JP2004063490A - Method of forming pattern and substrate treating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform slimming that is excellent in in-plane and inter-substrate dimensional controllability. <P>SOLUTION: A method of forming pattern includes a step (S101) of forming a photosensitive resin film on a substrate, a step (S101) of exposing the photosensitive resin film to light, and a step (S102) of forming a pattern of the photosensitive resin film by supplying a developing solution to the resin film. The method also includes a step (S106) of performing the slimming for removing the surface layer of the pattern by bringing activated water into contact with the pattern. <P>COPYRIGHT: (C)2004,JPO

Description

【０１０８】
表１に示すように、表層改質を行うことにより、試料の仕上がり寸法が、リファレンス試料より、細く加工することができることが分かる。また、オゾン水濃度が高い方が寸法が細くなっていることが分かる。
【０１０９】
本発明の具体的な適用範囲は、リソグラフィ工程後のパターン寸法（本実施例では１３０ｎｍ）をＬ［ｎｍ］、露光波長をλ［ｎｍ］、投影光学系の開口数をＮＡとしたときに、Ｌをλ／ＮＡで規格化した値が１．２以下である。（本実施例では０．８７）
（その他の望ましい実施形態）
第１及び第２の実施形態で現像処理後のレジストパターンを酸化処理することでパターン寸法を細く加工する例を示した。また、第３の実施形態で、現像処理前のレジストパターンを酸化処理することでパターン寸法を細く加工する例、現像処理後のレジストパターンを酸化処理・さらに現像処理することでパターン寸法を細く加工する例を示した。
【０１１０】
酸化処理方法として、第１の実施形態では超臨界水もしくは亜臨界水をレジストに接触させる方法、第２の実施形態では水に光を照射しラジカルを発生させレジストに接触させる方法、第３の実施形態では酸化性液体をレジストに接触させる方法を示した。これらの処理のシーケンスおよび酸化処理方法の組み合わせは任意に選ぶことが可能である。
【０１１１】
なお、第２及び第３の実施形態における、スリミング処理及び表層改質処理に用いられる活性化した水として、酸化性液体を用いることができる。酸化性液体としては、オゾン、酸素、過酸化水素を溶解させた純水を用いることができる。
【０１１２】
スリミング処理及び表層改質処理では、レジストパターンの表面を酸化して５ｎｍ以上の酸化する。５ｎｍ以上の酸化するためは、レジストパターンに純水に１ｐｐｍのオゾンを溶解させたオゾン水の場合では１０秒以上接触させることが好ましい。酸化層の厚さは、オゾン水を処理した場合と、そうでない場合とで、それぞれの処理後に現像処理を行ったときに、溶解しないレジストの領域（ポジ型レジストの場合は未露光部）の膜厚差を計測すればわかる。
【０１１３】
本発明で示した３通りの酸化処理方法の酸化力を比較すると、酸化性液体をレジストに接触させる方法の酸化力が比較的弱い。そのほかの２つの方法は酸化力が強いため、どのようなレジストに対しても効果がある。酸化力が比較的弱い酸化性液体をレジストに接触させる方法は、比較的弱い酸化力でも酸化されるノボラック樹脂で構成されるｉ線レジストやポリヒドロキシスチレン樹脂で構成されるＫｒＦレジストでは有効であるが、強い酸化力でないと酸化されない脂環式樹脂（アクリル系、コマ系、ハイブリッド系樹脂）で構成されるＡｒＦレジストでは効果が十分ではない。レジスト樹脂の酸化に必要な酸化力を有する酸化方法を選べばよい。
【０１１４】
なお、本発明は、上記各実施形態に限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で種々に変形することが可能である。更に、上記実施形態には種々の段階の発明が含まれており、開示される複数の構成要件における適宜な組み合わせにより種々の発明が抽出され得る。例えば、実施形態に示される全構成要件から幾つかの構成要件が削除されても、発明が解決しようとする課題の欄で述べた課題が解決でき、発明の効果の欄で述べられている効果の少なくとも１つが得られる場合には、この構成要件が削除された構成が発明として抽出され得る。
【０１１５】
【発明の効果】
以上説明したように本発明によれば、活性な水を用いてスリミング処理を行うことにより、面内、基板間とも寸法制御性よくレジストパターンのスリミング処理が可能となる。
【図面の簡単な説明】
【図１】第一の実施形態に係るパターン形成方法の処理手順を示すフローチャートを示す図。
【図２】第一の実施形態に係るパターン形成方法を実現するための処理装置の構成を示す図。
【図３】水の相図を示す図。
【図４】二酸化炭素の相図を示す図。
【図５】第２の実施形態に係るパターン形成方法の処理手順を示すフローチャートを示す図。
【図６】第２の実施形態に係わるパターン形成方法を行う基板処理装置の概略構成を示す図
【図７】第２の実施形態に係わる基板処理装置の光照射部の概略構成を示す図。
【図８】第２の実施形態に係わるパターン形成方法を示す図。
【図９】第２の実施形態に係わるパターン形成方法を示す図。
【図１０】第２の実施形態に係わるパターン形成方法を示す図。
【図１１】第２の実施形態に係わるパターン形成方法を示す図。
【図１２】第２の実施形態に係わるパターン形成方法を示す図。
【図１３】第２の実施形態に係わるパターン形成方法を示す図。
【図１４】１７２ｎｍの光における水の液厚と透過率の関係を示す示す図。
【図１５】光照射部の概略構成を示す図。
【図１６】光照射部の概略構成を示す図。
【図１７】光照射部の概略構成を示す図。
【図１８】光照射部の概略構成を示す図。
【図１９】光照射部の概略構成を示す図。
【図２０】光照射部の概略構成を示す図。
【図２１】光照射部の概略構成を示す図。
【図２２】光照射部の概略構成を示す図。
【図２３】基板処理装置の概略構成を示す図。
【図２４】第３の実施形態に係るパターン形成方法の処理手順を示すフローチャートを示す図。
【図２５】従来の現像法における現像課程を模式的に表した図。
【図２６】第３の実施形態に係わる前処理の作用・効果の説明図。
【図２７】第３の実施形態に係わる改質処理の作用・効果の説明図。
【符号の説明】
２０…スリミング処理装置
２１…処理容器
２２…ウエハ
２３…基板保持機構
２４…温調器
２５…バルブ
２６…純水タンク
２７…温調器
２８…高圧ポンプ
２９…バルブ
３０…二酸化炭素ボンベ
３１…温調器
３２…高圧ポンプ
３３…バルブ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pattern forming method for developing a photosensitive resin film formed on a substrate and a substrate processing apparatus.
[0002]
[Prior art]
In recent years, in microfabrication technology, formation of a device pattern having an extremely small size of less than 100 nm has been demanded, while extremely high precision processing has been demanded. In the photolithography used for these processes, KrF → ArF → F ₂ In addition, miniaturization is being promoted by shortening the wavelength of an excimer laser used for exposure.
[0003]
However, even if pattern formation is performed using these excimer lasers, it is not sufficient for the demand for miniaturization, and a larger size than the target is formed by optical lithography, followed by dry etching and UV light irradiation. A slimming process for thinning the resist pattern is performed by a dry process such as ashing with ozone (Japanese Patent Application Laid-Open No. 2001-85407). Since the dry process is highly reactive, it is effective in reducing the thickness of the resist pattern, but there is a problem in controllability of dimensions within and between substrates.
[0004]
[Problems to be solved by the invention]
The conventional slimming process using a dry process is effective in terms of making the resist pattern thin because the etching gas is rich in reactivity, but has a problem in the controllability of the dimensions within the substrate and between the substrates.
[0005]
An object of the present invention is to provide a pattern method and a substrate processing apparatus for realizing a fine resist pattern while improving controllability of dimensions within a substrate surface and between substrates.
[0006]
[Means for Solving the Problems]
The present invention is configured as described below to achieve the above object.
[0007]
(1) A pattern forming method according to an example of the present invention includes a step of forming a photosensitive resin film on a substrate, a step of exposing the photosensitive resin film, and a step of supplying a developer to the photosensitive resin film. Forming a pattern of the photosensitive resin film, and performing a slimming process of removing a surface layer of the pattern by bringing activated water into contact with the pattern.
[0008]
(2) A pattern forming method according to an example of the present invention includes a step of forming a photosensitive resin film on a substrate, a step of exposing the photosensitive resin film, and a step of supplying a developer to the photosensitive resin film. Forming a pattern of the photosensitive resin film, modifying the surface layer of the pattern by contacting activated water with the pattern, supplying a developer to the pattern, the surface layer of the pattern And removing the.
[0009]
(3) A pattern forming method according to an embodiment of the present invention includes a step of forming a photosensitive resin film on a substrate, a step of exposing the photosensitive resin film, and a step of contacting activated water with the photosensitive resin film. Modifying the surface layer of the photosensitive resin film, and supplying a developing solution to the surface-modified photosensitive resin film to form a pattern of the photosensitive resin film. Features.
[0010]
(4) A substrate processing apparatus according to an example of the present invention includes a substrate holding mechanism that holds a substrate substantially horizontally, and a transparent plate that is arranged to face the substrate holding mechanism, and transmits the transparent plate to the substrate. A light irradiating unit for irradiating light, and a distance for adjusting a distance between the light irradiating unit and the substrate so that the transparent plate is in contact with the liquid film when a liquid film is formed on the substrate. And an adjusting mechanism.
[0011]
(5) A substrate processing apparatus according to an example of the present invention includes a substrate holding mechanism that holds a substrate substantially horizontally, a liquid supply unit that supplies a liquid onto the substrate, and a light source that supplies a liquid before being supplied to the substrate. And a movement mechanism for relatively horizontally moving the liquid supply unit and the light irradiation unit and the substrate holding mechanism.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
(1st Embodiment)
FIG. 1 is a flowchart showing a processing procedure of the pattern forming method according to the first embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a processing apparatus for realizing the pattern forming method according to the first embodiment of the present invention. A pattern forming method according to the first embodiment of the present invention will be described with reference to FIGS.
[0014]
(Step S101)
An antireflection film and a chemically amplified resist are applied on a substrate, for example, a semiconductor wafer. An ArF excimer laser is irradiated onto the chemically amplified resist through the exposure reticle, and the pattern formed on the exposure reticle is subjected to reduction projection exposure. The wafer is heat-treated and transferred to a developing device.
[0015]
(Step S102)
In the developing device, a developing solution is supplied onto the wafer to form a resist pattern.
[0016]
(Step S103)
After a lapse of a predetermined time, pure water is supplied while rotating the wafer, and development is stopped and the wafer is cleaned.
[0017]
(Step S104)
Next, the wafer is rotated at a high speed to dry the wafer.
[0018]
(Step S105)
The wafer after the development processing is transferred to the slimming processing apparatus 20 shown in FIG. The wafer 22 is placed on the substrate holding mechanism 23 in the processing container 21.
[0019]
In this slimming processing apparatus 20, slimming (processing to reduce the remaining dimension of the resist) is performed by bringing supercritical or subcritical water into contact with the resist pattern on the wafer.
[0020]
(Step S106)
Next, slimming treatment is performed by bringing supercritical or subcritical water into contact with the resist pattern on the wafer. The slimming process is performed according to the following procedure.
[0021]
The valve 29 is opened, and supercritical pure water is introduced into the processing vessel 21 from the pure water tank 26. By operating the temperature controller 27 and the high-pressure pump 28 to set the pure water to a predetermined temperature and pressure, pure water in a supercritical state is introduced into the processing vessel 21.
[0022]
Further, the temperature inside the processing container 21 is controlled to a predetermined temperature by the temperature controller 24. When the resist pattern comes into contact with supercritical water, a slimming process is performed. After the introduction of the supercritical water, the valve 29 is closed, and the temperature controller 27 and the high-pressure pump 28 are stopped. The slimming process is performed for a predetermined time to finish the pattern to a desired size.
[0023]
(Step S107)
After a lapse of a predetermined time, the temperature inside the processing container 21 is lowered by the temperature controller 24. After that, the valve 25 is opened to stop the slimming process. At this time, the temperature controller 24 and the valve 25 are controlled so that the water remains on the wafer when the water returns from the supercritical state to the normal temperature and normal pressure state.
[0024]
(Step S108)
Next, the wafer is cleaned. The cleaning of the wafer is performed in the following procedure. After closing the valve 25, the valve 33 is opened, and carbon dioxide in a supercritical state is introduced from the carbon dioxide cylinder 30 into the processing vessel 21. By operating the temperature controller 31 and the high-pressure pump 32 to bring the carbon dioxide to a predetermined temperature and pressure, carbon dioxide in a supercritical state is introduced into the processing vessel 21. Further, the temperature of the processing container 21 is set to a predetermined temperature by the temperature controller 24. While continuously supplying the supercritical carbon dioxide into the processing container 21, the valve 25 is opened, and the supercritical carbon dioxide containing water is discharged from the processing container 21 to clean the wafer 22. .
[0025]
(Step S109)
After the water on the wafer 22 is completely removed, the temperature controller 31 and the high-pressure pump 32 are controlled so that the carbon dioxide in a supercritical state is converted into a gas state without passing through a liquid state and the wafer 22 is dried. . After the wafer 22 has dried, the valve 33 is closed, and the temperature controller 31 and the high-pressure pump 32 are stopped.
[0026]
Next, the action of slimming using supercritical water will be described below.
FIG. 3 shows a water phase diagram. As shown in FIG. 3, the critical point of water is 374 ° C. and 22 Mpa. Supercritical water at a temperature and pressure higher than the critical point or subcritical water near the critical point has a large ionic product and undergoes oxidative decomposition / hydrolysis reaction with organic substances. Therefore, when the resist, which is an organic substance, is allowed to act on supercritical water or subcritical water, the resist is decomposed and the remaining dimension of the resist pattern is reduced (slimming). In addition, by setting the temperature and pressure to appropriate values, the reaction speed can be controlled, so that the slimming amount can be controlled. In the supercritical state, the diffusion speed of the substance is faster than that of the liquid state, and the diffusion of the reaction product is faster, so that uniform slimming can be performed over the entire wafer. In addition, since a uniform oxidative decomposition reaction occurs slowly, line edge roughness can be reduced.
[0027]
Next, the action of cleaning and drying using carbon dioxide in a supercritical state will be described.
FIG. 4 shows a phase diagram of carbon dioxide. As shown in FIG. 4, the critical point of carbon dioxide is 31 ° C. and 7.4 Mpa. Carbon dioxide enters a supercritical state at a higher temperature and a higher pressure than the critical point. Carbon dioxide in a supercritical state has low viscosity and surface tension, has a large penetrating power into minute gaps, and dissolves water. Moreover, it is suitable for cleaning because it is dried when it is returned to normal temperature and normal pressure. It is also known that when a liquid on the surface of a fine resist pattern having a high aspect ratio is dried in a liquid state, pattern collapse occurs. By dissolving and drying the liquid on the resist pattern surface with gas from the supercritical state, pattern collapse can be prevented. From the viewpoint of preventing the pattern from collapsing, after the slimming process, it is also possible to dry the supercritical water in a gaseous state without passing through a liquid state. In the present embodiment, a reaction product due to the slimming reaction may remain as a defect. Therefore, in the present embodiment, cleaning and drying are performed with carbon dioxide in a supercritical state.
[0028]
Next, effects of the pattern forming method of the present embodiment will be described based on experimental results.
An antireflection film (film thickness 50 nm) and a chemically amplified resist (film thickness 300 nm) are applied on the wafer. An ArF excimer laser (exposure wavelength λ: 193 nm) is irradiated to the chemically amplified resist through an exposure reticle, and the pattern formed on the reticle is subjected to reduced projection exposure. The numerical aperture (NA) of the projection optical system is 0.6. The wafer is heat treated at 120 ° C. for 90 seconds. Develop with an alkaline developer for 60 seconds. Pure water is supplied to stop and wash the reaction. By the lithography process described above, a 100 nm isolated pattern is formed on the wafer. When the variation in the pattern dimension was measured in this state, it was 3 nm at 3σ.
[0029]
Thereafter, the wafer is transferred to a slimming processing apparatus. A slimming treatment is performed in supercritical water at 380 ° C. and 23 MPa for 120 seconds. As shown by the solid line in FIG. 3, the pressure is returned to 25 ° C. and the atmospheric pressure to stop the reaction. With the water remaining on the wafer, the wafer is washed with supercritical carbon dioxide at 35 ° C. and 10 MPa for 30 seconds. After the cleaning, the inside of the processing container 201 is returned to 25 ° C. and atmospheric pressure and dried as shown by the solid line in FIG.
[0030]
As a result, the size of the isolated pattern became 50 nm (resist film thickness: 275 nm). When the variation of the pattern dimension was measured, it was 4 nm in 3σ. After slimming by the conventional dry process, the variation in the pattern dimension was 5 nm at 3σ. Neither resist residue nor pattern collapse was observed. As a reference sample, a resist residue was slightly observed in the sample dried from the supercritical state of water. Further, when 24 wafers were continuously processed, the variation between the wafers was 2 nm at 3σ. In the conventional dry process, the variation between wafers was 4 nm at 3σ. Therefore, it can be seen that high uniformity can be obtained by slimming with critical water. Further, the line edge roughness was half that of the conventional dry process, which was excellent.
[0031]
As described above, by performing slimming using supercritical water, slimming of pattern dimensions can be performed with good dimensional controllability both in-plane and between wafers. Further, by cleaning with carbon dioxide in a supercritical state, resist residues can be reduced. In addition, by drying the wafer from a state in which carbon dioxide in a supercritical state is introduced, a resist pattern without pattern collapse can be formed even when the aspect ratio is high.
[0032]
In the present embodiment, the substrate is washed with pure water and spin-dried in the development process. However, when the aspect ratio of the resist is high or the adhesion is not good, pattern collapse may occur. Instead, it is better to transport the wafer to a slimming processing apparatus in a state where a liquid film of water is formed on the wafer. In this case, it is necessary to control the pressure and temperature so that the water on the wafer does not evaporate when the water is brought into a supercritical state in the processing chamber.
[0033]
In addition, after slimming treatment with supercritical water, washing and drying are performed with carbon dioxide in a supercritical state.If there is no problem of pattern collapse, washing with liquid water and spin drying may be performed. . When there is no problem of the resist residue, the pressure and temperature may be changed from the state of supercritical water to the state of water gas to dry.
[0034]
In the present embodiment, an example of a resist pattern is shown as a slimming pattern. However, the pattern is not limited to this as long as the pattern size is reduced by supercritical water or subcritical water. For example, the dimensions of the silicon nitride film pattern are also reduced.
[0035]
The specific application range of the present invention is as follows: when the pattern dimension (100 nm in this embodiment) after the lithography step is L [nm], the exposure wavelength is λ [nm], and the numerical aperture of the projection optical system is NA. The value obtained by standardizing L by λ / NA is 1.2 or less. (0.86 in this embodiment)
(Second embodiment)
A pattern forming method according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a flowchart showing a processing procedure of the pattern forming method according to the second embodiment of the present invention. FIG. 6 is a diagram showing a schematic configuration of a substrate processing apparatus that performs a pattern forming method. FIG. 7 is a diagram illustrating a schematic configuration of a light irradiation unit according to the second embodiment of the present invention. FIG. 8 is a diagram schematically illustrating the light irradiation unit, the moving mechanism, and the gap adjusting mechanism illustrated in FIG. 9 to 13 are diagrams used for describing the pattern forming method of the present embodiment.
[0036]
(Step S201)
An antireflection film and a chemically amplified resist are applied on the wafer, and a desired pattern is reduced and projected through a reticle for exposure using an ArF excimer laser. The wafer is heat-treated and transferred to the substrate processing apparatus shown in FIG. As shown in FIG. 6, a wafer 61 is placed substantially horizontally on a substrate holding mechanism 62 of a substrate processing apparatus. The substrate holding mechanism 62 is rotated by a rotation mechanism 63 connected to a substantially central portion of the substrate holding mechanism 62. The rotation of the substrate holding mechanism 62 causes the wafer 61 to rotate. The substrate processing apparatus includes a developing solution discharge nozzle 64, a rinsing solution discharge nozzle 65, and a light irradiation unit 70.
[0037]
The configuration of the light irradiation unit that irradiates light to water will be described with reference to FIG. FIG. 7A is a front view of the light irradiation unit, and FIG. 7B is a cross-sectional view of the light irradiation unit. FIG. 7A is a view seen from the scanning direction, and FIG. 7B is a cross-sectional view in a direction orthogonal to the scanning direction.
[0038]
As shown in FIGS. 7A and 7B, a plurality of lamps 72 are arranged in a lamp house 71 along a direction orthogonal to the scanning direction. On the side of the lamp house 71 facing the wafer, a quartz glass (transparent plate) 73 is provided. Power is input to the lamp 72 from the power input unit 75. The power input unit 75 can independently supply power to each lamp 72 and adjust the illuminance of each lamp 72.
[0039]
A reflector 76 is provided in the lamp house 71 to efficiently irradiate the light emitted from the lamp 72 to the wafer side. Further, a diffusion plate 77 for reducing uneven illuminance is provided between the lamp 72 and the quartz glass 73.
[0040]
The reason for using a plurality of lamps 72 as lamps is to increase the uniformity of illuminance by adjusting the input power to each lamp, and it is not necessary to use divided lamps as long as they are uniform without being divided. .
[0041]
An excimer lamp was used as the lamp 72. Excimer lamp light includes a component having a wavelength of 172 nm. Light having a wavelength of 172 nm is also absorbed by oxygen in the air. Therefore, if oxygen exists in the lamp house 71, the amount of light absorbed by water decreases. Therefore, it is desirable to replace the interior of the lamp house 71 with nitrogen or to evacuate the interior. It is also desirable that the quartz glass 73 be transparent to the irradiation light.
[0042]
Next, a mechanism for holding the light irradiation unit 70 and a moving mechanism for horizontally moving the light irradiation unit 70 will be described with reference to FIG.
[0043]
As shown in FIG. 8, a gap measuring mechanism 82 is provided on a side surface of the light irradiation unit 70 on the scanning direction side. The gap measuring mechanism 82 is a distance measuring device using laser light. The gap measuring mechanism 82 measures the distance between the quartz glass 73 of the light irradiation unit 70 and the upper surface of the semiconductor wafer 61 placed on the substrate holding mechanism 62. Since the measurement target is the distance between the wafer 61 and the quartz glass 73, the irradiation position of the laser beam from the gap measurement mechanism 82 does not have to be on the wafer 61 as long as the plane is parallel to the wafer 61.
[0044]
The gap adjusting mechanisms 83 are provided at both ends of the light irradiation unit 70. The gap adjusting mechanism 83 adjusts the distance between the quartz glass 73 and the upper surface of the wafer 61 based on the measurement result of the gap measuring mechanism 82 so that the quartz glass 73 contacts the pure water 67 on the wafer 61. The gap adjusting mechanism 83 adjusts the gap by expanding and contracting the piezo element.
[0045]
The moving mechanism 84 moves the light irradiating unit 70 in which the distance is maintained at a predetermined value by the gap adjusting mechanism 83 in the horizontal direction.
[0046]
Further, it is necessary to precisely maintain the distance between the wafer 61 and the light irradiation unit 70 at a constant distance. Therefore, it is preferable that the diameter of the substrate holding mechanism 62 be approximately the same size as the wafer so that the wafer 61 is not bent.
[0047]
(Step S202)
As shown in FIG. 9, a developing solution 66 is supplied from the developing solution discharge nozzle 64 onto the wafer 61 to develop the resist film.
[0048]
Here, the developer 66 was supplied onto the wafer 61 by causing the developer discharge nozzle 64 to scan from one end of the wafer 61 to the other end and discharge the developer in a curtain shape. In the developer discharge nozzle 64 used here, the width of the discharge port in the direction orthogonal to the nozzle scanning direction is larger than the diameter of the wafer.
[0049]
Note that a developing solution supply mechanism has a mechanism for scanning from one end of the wafer to the other end. In addition, as shown in FIG. By using a mechanism for supplying the developer while rotating relatively, or as shown in FIG. 11, the wafer 61 is rotated while supplying the solution using a straight tubular nozzle 114 to supply the developer to the entire surface of the wafer. A mechanism or a mechanism for supplying the developing solution by uniformly spraying the developing solution from a spray nozzle on the entire surface of the wafer may be used.
[0050]
(Step S203)
After a resist pattern for which a predetermined development time has elapsed is formed, as shown in FIG. 12, pure water 67 is supplied from a rinse liquid discharge nozzle 65 onto the wafer 61 to stop the development reaction and perform cleaning. The supply of pure water is performed while rotating the wafer 61 by the rotation mechanism 63. After the completion of the cleaning, the spinning of the wafer 61 is stopped without spin drying, so that a liquid film of the pure water 67 is formed on the wafer 61.
[0051]
(Step S204)
Next, a slimming process of the resist pattern is performed in the same substrate processing apparatus. As shown in FIG. 13, the slimming process is performed by irradiating the pure water on the wafer 61 with light from the light irradiating unit 70 while scanning the light irradiating unit 70 in one direction.
[0052]
The light irradiated from the light irradiation unit 70 includes a wavelength of 250 nm or less that is absorbed by water. When water is irradiated with light having a wavelength of 250 nm or less, active radical molecules or radical atoms are generated from the water. Slimming treatment is performed by the radical molecules and atoms.
[0053]
The transmittance of light to water greatly changes depending on the thickness of the water. Therefore, it is necessary to precisely control the distance between the light irradiation unit and the wafer. FIG. 14 shows the relationship between the liquid thickness of water and the transmittance for light of 172 nm. From this relationship, it is understood that the liquid thickness needs to be controlled on the order of μm.
[0054]
When the transmittance of the liquid between the quartz glass 73 and the surface of the wafer 61 is less than 5%, the generation efficiency of radical molecules and atoms decreases, and it becomes difficult to perform a slimming process. Therefore, the gap is adjusted by the gap measuring mechanism 82 so that the transmittance of the liquid between the quartz glass 73 and the surface of the wafer 61 is 5% or more.
[0055]
(Step S205)
After the slimming process is completed, pure water is supplied while rotating the wafer 61 again to wash the wafer 61.
[0056]
(Step S206)
Next, the wafer 61 is dried. The drying process is performed by transporting the wafer 61 on which the liquid film of water has been formed to the substrate processing apparatus shown in FIG. 2 without spin drying.
[0057]
After being transported to the processing vessel 21, the valve 33 is opened, the temperature controller 31 and the high-pressure pump 32 are operated, and supercritical carbon dioxide is introduced into the processing vessel 21 at a predetermined temperature and pressure. Further, the temperature inside the processing container 21 is set to a predetermined temperature by the temperature controller 24 of the processing container 21. While continuously supplying the supercritical carbon dioxide into the processing vessel 21, the valve 25 is opened, and the supercritical carbon dioxide containing water is discharged. After the water on the wafer 61 is completely removed, the valve 33 is closed, the temperature controller 31 and the high-pressure pump 32 are stopped, the pressure inside the processing container 21 is reduced, and the wafer 61 is dried.
[0058]
Next, the operation and effect of the pattern forming method of the present embodiment will be described.
[0059]
(Slimming reaction: Step 203)
When water is irradiated with light having a wavelength of 250 nm or less, OH radicals and O radicals are generated. Both radicals have a strong oxidizing property, and in particular, the OH radical has a very strong oxidizing property. Therefore, the organic resist is oxidatively decomposed by both radicals.
[0060]
Accordingly, in a state where a liquid film of water is formed on the wafer, light is irradiated to generate OH radicals and O radicals. By causing the OH radicals and O radicals to act on the resist, the resist is oxidized and decomposed, and the remaining dimension of the resist pattern is reduced (slimming). The reaction amount can be controlled by setting the light irradiation amount, irradiation time, and liquid thickness of water to appropriate values. Therefore, the slimming amount can be controlled. Further, since the uniform oxidative decomposition reaction occurs slowly, the line edge roughness of the resist pattern can be reduced.
[0061]
In this embodiment, water is used as a radical source, but it is possible to generate OH radicals and O radicals even with hydrogen peroxide water. Hydrogen peroxide is more efficient because it can generate bimolecular OH radicals from one molecule. In the case of water, the absorption increases at a wavelength of 250 nm or less, so that OH radicals can be generated by irradiation with light of 250 nm or less. In the case of a hydrogen peroxide solution, the absorption increases at 300 nm or less. Therefore, irradiation with light including light having a wavelength of 300 nm or less generates OH radicals.
[0062]
In addition, OH radicals and O radicals can also be generated by irradiating water in which oxygen molecules and ozone molecules are dissolved with light. Slimming is caused by O radicals generated from dissolved oxygen or ozone, and OH radicals and O radicals generated from water. The absorption of water, oxygen and ozone increases at 250 nm or less. Therefore, irradiation with light having a wavelength of 250 nm or less generates radicals.
[0063]
Next, effects of the present invention will be described based on experimental results.
An antireflection film (film thickness 50 nm) and a chemically amplified resist (film thickness 300 nm) are applied on the wafer. The chemical amplification type resist is irradiated with an ArF excimer laser (exposure wavelength λ: 193 nm) via an exposure reticle, and the pattern formed on the reticle is subjected to reduced projection exposure. The numerical aperture (NA) of the projection optical system is 0.6. The wafer is heat treated at 120 ° C. for 90 seconds. After development with an alkaline developer for 60 seconds, pure water was supplied to stop and wash the development, thereby forming a 100 nm isolated pattern. In the present embodiment, spin drying is not performed after cleaning. However, as shown in the first embodiment, the variation in pattern dimension after development was 3 nm at 3σ.
[0064]
The slimming process has a lamp output of 100 mW / cm ² The scanning speed was 2 mm / sec, and the distance between the quartz glass and the wafer was 50 μm. For drying after the slimming treatment, the wafer is washed with supercritical carbon dioxide at 35 ° C. and 10 MPa for 30 seconds. After the cleaning, the inside of the processing chamber was returned to 25 ° C. and atmospheric pressure as shown by the solid line in FIG. 4 and dried.
[0065]
As a result, the size of the isolated pattern became 50 nm (resist film thickness: 275 nm). When the variation of the pattern dimension was measured, it was 3.5 nm in 3σ. Neither resist residue nor pattern collapse was observed. Further, when 24 wafers were continuously processed, the variation between the wafers was 3 nm at 3σ, and high uniformity was obtained. In the case of the conventional dry process, the variation between wafers was 4 nm at 3σ. Further, the line edge roughness was half that of the conventional dry process, which was excellent.
[0066]
By performing slimming processing using water activated by light irradiation, slimming of pattern dimensions can be performed with good dimensional controllability both in-plane and between wafers. After that, the resist residue was reduced by washing with carbon dioxide in a supercritical state. Further, by drying from carbon dioxide in a supercritical state, a resist pattern having a high aspect ratio could be formed.
[0067]
In this embodiment, after slimming, cleaning and drying are performed with carbon dioxide in a supercritical state. However, when there is no problem of pattern collapse, cleaning and spin drying may be performed with liquid water. When there is no problem of the resist residue, the pressure and temperature may be changed from the state of supercritical water to the state of water gas to dry.
[0068]
Next, other desirable modes of the present invention will be described.
[0069]
In the present embodiment, the light irradiating unit shown in FIG. 6 is used, but other forms shown in FIGS. 15 to 22 can be used.
[0070]
Further, the present invention is not limited to a configuration in which a plurality of lamps are arranged as an irradiation source. For example, the light irradiation unit 150 shown in FIG. 15 may be used. In the light irradiation section 150, one ends of the plurality of optical fibers 152 are arranged so as to face the wafer. The other end of each optical fiber 152 is arranged in a lamp house 154. Light from a lamp 155 provided in the lamp house 154 is incident on the other end of each optical fiber. Light from a lamp (light source) 155 is applied to the wafer from one end of each optical fiber 152. By separating the lamp 155 and the light irradiation unit 150, the weight of the light irradiation unit 150 is reduced. As a result, the movement control of the light irradiation unit 150 and the distance control between the light irradiation unit 150 and the wafer become easy.
[0071]
Further, a light irradiation unit in which a plurality of lamps are arranged along the scanning direction may be used. FIG. 16 shows a light irradiation unit 160 in which two lamps 162a and 162b are arranged along the scanning direction. When the same irradiation amount is given by scanning of the light irradiation unit 160 and the light irradiation unit 70 shown in FIG. 7, the moving speed of the light irradiation unit 160 can be twice the moving speed of the light irradiation unit 70. Therefore, when the light irradiation unit 160 is used, processing can be performed in a shorter time as compared with the case where the light irradiation unit 70 is used.
[0072]
In the case where uniformity of illuminance can be obtained in a wide area, a light irradiation section 170 having an irradiation area larger than the wafer 61 can be used as shown in FIG. Lamps 172a to 172i are arranged in the lamp house of the light irradiation section 170. A reflector 176 is arranged above the lamps 172a to 172i. Then, a diffusion plate 177 is arranged between the lamps 172a to 172i and the quartz glass 173. It is not necessary to move the light at the time of light irradiation by the light irradiation unit. Therefore, the processing time can be considerably reduced.
[0073]
Also, instead of scanning the light irradiation part on the wafer on which the pure water liquid film is formed, the liquid supply nozzle that supplies the pure water on the wafer is scanned to form a pure water liquid film on the wafer. Alternatively, the light irradiation unit may be scanned.
[0074]
When a slimming reaction occurs due to OH radicals or the like, the organic resist is decomposed and water or carbon dioxide gas is generated. When the gas is generated, the gas enters between the plate member and the wafer, the intensity of light on the wafer changes, and the amount of generated radicals greatly changes. However, by supplying a liquid while irradiating light, generated gas can be removed.
[0075]
As shown in FIG. 18, the light irradiation unit 70 and the liquid supply nozzle 181 for supplying pure water onto the wafer are preferably integrated. With the integrated structure, the movement of the liquid supply nozzle 181 and the light irradiation unit 70 and the gap adjustment can be performed by one moving mechanism and the gap adjusting mechanism. The liquid 182 a in the nozzle 181 is supplied onto the wafer 61. The liquid 132b supplied onto the wafer 61 is irradiated with light from the lamp 72.
[0076]
If the liquid 132b on the wafer 61 is thicker than 0.5 μm, it becomes difficult to remove the gas. Therefore, it is preferable that the light irradiation unit holding mechanism sets the distance between the upper surface of the wafer and the quartz glass to 0.5 mm or less.
[0077]
In the structure shown in FIG. 18, light from the lamp 72 is applied to the liquid 182b and the wafer 61, and the resist reacts with both the light and the generated radicals. When it is desired to suppress the reaction between the light and the resist, the structure shown in FIG. 19 may be used. As shown in FIG. 19, the quartz glass 73 is a part of the liquid supply nozzle 191. The lamp 72 irradiates the liquid 192a in the nozzle 191 with light. Radical atoms and molecules are generated in the nozzle 141. The generated radical atoms and molecules are supplied onto the wafer 61 by the flow of the liquid 192b. It is preferable to have a gap adjusting mechanism for adjusting the distance between the liquid supply nozzle 191 and the substrate shown in FIG. The generated radical molecules / atoms die immediately. Therefore, it is preferable to perform the scanning while reducing the distance between the liquid supply nozzle 191 and the substrate so that the radical molecules and atoms are not alive. Further, it is preferable to provide a gap measuring mechanism and adjust the distance by the gap adjusting mechanism while measuring the distance between the lower surface of the liquid supply nozzle 191 and the substrate surface during scanning.
[0078]
As shown in FIG. 20, a double mesh structure 202 is provided between the quartz glass 73 and the wafer 61 so that light from the lamp 72 does not directly hit the wafer 61. The generated radical molecules and atoms pass through the network-like structures 201 and 202 and are supplied to the surface of the wafer 61.
[0079]
Further, as shown in FIG. 21, the gap between the structure 211 and the wafer 61 downstream of the quartz glass may be narrower than the gap between the quartz glass 73 and the wafer 61. With this structure, radicals can be efficiently supplied to the surface of the wafer 61.
[0080]
Further, the liquid suction nozzle for collecting the liquid on the wafer may be scanned together with the light irradiation unit and the liquid supply nozzle. By collecting the liquid on the wafer with the liquid collection nozzle, the flow of the liquid can be made smooth. As a result, gas generated by the reaction can be efficiently removed.
[0081]
As shown in FIG. 22, it is preferable that the light irradiation unit 70, the liquid supply nozzle 181, and the liquid suction nozzle 221 have an integral structure. With the integrated structure, the movement and gap adjustment of the liquid supply nozzle 181, the light irradiation section 70, and the liquid suction nozzle 221 can be performed by one moving mechanism and gap adjusting mechanism.
[0082]
In the present embodiment, the slimming is performed by moving the light irradiation unit only once at 2 mm / sec, but it is also effective to move the light irradiation unit a plurality of times (for example, four times at 8 mm / sec). By moving faster, the amount of generated gas is reduced, and the variation in the reaction is reduced.
[0083]
In addition, when performing a plurality of movements, it is effective to measure the dimensions of the pattern before performing the slimming process. By measuring the pattern size, the amount of reaction can be known. The desired reaction amount may be obtained by changing the number of scans, the scanning speed, and the irradiation conditions (irradiation amount and gap) of the light irradiation unit according to the reaction amount. By changing the number of scans, the scanning speed, and the irradiation conditions according to the reaction amount, it is possible to reduce the variation in the reaction amount between wafers.
Further, when the dimension measurement result reaches a desired amount, the scanning of the light irradiation unit may be stopped to control the slimming process to be stopped. This control method can also reduce the variation in the reaction amount between wafers.
As a method of measuring the pattern dimension, a method of irradiating a measurement area with light and measuring the dimension from the intensity of the diffracted light (JP-A-10-304288, JP-A-2000-269120) is effective.
[0084]
Further, it is desirable to measure the illuminance of the irradiation light of the light irradiation unit before the slimming process. As shown in FIG. 23, the illuminance of the irradiation light from the light irradiation unit 70a before the processing is measured by the illuminance measurement mechanism 231. If the lamp is divided, measure for each lamp. When the illuminance varies among the lamps, the illuminance is controlled by the feedback mechanism 232 so as to be the same.
[0085]
Further, by comparing the measured illuminance with the set reference value, the moving speed of the light irradiation unit 70 and the gap between the light irradiation unit and the wafer are controlled. As the reference value, it is possible to set the illuminance at the time of the previous processing. With this control, a constant irradiation amount can be given when the illuminance changes according to time such as deterioration of the lamp.
[0086]
When the illuminance is higher than the reference value, the moving speed of the light irradiation unit 70 is increased or the gap is increased by the feedback mechanism 232. If the illuminance is lower than the reference value, the moving speed of the light irradiation unit 70 is reduced or the gap is reduced.
[0087]
In addition, as shown in FIG. 23, it is desirable that the quartz glass of the light irradiation unit 70 be cleaned by the cleaning device 233 after the processing. The treated quartz glass is washed with a washing liquid. In the case of an organic substance, it can be cleaned even with light of 172 nm, so that it can be cleaned simply by irradiating a lamp.
[0088]
(Third embodiment)
FIG. 24 is a flowchart illustrating a processing procedure of a pattern forming method according to the third embodiment of the present invention.
[0089]
(Step S301)
An antireflection film and a chemically amplified resist are applied on a semiconductor wafer. A chemically amplified resist is irradiated with a KrF excimer laser via an exposure reticle to reduce and expose a desired pattern. The wafer is heat-treated, transferred by a transfer robot (not shown) to an upper portion of the substrate holding unit, and fixed to the substrate holding unit by suction (not shown).
[0090]
(Step S302)
A liquid film of pure water is formed on the resist surface, and the resist surface is modified using O radicals and / or OH radicals generated by irradiating the liquid film with pure water.
[0091]
As in the slimming process (step S206) in the second embodiment, after a liquid film of pure water is formed on the wafer, the light irradiation unit is scanned with the lamp turned on. However, in this embodiment, since the purpose is to modify the surface of the resist film, the irradiation amount of pure water is made smaller than that in the second embodiment. After the reforming process, the wafer is washed by supplying pure water while rotating the wafer again, and the wafer is dried by rotating the wafer at a high speed.
[0092]
(Step S303: first development processing)
Next, as in the second embodiment, a developing solution is supplied onto the wafer, and a developing process for selectively removing exposed portions (unexposed portions) of the resist film is performed to form a resist pattern.
[0093]
(Step S304)
After about 5 seconds have passed since the developer was supplied to the main surface of the wafer, the resist on the wafer was rotated for 10 seconds by simultaneously discharging the ozone water (oxidizing liquid) from the rinse liquid discharge nozzle and rotating the wafer. The surface layer of the pattern is modified.
[0094]
Next, the wafer is rotated at a high speed to dry the wafer. In this embodiment, ozone water is used as the oxidizing liquid. Oxygen water, hydrogen peroxide water, or the like may be used as the liquid having the same oxidizing action.
[0095]
(Step S305: second development processing)
Next, similarly to the first developing process, a developing solution for processing the resist film on the wafer is supplied onto the wafer, and the second developing process is performed.
[0096]
(Step S306)
After about 25 seconds have passed since the supply of the developing solution to the main surface of the wafer, pure water is discharged from the rinsing liquid discharge nozzle and the wafer is rotated at 500 rpm and washed.
[0097]
(Step S307)
Subsequently, the wafer is rotated at a high speed to dry the wafer. Thus, the developing process is completed, and the wafer is collected by the transfer robot.
[0098]
The operation and effect of the pattern forming method described in the present embodiment will be described below.
[0099]
(Preprocessing: Step S302)
FIG. 25 schematically shows a developing process in a conventional developing method. Here, it is assumed that the resist film is a positive type.
[0100]
As shown in FIG. 25A, the exposed portion 253 of the exposed and unexposed portion of the exposed and baked resist film on the wafer 251 is selectively removed by a developing process, so that the resist is removed. A pattern is formed.
[0101]
Generally, in a chemically amplified photosensitive resist, the surface layer of the resist is a surface hardly soluble layer 254 that is relatively hard to dissolve in an alkali developing solution in order to maintain a rectangular pattern shape. Therefore, in the first half of the development, as shown in FIG. 25B, the developer hardly permeates between the patterns.
[0102]
Next, the operation and effect of the preprocessing of the present embodiment will be described with reference to FIG. On the other hand, when processing is performed with an oxidizing liquid before the development processing as in the present embodiment, an oxide layer 261 is formed on the surface of the resist, as shown in FIG. By performing the development process in a state where the oxide layer 261 is formed, the developer easily permeates between the patterns as shown in FIG. As a result, the developing speed is higher than in the past, and a thinner pattern can be formed.
[0103]
Surface modification process: S304
In the pattern forming method according to the present invention, between the first development (S303) and the second development (S305), the surface layer modification treatment (S304) is performed with an oxidizing liquid such as ozone water. The operation and effect of the reforming process will be described with reference to FIG.
[0104]
When the first development is completed, as shown in FIG. 27A, the exposed portion 253 is selectively removed by the developing solution, and the unexposed portion 252 remains to form a resist pattern. After that, by performing a surface layer modification treatment with an oxidizing liquid, an oxide layer 271 is formed on the surface layer of the pattern as shown in FIG. By performing development again after the oxidation treatment of the pattern surface layer, the oxide layer 271 is removed as shown in FIG. 27C, and a thinner pattern can be formed.
[0105]
Next, the respective effects of the pretreatment and the surface layer modification will be described based on the experimental results.
An antireflection film (film thickness 50 nm) and a chemically amplified resist (film thickness 300 nm) are applied on the wafer. The KrF excimer laser (exposure wavelength λ: 248 nm) is irradiated onto the chemically amplified resist through an exposure reticle including an isolated residual pattern of 150 nm (converted on a wafer by a mask design) to form a pattern formed on the reticle. Is subjected to reduced projection exposure. The numerical aperture (NA) of the projection optical system is 0.6. After the heat treatment, a development process is performed.
First, the effect of the pre-processing will be described. A reference sample was prepared by performing development processing once without performing pre-processing, and the exposure amount was set so that the finished dimension at this time was 130 nm. In addition, a sample was prepared in which the pre-processing was performed and the development processing was performed once. In order to confirm the effect of the pretreatment, conditions other than the pretreatment were the same as those of the reference sample. The condition of the pretreatment is that the lamp output is 100 mW / cm ² The scanning speed was 4 mm / sec, and the distance between the quartz glass and the wafer was 50 μm. The finished dimension of the pattern of the pre-processed sample was 110 nm, and the pattern dimension could be processed to be smaller than that of the reference sample.
[0106]
Next, the effect of the surface layer modification will be described. A reference sample was prepared by performing development processing once without performing pre-processing, and the exposure amount was set so that the finished dimension at this time was 130 nm. In addition, a sample was prepared in which the pre-processing was performed and the development processing was performed once. A sample for confirming the effect of surface modification was prepared. Table 1 shows the preparation conditions and finished dimensions of the samples.
[0107]
[Table 1]

[0108]
As shown in Table 1, it can be seen that by performing surface modification, the finished dimensions of the sample can be processed to be thinner than the reference sample. Also, it can be seen that the higher the ozone water concentration, the smaller the dimensions.
[0109]
The specific application range of the present invention is as follows: when the pattern dimension (130 nm in this embodiment) after the lithography step is L [nm], the exposure wavelength is λ [nm], and the numerical aperture of the projection optical system is NA. The value obtained by standardizing L by λ / NA is 1.2 or less. (0.87 in this embodiment)
(Other desirable embodiments)
In the first and second embodiments, examples have been described in which the resist pattern after the development processing is oxidized to reduce the pattern dimension. Further, in the third embodiment, an example in which the resist pattern before development processing is oxidized to reduce the pattern dimension, and the resist pattern after development processing is oxidized and further processed to reduce the pattern dimension An example is shown.
[0110]
As the oxidation treatment method, in the first embodiment, a method in which supercritical water or subcritical water is brought into contact with a resist, in the second embodiment, a method in which water is irradiated with light to generate radicals and contact with the resist, In the embodiment, the method of bringing the oxidizing liquid into contact with the resist has been described. The sequence of these treatments and the combination of the oxidation treatment methods can be arbitrarily selected.
[0111]
An oxidizing liquid can be used as the activated water used in the slimming process and the surface layer reforming process in the second and third embodiments. Pure water in which ozone, oxygen, and hydrogen peroxide are dissolved can be used as the oxidizing liquid.
[0112]
In the slimming process and the surface layer modification process, the surface of the resist pattern is oxidized to 5 nm or more. In order to oxidize the resist pattern to 5 nm or more, it is preferable that the resist pattern is brought into contact with the resist pattern for 10 seconds or more in the case of ozone water in which 1 ppm of ozone is dissolved in pure water. The thickness of the oxide layer depends on whether the ozone water is treated or not, and when the developing treatment is performed after each treatment, the thickness of the undissolved resist region (unexposed part in the case of a positive resist) It can be understood by measuring the film thickness difference.
[0113]
Comparing the oxidizing power of the three oxidation treatment methods shown in the present invention, the oxidizing power of the method of contacting the oxidizing liquid with the resist is relatively weak. Since the other two methods have strong oxidizing power, they are effective for any resist. The method of contacting the resist with an oxidizing liquid having a relatively weak oxidizing power is effective for an i-line resist composed of a novolak resin that is oxidized even with a relatively weak oxidizing power and a KrF resist composed of a polyhydroxystyrene resin. However, an ArF resist composed of an alicyclic resin (acrylic, coma-based, hybrid-based resin) which is not oxidized unless it has a strong oxidizing power is not sufficiently effective. An oxidation method having an oxidizing power necessary for oxidizing the resist resin may be selected.
[0114]
Note that the present invention is not limited to the above embodiments, and can be variously modified in an implementation stage without departing from the scope of the invention. Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effects described in the column of the effect of the invention can be solved. When at least one of the above is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.
[0115]
【The invention's effect】
As described above, according to the present invention, by performing slimming processing using active water, it is possible to perform slimming processing of a resist pattern with good dimensional control over both surfaces and between substrates.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating a processing procedure of a pattern forming method according to a first embodiment.
FIG. 2 is a diagram showing a configuration of a processing apparatus for realizing the pattern forming method according to the first embodiment.
FIG. 3 shows a phase diagram of water.
FIG. 4 is a diagram showing a phase diagram of carbon dioxide.
FIG. 5 is a flowchart illustrating a processing procedure of a pattern forming method according to a second embodiment.
FIG. 6 is a diagram illustrating a schematic configuration of a substrate processing apparatus that performs a pattern forming method according to a second embodiment;
FIG. 7 is a diagram illustrating a schematic configuration of a light irradiation unit of the substrate processing apparatus according to the second embodiment.
FIG. 8 is a view showing a pattern forming method according to the second embodiment.
FIG. 9 is a view showing a pattern forming method according to the second embodiment.
FIG. 10 is a diagram showing a pattern forming method according to the second embodiment.
FIG. 11 is a diagram showing a pattern forming method according to the second embodiment.
FIG. 12 is a diagram showing a pattern forming method according to the second embodiment.
FIG. 13 is a view showing a pattern forming method according to the second embodiment.
FIG. 14 is a diagram showing the relationship between the liquid thickness of water and the transmittance for light of 172 nm.
FIG. 15 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 16 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 17 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 18 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 19 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 20 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 21 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 22 is a diagram showing a schematic configuration of a light irradiation unit.
FIG. 23 is a view showing a schematic configuration of a substrate processing apparatus.
FIG. 24 is a flowchart showing a processing procedure of a pattern forming method according to the third embodiment.
FIG. 25 is a view schematically showing a development process in a conventional development method.
FIG. 26 is an explanatory diagram of the operation and effect of the preprocessing according to the third embodiment.
FIG. 27 is an explanatory diagram of the operation and effect of the reforming process according to the third embodiment.
[Explanation of symbols]
20 slimming processing device
21 ... Processing container
22 ... Wafer
23 ... Substrate holding mechanism
24 ... temperature controller
25 ... Valve
26 ... Pure water tank
27 ... Temperature controller
28 ... High pressure pump
29… Valve
30 ... Carbon dioxide cylinder
31 ... Temperature controller
32 ... High pressure pump
33 ... Valve

Claims (52)

Forming a photosensitive resin film on the substrate,
Exposing the photosensitive resin film,
Supplying a developer to the photosensitive resin film, forming a pattern of the photosensitive resin film,
Performing a slimming process of removing a surface layer of the pattern by bringing the activated water into contact with the pattern. Forming a photosensitive resin film on the substrate,
Exposing the photosensitive resin film,
Supplying a developer to the photosensitive resin film, forming a pattern of the photosensitive resin film,
Modifying the surface layer of the pattern by contacting activated water with the pattern,
Supplying a developer to the pattern to remove a surface layer of the pattern. Forming a photosensitive resin film on the substrate,
Exposing the photosensitive resin film,
Modifying the surface layer of the photosensitive resin film by contacting activated water with the photosensitive resin film,
Supplying a developing solution to the photosensitive resin film whose surface layer has been modified to form a pattern of the photosensitive resin film. 4. The pattern forming method according to claim 1, wherein supercritical water or subcritical water is used as the activated water. 4. The pattern forming method according to claim 1, wherein the activated water includes an atomic or molecular radical generated by irradiating the water with light. 5. The pattern forming method according to claim 5, wherein the light has a wavelength of 250 nm or less. The pattern forming method according to any one of claims 1 to 3, wherein the activated water contains radicals generated by irradiating water in which gas molecules are dissolved with light. The pattern forming method according to claim 7, wherein when hydrogen peroxide is selected as the gas molecule, the light has a wavelength of 300 nm or less. The pattern forming method according to claim 7, wherein when oxygen or ozone is selected as the gas molecule, the light has a wavelength of 250 nm or less. The activated water is ozone water obtained by dissolving ozone in pure water, and the surface of the pattern is oxidized by 5 nm or more by the ozone water. Pattern forming method. 2. The pattern forming method according to claim 1, wherein dimensions of the pattern are measured before performing the slimming process, and conditions for the slimming process are determined based on the measurement result. 2. The pattern forming method according to claim 1, wherein after the slimming process, a re-slimming process for removing a surface layer of the pattern is performed one or more times by bringing the activated water into contact with the pattern. The pattern forming method according to claim 12, wherein dimensions of the pattern are measured before the re-slimming process. 14. The pattern forming method according to claim 13, wherein a condition of the re-slimming process is determined based on a measurement result of the measured dimension of the pattern. 14. The pattern forming method according to claim 13, wherein the re-slimming process is stopped when the measured dimension of the pattern becomes a desired dimension. 2. The pattern forming method according to claim 1, wherein the dimension of the pattern is measured together with the slimming process, and the slimming process is stopped when the measured size reaches a desired size. After the step of removing the surface layer of the pattern,
A re-modification treatment for modifying the pattern surface layer by contacting the activated water with the pattern, and a re-development treatment for removing a surface layer of the pattern by supplying a developer to the re-modified pattern. 3. The pattern forming method according to claim 2, wherein a series of processes is performed at least once. 18. The pattern forming method according to claim 17, wherein dimensions of the pattern are measured before the re-modification process. 19. The pattern forming method according to claim 18, wherein conditions for the re-modification processing and the re-development processing are determined based on the measured pattern dimensions. The measurement of the pattern dimension is performed by irradiating the measurement region of the substrate with measurement light, and diffracted light intensity from the measurement region, or the wavelength dispersion of the diffracted light intensity, or the wavelength dispersion of the polarization information of the diffracted light. 19. The pattern forming method according to claim 11, wherein the method is performed. After the formation of the pattern,
2. The pattern forming method according to claim 1, wherein a cleaning liquid is supplied onto the substrate to which the developing liquid has been supplied, and the slimming process is performed with the cleaning liquid remaining on the substrate. After the formation of the pattern,
2. The pattern forming method according to claim 1, wherein a cleaning liquid is supplied onto the substrate to which the developing liquid has been supplied, and the slimming process is performed with the cleaning liquid removed on the substrate. After the slimming process,
Supplying carbon dioxide in a supercritical state on the substrate to dissolve water on the substrate,
2. The pattern forming method according to claim 1, further comprising a step of drying the substrate while changing the pressure and temperature so that carbon dioxide in a supercritical state does not pass through a liquid state but becomes a gas state. After the slimming process,
A step of changing the pressure and temperature so that the activated water does not vaporize to bring the water into a supercritical state,
2. The pattern forming method according to claim 1, further comprising the step of drying the substrate while changing the pressure and temperature so that water in a supercritical state becomes a gas state without passing through a liquid state. A substrate holding mechanism for holding the substrate substantially horizontally,
A light irradiator that includes a transparent plate disposed to face the substrate holding mechanism, and irradiates the substrate with light by transmitting the transparent plate.
When a liquid film is formed on the substrate, the transparent plate is provided with a distance adjusting mechanism for adjusting a distance between the light irradiation unit and the substrate so that the transparent plate contacts the liquid film. A substrate processing apparatus characterized by the above-mentioned. 26. The substrate processing apparatus according to claim 25, further comprising a moving mechanism that relatively horizontally moves the light irradiation unit and the substrate holding mechanism. A substrate holding mechanism for holding the substrate substantially horizontally,
A liquid supply unit for supplying a liquid on the substrate,
A light irradiating unit that irradiates light to the liquid before being supplied to the substrate,
A substrate processing apparatus, comprising: a moving mechanism that relatively horizontally moves the liquid supply unit and the light irradiation unit and the substrate holding mechanism. The substrate processing apparatus according to claim 27, further comprising a distance adjusting mechanism that adjusts a distance between the liquid supply unit and the substrate. Further comprising a measurement mechanism for measuring the distance between the substrate and the liquid supply unit,
29. The substrate processing apparatus according to claim 28, wherein the distance adjusting mechanism adjusts the distance based on a measurement result of the measuring mechanism. The substrate processing apparatus according to any one of claims 25 to 27, wherein the substrate holding mechanism has substantially the same diameter as the substrate. The substrate processing apparatus according to any one of claims 25 to 27, further comprising a rotation mechanism configured to rotate the substrate held by the substrate holding mechanism. The distance adjusting mechanism adjusts a distance between the upper surface of the substrate and the transparent plate such that a transmittance of irradiation light to a liquid between the transparent plate and the substrate becomes 1% higher. The substrate processing apparatus according to claim 25 or claim 26, wherein Further comprising a measurement mechanism for measuring the distance between the substrate and the light irradiation unit,
27. The substrate processing apparatus according to claim 25, wherein the distance adjustment mechanism adjusts the distance based on a measurement result of the measurement mechanism. The substrate processing apparatus according to any one of claims 25 to 27, further comprising an illuminance detection mechanism configured to detect illuminance of light emitted from the light irradiation unit. 35. The substrate according to claim 34, wherein when the detected illuminance is larger than a reference value, the distance adjustment mechanism sets a distance between the substrate and the light irradiation unit to be larger than a distance corresponding to the reference value. Processing equipment. 35. The substrate according to claim 34, wherein when the detected illuminance is smaller than a reference value, the distance adjustment mechanism sets a distance between the substrate and the light irradiation unit to be smaller than a distance corresponding to the reference value. Processing equipment. The light irradiation unit further includes an illuminance detection mechanism that detects illuminance of light emitted from the light irradiation unit, and when the detected illuminance is larger than a reference value, the moving mechanism determines a relative position between the light irradiation unit and the substrate holding mechanism. 28. The substrate processing apparatus according to claim 26, wherein the target moving speed is faster than a moving speed corresponding to the reference value. The light irradiation unit further includes an illuminance detection mechanism that detects illuminance of light emitted from the light irradiation unit, and when the detected illuminance is smaller than a reference value, the moving mechanism determines a relative position between the light irradiation unit and the substrate holding mechanism. 28. The substrate processing apparatus according to claim 26, wherein a typical moving speed is lower than a moving speed corresponding to the reference value. 26. The substrate processing apparatus according to claim 25, further comprising a liquid supply device that supplies the liquid onto the substrate to form a film of the liquid. 27. The liquid supply apparatus according to claim 26, further comprising: a liquid supply device that supplies the liquid onto the substrate to form a film of the liquid; and a liquid suction device that suctions the liquid on the substrate. A substrate processing apparatus according to claim 1. 41. The substrate processing apparatus according to claim 39, wherein the distance adjusting mechanism sets a distance between the upper surface of the substrate and the transparent plate to 0.5 mm or less. The substrate processing apparatus according to claim 39, wherein the moving mechanism relatively horizontally moves the light irradiation unit and the liquid supply device and the substrate holding mechanism. 43. The substrate processing apparatus according to claim 42, wherein the liquid supply unit and the light irradiation unit are arranged in this order from the front side in the moving direction of the light irradiation unit and the liquid supply unit with respect to the substrate holding mechanism. apparatus. 41. The substrate processing apparatus according to claim 40, wherein the moving mechanism relatively horizontally moves the light irradiation unit, the liquid supply device and the liquid suction device, and the substrate holding mechanism. The liquid supply unit, the light irradiation unit, and the liquid suction unit are arranged in this order from the front side in the moving direction of the light irradiation unit, the liquid supply unit, and the liquid suction unit with respect to the substrate holding mechanism. The substrate processing apparatus according to claim 44. 28. The substrate processing apparatus according to claim 25, wherein the light irradiator includes a plurality of light sources and an illuminance adjustment mechanism for adjusting the illuminance of each light source. 28. The substrate processing apparatus according to claim 25, wherein the light irradiator distributes light from a light source and irradiates the light to a plurality of regions on the substrate. 28. The substrate processing apparatus according to claim 26, wherein a width of an irradiation area of the light irradiation unit in a direction orthogonal to the horizontal movement direction has substantially the same diameter as the substrate. 28. The substrate processing apparatus according to claim 25, further comprising a developer supply device that supplies a developer to the substrate. 28. The substrate processing apparatus according to claim 25, wherein when the liquid is water, the wavelength of the light is 250 nm or less. 28. The substrate processing apparatus according to claim 25, wherein when the liquid is a hydrogen peroxide solution, the wavelength of the light is 300 nm or less. 28. The substrate processing apparatus according to claim 25, wherein when the liquid is water in which ozone or oxygen is dissolved, the wavelength of the light is 250 nm or less.

Images