JP3081655B2 - Method of forming resist pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

The present invention relates to a method for forming a resist pattern in a semiconductor device manufacturing process.

[0003]

2. Description of the Related Art In recent years, the trend toward miniaturization of LSI devices has been progressing, and lithography techniques capable of forming a fine pattern in a submicron region, which are difficult to realize with conventional optical lithography, include electron beams and deep ultraviolet light ( Lithography by an excimer laser or the like is drawing attention.

However, electron beam lithography inherently has a defect that the pattern shape and dimensions after drawing and development are significantly deteriorated due to the so-called proximity effect caused by scattering of the electron beam in the solid. In addition, since electron beam lithography is inferior in throughput to conventional optical lithography, a method for irradiating with a higher current density than before has been proposed as a solution.

However, even in this method, as the current density increases, the energy of the electron beam is converted into thermal energy by scattering in a solid, and the heat is deposited and absorbed in the resist, so-called resist heating. There is a defect that the contrast of the pattern is deteriorated due to the heat resistance of the resist because the effect becomes apparent.

In particular, remarkable pattern deterioration due to a resist heating effect in a radiation-decomposition type resist, such as PMMA (polymethyl methacrylate), is described in, for example, "Journal of Vacuum Science".
e Technology B, Vol. 6, PP. 8
53-857 ".

[0007] The effect of the resist heating effect has been pointed out also in excimer laser lithography of short wavelength.

Further, there has been no resist material having high sensitivity, high contrast, and excellent dry etching resistance required for putting the above-mentioned submicron lithography technique into practical use.

However, recently, a highly amplified resist material called a chemically amplified type having characteristics different from those of conventional resist materials has appeared, and lithography using deep ultraviolet light (excimer laser or the like) or electron beam has been put into practical use. It is expected as a possible resist material.

This chemically amplified resist material is intended to improve sensitivity and resolution by utilizing an acid catalytic reaction. For example, a chemically amplified negative resist material comprises a resin, a crosslinking agent, and an acid generator. It is composed of When this resist material is exposed, it is generated from an acid generator. Thereafter, heat treatment (post-exposure bake treatment, hereinafter, referred to as “PEB treatment”)
By doing so, the acid acts on the post-crosslinking agent while diffusing in the resist material to create active sites therein. Crosslinking with the resin proceeds through these active sites, and as a result, the crosslinked portion becomes hardly soluble in the developer, and a pattern is formed after development.

In this chemically amplified negative resist material, crosslinking proceeds even if the amount of acid generated by exposure is small, so that even a portion with a small amount of exposure becomes slightly insoluble. Therefore, there is an advantage in that a pattern having good verticality of the side wall and excellent in dimensional accuracy can be easily formed as compared with a conventional resist material in which a pattern is formed largely depending on the amount of exposure as in the case of a conventional resist material.

However, the barrier energy in the diffusion process of an acid in a chemically amplified resist material is low, and the diffusion of the acid slightly proceeds even at room temperature. As a result, a difference in sensitivity occurs depending on the standing time after exposure.
As shown in FIG. 10, such a change in sensitivity with time tends to increase in sensitivity with time until PEB processing after exposure, and tends to saturate with time due to characteristics of the resist material. As described above, in a region where the change in the sensitivity of the resist material is large, the contrast of the resist material also varies, thereby lowering the processing accuracy of the fine pattern.

Therefore, in order to obtain stable sensitivity and contrast, it is sufficient to take a certain time between the exposure and the PEB process, which is sufficient for the resist material to be stable. However, in such a method, the processing time becomes longer, and the throughput decreases.

Further, the PEB treatment of a chemically amplified resist material is described in the document "Journal of Vacuum".
um Science Technology B, V
ol. 6, PP. As shown in “379-383”, it is known that differences in processing conditions such as processing temperature and processing time significantly affect sensitivity characteristics and contrast characteristics. For this reason, in order to improve the dimensional accuracy and the cross-sectional shape of the resist pattern, it is necessary to enhance the controllability of the resist pattern shape in the PEB process.

[0015]

As described above,
For chemically amplified resist materials that bring out the excellent fine workability of energy rays such as deep ultraviolet light such as excimer lasers and electron beams, proximity effects and resist heating effects caused by scattering of energy rays in solids Deterioration of pattern dimensions and cross-sectional shape due to the above has not been sufficiently improved.

[0016]

[0017]

Therefore, the present invention has been made in view of the above, and it is an object of the present invention to reduce the number of steps and improve the dimensional accuracy of a pattern and the verticality of a side wall in a chemically amplified resist material. It is an object of the present invention to provide a method for forming a resist pattern which contributes to fine processing and high integration in a semiconductor device.

[Structure of the Invention]

[0020]

In order to achieve the above object, a first means for solving the problems is a first step of coating and forming a chemically amplified resist layer on a layer to be processed; Irradiating the entire surface of the resist layer applied in step 1 with an energy ray having an energy that does not allow a thermal crosslinking reaction or a thermal decomposition reaction to proceed without heating the resist layer to generate an acid in the resist layer. A second step, and a third step of selectively irradiating the resist layer with an energy ray having energy sufficient to cause a thermal crosslinking reaction or a thermal decomposition reaction in the resist layer after the second step to generate heat. And a fourth step of developing and selectively removing the resist layer after the third step.

The second means is a first step of applying and forming a chemically amplified resist layer on the layer to be processed, and heating the resist layer on the resist layer applied in the first step. A second method for selectively generating an acid in the resist layer by selectively irradiating an energy ray having an energy that does not allow a thermal crosslinking reaction or a thermal decomposition reaction to proceed.
And selectively applying an energy ray having energy sufficient to cause a thermal crosslinking reaction or a thermal decomposition reaction to proceed in the resist layer after the second step to a region of the resist layer where an acid is generated in the second step. And a fourth step in which the resist layer after the third step is developed and selectively removed.

[0022]

[0023]

[0024]

According to the first or second aspect of the present invention, the irradiation of an energy beam such as an electron beam or an excimer laser is not used as a trigger of acid generation in a chemically amplified resist as in the prior art, but rather has a high convergence. It is characterized by being used as a heat source having.

That is, after activating the acid generator by irradiation with an electron beam or an excimer laser or the like, a cross-linking or decomposition reaction is caused by applying heat to a place where the generated acid is present by an energy beam having a high current density. Then, thermal deposition in the resist by the resist heating effect is used for selective heating of only the patterning portion. That is, only the patterning portion is selectively heated in the presence of an acid to cause a crosslinking or decomposition reaction to proceed.

Accordingly, the cross-linking or decomposition reaction near the patterning portion is eliminated, and the influence of the proximity effect is significantly reduced. This actually leads to higher contrast of the resist pattern.

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

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

FIG. 1 is a diagram showing sensitivity characteristics of a chemically amplified resist material patterned by a method of forming a resist pattern according to one embodiment of the present invention. The method of forming a resist pattern for obtaining the sensitivity characteristics shown in FIG.
After the acid generator that is included in the chemically amplified negative resist material and becomes the precursor of the thermal crosslinking reaction is activated in advance, it remains by drawing with a high current density electron beam or short wavelength excimer laser. The heat generated by the resist heating effect is selectively generated only in the resist portion to be heated, and the thermal crosslinking reaction proceeds only in this portion.

In FIG. 1, the sensitivity characteristic is 0.5 (μ
m) of a chemically amplified negative resist material of SAL601-ER7 (manufactured by Shipley Co., Ltd.) having a film thickness of about 40 m).
It is a measurement result at the time of performing exposure using an electron beam exposure apparatus having an acceleration energy of about (KeV).

FIGS. 1 (a), 1 (b) and 1 (c) respectively show
Current density 10 (A / cm ² ), current density 60 (A / cm ² )
² ) shows the beam size dependence at a current density of 400 (A / cm ² ). From FIG. 1, it can be seen that the exposure amount at the remaining film thickness of 0 (μm) gradually decreases as the current density increases. Further, as can be seen from FIG. 1C, the sensitivity increases as the beam size increases and the amount of heat generation increases.

Therefore, considering that the irradiation time becomes shorter as the current density becomes higher for the same irradiation amount, FIG.
Are considered to be the result of the resist heating effect having an advantageous effect on the pattern formation.

FIG. 2 shows an exposure amount at a residual film thickness of 0 (μm) for a beam size of 0.5 (μm) and a beam size of 1.5 (μm).
(Μm) and the difference from the exposure amount when the remaining film thickness is 0 (μm).
FIG. 9 is a diagram showing D with respect to current density. Exposure difference △ D
Is considered to be an index indicating the degree of heat generation due to resist heating, and it can be seen from FIG. 2 that the heat generation increases as the current density increases. That is, it is understood that the larger the irradiation energy and the irradiation area, the larger the amount of heat generated in the resist.

FIG. 3 shows an electron beam having a high current density as a heat source.
It is a figure which shows the pattern formation method at the time of utilizing for a thermal crosslinking reaction.

First, a chemically amplified negative resist (SAL601-ER7) is applied and baked on the layer 1 to be processed to form a coating film 2 having a thickness of 0.5 (μm). 2 to generate acid 3 in the resist.
However, in this exposure step, it is required not to give sufficient energy for the thermal crosslinking reaction to proceed. That is, when an electron beam lithography apparatus is used, the acceleration energy is 40 (KeV) and the current density is 10 (A / c).
m ^2), subjected to irradiation with a dose of 10 (μC / cm2), in the case of using an optical stepper, such as excimer laser, an exposure time 0.3 (s), E = 200 (mJ
Irradiation is performed under an exposure condition that reaches an energy amount of (/ cm ² ) (FIG. 3A).

Next, using an electron beam having a high current density as a heat source,
Irradiate the patterning part. As a result, almost simultaneously with the generation of new acid according to the irradiation amount, the resist temperature in the patterning portion is selectively increased under the influence of the resist heating effect. For example, when an electron beam lithography system using a variable-shaped vector scan system is used, the acceleration energy 40
(KeV), current density 200 (A / cm ² ), dose amount 20 (μC / cm ² ), shot size 1.0 × 1.0
When irradiation is performed with a (μm) rectangular beam, the resist temperature in the patterning portion rises to about 100 ° C., and a crosslinking reaction proceeds selectively.

Next, the resist material is developed to obtain a desired resist pattern (FIG. 3C).

In such a forming method, even if an acid is present in a region other than the patterning portion, sufficient heat is not applied to cause the reaction to proceed.
After the development of the resist, a resist pattern having a high contrast in which the influence of the proximity effect is significantly reduced as shown in FIG. 3C can be formed.

On the other hand, an excimer laser having a short wavelength may be used as a heat source for the thermal crosslinking reaction. For example, when a KrF excimer laser is used, 100 (mJ / pu) is used.
1se / cm @ 2) energy pulse of 10 (m
When irradiation is performed at intervals of 1 (s) for 1 (s), the resist temperature of the patterning portion rises to about 100 ° C., and the thermal crosslinking reaction proceeds selectively, and the same effect as in the above-described embodiment can be obtained. .

FIG. 4 shows a case where a high current density electron beam is used as a heat source.
It is a figure which shows one Example of the pattern formation method at the time of utilizing for a thermal crosslinking reaction.

First, a chemically amplified resist (SAL601-ER7) is applied and baked on the layer to be processed 1 to form a coating film 2 having a thickness of 0.5 (μm). Then, acid 3 is generated only in the resist in the patterning portion. However, even in this exposure step, it is required that sufficient energy is not given to advance the thermal crosslinking reaction. That is, when an electron beam lithography apparatus is used, the acceleration energy is 40 (KeV), the current density is 10 (A / cm ² ), and the dose is 10 (μC / cm ² ).
When irradiation is performed under the conditions described above and an optical stepper such as an excimer laser is used, the exposure time is 0.3 (s).
Then, irradiation is performed under an exposure amount condition that reaches an energy amount of E = 200 (mJ / cm ² ) (FIG. 4A).

Next, by irradiating the patterning portion with an electron beam having a high current density as a heat source, almost at the same time as the generation of new acid according to the irradiation amount, as in the above-described embodiment.
Under the influence of the resist heating effect, the resist temperature in the patterning portion is selectively increased. For example, when an electron beam lithography system using a variable-shaped vector scan system is used, a temperature rise similar to that of the above-described embodiment can be obtained (FIG. 4).
(B)).

Next, the resist material is developed to obtain a desired pattern (FIG. 4C).

Even with such a method, it is possible to form a resist pattern having a high contrast in which the influence of the proximity effect as shown in FIG.

Also, in the above embodiment, a short wavelength excimer laser may be used as a heat source of the thermal crosslinking reaction, as described above, and the same effect can be obtained.

Further, in all of the above-described embodiments, the contrast can be further improved by adding heating (PEB processing) to the entire surface of the wafer using a hot plate or the like. Further, since the ordinary PEB process can be omitted, the number of steps and the development time can be reduced as compared with a conventional pattern formation process using a chemically amplified resist.

As described above, according to the present invention, the influence of the proximity effect and the resist heating effect, which are problems in realizing the formation of a fine pattern in a submicron region, by an electron beam or far ultraviolet light (excimer laser, etc.). Thus, the deterioration of pattern accuracy due to the above can be eliminated, and the development time can be greatly reduced, and at the same time, the contrast can be significantly improved.

FIG. 5 is a sectional view showing one step of a method for forming a resist pattern according to an embodiment of the present invention. In the pattern forming method of the embodiment shown in FIG. 2, PEB processing in a pattern forming step using a chemically amplified negative resist material is performed in two steps.
This is done in stages.

In FIG. 5, first, a silicon semiconductor substrate 4 is oxidized to form an oxide film 5 having a thickness of about 0.8 (μm).
To form Next, a chemically amplified negative resist material (S
AL601-ER7) is applied on the oxide film 5 and a pre-bake process is performed to form a resist film 6 having a thickness of about 0.5 (μm) on the oxide film 5.

Next, 248.4 in an excimer laser using a mixed gas of krypton, fluorine and helium.
The resist material 6 is subjected to pattern exposure through a mask by a reduction projection exposure apparatus using (nm) oscillation light as irradiation light. The energy intensity during this exposure is 50 to 100 (mJ
/ Cm ² ).

Next, as the first stage PEB treatment, a sample subjected to PEB treatment at a treatment temperature of 50 ° C. for 60 seconds immediately after exposure and a sample subjected to PEB treatment under the same treatment conditions two hours after exposure were used. prepare.

Next, as a second stage PEB treatment, a PEB treatment is performed for 120 seconds at a treatment temperature of 100 ° C. that is sufficient to cause a thermal crosslinking reaction on the resist material 6 of both samples in the above-described process. 0.27 (N) obtained by diluting an alkali developing solution (for example, a metal-free developing solution MF312, manufactured by Shipley, trade name) 1: 1 with deionized water.
The development is carried out by immersion in a developer having a moderate concentration for 100 seconds.

In the resist pattern formed through such a process, even if the time required from the exposure to the first stage PEB processing is different for each of the samples, the same exposure energy is applied to each of the samples. .35 (μm)
Vertical sidewalls were obtained with spacing accuracy.

On the other hand, when only the second stage PEB process is performed without performing the first stage PEB process, the PEB process performed immediately after the exposure is performed on the sample subjected to the PEB process two hours after the exposure. Exposure energy was required to be about 15 (%) higher than the
Patterns at 5 (μm) intervals could not be formed with high accuracy.

Therefore, according to the above embodiment, it is possible to stabilize the sensitivity of the resist material without being affected by the time until the PEB processing after exposure, and it is possible to obtain a highly accurate resist pattern.

Next, another embodiment in which the PEB process after exposure is performed in two stages will be described.

First, 24 samples coated with a resist material in the same manner as in the above-described embodiment were continuously exposed,
All the samples after exposure are left in an atmosphere at a temperature of about 10 ° C. This processing can be called PEB processing in a broad sense although the processing temperature is lower than room temperature, and corresponds to the first stage PEB processing.

Next, as the second stage PEB processing, 95%
A PEB treatment was performed at a processing temperature of 120 ° C. for 120 seconds, and a development treatment was performed in the same manner as described above.

In such a PEB process, the same exposure dose was applied to all 24 samples to 0.35 (μm).
m) A resist pattern having vertical side walls at intervals was obtained, and the same effect as in the above-described embodiment was obtained. This is because the diffusion of the acid generated by the exposure in the first stage PEB treatment was stopped because of the low temperature, and the second stage PEB treatment acted on any sample regardless of the time after exposure. It is.

On the other hand, when the first stage PEB treatment is performed in an atmosphere at room temperature, first, the second stage PB treatment is performed.
A difference in sensitivity of about 15 (%) occurred between the sample subjected to the EB treatment and the last sample, and a resist pattern with good accuracy could not be obtained.

In the above embodiment, the processing conditions in the exposure processing and the development processing are not limited to those described above, and the same effects can be obtained by appropriately changing the processing conditions.

Next, the sensitivity characteristics of the chemically amplified negative resist material to the PEB processing temperature or PEB processing time will be described.

FIG. 6 shows the results of measuring the sensitivity characteristics of a chemically amplified negative resist material using an electron beam exposure apparatus.

FIG. 6A is a diagram showing the PEB temperature dependence of the sensitivity characteristics. From FIG. 7A, it can be seen that the sensitivity characteristics increase with increasing PEB temperature. That is, by raising the PEB temperature, the same effect as when the dose is increased can be obtained effectively.

FIG. 6B is a diagram showing the PEB time dependence of the sensitivity characteristics. As can be seen from FIG.
It can be seen that the sensitivity increases as the time increases. That is, by increasing the PEB time, the same effect as when the dose is increased can be obtained effectively.

From the above, the sensitivity characteristics of the chemically amplified resist can be controlled by changing the temperature and time of the PEB treatment after exposure.

FIG. 7 is a graph showing the results of measurement of contrast characteristics (γ value) of a chemically amplified negative resist using an electron beam exposure apparatus.

FIG. 7A is a diagram showing the PEB temperature dependence of the γ value. FIG. 7A shows that the γ value increases as the PEB temperature increases. That is, by increasing the PEB temperature, the contrast characteristics can be improved.

FIG. 7B is a diagram showing the PEB time dependency of the γ value. FIG. 4B also shows that the γ value increases as the PEB time increases. That is, PEB
By increasing the time, the contrast characteristics can be improved.

That is, by applying the temperature-time characteristics of the sensitivity characteristics or the contrast characteristics of the chemically amplified resist to the depth direction of the resist during the developing process or the rinsing process, the cross-sectional shape of the pattern can be improved. Can be controlled.

Next, an embodiment of a method for forming a resist pattern by repeating the PEB treatment according to the present invention a plurality of times simultaneously with the surface treatment and the rinsing treatment and alternately with the development treatment is shown in FIG. Description will be made with reference to a cross-sectional view.

First, a chemically amplified negative resist material (for example, SAL601-ER7, manufactured by Shipley Co., trade name) is applied and baked on the layer 11 to be processed to form a film having a thickness of 0.6 (μm).
A resist film 12 of about m) is formed on the processing target layer 11. Thereafter, the resist film 12 is irradiated with a predetermined pattern using a far ultraviolet exposure device such as an excimer laser or an electron beam exposure device (FIG. 8A).

Next, at a temperature of about 100 ° C. for 1.5 minutes,
The PEB process is performed by heating on a hot plate. Thus, a tapered latent image 13 unique to the negative resist due to the influence of the proximity effect is formed on the resist film 12.
(B)).

Next, the film is immersed in an alkali developing solution (for example, MF-622, manufactured by Shipley Co., trade name) 14 whose temperature is controlled to about 20 ° C. for 0.5 minutes for development. This allows
A part of the resist film 12 is removed (FIG. 8C).

Next, pure water 1 temperature-controlled to about 80 ° C.
After performing a rinsing treatment at 0.5 for 0.5 minutes, the whole is sufficiently dried. The rinsing treatment in this step has the same function as the PEB treatment again as a result together with the original rinsing treatment, and is a surface insolubilization treatment with pure water, so that the hardly-solubilized layer 16 is formed on the surface of the resist film 12,
The rate of dissolution of the remaining resist film 12 on the surface of the developing solution is significantly reduced (FIG. 8D).

Further, in the above process, the PEB treatment with pure water is performed again, so that the exposed region of the remaining resist film 12 is subjected to the PEB treatment for 2 minutes in total. The contrast characteristics will be improved.

Next, the film is immersed again for 6 minutes in an alkali developing solution 14 whose temperature is controlled to about 20 ° C., and developed.
A normal rinsing process is performed with pure water whose temperature has been controlled to a certain degree (FIG. 8E).

Finally, the whole is sufficiently dried to obtain a desired resist pattern 17 (FIG. 8F).

As described above, in the above embodiment, PE
The sensitivity characteristic and the contrast characteristic of the resist film 12 are improved by performing the B treatment and the rinsing treatment simultaneously and repeatedly a plurality of times. Further, the resist film 12 that is in contact with pure water during the rinsing process is always supplied with heat from pure water, and the temperature decreases as the resist film 12 becomes lower, and the crosslinking density decreases in the lower layer. In particular, the taper shape of the pattern due to the proximity effect that becomes apparent when irradiation is performed using an electron beam exposure apparatus is particularly improved, and a resist pattern having a vertical side wall can be formed.

FIG. 9 is a process sectional view showing another embodiment of the above-described resist pattern forming method. The feature of the embodiment shown in FIG.
In the step shown in FIG. 9B, as shown in FIG.
1.5% of pure water 18 whose temperature is controlled to about 90 ° C after exposure.
8 minutes, the surface was hardly insolubilized with pure water at the same time as the PEB process to form the hardly-solubilized layer 18 on the entire surface of the resist film 12. The other steps were the same as those of the embodiment shown in FIG. The same is true.

According to the above steps, in the above embodiment, the hardly-solubilized layer 19 is formed on the latent image 13 of the resist film 12.
Is formed, it is possible to avoid rounding of the upper part of the latent image 13 which will be the remaining resist film 12 in the developing process of the next step, and it is possible to further improve the verticality of the side wall in the resist pattern. it can.

In the above embodiment, the PEB process may be performed in a plurality of stages as described above.

As described above, in the present invention corresponding to the above embodiment, the PEB processing step peculiar to the pattern forming method using the chemically amplified resist material is incorporated into the developing step and the rinsing step. In addition, the effect of the surface treatment for protecting the side wall of the pattern and the like can be obtained while reducing the burden of the number of steps. Further, the effect of changing the sensitivity characteristic and the contrast characteristic stepwise or continuously in the depth direction of the resist film makes it possible to control the cross-sectional shape of the pattern.

[0088]

As described above, according to the present invention, in the formation of a pattern using a chemically amplified resist material, thermal crosslinking or thermal decomposition reaction is caused by heat generated by selective irradiation of high energy rays. Therefore, the precision of the pattern and the verticality of the side wall shape in the chemically amplified resist material are improved, which can contribute to fine processing and high integration in a semiconductor device.

[Brief description of the drawings]

FIG. 1 is a diagram showing measurement results of sensitivity characteristics of a chemically amplified resist material in a method for forming a resist pattern according to one embodiment of the present invention.

FIG. 2 is a diagram showing characteristics of a resist material obtained from the sensitivity characteristics shown in FIG.

FIG. 3 is a process cross-section showing a process of forming a resist pattern using the sensitivity characteristics shown in FIG.

FIG. 4 is a process cross-sectional view showing another process of forming a resist pattern using the sensitivity characteristics shown in FIG.

FIG. 5 is a cross-sectional view showing some steps of a method of forming a resist pattern according to one embodiment of the present invention.

FIG. 6 is a diagram showing a measurement result of a sensitivity characteristic of a chemically amplified resist material with respect to a PEB processing temperature in a method of forming a resist pattern according to one embodiment of the present invention.

FIG. 7 is a diagram showing a measurement result of a contrast characteristic with respect to a PEB processing time of a chemically amplified resist material in a method of forming a resist pattern according to one embodiment of the present invention.

FIG. 8 is a cross-sectional view showing steps in a method for forming a resist pattern according to one embodiment of the present invention.

FIG. 9 is a cross-sectional view showing steps in a method for forming a resist pattern according to one embodiment of the present invention.

FIG. 10 is a diagram showing how the sensitivity of a chemically amplified resist material changes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,11 Layer to be processed 2,6,12 Resist layer 3 Acid 13 Latent image 14 Developing solution 15 Pure water 16,18 Insoluble layer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Sato 1 Komukai Toshiba-cho, Saiyuki-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Research Institute Co., Ltd. (56) References JP-A-4-60551 (JP, A) JP-A-4-204848 (JP, A) JP-A-4-77746 (JP, A) JP-A-3-161920 (JP JP, A) JP-A-3-142918 (JP, A) JP-A-4-62914 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (4)

(57) [Claims] A first step of coating and forming a chemically amplified resist layer on a layer to be processed; and a step of forming a chemically amplified resist layer on the entire surface of the resist layer applied in the first step.
Without heating the resist layer, a thermal crosslinking reaction or
Energy with energy that does not allow the pyrolysis reaction to proceed
A second step of generating an acid in the resist layer by irradiating a
And a third step of selectively irradiating the resist layer with an energy ray having energy sufficient to cause a thermal crosslinking reaction or a thermal decomposition reaction to proceed in the resist layer after the second step, thereby generating heat. And a fourth step of developing and selectively removing the resist layer after the third step. Wherein a first step of applying a resist layer chemically amplified onto the treated layer, the resist layer applied in the first step, the Le
Thermal crosslinking reaction or heat
Energy rays with energy that does not allow the solution reaction to proceed
A second step of selectively irradiating the resist layer to selectively generate an acid in the resist layer; and having an energy sufficient to cause a thermal crosslinking reaction or a thermal decomposition reaction in the resist layer after the second step. A third step of selectively irradiating the resist layer with acid rays generated in the second step with an energy beam to generate heat, and developing and selectively removing the resist layer after the third step by heating; Forming a resist pattern. 3. The method according to claim 1, wherein in the second step, an acid is generated by irradiation with an electron beam or far ultraviolet light. 4. The method according to claim 1, wherein the energy beam used in the third step is an electron beam or a deep ultraviolet light.