10
Mounts the wafer cassette CR as shown in FIG.
Plural (4 in the figure) on the mounting table 20 along the X direction in the figure
The positioning protrusion 20a of the
Wafer cassette CR goes in and out of each wafer at position a.
Can be placed in a line with the mouth facing the processing station 11 side
Has become. In the wafer cassette CR, the wafer W
They are arranged in the vertical direction (Z direction). Also cassette
The station 10 includes a mounting table 20 and a processing station 1.
1 and a wafer transfer mechanism 21 located between the two.
The wafer transfer mechanism 21 is arranged in the cassette arrangement direction (X direction).
Direction) and the wafer arranging direction of the wafers W therein (Z direction)
Direction) and has a wafer transfer arm 21a
This wafer transfer arm 21a
Selectable access to the Eha cassette CR
ing. Further, the wafer transfer arm 21a moves in the θ direction.
A processing station that is configured to be rotatable and will be described later
11th side third processing unit group G _ThreeAllimen belonging to
Unit (ALIM) and extension unit
You can also access the EXT.

The processing station 11 is provided with a plurality of processing units for carrying out a series of steps for coating / developing the wafer W, and these processing units are arranged in multiple stages at predetermined positions. The wafers W are processed one by one. As shown in FIG. 1, the processing station 11 has a transfer path 22a in the center thereof, a main wafer transfer mechanism 22 is provided in the transfer path 22a, and all the processing units are arranged around the transfer path 22a. . The plurality of processing units are divided into a plurality of processing unit groups, and each processing unit group includes a plurality of processing units arranged in multiple stages along the vertical direction.

As shown in FIG. 3, the main wafer transfer mechanism 22 is equipped with a wafer transfer device 46 inside a cylindrical support 49 so as to be vertically movable (Z direction). The cylindrical support 49 is rotatable by a rotational driving force of a motor (not shown), and the wafer transfer device 4 is accordingly rotated.
6 is also rotatable integrally.

The wafer transfer device 46 is provided with a plurality of holding members 48 that are movable in the front-back direction of the transfer base 47, and these holding members 48 realize the transfer of the wafer W between the processing units. .

Further, as shown in FIG. 1, in this embodiment, four processing unit groups G ₁ , G ₂ , G ₃ ,
G ₄ is arranged around the transport path 22a, and the processing unit group G ₅ can be arranged as necessary.

Of these, the first and second processing unit groups G ₁ and G ₂ are arranged in parallel on the front side of the system,
The third processing unit group G ₃ is the cassette station 10
And the fourth processing unit group G ₄ is arranged adjacent to the interface unit 12. Also,
The fifth processing unit group G ₅ can be arranged on the back surface.

In the first processing unit group G ₁ , the cup C
A resist coating processing unit (COT) that mounts the wafer W on a spin chuck (not shown) in P to coat the resist on the wafer W, and a developing processing unit (DEV that similarly develops the resist pattern in the cup CP). ) Are stacked in two steps in order from the bottom. Second processing unit group G
₂ Similarly, the resist coating unit (COT) and developing unit (DEV) are two-tiered in order from the bottom as two spinner-type processing units.

In the third processing unit group G ₃ , as shown in FIG. 3, a plurality of oven-type processing units for stacking the wafer W on the mounting table SP and performing a predetermined processing are stacked. That is, the adhesion unit (A) that performs a so-called hydrophobic treatment for improving the fixability of the resist.
D), an alignment unit (ALIM) for aligning the wafer W, an extension unit (EXT) for loading / unloading the wafer W, a cooling unit (COL) for cooling processing, before and after exposure processing, and further for development. Four hot plate units (HP) for heating the wafer W after the processing are stacked in eight stages in order from the bottom. Alignment unit (ALIM)
Alternatively, a cooling unit (COL) may be provided and the cooling unit (COL) may have an alignment function.

Also in the fourth processing unit group G ₄ , oven type processing units are stacked in multiple stages. That is, a cooling unit (COL), an extension / cooling unit (EXTCOL) that is a wafer loading / unloading unit equipped with a cooling plate, an extension unit (EXT), a cooling unit (COL), and four hot plate units (HP) are located below. In order from 8
It is stacked in columns.

When the fifth processing unit group G ₅ is provided on the back side of the main wafer transfer mechanism 22, it can be moved laterally along the guide rail 25 as viewed from the main wafer transfer mechanism 22. . Therefore, even when the fifth processing unit group G ₅ is provided, the space is secured by sliding the fifth processing unit group G ₅ along the guide rail 25, so that maintenance work can be easily performed from the rear side with respect to the main wafer transfer mechanism 22. Can be done.

The interface section 12 has the same length in the depth direction (X direction) as that of the processing station 11. As shown in FIGS. 1 and 2, the interface section 12 has a portable front surface. Pick-up cassette CR
The stationary buffer cassette BR is arranged in two stages, the peripheral exposure device 23 is arranged at the back surface, and the wafer transfer mechanism 24 is arranged at the central part. The wafer transfer mechanism 24 has a wafer transfer arm 24a. The wafer transfer arm 24a moves in the X and Z directions to access both cassettes CR, BR and the peripheral exposure device 23. ing. Further, the wafer transfer arm 24a is rotatable in the θ direction, and an extension unit (EXT) belonging to the fourth processing unit group G ₄ of the processing station 11 or a wafer transfer table of the adjacent exposure apparatus side. It is also accessible (not shown).

In the resist coating / developing processing system 1 configured as described above, the unprocessed wafers W are taken out one by one by the wafer transfer mechanism 21 from the wafer cassette CR and carried into the alignment unit (ALIM) of the processing station 11. . Next, the wafer W positioned here is carried out by the main wafer transfer mechanism 22 and carried into the adhesion unit (AD) to be subjected to the adhesion processing. After the completion of this adhesion process, the wafer W is unloaded by the main wafer transfer mechanism 22 and transferred to the cooling unit (COL) where it is cooled. Next, the wafer W is transferred to a resist coating unit (COT) for resist coating, and further, prebaking processing is performed by a hot plate unit (HP), and an extension cooling unit (EXTCOL) is used.
The wafer is transferred to the interface section 12 and then transferred from the wafer transfer mechanism 24 to an adjacent exposure apparatus. further,
The wafer W that has been subjected to the exposure processing by the exposure apparatus is processed by the wafer transfer mechanism 24 via the interface unit 12 and the extension unit (EXT) to the processing station 1.
Transport to 1. In the processing station 11, the main wafer transfer mechanism 22 transfers the wafer W to the hot plate unit (HP) for post exposure processing, and then to the developing unit (DEV) for development processing, and then the hot plate unit. (HP) post-bake process, and after cooling in the cooling unit (COL), the extension unit (EXT)
It is conveyed to the cassette station 10 via. The wafer transfer mechanism 21 stores the wafer W, which has been subjected to the predetermined processing as described above, in the wafer cassette CR.

Next, a development processing unit (DEV) for carrying out the development processing method of the present invention will be described with reference to FIGS. 4 and 5. 4 and 5 are a cross-sectional view and a plan view showing the overall configuration of the development processing unit (DEV).

This development processing unit (DEV) is a housing 5
0, the annular cup CP is arranged in the center thereof, and the spin chuck 52 is arranged inside the cup CP. The spin chuck 52 is rotationally driven by a drive motor 54 while holding the wafer W fixed by vacuum suction. The drive motor 54 is a bottom plate 50 a of the housing 50.
Is arranged so as to be able to move up and down in the opening, and is connected to a lifting drive mechanism 58 and a lifting guide 60, which are, for example, air cylinders, via a cap-shaped flange member 56, which is made of, for example, aluminum. A cylindrical cooling jacket 62 made of, for example, stainless steel (SUS) is attached to the side surface of the drive motor 54, and the flange member 56 is
It is attached so as to cover the upper half of the cooling jacket 62.

When the developing solution is applied, the lower end of the flange member 56 is in close contact with the bottom plate 50a near the outer periphery of the opening of the bottom plate 50a, thereby sealing the inside of the unit. When the wafer W is transferred between the spin chuck 52 and the main wafer transfer mechanism 22, the lift drive mechanism 58 lifts the drive motor 54 and the spin chuck 52 upward so that the lower end of the flange member 56 is moved to the housing 50. It is designed to rise from the bottom plate 50a.

At the bottom of the cup CP, an exhaust pipe 64 is connected to the central portion thereof, and a drain pipe 66 is connected to the outer portion thereof. Then, the gas in the cup CP is exhausted from the exhaust pipe 64, and the drain pipe 66 is discharged.
From the above, the developing solution scattered when the developing solution is shaken off, the cleaning solution for washing away the developing solution, and the organic solvent are discharged. An opening 70 for the wafer holding member 48 to enter is formed in the side wall of the housing 50 of the development processing unit (DEV).
Are formed.

Above the cup CP, a developing solution supply nozzle 81 for supplying a developing solution to the surface of the wafer W, and an aqueous cleaning solution supply for supplying an aqueous cleaning solution such as pure water to the wafer W after development. The nozzle 84 and a liquid agent supply nozzle 87 for supplying a liquid agent that does not substantially dissolve the resist in the wafer W after the aqueous cleaning solution is supplied and has a surface tension smaller than that of water.
Are provided so as to be movable between a supply position on the wafer W and a standby position outside the wafer W. The developing solution supply nozzle 81 is connected to the developing solution supply section 83 via a developing solution supply pipe 82, and the water-based cleaning solution supply nozzle 84.
Is a water-based cleaning liquid supply unit 8 via a water-based cleaning liquid supply pipe 85.
6, the liquid agent supply nozzle 87 is connected to the liquid agent supply section 89 via a liquid agent supply pipe 88.

The developing solution supply nozzle 81 is detachably attached to the tip of the first nozzle scan arm 91, and the aqueous cleaning solution supply nozzle 84 is detachably attached to the tip of the second nozzle scan arm 92. And
The liquid agent supply nozzle 87 is the third nozzle scan arm 93.
It is detachably attached to the tip of. Then, these first, second, and third nozzle scan arms 91, 9
2 and 93 are Y on the bottom plate 50a of the housing 50, respectively.
A first vertical support member 95, a second vertical support member 96, and a third vertical support member 95 that extend vertically from a guide rail 94 laid along the direction and are horizontally movable on the guide rail 94.
Attached to the upper end of the vertical support member 97 of the developing solution supply nozzle 81, the water-based cleaning solution supply nozzle 84, and the liquid agent supply nozzle 87, these first, second, and third vertical support members 95, 96, Along with 97, a Y-axis drive mechanism (not shown) moves along the Y direction. In addition, the first, second and third vertical support members 95, 9
6, 97 can be moved in the Z direction by a Z-axis drive mechanism (not shown). It is configured to be moved between a discharge position close to and a non-discharge position above it. The developing solution supply nozzle 81 is placed in a standby state in a nozzle standby section 98, and the nozzle standby section 98 is provided with a nozzle cleaning mechanism 99 for cleaning the developing solution supply nozzle 81.

The developing solution supply nozzle 81 has a long shape and is arranged with its longitudinal direction horizontal, and has a plurality of discharge ports on the lower surface so that the discharged developing solution becomes a band shape as a whole. It has become. Then, when the developing solution is applied, the developing solution is discharged in a belt shape from the developing solution supply nozzle 81 located above the wafer W, and the wafer W is rotated by 1/2 rotation or more, for example, once, so that the development is performed. The liquid is applied to the entire surface of the wafer W. When discharging the developing solution, the developing solution supply nozzle 81 may be scanned along the guide rail 94 without rotating the wafer W.

The water-based cleaning liquid supply nozzle 84 and the liquid agent supply nozzle 87 are straight nozzles. The water-based cleaning liquid supply nozzle 84 is provided after the development process.
An aqueous cleaning solution is supplied to the resist film on the wafer W, on which the development pattern is formed, to clean the resist film, and the liquid agent supply nozzle 87 does not substantially dissolve the resist after cleaning with the aqueous cleaning solution. A liquid agent having a surface tension lower than that of the aqueous cleaning solution is replaced.

Developer supply section 83, water-based cleaning solution supply section 86
The supply of the developing solution, the water-based cleaning solution, and the liquid agent from the liquid agent supply unit 89 is controlled by the liquid supply control unit 100.

Next, the operation of the developing processing in the developing processing unit (DEV) thus constructed will be described with reference to the process chart of FIG. The wafer W, which has been subjected to post-exposure bake processing and cooling processing with a predetermined pattern exposed, is transferred by the main wafer transfer mechanism 22 to just above the cup CP in the development processing unit (DEV), and the spin chuck 52 is driven up and down. Then, the spin chuck 52 is vacuum-adsorbed on the spin chuck 52 (ST1).

Next, the developing solution supply nozzle 81 is attached to the wafer W.
Of the developing solution supply nozzle 81.
Wafer W is halved while discharging the developing solution from the
The developing solution is discharged by rotating the developing solution supply nozzle 81 from one end of the wafer W to the other end by rotating the developing solution supply nozzle 81 along the guide rail 94 or more, for example, by making one rotation or more. Is applied to the entire surface of the wafer W, and as shown in FIG. 7A, a developer paddle 101 having a thickness of 1.2 mm is formed (ST2). In this way, the developing solution paddle 101 is kept stationary on the wafer W to proceed with the development (ST3). While the development is proceeding in this way, as shown in FIG. 7B, the developing solution supply nozzle 81 is moved to the standby position 98, and the water-based cleaning solution supply nozzle 84 is moved substantially above the center of the wafer W. (ST4).

After the lapse of a predetermined time, the spin chuck 52 is rotated at a predetermined rotation speed to shake off the developing solution from the wafer W (ST5), and at the same time, the wafer W is rotated as shown in FIG. 7C. While rotating at a predetermined rotation speed, a water-based cleaning liquid supply nozzle 84 supplies a water-based cleaning liquid, for example, pure water, to the resist film on the wafer W on which the development pattern is formed, to wash away the developer existing on the resist film (ST6). .

After such a cleaning process, as shown in FIG. 7D, the liquid agent supply nozzle 87 is moved substantially above the center of the wafer W, and the wafer W is rotated at a predetermined rotation speed while being developed. A liquid agent which does not substantially dissolve the resist and has a surface tension smaller than that of water is supplied to the patterned resist on which the resist film has been washed (ST7). As a result, most of the aqueous cleaning solution on the resist film and the remaining developing solution are replaced with the above liquid agent. That is, the surface of the resist film is covered with the liquid agent. When the liquid agent is supplied, the wafer may be stopped for a part of the supplying period.

After the water-based cleaning liquid for the resist film on the wafer W is thus replaced with the liquid agent, the wafer W is rotated at a high speed to shake off the liquid agent remaining on the wafer W to dry the wafer W (ST8). As a result, a series of development processing ends.

As described above, in the present embodiment, the resist film on the wafer W is washed with the water-based cleaning liquid after the development process is completed, and then the liquid agent having a surface tension smaller than that of water is supplied to the resist film. The large aqueous cleaning liquid is replaced with a liquid agent having a smaller surface tension, and the stress exerted on the resist pattern at the time of dry-off can be reduced, and the collapse of the resist pattern can be suppressed. That is, since an aqueous cleaning liquid such as pure water has a large surface tension, a large stress against the surface tension is exerted on the resist pattern when the wafer W is removed from the concave portion of the resist pattern by the centrifugal force accompanying the rotation of the wafer W. As described above, by supplying a liquid agent having a surface tension smaller than that of water, the aqueous cleaning solution is replaced by the liquid agent, and since such a liquid agent having a surface tension smaller than that of water is present in the concave portion of the resist pattern, when the liquid agent is removed from the concave portion, The stress exerted on the resist pattern can be markedly reduced as compared with the case of using an aqueous cleaning solution, and the resist pattern is less likely to collapse. In this case, the liquid agent supply time or the liquid agent supply amount is adjusted so that the contact angle θ between the resist pattern 102 shown in FIG. 8 and the liquid agent 103 therebetween is 60 ° or more and 120 °.
If it is less than 70 °, preferably less than 70 ° and less than 120 °, the surface tension of the liquid agent becomes extremely small, and the occurrence of resist pattern collapse can be more effectively prevented. Further, since the liquid agent that does not substantially dissolve the resist is used as described above, it does not adversely affect the resist pattern.

By the way, the contact angle θ is actually measured in the state where the liquid agent is present between the patterns. However, when such a highly volatile liquid agent is used, the contact angle θ is directly measured. It is difficult to measure. In such a case, after the above ST8 is completed, pure water is put between the patterns and the contact angle is measured, whereby the contact angle θ of the liquid agent can be approximately obtained. This is because the contact angle θ is determined by the surface modification effect of the resist by the liquid agent and the surface tension of the solution, and the surface modification effect is dominant among them. That is, the value of the contact angle after the pure water is added is only a value in which the contribution of the surface tension is changed from the liquid agent to pure water, and is a value close to the contact angle θ of the liquid agent. In order to improve the accuracy, the contribution of the surface tension may be corrected by some method.

The liquid agent used here is not particularly limited as long as it does not dissolve the resist.
It is preferable to use an organic solvent which is generally known to have a small surface tension.

The organic solvent is preferably a hydrophobic solvent having a low affinity with the aqueous cleaning solution. By using such a hydrophobic organic solvent, the organic solvent can be easily separated and recovered, and the organic solvent can be reused. As such a hydrophobic organic solvent,
At least one of hydrofluoroethers, xylene, and hexamethyldisilazane (HMDS) can be preferably used.

In this case, from the viewpoint of further facilitating separation and recovery, it is preferable to use an organic solvent having a higher specific gravity than the aqueous cleaning liquid. The above hydrofluoroethers correspond to such an organic solvent. Examples of hydrofluoroethers include methyl perfluoroisobutyl ether and methyl perfluorobutyl ether, which may be used alone or in combination.

Of course, the liquid agent may be other than the organic solvent, and examples thereof include dilute hydrofluoric acid.
The dilute hydrofluoric acid preferably has a concentration of 0.1 to 10%, more preferably 0.5 to 2%.

Next, an experiment confirming the effect of the present invention will be described. A resist film having a thickness of 0.8 μm was formed on the wafer, and exposure was performed so that stripe patterns having a width of 0.2 μm and a length of 7.0 μm were formed in parallel at intervals of 0.2 μm. Focus calibration at the time of exposure is -0.1 (1.0), -0.2 with 1.1 as a reference.
(0.9). After the exposure, as shown in FIG. 9, the developer was supplied by applying the developer while scanning the developing solution supply nozzle in the direction perpendicular to the pattern direction, and the developer was supplied by applying the developer in the direction parallel to the pattern direction. For both of them, the developing paddle was allowed to stand for a predetermined time to carry out the developing treatment, and subsequently, the following treatment was carried out.

First, the wafer was rotated to shake off the developing solution on the resist film, and then pure water was supplied as a cleaning solution while the wafer was rotated to clean the resist film. At this time, the rotation speed of the wafer was first set to 1200 rpm for 5 seconds, and then the wafer was decelerated to 500 rpm for 10 seconds.
Then, while the rotation of the wafer was stopped, a hydrofluoroether (HFE) -based solvent (a mixture of methyl perfluoroisobutyl ether and methyl perfluorobutyl ether) was supplied to the resist film on the wafer for 5 seconds, followed by The wafer was rotated at 500 rpm for 10 seconds, stopped again, and left for 15 seconds to replace the pure water adhering to the resist on the wafer with the above solvent. Then, the wafer was rotated at 2000 rpm for 15 seconds to shake off the organic solvent, and the wafer was dried.

For comparison, a wafer was also cleaned in the same manner and then washed with HFE solvent without rotating the wafer at 2000 rpm for 15 seconds to shake off the pure water. .

In these wafers, the resist pattern after development was observed with a scanning electron microscope (SEM) photograph for 21 regions (shots) in the cross direction and the cross direction shown in FIG. Each shot was set as a field of view including five resist patterns after development, and it was determined whether or not there was pattern collapse for each shot by 1.0.
Then, the proportion of shots in which the pattern collapsed was grasped. The result is shown in FIG. As shown in FIG. 11, when the pure water is replaced with an organic solvent and then shaken off and dried after washing with pure water, the pattern collapse is remarkably increased under any condition as compared with the case where shaken off and is dried after washing with pure water. Diminished. Thus, the effect of the present invention was confirmed by experiments.

As described above, when a hydrophobic organic solvent is used as a liquid agent which does not substantially dissolve the resist and has a surface tension smaller than that of water, the organic solvent can be separated and recovered easily. In particular, when the specific gravity is higher than that of the aqueous cleaning liquid, the separation and recovery can be performed more easily. In this case, an organic solvent recovery mechanism that can realize the separation and recovery of the organic solvent will be described with reference to FIG.

As shown in FIG. 12, a drainage pipe 66 provided at the bottom of the cup CP has a developing drainage pipe 111 for guiding the drainage of the developer which has been shaken off after the development process is completed, an aqueous cleaning liquid and Cleaning drainage pipe 11 for guiding drainage of organic solvent
Valve 1 provided in the pipe 111.
By opening and closing a valve 114 provided in 12 and the pipe 113, the pipe for draining liquid can be switched. The organic solvent recovery mechanism 130 uses the cleaning drainage pipe 11
3 and an intermediate tank 115 to which the cleaning drainage pipe 113 is connected. The aqueous cleaning liquid 117 and the organic solvent 118 are stored in the intermediate tank 115. Since an organic solvent 118 having a specific gravity larger than that of the water-based cleaning liquid 117, such as HFE, is used, the water-based cleaning liquid 117 is used.
In the intermediate tank 115 so that the organic solvent 118 is on the upper side and the organic solvent 118 is on the lower side. In addition, the organic solvent recovery mechanism 130
Has an organic solvent recovery pipe 119 connected to the bottom of the intermediate tank 115.
Is connected to the liquid agent supply pipe 88. A pump 120, a filter 121, and a valve 122 are interposed in the organic solvent recovery pipe 119, and the driving force of the pump 120 can send the organic solvent 118 from the intermediate tank 115 to the liquid agent supply pipe 88 for reuse. . Then, the switching between the new organic solvent from the liquid agent supply unit 89 and the recovered organic solvent is performed by opening and closing the valve 122 provided in the organic solvent recovery pipe 119 and the valve 123 provided in the liquid agent supply pipe 88. be able to.
On the other hand, a water-based cleaning liquid drain pipe 116 is connected to the upper part of the side wall of the intermediate tank 115, and only the water-based cleaning liquid 117 having a relatively small specific gravity is allowed to flow as a drain to the waste liquid line of the factory through this pipe 116. Is possible.

According to the above-mentioned constitution, the water-based cleaning liquid and the organic solvent used for preventing the pattern collapse can be separated very easily, and only the organic solvent can be recovered. Therefore, the organic solvent can be recycled very easily.

When an organic solvent such as HMDS which is hydrophobic but has a specific gravity smaller than that of the water-based cleaning liquid is used, an organic solvent recovery pipe is provided at the upper part of the intermediate tank and the water-based cleaning liquid drain is provided at the bottom. By providing piping,
It is possible to carry out the separation and collection.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, pure water is used as an example of the water-based cleaning liquid, but pure water to which some other substance is added may be used. Further, in the above-described embodiment, the wafer is rotated at the time of supplying the water-based cleaning liquid and at the time of supplying the liquid agent, but it is not always necessary to rotate the wafer. Further, although the present invention is applied to the development processing of the semiconductor wafer in the above-described embodiments, the present invention is not limited to this, and any other substrate such as a liquid crystal display (LCD) substrate may be used as long as the substrate has a fine resist pattern formed thereon. Can also be applied to the development processing of.

[0055]

As described above, according to the present invention,
After cleaning the developer on the substrate with an aqueous cleaning solution, a liquid agent with a smaller surface tension than water is supplied, so an aqueous cleaning solution with a large surface tension is replaced with a liquid agent with a small surface tension, and the resist pattern is formed on the resist pattern when it is shaken off and dried. The stress exerted can be reduced. Therefore, the resist pattern collapse can be suppressed. Further, since the liquid agent that does not dissolve the resist is used, the resist pattern is not adversely affected.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall configuration of a resist coating and developing treatment system for a semiconductor wafer equipped with a developing treatment unit for carrying out the developing treatment method of the present invention.

FIG. 2 is a front view showing the resist coating and developing treatment system shown in FIG.

FIG. 3 is a rear view showing the resist coating and developing treatment system shown in FIG.

FIG. 4 is a sectional view showing the overall configuration of a development processing unit to which the present invention is applied.

FIG. 5 is a plan view showing a development processing unit to which the present invention is applied.

FIG. 6 is a flowchart showing steps of a development processing method according to an embodiment of the present invention.

FIG. 7 is a diagram showing a processing state of each step of the development processing method according to the embodiment of the present invention.

FIG. 8 is a diagram showing a contact angle between a resist pattern and a liquid agent between them.

FIG. 9 is a diagram for explaining the relationship between the pattern and the scanning direction of the developing solution supply nozzle in an experiment showing the effect of the present invention.

FIG. 10 is a diagram showing a region (shot) where pattern collapse is confirmed in an experiment showing the effect of the present invention.

FIG. 11 is a diagram showing the results of an experiment showing the effect of the present invention.

12 is a schematic diagram showing an organic solvent recovery mechanism for separating and recovering an organic solvent, which is provided in the development processing unit shown in FIGS. 4 and 5. FIG.

[Explanation of symbols]

51 ... Spin chuck 81 ... Developer supply nozzle 83 ... Developer supply unit 84 ... Water-based cleaning liquid supply nozzle 86 ... Water-based cleaning liquid supply unit 87 ... Liquid supply nozzle 89 ... Liquid supply section 130: Organic solvent recovery mechanism DEV ... Development processing unit W: Semiconductor wafer

Continued front page    (72) Inventor Hiroyuki Iwaki             TBS release, 5-3-6 Akasaka, Minato-ku, Tokyo             Sending Center Tokyo Electron Limited F-term (reference) 2H096 AA25 GA18 LA25 LA30                 5F046 LA01 LA03 LA12 LA14

Claims (15)

[Claims] 1. A developing step of supplying a developing solution to a resist film after exposure on a substrate to develop an exposure pattern, a step of supplying a water-based cleaning solution to the resist film having a development pattern formed thereon, and the aqueous cleaning solution comprising: A developing process comprising: a step of supplying a liquid agent having a surface tension smaller than that of water, which does not substantially dissolve the resist, to the supplied resist film; and a step of rotating and drying the substrate. Method. 2. A developing step of supplying a developing solution to a resist film after exposure on a substrate to develop an exposure pattern, and a step of supplying an aqueous cleaning solution to the resist film on which the developing pattern is formed while rotating the substrate. A step of replacing the water-based cleaning liquid by supplying a liquid agent having a surface tension smaller than water that does not substantially dissolve the resist to the resist film to which the water-based cleaning liquid is supplied while rotating the substrate; A step of rotating and drying. 3. The development processing method according to claim 1, wherein the liquid agent is an organic solvent. 4. The development processing method according to claim 3, wherein the organic solvent is hydrophobic. 5. The development processing method according to claim 4, wherein the organic solvent is at least one kind of hydrofluoroethers, xylene, and hexamethyldisilazane. 6. The development processing method according to claim 4, wherein the organic solvent has a specific gravity larger than that of the aqueous cleaning liquid. 7. The development processing method according to claim 4, further comprising a step of recovering the organic solvent. 8. The development processing method according to claim 1, wherein the liquid agent is diluted hydrofluoric acid. 9. A development processing apparatus for developing a light exposure pattern by supplying a developing solution to a resist film after exposure on a substrate, comprising: a substrate holding member for holding the substrate substantially horizontally; and rotating the substrate holding member. Rotating mechanism, a developing solution supply mechanism that supplies a developing solution to the substrate on the substrate holding member, an aqueous cleaning solution supply mechanism that supplies an aqueous cleaning solution to the resist film on which the development pattern is formed, and the aqueous cleaning solution is supplied. The resist film is provided with a liquid agent supply mechanism that substantially does not dissolve the resist and has a surface tension smaller than that of water, and after the liquid agent is supplied from the liquid agent supply mechanism, the substrate is rotated by the rotation mechanism. A development processing apparatus, which is rotated and dried. 10. The development processing apparatus according to claim 9, wherein the liquid agent supply mechanism supplies an organic solvent to the substrate. 11. The development processing apparatus according to claim 10, wherein the liquid agent supply mechanism supplies a hydrophobic organic solvent to the substrate. 12. The development according to claim 11, wherein the liquid agent supply mechanism supplies at least one of hydrofluoroethers, xylene, and hexamethyldisilazane to the substrate as a hydrophobic organic solvent. Processing equipment. 13. The development processing apparatus according to claim 11, wherein the liquid agent supply mechanism supplies a hydrophobic organic solvent having a specific gravity larger than that of the aqueous cleaning liquid to the substrate. 14. The development processing apparatus according to claim 11, further comprising a recovery mechanism for recovering the hydrophobic organic solvent supplied from the liquid agent supply mechanism. 15. The development processing apparatus according to claim 9, wherein the liquid agent supply mechanism supplies dilute hydrofluoric acid to the substrate.