JP2007096340A - Processing method and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the occurrence of particles and suppress the occurrence of defects at the processings a processed film. <P>SOLUTION: The invention comprises steps of forming a liquid film 204 on the principal surface of a substrate supplying application film, forming medicinal solution 206 containing solvent on the substrate, forming a processed film 207 by removing a part of the solvent contained in the liquid film 204, selectively irradiating processing light on the processing region of the processed film 207, selectively removing the processed film 207, and carrying out a heating process for almost completely removing the solvent contained in the processed film 207, after the irradiation of the processing light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processing method for processing by light irradiation and a method for manufacturing a semiconductor device using the processing method.

  With the miniaturization of semiconductor elements, high precision of alignment technology with the lower layer is essential in the lithography process in the semiconductor device manufacturing process.

  However, when the film formed under the resist has a large reflection and absorption with respect to the alignment light, it is difficult to detect the position information from the alignment mark. For example, in the lithography process for forming a metal wiring such as Al, the position of the alignment mark formed in the lower layer of the Al film cannot be directly detected. Therefore, alignment must be performed by providing a step on the alignment mark itself, forming an Al film after that, and detecting the uneven shape of the Al film generated on the alignment mark. However, the surface unevenness on the Al film is asymmetric with respect to the underlying unevenness due to the nature of the film forming method such as sputter deposition, so that the alignment error increases and the yield decreases. Therefore, a method of selectively removing a film opaque to alignment light such as an Al film by an ablation technique has been proposed.

  The ablation technique is one of processing techniques using light such as a laser, and since fine patterns can be formed without using a lithography technique, it has recently attracted attention as a processing technique for semiconductor devices. Ablation is a reaction in which when a film to be processed is irradiated with light, the film to be processed melts and gasifies when the irradiation intensity reaches a certain threshold value or more. By using this reaction, fine processing such as drilling and cutting can be performed.

  However, when ablation technology is used in the semiconductor manufacturing process, when ablation technology is used, a part of the film to be processed, such as a metal film that could not be completely gasified during ablation, is scattered around the processing region, resulting in particles Adhere as. If a chemically amplified positive resist film is formed next as an upper layer in a state where particles are attached to the device pattern region, a difference in resist film thickness occurs. Therefore, the resist pattern after exposure / development cannot be formed in a predetermined dimension. A problem with semiconductor devices created by processing a resist pattern created in this way as a mask is that device characteristics vary greatly.

  In order to suppress such defects caused by particles, there is a technique in which optical processing is performed after forming a protective film on the film to be processed, and particles are removed together with the protective film after the processing is completed (see, for example, Patent Document 1). ).

In Cited Document 1, a heat-resistant organic material such as polyimide or polyamide is used as a protective film. Such a heat-resistant organic material does not dissolve in a solvent, and it is difficult to remove the protective film. Further, as a result of investigation by the present inventor, it was found that particles remain on the film to be processed even after removal of the protective film. Further, depending on the mechanical characteristics of the protective film, there is a problem that film peeling occurs during processing, resulting in processing failure.
JP-A-5-337661

  As described above, when optical processing is performed by forming a heat resistant organic material on a film to be processed, there is a problem that it is difficult to remove the heat resistant organic material.

  At the time of laser processing, there is a problem that particles generated when the processed film in the processing region is selectively processed adheres to the outside of the processing region and causes defects. Further, there has been a problem that film peeling occurs during processing, resulting in processing failure.

  An object of the present invention is to provide a processing method capable of suppressing generation of defects by eliminating generation of particles when processing a film to be processed, and a method of manufacturing a semiconductor device using the processing method.

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

  A processing method according to an example of the present invention includes a step of supplying a chemical solution for forming a coating film containing a solvent on a substrate to form a liquid film on the main surface of the substrate, and removing a part of the solvent contained in the liquid film. A step of forming a film to be processed, a step of selectively irradiating a processing region of the processing film with a processing light to selectively remove the processing film, and after the irradiation of the processing light, into the processing film And a step of performing a main heat treatment for almost completely removing the contained solvent.

  A method of manufacturing a semiconductor device according to an example of the present invention forms a liquid film on a main surface of a substrate by supplying a chemical solution for forming a coating film containing a solvent onto a substrate to be processed having a semiconductor substrate and an alignment mark. A step of forming a film to be processed by removing a part of the solvent contained in the liquid film, and selectively irradiating the processing film in the region including the alignment mark with the processing light. A step of selectively removing a processed film, a step of performing a main heat treatment for almost completely removing a solvent contained in the processed film after the irradiation of the processing light, and a step of forming a photosensitive film on the processed film Irradiating the alignment mark with reference light to recognize the position of the mark, and irradiating a predetermined position of the photosensitive film with energy rays based on the recognized position information of the alignment mark. Forming a latent image on the photosensitive film; Characterized in that it comprises a step of developing the photosensitive film in which the latent image has been formed.

  According to the present invention, regarding a technique for selectively removing a film to be processed formed on a substrate to be processed and forming a pattern, the protective film and the film to be processed are formed after a water-soluble protective film is formed on the film to be processed. By performing the above processing in a lump or processing for reducing the internal stress of the film to be processed, optical processing without particles and residues can be performed around the processing region.

  The details of the present invention will be described below with reference to the illustrated embodiments.

(First embodiment)
First, a description will be given of a pattern forming method capable of performing predetermined processing without attaching particles generated during optical processing to the periphery of the processing region.

  1 and 2 are cross-sectional views showing a manufacturing process of a semiconductor device according to the first embodiment of the present invention.

  A semiconductor device in the stage before forming the Al wiring shown in FIG. As shown in FIG. 1A, a via plug 105 connected to an Al wiring to be formed later, and an alignment mark 106 for alignment are formed on the surface layer of the interlayer insulating film 102 formed on the semiconductor substrate 101. At least formed. Reference numerals 103 and 104 denote plugs and lower wiring layers.

  As shown in FIG. 1B, an Al film 107 and a protective film 109 are sequentially formed on the surface of the semiconductor element. The protective film 109 is formed by applying a polyacrylic acid resin (hereinafter referred to as a protective film), which is a water-soluble resin having a film thickness of 100 nm, to the substrate to be processed by a spin coating method, and then volatilizing the solvent.

As shown in FIG. 1C, the protective film 109 is irradiated by irradiating the processing light 110 five times on the processing region (100 μm long × 200 μm wide) in which the alignment mark 106 is formed below in the atmosphere. And an opening is formed in the Al film 107. The protective film should not be vitrified by processing light irradiation. In the present embodiment, the processing light 208 is the third harmonic (wavelength 355 nm) of a Q-switch YAG laser, and the fluence of the processing light 208 is 0.4 J / cm ² · pulse. Reference numeral 111 denotes particles of the protective film 109 and the Al film 107 that are not completely gasified during ablation and are scattered.

Next, the substrate to be processed 100 is transferred to the cleaning unit by the transfer robot after the optical processing, and the protective film 109 is peeled off by supplying water as shown in FIG. As shown in FIG. 3, the protective film 109 is peeled off by supplying pure water (flow rate: 1 L / min) 122 from a nozzle 121 disposed above the substrate to be processed and cleaning the substrate 100 for 60 seconds while rotating the substrate 100 at 100 rpm. To do. After cleaning with pure water, the number of rotations is increased to 4000 rpm, and the substrate is dried.
As a result of SEM observation after the above-mentioned optical processing, it was confirmed that no particles remained around the processing region of the metal film and that favorable processing was possible.

  After the metal film on the alignment mark is removed by such a method, an I-line resist film 112 is formed as shown in FIG. Next, as shown in FIG. 2 (f), the position of the alignment mark 106 is recognized by the alignment light (reference light) 113. A pattern is transferred based on the recognized position to form a latent image on the resist. The resist film on which the latent image is formed is developed to form a resist pattern. The Al film 107 is etched using the resist pattern as a mask to form a wiring pattern as shown in FIG. The resist pattern is removed.

  A device produced using this as a mask can obtain stable device characteristics produced without performing this process, and the yield is improved.

  In this embodiment, polyacrylic acid is used as the protective film. However, it is desirable to use a material that is water-soluble and has a higher transmittance at the wavelength of the processing light than the film to be processed. By using a highly permeable protective film, the protective film hardly absorbs laser light, and heat generation from the protective film itself is small. Therefore, the protective film that could not be decomposed during the light irradiation is scattered around the processing region in a solid state without melting. The protective film scattered around the processing region as a solid is quickly removed by washing with water after processing. Furthermore, since it is water-soluble, the protective film can be removed at a relatively low cost.

  On the other hand, when the transmittance of the protective film with respect to the wavelength of the laser beam is larger than that of the film to be processed, the protective film itself generates heat and melts because the light absorption by the protective film is large. For this reason, when the molten protective film adheres to the protective film around the processing region as particles, the protective film is altered or welded to the underlying processed film by the heat of the attached particles. As a result, even when the protective film is removed after processing, the protective film in the region where the molten particles are attached cannot be removed, resulting in a defect.

  In this embodiment, polyacrylic acid is used for the protective film, but the material is not limited to this. What is necessary is that the light absorption by the laser beam is smaller than that of the film to be processed. When the extinction coefficient k of the protective film and the extinction coefficient k ′ of the film to be processed are set at the wavelength λ (nm) of the laser beam, A material and processing light that use a protective film that satisfies the relational expression described in the following expression (1) may be selected.

k <k ′ (1)
In this embodiment, the extinction coefficient of polyacrylic acid and Al as the film to be processed with respect to a wavelength of 355 nm is 1.0 × 10 ⁻⁴ , 3.36.

Furthermore, it is desirable that the protective film irradiated with the laser can maintain a solid state. Therefore, it is only necessary that the protective film can be maintained at a melting point (Tm) or less when one pulse of laser is irradiated. As the criteria for selecting the protective film, the specific heat CF (J / cm ³ · K) of the protective film, the absorption coefficient α (1 / nm), the extinction coefficient k, the reflectance R _F (%), and the temperature change ΔT of the protective film When (K), melting point Tm (K) of protective film, atmospheric temperature T ₀ (K), laser fluence F (J / cm ² · pulse), and laser wavelength λ (nm), the following equation (2) From the above, it is preferable to select a material and processing light that satisfy the relational expression described in Expression (4).

Tm> T ₀ + ΔT (2)
ΔT = {α (1-R _F / 100) F / C _F } (3)
α = 4πk / λ (4)
The physical properties of polyacrylic acid with respect to a wavelength of 355 nm in this embodiment are shown in (Table 1).

  Alternatively, even when the protective film has a large light absorption for laser light and the protective film melted by optical processing adheres to the processing region, the protective film around the processing region is a protective film that maintains water solubility as before the optical processing. You can use anything as long as you want. For example, an organic material having a hydrophilic group such as a hydroxyl group, a carboxyl group or an amino group, or a water-soluble inorganic material may be used. A protective film having such characteristics can be used for the protective film of this embodiment because the protective film can be removed in the water washing step after optical processing.

In the present embodiment, the third harmonic of the Q-switch YAG laser is used as the light source for optical processing. A pulsed laser such as a laser and lamp light may be used. In this embodiment, laser processing is performed by irradiating 5 times at 0.4 J / cm ² · pulse. However, the processing conditions are not limited to this, and no residue is generated in the processing region, or the film to be processed Any fluence or number of irradiations that can be processed without damaging the metal film.

  In the present embodiment, the case where the film to be processed is a metal film has been described. However, the application example is not limited thereto, and the film to be processed is a metal oxide film, an antireflection film, a metal film, a silicon nitride film, or a silicon carbide film, You may use for a silicon oxide film, polycrystalline Si, etc.

  In this embodiment, an I-line resist film is formed and patterned after photoprocessing. However, the resist film used for patterning is not limited to this, and any KrF resist, ArF resist, EB resist, or the like may be used. I do not care.

  In this embodiment, the protective film is formed on the entire surface. However, as shown in FIG. 4, the protective film may be selectively formed only at a desired position. As a method for selectively forming the protective film, for example, a method described in JP-A-2000-79366 may be used. Here, as a method for selectively forming a protective film, the method described in Japanese Patent Laid-Open No. 2000-79366 was used as an example, but any method can be used as long as it can selectively form a protective film with a controlled film thickness on a substrate. May be used.

  In the present embodiment, the light irradiation region is processed to have the same size as the processing region at the time of optical processing. However, at the time of optical processing, as shown in FIGS. The processing light 141 may be formed in a strip shape, and processing may be performed by scanning the processing light 140 relative to the substrate. As a method of scanning light relative to the substrate, the substrate is moved while the optical axis is fixed. Alternatively, the optical axis may be moved by translating a slit (aperture) whose shape is controlled. Reference numeral 140 denotes a machining area. FIG. 5A is a cross-sectional view, and FIG. 5B is a plan view of a processing region.

For example, a slit of 100 μm × 5 μm is provided in a predetermined processing region (100 μm × 200 μm) in the atmosphere, and the third harmonic (wavelength 355 nm) of the Q-switch YAG laser is applied to a fluence of 1.0J. The protective film and the Al film are removed by irradiating a laser while scanning from one end of the processing region to the other end at / cm ² · pulse, an oscillation frequency of 250 Hz, and a slit scanning speed of 500 μm / sec.

  In general, particles are generated by blowing off a part of the film to be processed that cannot be gasified when the gas generated by ablation expands. Therefore, compared to the case where the entire processing area is optically processed by collective irradiation, the irradiation area constricted in the slit shape shown in FIG. 5 is scanned relative to the substrate to be processed and the optical processing is performed. In this case, the volume of gas generated by one light irradiation is reduced, and the number of particles around the processing region and the peeling of the protective film at the processing region boundary can be further suppressed. Further, as shown in FIGS. 6A and 6B, a plurality of strip-shaped processing lights 141a to 141d may be irradiated at equal intervals in the scanning direction. Further, as shown in FIGS. 6C and 6D, a plurality of dot-shaped processing lights 141c and 141d are irradiated at equal intervals in the scanning direction and at equal intervals in the direction orthogonal to the scanning direction. Also good. Further, as shown in FIG. 6D, the processing light 141d adjacent in the scanning direction may overlap.

  Note that the strip shape or the dot shape is a quadrangle whose length in the scanning direction is shorter than the length of the processing region. In particular, in the strip shape, the length in the direction orthogonal to the scanning direction is substantially equal to the length in the direction orthogonal to the scanning direction of the processing region. The dot shape is a quadrangle whose length in the scanning direction is shorter than the length of the processing area. In particular, in the strip shape, the length in the direction perpendicular to the scanning direction is shorter than the length in the direction perpendicular to the scanning direction of the processing region.

(Second Embodiment)
FIG. 7 is a cross-sectional view showing a manufacturing process of a semiconductor device according to the second embodiment of the present invention.

  First, as shown in FIG. 7A, an organic film 149 mainly composed of a novolak resin (organic material) containing a thermal decomposition agent is applied to the Al film 107 by a spin coating method. Next, heat treatment is performed on a hot plate under conditions of 100 ° C. for 60 seconds, and the solvent in the organic film 149 is volatilized to form a protective film. Here, the thermal decomposition agent is not particularly limited as long as it has a function as a catalyst capable of inducing a thermal decomposition reaction and can decompose a resin constituting an organic film serving as a mask film.

  Next, as shown in FIG. 7B, an organic film 150 is obtained in which the substrate to be processed is heat-treated at 150 ° C. for 60 seconds. In the heat treatment, the thermal decomposition agent acts as a catalyst for the thermal decomposition reaction of the resin constituting the organic film. The main chain of the resin is cleaved by the thermal decomposition reaction. The main chain of the resin is cut, the molecular weight is reduced, and the internal stress of the organic film 150 is reduced.

Then, as shown in FIG. 7C, the third harmonic (wavelength 355 nm) of the Q-switch YAG laser is used in the atmosphere, and the laser fluence is 0 with respect to the processing region (vertical 100 μm × horizontal 200 μm). An opening is formed in the resin film 150 by irradiating 5 times at 6 J / cm ² · pulse.

  Next, as shown in FIG. 7D, the Al film is selectively removed by wet etching using the resin film as a mask. At this time, the processing defect derived from film peeling did not occur.

  After removing the resin film, as in the first embodiment, an I-line resist film is formed on the Al film 107, and the alignment mark 106 is irradiated with alignment light (reference light) to recognize the position of the alignment mark. . After exposure based on the recognized position of the alignment mark 106, development is performed to form a resist pattern pattern. The Al film 107 is etched using the resist pattern as a mask to form a wiring pattern. The semiconductor device produced by the above-described process can obtain stable device characteristics produced without performing this treatment, and the yield is improved.

  As described above, since the stress applied to the inside of the protective film is reduced by cutting the main chain of the resin constituting the organic film serving as the mask film by the thermal decomposition reaction, even a material having a large internal stress is used as the protective film. be able to.

  Moreover, the thermal decomposition agent in this embodiment contains the thermal decomposition agent which reaction starts in the temperature range of the film formation temperature (100 degreeC in this embodiment) of a mask film | membrane to 200 degreeC. When the reaction initiation temperature of the thermal decomposition agent is lower than the film formation temperature, the decomposition of the novolac resin proceeds excessively during the heat treatment during film formation, which causes a problem that processing characteristics deteriorate. On the other hand, if the reaction start temperature exceeds 200 ° C., the film characteristics may be deteriorated due to the oxidation reaction of the novolak resin. Accordingly, the reaction start temperature of the thermal decomposition agent is desirably in the range of 200 ° C. from the film formation temperature. Further, if the amount of the thermal decomposition agent added is too small, the decomposition reaction hardly proceeds, so that the optical processing characteristics are not changed, and the film is peeled off. In addition, if the amount of the thermal decomposition agent added is too large, the decomposition reaction is promoted, so that chemical resistance at the time of wet etching after optical processing may be deteriorated. Therefore, it is desirable that the amount of the thermal decomposition agent added to the novolac resin is in an appropriate range.

  If a sufficient fluence of the optical processing apparatus cannot be obtained for the metal film to be processed, it is not easy to form a desired pattern by the pattern forming method of the first embodiment. However, according to the pattern forming method described in the present embodiment, since the fluence of processing light is not related to the processing of the Al film, a desired pattern can be formed.

  In the present embodiment, the mask film is reformed by heating with a hot plate. However, the heating method is not limited to this, and the substrate to be processed may be irradiated with infrared rays, and the substrate to be processed is heated. Anything can be used as long as it is possible.

  Further, the mask film modification treatment is not limited to the heat treatment. In addition to this, a photocatalyst having a function of decomposing the mask film may be used by activating the catalyst contained in the mask film by irradiating energy rays. In addition, any energy source that activates the photocatalyst can be activated by irradiating light such as ultraviolet rays, far ultraviolet rays, deep ultraviolet rays, electron beams, etc., and the catalyst film can be decomposed to cause a decomposition reaction of the mask film. It may be used.

  In the present embodiment, optical processing is performed in the air, but it may be performed in running water.

  In this embodiment, the etching method of the metal film performed after the optical processing of the mask film is performed by wet etching. However, the etching method is not limited to this, and dry etching or anisotropic etching may be used. An optimum method may be selected as appropriate depending on the characteristics of the above.

In the present embodiment, the case where the film to be processed is a metal film has been described. However, the application example is not limited thereto, and the film to be processed is a metal oxide film, an antireflection film, a metal film, a silicon nitride film, or a silicon carbide film, In this embodiment, an I-line resist film is formed and patterned after optical processing. However, the resist film used for patterning is not limited to this. Any of KrF resist, ArF resist, EB resist, etc. may be used.

  In this embodiment, the light irradiation area is processed to the same size as the processing area at the time of light processing. However, as described in the first embodiment, the light irradiation shape is changed to a strip shape or a dot shape. The processing may be performed by scanning the processing light relative to the substrate.

(Third embodiment)
FIG. 8 is a cross-sectional view showing a manufacturing process of a semiconductor device according to the third embodiment of the present invention. In FIG. 8, only the region where the alignment mark is formed is shown.

As shown in FIG. 8A, while the semiconductor substrate 101 is rotated, a chemical liquid 206 for forming an antireflection film containing a solvent and an antireflection material is supplied from a nozzle 205 onto the SiO ₂ film 203, and the liquid film 204 is liquid. Form. Reference numeral 106 denotes an alignment mark embedded in a silicon substrate, and reference numeral 201 denotes a silicon nitride film.

  Next, as shown in FIG. 8B, the semiconductor substrate 101 is rotated, and an antireflection film 207 from which a part of the solvent is removed from the liquid film 204 is obtained by a spin dry process. In addition to the spin dry process, a substrate on which a liquid film is formed may be placed under reduced pressure to remove a part of the solvent from the liquid film.

Next, as shown in FIG. 8C, an opening is formed in the antireflection film 207 by irradiating the processing region 208 (length 100 μm × width 200 μm) five times with the processing light 208 in the atmosphere. The opening is formed above the alignment mark. As a result of SEM observation after optical processing, it was confirmed that good processing was possible without particles remaining around the processing region of the antireflection film. The processing light 208 is the third harmonic (wavelength 355 nm) of a Q-switch YAG laser, and the fluence of the processing light 208 is 0.4 J / cm ² · pulse.

  Next, as shown in FIG. 8D, the semiconductor substrate 101 is placed on the hot plate 210 and heat treatment (main heat treatment) is performed at 300 ° C. for 120 seconds in order to obtain desired antireflection properties. To obtain an antireflection film 209 from which the solvent is almost completely removed.

  After the above treatment, a chemically amplified positive resist for ArF light (wavelength 193 nm) having a thickness of 200 nm was formed on the antireflection film. Next, the substrate is transported to an exposure apparatus in which an ArF excimer laser is a light source, and alignment light (reference light) is irradiated through an exposure reticle to recognize the position of the alignment mark 106. The gate processing pattern is transferred according to the position of the alignment mark 106. The substrate is developed after the heat treatment to form a gate processing pattern. The device created by processing the resist pattern created in this way into a mask does not generate particles during laser processing and can be formed to a predetermined gate size, so the characteristics of the device produced through the subsequent steps The semiconductor device could be manufactured without any influence.

  The present embodiment is characterized in that optical processing is performed before heat treatment for completely removing the solvent. By performing optical processing before the heat treatment, the antireflection film can be quickly vaporized and processing without particles can be performed. On the other hand, when optical processing is performed after the heat treatment at a high temperature of 300 ° C., particles are generated because the antireflection film is hard to vaporize. In particular, some antireflection films can obtain antireflection properties by a crosslinking reaction by heat treatment. In the case where the antireflection film is cross-linked, it is more difficult to evaporate at the time of optical processing, so that more particles are generated.

  In the present embodiment, the third harmonic of the Q-switch YAG laser is used as the processing light. However, the processing light is not limited to this, and the fourth harmonic (wavelength 266 nm) of the Q-switch YAG laser, a KrF excimer laser, or the like. The pulse laser and lamp light may be used. In the present embodiment, the optical processing is not limited to the above-described conditions, and any fluence or number of irradiations that can be processed without causing a residue in the processing region or damaging the lower layer film of the antireflection film may be used. Moreover, in this embodiment, although optical processing was performed in air | atmosphere, you may carry out in the state in which the liquid flow or the airflow was formed on the process area | region.

  In the present embodiment, the light irradiation region is processed with the same size as the processing region at the time of the optical processing. However, as described in the first embodiment, the light irradiation region is narrowed down into a slit shape to form a substrate. Processing may be performed by relatively scanning light.

  In this embodiment, the case where the film to be processed is an antireflection film has been described. However, the film to be processed is not limited to this, and any film can be used as long as it is a coating film such as a resist film, a silicon oxide film, or a polyimide film. I do not care.

(Fourth embodiment)
FIG. 9 is a process cross-sectional view illustrating a manufacturing process of a semiconductor device according to the fourth embodiment of the present invention. 9, parts that are the same as those in FIG. 1 are given the same reference numerals, and explanation thereof is omitted.

  First, as shown in FIG. 9A, a chemical liquid 206 for forming an antireflection film containing a solvent is supplied by a spin coating method to form a liquid film 204. Thereafter, a spin dry process is performed to form an antireflection film from which a part of the solvent has been removed from the liquid film on the substrate to be processed. In addition to the spin dry process, a substrate on which a liquid film is formed may be placed under reduced pressure to remove a part of the solvent from the liquid film.

  Next, as shown in FIG. 9B, the semiconductor substrate 101 is placed on a hot plate 210 and pre-heated at 150 ° C. for 60 seconds, and a part of the solvent contained in the film is removed. The removed antireflection film 217 is obtained. In order for the antireflection film used in this embodiment to obtain antireflection characteristics necessary for the lithography process, heat treatment is usually performed at 300 ° C. However, the heat treatment of the substrate at this stage is performed at a temperature lower than that.

Next, as shown in FIG. 9C, an opening is formed in the antireflection film 207 by irradiating the processing region 208 (vertical 100 μm × horizontal 200 μm) with the processing light 208 five times in the atmosphere. The opening is formed above the alignment mark. As a result of SEM observation after optical processing, it was confirmed that good processing was possible without particles remaining around the processing region of the antireflection film. The processing light 208 is the third harmonic (wavelength 355 nm) of a Q-switch YAG laser, and the fluence of the processing light 208 is 0.4 J / cm ² · pulse.

  Next, as shown in FIG. 9D, the semiconductor substrate 101 is placed on the hot plate 210, and the main heat treatment is performed under the conditions of 350 ° C. and 120 seconds, so that the solvent in the film is almost removed and the crosslinking is performed. An antireflection film 218 in which a reaction has occurred is obtained.

  After the above treatment, a chemically amplified positive resist for ArF light (wavelength 193 nm) having a thickness of 200 nm was formed on the antireflection film. Next, the substrate is transported to an exposure apparatus in which an ArF excimer laser is a light source, and alignment light (reference light) is irradiated onto the alignment mark 106 via an exposure reticle to obtain the position of the alignment mark 106. The gate processing pattern is transferred according to the position of the alignment mark 106. The substrate is developed after the heat treatment to form a gate processing pattern. The device created by processing the resist pattern created in this way into a mask does not generate particles during laser processing and can be formed to a predetermined gate size, so the characteristics of the device produced through the subsequent steps A semiconductor device can be manufactured without affecting the semiconductor device.

  In the third embodiment, a part of the solvent in the station film is removed using the spin dry process. However, the step film formed by the spin coating method includes a large amount of solvent in the film to be processed, and therefore, if the optical processing is performed in this state, the film may be peeled off. In this embodiment, since the solvent is further removed by the pre-heating process by the spin dry process, no film is peeled off and no particles are generated.

  In this embodiment, the heating temperature condition of the preheating treatment for obtaining the antireflection film is 150 ° C. As described in the third embodiment, when the heating temperature before the optical processing is too high, the antireflection film is hardly vaporized during the optical processing, and particles are generated. In particular, since the film to be processed causes a cross-linking reaction by heat treatment, it becomes more prominent. Therefore, when performing optical processing of such a film to be processed, the heating temperature of the substrate before the optical processing is the antireflection film. It is desirable that the temperature be lower than the crosslinking temperature.

  On the other hand, if the heating temperature is too low, depending on the material, a large amount of solvent remains in the film, so that the film strength deteriorates. For this reason, film peeling or the like may occur during optical processing. Therefore, it is necessary that the heating temperature of the substrate before the optical processing is less than the crosslinking temperature of the antireflection film and is in a range that does not affect the processed shape.

In the present embodiment, the third harmonic of the Q-switch YAG laser is used as the light source for optical processing. A pulsed laser such as a laser and lamp light may be used. In this embodiment, laser processing is performed by irradiating 5 times at 0.4 J / cm ² · pulse. However, the processing conditions are not limited to this, and no residue is generated in the processing region, or an antireflection film. Any fluence or number of irradiations that can be processed without damaging the interlayer insulating film formed in the lower layer may be used. Further, in this embodiment, the optical processing is performed under the atmosphere, but it may be performed under running water.

  In the present embodiment, the light irradiation region is processed with the same size as the processing region at the time of the optical processing. However, as described in the first embodiment, the light irradiation region is narrowed down into a slit shape to form a substrate. Processing may be performed by relatively scanning light.

  In the present embodiment, the case where the film to be processed is an antireflection film has been described. However, the film to be processed is not limited to this, and any film can be used as long as it is a coating film such as a resist film, a silicon oxide film, or a polyimide film. It doesn't matter.

In addition, this invention is not limited to the said embodiment. For example, in each embodiment, although the example applied to the manufacturing process of a semiconductor device was shown, it can be used for other purposes.
In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

Sectional drawing which shows the manufacturing process of the semiconductor device concerning 1st Embodiment. Sectional drawing which shows the manufacturing process of the semiconductor device concerning 1st Embodiment. The figure which shows the removal process of the protective film concerning 1st Embodiment. The figure which shows the modification of the manufacturing process of the semiconductor device concerning 1st Embodiment. The figure which shows the modification of the manufacturing process of the semiconductor device concerning 1st Embodiment. The figure which shows the modification of the manufacturing process of the semiconductor device concerning 1st Embodiment. Sectional drawing which shows the manufacturing process of the semiconductor device concerning 2nd Embodiment. Sectional drawing which shows the manufacturing process of the semiconductor device concerning 3rd Embodiment. Sectional drawing which shows the manufacturing process of the semiconductor device concerning 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Semiconductor substrate 102 ... Interlayer insulating film 105 ... Via plug 106 ... Alignment mark 107 ... Al film 109 ... Protective film 110 ... Processing light 112 ... Resist film 113 ... Alignment light (reference light)

Claims (13)

Supplying a coating film forming chemical solution containing a solvent on the substrate to form a liquid film on the substrate main surface;
Forming a film to be processed by removing a part of the solvent contained in the liquid film;
Selectively irradiating the processing region of the processing film with processing light to selectively remove the processing film;
A step of performing a main heat treatment for almost completely removing the solvent contained in the film to be processed after the processing light irradiation;
The processing method characterized by including.   2. The processing method according to claim 1, wherein part of the solvent contained in the liquid film is removed by combining at least one process selected from the group including a spin dry process, a reduced pressure process, and a preheating process. .   The processing method according to claim 2, wherein a processing temperature of the preheating treatment is equal to or lower than a processing temperature of the main heat treatment.   The processing method according to claim 1, wherein the irradiation of the processing light is performed in a state where an air flow or a liquid flow is formed on the processing region.   The processing method according to claim 1, wherein the substrate includes an alignment mark or a displacement measurement mark formed in the processing region.   2. The processing method according to claim 1, wherein the film to be processed is any one of an antireflection film, a metal film, a metal oxide film, a silicon nitride film, a silicon carbide film, a silicon oxide film, and polycrystalline Si. .   The processing method according to claim 1, wherein the processing light is laser light or lamp light.   The processing method according to claim 1, wherein an irradiation shape of the processing light on the substrate is smaller than the processing region, and the processing light is scanned with respect to the substrate.   The processing method according to claim 8, wherein the irradiation shape of the processing light is a quadrangle whose width in the scanning direction of the processing light is shorter than the width of the processing region in the scanning direction.   The processing method according to claim 8, wherein a plurality of the processing lights are irradiated at equal intervals along the scanning direction. Supplying a coating film forming chemical solution containing a solvent on a substrate to be processed having a semiconductor substrate and an alignment mark to form a liquid film on the main surface of the substrate;
Forming a film to be processed by removing a part of the solvent contained in the liquid film;
Selectively irradiating the processing film in the region including the alignment mark with processing light to selectively remove the processing film;
A step of performing a main heat treatment for almost completely removing the solvent contained in the film to be processed after the processing light irradiation;
Forming a photosensitive film on the film to be processed;
Irradiating the alignment mark with reference light to recognize the position of the mark;
Irradiating a predetermined position of the photosensitive film with energy rays based on the recognized position information of the alignment mark to form a latent image on the photosensitive film;
Developing the photosensitive film on which the latent image is formed;
A method for manufacturing a semiconductor device, comprising:   12. The semiconductor device according to claim 11, wherein part of the solvent contained in the liquid film is removed by combining at least one process selected from the group including a spin dry process, a reduced pressure process, and a preheating process. Manufacturing method.   The method for manufacturing a semiconductor device according to claim 12, wherein a processing temperature of the preheating treatment is equal to or lower than a processing temperature of the main heat treatment.

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