JPH1124282A - Device and method for developing resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device and a developing method for uniformly forming high resolution by perfectly substituting final rinse liquid which will not mix with intermediate rinse liquid and developer for the intermediate rinse liquid or the developer. SOLUTION: The developing device developing a pattern on a substrate (wafer) 2 is provided with a mechanism inclining the substrate 2 while rotating it and a mechanism supplying the developer and the rinse liquid to the substrate 2. This developing method is provided with a process that the developer and the rinse liquid are continuously supplied to the substrate 2 while rotating the substrate 2 in an inclined state. Or it is provided with a process that the developer and the intermediate rinse liquid are continuously supplied to the substrate 2 while rotating the substrate 2 in a substantially horizontal state and a process that the developer and the final rinse liquid are continuously supplied to the substrate 2 while rotating the substrate 2 in the inclined state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing apparatus and a developing method used for forming an ultrafine pattern.

[0002]

2. Description of the Related Art In the ultra LSI processing technology, patterns have been miniaturized, and are now entering a region of 0.2 μm or less in a development stage. A dry etching process is employed in LSI substrate processing, and a fine pattern is usually transferred to a substrate using a resist as a mask. In order to use this resist pattern as a mask for dry etching, a certain thickness (usually, about 0.5 μm) is required, and a certain film thickness is required to eliminate defects such as pinholes during resist coating. It is necessary to secure the thickness. In this case, as the pattern becomes finer, the ratio between the height and width of the resist pattern (called the aspect ratio) increases, and a phenomenon occurs in which adjacent patterns are stuck together during the development process and collapse. This pattern collapse is caused by the mechanical force acting on the fine resist pattern due to the surface tension of the solvent when the final rinse liquid is dried. In order to reduce this problem, a method of freeze-drying the final rinse solution has been proposed.However, the use of liquid nitrogen and the need for a vacuum drying process have resulted in significant cost increases and the effects of residual impurities. You. On the other hand, as a simpler method for preventing pattern collapse, there is a method in which a low surface tension solvent is used for the final rinse liquid. The most suitable as such a solvent is a perfluorocarbon solvent such as perfluoropentane, perfluorohexane and perfluoroheptane having a surface tension at room temperature of 15 dyn / cm or less.

[0003] However, these perfluorocarbon solvents are not mixed at all with solvents such as water and isopropyl alcohol which are usually used as a rinsing liquid for a resist for ultra-fine processing, so that when used as a final rinsing liquid, an intermediate rinsing liquid is used. It is difficult to completely replace the solution. This problem is exacerbated by increasing substrate dimensions and increasing aspect ratios, causing substantial non-uniformity in substantial resolution.

[0004] When forming various fine elements using ultra-fine processing of 0.1 μm or less besides the VLSI, as the miniaturization progresses, even if an extremely thin resist of about 100 nm is used, this pattern collapse may occur. Since the actual resolution is determined, essentially the same problem as in the above-mentioned LSI manufacturing is encountered.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an intermediate rinsing solution and a final rinsing solution which are not mixed with each other, or a developing solution and a final rinsing solution when no intermediate rinsing is used. It is an object of the present invention to provide a developing device and a developing method for completely replacing a developing solution with a final rinsing solution to form a high resolution with uniformity.

[0006]

In order to solve the above-mentioned problems, the present invention is characterized in that, when final rinsing is performed with a perfluorocarbon solvent, a final rinsing liquid is supplied while rotating the substrate in an inclined state. I have. In the conventional developing method, a transported substrate is placed on a cup of a developing device and held, and then a developer and a rinsing liquid are sequentially supplied, and finally, the substrate is dried with dry air or nitrogen gas. During this time,
The substrate is stationary or rotating at a low speed.
When a perfluorocarbon solvent that does not mix with the intermediate rinsing liquid or the developing solution is used as the final rinsing liquid in such a developing method, the intermediate rinsing liquid or the developing liquid is confined in the substrate, particularly in a pattern having a high aspect ratio. It is not completely replaced. For this reason, the present inventors studied a technique for efficiently performing this replacement by devising a developing device. As a result, the perfluorocarbon solvent was not rotated during the final rinsing, but rotated while rotating the substrate in an inclined state. Was found to be completely replaced by supplying on the substrate, and the present invention was reached.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. The developing device of the present embodiment has a mechanism for supplying a developing solution and a rinsing liquid (intermediate rinsing liquid and final rinsing liquid) onto the substrate while tilting and simultaneously rotating the substrate to be processed. An example of this is shown in FIG.

In this developing device, a wafer support 3 for holding a wafer 2 (substrate to be processed), a motor 4 having the support 3 fixed to a rotating shaft, and a motor 4 Then, a tilt mechanism 5 for tilting the motor 4 and the support 3 is provided, and the tilt mechanism 5 can rotate the wafer 2 fixed to the support 3 in a tilted state. I have. The tilt angle of the tilt mechanism 5 is
The range is 10 to 90 degrees. At the bottom of the developing cup 1, a drain 6 for discharging a developing solution and a rinsing solution in the cup is provided.

A nozzle 7 for supplying a developing solution or a rinsing liquid (intermediate rinsing liquid, final rinsing liquid) to the wafer 2 is provided above the wafer 2. As a supply mechanism for supplying the developing solution or the rinsing liquid to the wafer 2, a tank for accommodating each of the above-described liquids, and one end inserted into the tank,
At the other end, a pipe having a nozzle 7 directed to the wafer 2 is provided. By supplying a high-pressure gas into the tank and opening and closing an electromagnetic valve provided in the pipe, the liquid in the tank is supplied to the nozzle. A mechanism for supplying the wafer 7 to the wafer 2 is preferably used (not shown). Each liquid supply mechanism may be configured to be able to supply each liquid through a single nozzle 7, or may be provided with an independent nozzle for each liquid supply mechanism and supply each liquid to the wafer 2. A configuration in which each nozzle is arranged at a position where supply is possible may be adopted.

An embodiment of the developing method according to the present invention will be described with reference to an example in which the above-described developing device is used. The developing method according to this embodiment includes a step of tilting the wafer 2 while rotating the wafer 2, a developing solution and a rinsing solution (intermediate rinsing solution,
(A final rinsing liquid) is continuously supplied onto the wafer 2. A wafer 2 to be processed is suction-held on a wafer support 3 in a developing cup. This wafer 2
Is a pattern in which a fine pattern is drawn after spin-coating a resist having an appropriate thickness and baking it under appropriate conditions. In a state where the wafer 2 is inclined, the motor 4 is driven to rotate the wafer 2 at a desired speed, and a developer, an intermediate rinse liquid, and a final rinse liquid are sequentially supplied. The developing solution or rinsing liquid (intermediate rinsing liquid, final rinsing liquid) supplied from the nozzle 7 is discharged from the drain 6. After the final rinsing liquid is supplied to the wafer 2, the wafer 2 is dried by blowing a dry gas, for example, a nitrogen gas or dry air.

In this embodiment, since the final rinsing liquid is supplied onto the wafer 2 which rotates while being inclined, the final rinsing liquid is efficiently replaced with a developing liquid or an intermediate rinsing liquid which does not mix with each other.

Further, as another embodiment, in the developing device shown in FIG. 1, the inclination angle by the inclination mechanism 5 can be changed, and in the developing step and the intermediate rinsing step, the wafer 2 is rotated horizontally (normally) and rotated. Alternatively, control means for tilting the wafer 2 at the time of final rinsing may be provided. It is desirable that the tilt mechanism 5 can accurately adjust the tilt angle by a servomotor or a cylinder.

In the developing apparatus provided with the control means, the wafer 2 is held on the wafer support 3 and rotated while being kept substantially horizontal, and a developing process is performed by supplying a developing solution. When the intermediate rinsing step of supplying the intermediate rinsing liquid is performed, the intermediate rinsing liquid is supplied while the wafer 2 is rotated while being kept substantially horizontal. After the intermediate rinsing step, or after the developing step when the intermediate rinsing step is not used, the tilt angle of the tilt mechanism 5 is automatically changed by the control means, and the wafer 2 is tilted to a predetermined angle in the range of 10 to 90 degrees. Let it. A final rinsing step of supplying a final rinsing liquid to the wafer 2 rotating in the inclined state is performed. After the final rinsing step, drying is performed by blowing a dry gas, for example, nitrogen gas or dry air.

Also in the present embodiment, since the final rinsing liquid is supplied onto the wafer 2 which rotates inclining, the final rinsing liquid is efficiently replaced with the developing liquid or the intermediate rinsing liquid which are not mixed with each other. Therefore, a perfluorocarbon solvent which is a low surface tension solvent can be used as the final rinsing liquid, and it is desirable to use the solvent.
As a perfluorocarbon-based solvent, the number of carbon atoms is 5,
Effective are perfluoropentane, perfluorohexane, perfluoroheptane and mixtures thereof corresponding to 6,7,8,9,9,1
Perfluorocarbon solvents such as 0, 11, 12, and 13 and mixtures thereof can also be used.

[0015]

Next, the present invention will be described more specifically with reference to examples. [Example 1] ZEP-520 on a 4-inch silicon substrate
The resist was spin-coated to a thickness of 0.25 μm,
After baking in an oven at 0 ° C. for 30 minutes, a fine pattern was drawn using an electron beam exposure apparatus (JBX-5FE manufactured by JEOL Ltd.). The drawn pattern is a set of a line and space pattern drawn at an exposure amount of 10 levels in each cycle from a 50 nm cycle to a 150 nm cycle in increments of 5 nm over a length of 2 mm and a cycle of 10 levels.
Writing was performed on the entire surface of the wafer in a matrix at 0 mm intervals.
Three substrates were prepared, and one was supplied with ZED-N50, which is a developer for a ZEP resist, at a rotation speed of 100 rpm without tilting the substrate, and developed for 5 minutes.
Then, IPA was supplied as an intermediate rinse for 60 seconds, and then perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown to dry. The second substrate is suctioned and held using a developing device having a substrate tilting function, tilted by 30 degrees, and rotated at a rotation speed of 100 rpm by ZE.
Supply D-N50 (manufactured by Nippon Zeon) and develop for 5 minutes, then supply IPA as an intermediate rinse for 60 seconds, then supply perfluorohexane for 60 seconds,
Finally, nitrogen gas was blown to dry. The third sheet uses a developing device having a substrate tilting function, and 100 rpm without tilting.
m, and ZED-N50 (manufactured by Nippon Zeon) was supplied and developed for 5 minutes. Then, IP was used as an intermediate rinse.
A was supplied for 60 seconds, then the substrate was tilted by 30 degrees, perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown and dried. When the resolution of these three samples was compared with an electron microscope, the first sample, which was placed and subjected to final rinsing, had adjacent patterns stuck to a line and space pattern with a period of 110 nm in the peripheral portion of the substrate. Although resolution could be achieved without pattern collapse, the central part of the substrate had a period of 110 nm, a period of 115 nm,
In many cases, line and space patterns with a period of nm could not be resolved depending on the location. On the other hand, the second and third samples in which the substrate was inclined at the time of the final rinsing were able to resolve the entire substrate up to a line-and-space pattern having a period of 110 nm without causing pattern collapse in which adjacent patterns were stuck together. As is clear from this result, in the sample in which the substrate was not tilted, the IPA of the intermediate rinsing liquid was not completely replaced by the perfluorohexane of the final rinsing liquid, and the IPA remained at the center of the substrate until the nitrogen gas was dried. On the other hand, when the substrate is rotated while being inclined during the final rinsing, the replacement with the final rinsing liquid becomes efficient, and the substrate can be completely replaced with the final rinsing of 60 seconds, and the aspect ratio is 4.
It was found that the above ultrafine patterns could be formed uniformly on the entire substrate.

[Embodiment 2] Z on a 4-inch silicon substrate
A mixture of EP-520 and Fullerene C60 (manufactured by MER) mixed at a ratio of 10% by weight based on the weight of the resist polymer was spin-coated to a thickness of 0.25 μm,
After baking in an oven at a temperature of 30 ° C. for 30 minutes, a fine pattern was drawn using an electron beam exposure apparatus (JBX-5FE manufactured by JEOL Ltd.). The drawn pattern is a set of a line and space pattern drawn at an exposure amount of 10 levels in each cycle from a 50 nm cycle to a 150 nm cycle in increments of 5 nm over a length of 2 mm and a cycle of 10 levels.
Writing was performed on the entire surface of the wafer in a matrix at mm intervals. Three of these substrates are prepared, and one is supplied with ZED-N50 (manufactured by Zeon Corporation) which is a developing solution of a ZEP resist at a rotation speed of 100 rpm without tilting the substrate.
After developing for 5 minutes, IPA was used as an intermediate rinse for 60 minutes.
Then, perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown to dry. The second substrate is supplied with ZED-N50 (manufactured by ZEON) at a rotation speed of 100 rpm while holding the substrate by suction using a developing device having a substrate tilting function and tilting the substrate by 30 degrees.
After developing for 5 minutes, IPA was used as an intermediate rinse for 60 minutes.
Then, perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown to dry. For the third sheet, use a developing device having a substrate tilting function.
At a rotation speed of 00 rpm, ZED-N50 (manufactured by Nippon Zeon) was supplied and development was performed for 5 minutes. Then, IPA was supplied as an intermediate rinse for 60 seconds. Thereafter, the substrate was inclined at 30 degrees, and perfluorohexane was supplied at 60 degrees. The mixture was supplied for 2 seconds, and finally dried by blowing nitrogen gas. When the resolution of these three samples was compared with an electron microscope, the first sample that had been subjected to final rinsing with its normal position was 90% in the peripheral portion of the substrate.
Up to a line and space pattern with a period of nm, resolution could be achieved without pattern collapse where adjacent patterns stick together, but in the center of the substrate, line and space patterns with a period of 90 nm to 105 nm could not be resolved depending on the location. There were many examples. On the other hand, in the second and third samples in which the substrates were inclined at the time of the final rinsing, resolution was possible over the entire substrate up to a line and space pattern having a period of 90 nm without adjacent patterns sticking together. As is clear from this result, in the sample in which the substrate was not tilted, the IPA of the intermediate rinsing liquid was not completely replaced by the perfluorohexane of the final rinsing liquid, and the IPA remained at the center of the substrate until the nitrogen gas was dried. Whereas
If the substrate is rotated while tilting at the time of final rinsing, the replacement with the final rinsing liquid becomes efficient, and the substrate can be completely replaced with the final rinse of 60 seconds, and an ultrafine pattern with an aspect ratio of 5 or more is applied to the entire substrate. It was found that uniform formation was possible.

Example 3 A chemically amplified X-ray resist SEPR-44-D (manufactured by Shin-Etsu Chemical Co., Ltd.) was spin-coated on a 6-inch silicon substrate to a thickness of 0.5 μm.
After prebaking under the condition of 120 seconds, X-ray exposure was performed using a SOR beam line. After exposure, post-baking was performed at 75 ° C. for 120 seconds. X-ray mask used is 20m
It has an m-square window, in which 1: 1 lines and 10 nm steps from 100 nm to 300 nm
A portion in which a 0.4 μm-thick tantalum line & space pattern having a space ratio over a length of 2 mm is arranged on a 2 × 2 matrix at an interval of 10 mm in both XY directions. This mask pattern is further 20 mm
Step-and-repeat exposure was performed on the entire wafer in the form of a matrix at intervals under the same conditions. Three substrates were prepared, and one substrate was supplied with a 2.1% aqueous solution of tetramethylammonium hydroxide at a rotation speed of 100 rpm without tilting the substrate, and developed for 1 minute. Then, pure water was supplied for 60 seconds, then perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown to dry. The second substrate is held by suction using a developing device having a substrate tilting function, and is tilted by 30 degrees to supply a 2.1% aqueous solution of tetramethylammonium hydroxide at a rotation speed of 100 rpm. Develop for 1 minute, then add 6 ml of pure water as intermediate rinse
After supplying for 0 second, perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown to dry. The third sheet is developed by using a developing device having a substrate tilting function and supplying a 2.1% aqueous solution of tetramethylammonium hydroxide at a rotation speed of 100 rpm without tilting, and developing for 1 minute. Then, pure water was supplied for 60 seconds, then the substrate was tilted by 30 degrees, perfluorohexane was supplied for 60 seconds, and finally, nitrogen gas was blown and dried. When the resolution of these three samples was compared with an electron microscope, the first sample, which had been subjected to final rinsing with its normal position, had adjacent patterns stuck to a line and space pattern with a period of 160 nm in the peripheral portion of the substrate. Resolution was possible without pattern collapse, but at the center of the substrate, 1
In many cases, the line and space pattern from the 60 nm cycle to the 180 nm cycle could not be resolved depending on the location. On the other hand, in the second and third samples in which the substrate was inclined at the time of the final rinsing, it was possible to resolve the entire substrate up to a line and space pattern having a cycle of 160 nm without causing a pattern collapse in which adjacent patterns are stuck together. As is clear from this result, in the sample in which the substrate is not tilted, the pure water of the intermediate rinsing liquid is not completely replaced by the perfluorohexane of the final rinsing liquid. On the other hand, if the substrate is rotated while tilting during the final rinsing, the replacement with the final rinsing liquid becomes efficient, and the substrate can be completely replaced with the final rinsing for 60 seconds, and the aspect ratio of 5 or more can be obtained. It was found that an ultrafine pattern could be uniformly formed on the entire substrate.

As described above, in the above-described embodiment, the case where the chemically amplified resist SEPR-44-D is exposed to X-rays, the case where ZEP or Z
Although the case where the EP is subjected to electron beam exposure has been described, it is apparent that high resolution can be obtained even if the EP is applied to light exposure using another type of resist or excimer laser. Similar effects were obtained when the tilt angle of the substrate was in the range of 10 to 90 degrees. As the final rinsing liquid, a perfluorocarbon solvent is preferable. As the perfluorocarbon-based solvent, perfluoropentane, perfluorohexane, perfluoroheptane and a mixture thereof having carbon numbers of 5, 6, and 7 are effective. , 10, 11, 12, and 13 perfluorocarbon solvents and mixtures thereof can also be used.

[0019]

According to the present invention, even when a large area substrate is used, a high aspect ratio pattern can be obtained with high uniformity by a perfluorocarbon-based rinse having a low surface tension. A great effect can be obtained in the manufacture of an X-ray mask used for manufacturing and the manufacture of optical components such as a fine diffraction grating.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a developing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing cup 2 Wafer (substrate to be processed) 3 Wafer support 4 Motor 5 Incline mechanism 6 Drain 7 Nozzle

Claims (6)

[Claims] 1. A developing solution and two or more rinsing liquids of a final rinsing liquid or an intermediate rinsing liquid and a final rinsing liquid are supplied onto the substrate to which the resist pattern has been transferred, and the pattern on the substrate is developed. A resist developing device, comprising: a mechanism for tilting a substrate while rotating it; and a mechanism for supplying a developing solution and a rinsing liquid onto the substrate. 2. The resist developing apparatus according to claim 1, wherein the substrate is kept substantially horizontal when the developing solution and the intermediate rinsing liquid are supplied to the substrate, and the substrate is inclined when the final rinsing liquid is supplied to the substrate. A resist developing device comprising control means. 3. A developing solution and two or more kinds of rinsing liquids of a final rinsing liquid or an intermediate rinsing liquid and a final rinsing liquid are supplied onto the substrate to which the resist pattern has been transferred, and the pattern on the substrate is developed. A method of continuously supplying a developing solution and a rinsing liquid onto a substrate while rotating the substrate in an inclined state. 4. A developing solution and two or more rinsing liquids of a final rinsing liquid or an intermediate rinsing liquid and a final rinsing liquid are supplied onto the substrate to which the resist pattern has been transferred, and the pattern on the substrate is developed. In a developing apparatus, a step of continuously supplying a developing solution or a developing solution and an intermediate rinsing liquid onto a substrate while rotating the substrate in a substantially horizontal state, and a step of rotating the substrate in an inclined state to supply a final rinsing liquid. Supplying the liquid onto a substrate. 5. The developing method according to claim 3, wherein the inclination angle of the substrate is in a range of 10 to 90 degrees. 6. The developing method according to claim 3, wherein the main component of the final rinsing liquid is a single perfluorocarbon solvent or a mixture of two or more perfluorocarbon solvents. A developing method characterized by the above-mentioned.