JPH07297100A - Pattern formation method - Google Patents

Abstract

PURPOSE:To form a pattern inexpensively with a high dimension controllability when machining a semiconductor. CONSTITUTION:Hexamethyldisilazane 13 is sucked on the surface of cresolnovolac 12 which is a result formed on silicon substrate 11. Electron beams 14 which are energy beams are selectively applied to eliminate the hexamethyldisilazane 13. Then, by performing oxygen plasma treatment, the remaining hexamethyldisilazane 13 becomes SiO2 15 and the cresolnovolac 12 at the eliminated part is etched, thus forming a pattern with a high dimension precision at a low cost since anisotropic development is performed by oxygen plasma after directly machining a mask.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming method used in fine processing of semiconductors, and more particularly to a pattern forming method suitable for pattern formation having high dimensional controllability.

[0002]

2. Description of the Related Art In semiconductor formation, a technique for forming a pattern is generally called lithography. In this fine pattern forming method by the lithography technique, a general method mainly used at present is according to the procedure shown in FIG. First, a semiconductor substrate 31 to be processed is subjected to a hydrophobizing treatment for enhancing the adhesiveness of a thin film mainly composed of an organic polymer called carbon called a resist to the substrate 31. Next, the solution of the resist 32 is dropped on the substrate 31,
As shown in FIG. 3A, the resist 3 is applied by a method such as spin coating.
2 is attached to the substrate 31. Then, heat treatment (baking) is performed in order to scatter the solvent in the resist solution. This baking is performed by allowing the substrate to stand for a certain period of time on a hot plate set to a constant temperature. And Figure 3
As shown in (b), an energy beam 33 such as an ultraviolet ray or an electron beam is selectively irradiated in accordance with a desired pattern to form a latent image 34 of the pattern. By irradiating the energy beam 33, a latent image 34, which is a pattern irradiation portion, is formed in the resist 32.
A chemical change occurs that causes a difference in the dissolution rate in the developer between the area and the area not irradiated with the pattern. A desired pattern can be formed by immersing the substrate 31 in a developing solution.

In the above chemical change, when the dissolution rate of the latent image 34 portion is increased and this portion is dissolved, FIG.
As shown in (c), a positive resist pattern is obtained. On the other hand, when the dissolution speed of the latent image 34 is reduced and this portion remains, a negative resist pattern is obtained as shown in FIG. After the resist pattern is formed in this way, the substrate 3 is formed by dry etching.
The process of No. 1 and the selective introduction of the impurity region into the substrate by ion implantation have been performed.

A method of using a liquid called a developing solution for forming a pattern in this way is called wet development. In the conventional semiconductor formation, wet development has been generally used in the lithography process from the viewpoint of simplicity. However, recently, the method is being reviewed. That is, with the miniaturization of the pattern size, the dimensional controllability may not be sufficiently obtained by wet development, and when light is used as the energy ray, the resist surface absorption increases as the wavelength is shortened due to the miniaturization. Since the shape deteriorates and it is necessary to reduce the amount of solution used in wet development in a large amount to reduce the impact on the environment, dry development (dry development) that does not use liquid during development is being considered. Has been. For example, as a problem of dimensional controllability, when wet development is used, it is difficult to control the pattern size after processing within 10 nm from the design pattern. Further, the cross section of the pattern after formation may be rounded, and dimensional variation may occur during etching in the next step.

On the other hand, the dry developing method generally follows the procedure shown in FIGS. For example, Journal of Vacuum Science and Technology B
Volume 11, Pages 681 to 687 (1993)
(J. Vac. Sci. Technol. B11 , 681-687 (1993).).

First, the resist 42 solution is dropped on the substrate 41, and the resist 42 is applied to the substrate 41 by the spin coating method as shown in FIG. Then, a baking treatment is performed to scatter the solvent in the resist solution. And Figure 4
As shown in (b), energy rays 43 such as ultraviolet rays are selectively irradiated in accordance with a desired pattern to form a bridge region 44. Here, by absorbing the energy of the energy rays 43, a cross-linking reaction (polymers are bridged to be further polymerized) to the constituent polymer of the resist 42 proceeds. Here, as the energy ray 43, a wavelength 1 which has a large absorption in the resist
Since short-wavelength light such as 93 nm deep ultraviolet rays is used, energy absorption is limited to the resist surface portion.

Next, the substrate 41 and the resist 42 are exposed to a gas or liquid of a substance called a silylating agent, so that the silylated region 45 is formed in the resist 42 by diffusion of the silylating agent. The silylating agent generally refers to a material containing Si as a constituent element. Here, the silylating agent is difficult to diffuse into the polymerized cross-linking region 44, so that the silylating region 45 is selectively introduced into the non-irradiated portion of the energy ray 43. Then, the oxygen plasma treatment of the substrate 41 and the resist 42 is performed. During this oxygen plasma treatment, the surface portion of the silylated region 45 reacts with oxygen to form silicon oxide (SiOx, where X is generally a number of 2 or less). In the following, SiO ₂ 46 is used for simplicity. Once
Once SiO ₂ 46 is formed, the reaction with oxygen plasma no longer proceeds. Therefore, it is difficult to be etched by oxygen plasma (has etching resistance), and the silylated region 45 serves as a mask to protect the region of the resist 42 thereunder. On the other hand, since the cross-linked region 44 contains carbon as a main component, it is removed (etched) due to the progress of the reaction with oxygen plasma. Therefore, the non-irradiated portion of the energy beam 43 remains, and a positive resist pattern is obtained as shown in FIG. On the other hand, depending on the silylating agent and the resist material, the silylating agent may selectively diffuse into the crosslinked region. In this case, the energy ray 4
The three irradiated portions remain, and a negative resist pattern is obtained as shown in FIG.

The above method is a method of introducing a mask region at the time of etching after irradiation with energy rays. On the other hand, as an approach to introduce the mask area before the energy beam irradiation,
For example, Japanese Journal of Applied
Physics Vol. 31, pages 4327 to 4331
Page (1992) (Jpn. J. Appl. Phys. 31 , 4327-4331)
(1992).) Or Applied Physics Letters, Vol. 62, pages 372-374 (1993).
Year) (Appl. Phys. Lett. 62 , 372-374 (1993).).

The method follows the procedure shown in FIG.
First, the first resist 52 solution is dropped on the substrate 51, and the first resist 52 is applied to the substrate 51 as shown in FIG. 5A mainly by a method such as spin coating. Then, a baking treatment is performed to scatter the solvent in the resist solution. Then, as shown in FIG. 5B, the second resist 5
Form three layers. The second resist 53 is a Si-containing material that undergoes an oxidation reaction to form SiO ₂ when irradiated with energy rays in the atmosphere. Second resist 5
The three layers may be thin films, and a spin coating method, a chemical vapor deposition method, or the like is used as the forming method. As shown in FIG. 5C, when the energy rays 54 such as ultraviolet rays are selectively irradiated according to a desired pattern, the oxidation reaction proceeds in the atmosphere as described above to form SiO ₂ 55. Then, the plasma treatment of the halogen gas is mainly performed to remove the second resist 53 in the energy ray non-irradiated region as shown in FIG. 5D. Here, SiO ₂ 55 has resistance to halogen gas plasma. After that, oxygen plasma treatment is performed. Here, the second resist 5 that became SiO ₂ 55
3 functions as a mask, and the portion of the first resist 52 not covered with SiO ₂ 55 is removed. As a result, the portion irradiated with the energy ray 54 remains, and a negative resist pattern is obtained as shown in FIG.

Although the spin coating method is used as the method for forming the first resist 52, other methods such as eye coating are also used.
EE Electron Device Letters Vol. 11, pp. 391-393 (1990) (I
The chemical vapor deposition method disclosed in EEE Electron Devices Lett. 11 , 391-393 (1990).) Can also be used.

As a method of directly removing the resist material by irradiation with energy rays, Applied Physics Letters, Vol. 40 , pages 374 to 375 (1982) (Appl. Phys. Lett. 40 , 374-375 (198).
The ablation disclosed in 2).) Can be used. Ablation refers to a phenomenon in which a bond of a polymer compound is rapidly cleaved by irradiation with an energy beam having a high energy density, and the decomposed portion becomes a plasma state and scatters at high speed with light emission.

Alternatively, Applied Physics Letters, Vol. 64, pages 563 to 565 (199
4 years) (Appl. Phys. Lett. 64 , 563-565 (1994).) It is also possible to use the laser-induced reaction. Here, the polymer forms a line-and-space pattern in a self-organized manner by a laser-induced reaction even by irradiation with a low-density energy beam (here, an excimer laser) that does not cause ablation. Therefore, the pattern can be transferred to the second resist by using the first resist pattern formed here. In the first resist, even if the removed portion (space portion) of the first resist pattern is not completely removed, the space portion can be removed by performing additional etching.

Further, as a method of directly removing the second resist after forming it by the spin coating method, for example, Polymer Engineering and Science Vol. 14, Vol. 52,
Pages 5 to 528 (1974) (Polymer Eng. Sci.
14 , 525-528 (1974).) "Evaporative development method" (V
apor Development) and the "photooxidation etching method" described in JP-A-60-43824.

[0014]

By the way, in the method of introducing the above-mentioned mask region after irradiation of energy rays, since the introduction of the silylating agent is carried out based on diffusion, in principle, the selectivity in the direction of diffusion is low. . Therefore, the controllability of the pattern size or the uniformity within the wafer is deteriorated. Therefore, it is necessary to control the process conditions with high accuracy, and it was found that there are many problems in practical use.

Further, in the method of introducing the mask region before the energy ray irradiation, since there is no introduction by diffusion of the mask material as described above, there is little problem in controllability of the pattern dimension or uniformity in the wafer. However, this method requires the plasma treatment of the halogen gas for removing the second resist, which has a problem that the process is complicated and the process cost is increased. Therefore, in order to put this technology into practical use, it was necessary to introduce a method for cost reduction.

In a known example of a direct resist processing method, a resist is formed by a spin coating method, and when the substrate or the first resist has irregularities (steps) due to element formation, spin coating is performed. The film thickness varies with the method. Therefore, there has been a problem that the dimension of the formed pattern varies with the change of the film thickness.

[0017]

In order to solve the above-mentioned problems, a pattern forming method for forming a pattern on a substrate comprises a step of forming a first material on the substrate, and a step of forming a first material on the surface of the first material. A step of forming the second material, a step of directly irradiating the second material with an energy ray to directly process the second material, and a first material that is not covered by the second material that appears as a result of the direct processing In the pattern forming method including the step of removing a portion, the step of forming the second material on the surface portion of the first material is at least surface adsorption or diffusion of the second material to the surface portion of the first material. A pattern forming method depending on the above may be used.

[0018]

[Function] As a result of the research conducted by the present inventors, the following has been revealed.

First, as shown in FIG. 6A, the first material 62 is deposited on the substrate 61. The main component of the first material 62 is carbon (C). As the method, a spin coating method, a chemical vapor deposition method, or the like is used. And FIG.
As shown in (b), the second material 63 layer is formed by surface adsorption. This surface adsorption may be either physical adsorption based on intermolecular force or chemical adsorption based on chemical bond.

After that, energy rays 6 such as ultraviolet rays and electron rays
4 is selectively irradiated according to a desired pattern. Here, since the adsorption energy of the second material 63 on the surface of the first material 62 is low, the second material 63 of the energy ray 64 irradiation portion is desorbed and removed as shown in FIG. 6C.

Subsequent to this, the entire substrate 61 is subjected to oxygen plasma treatment. The second material 63 reacts with oxygen in the oxygen plasma to form SiO ₂ 65. Once SiO ₂ 65 is formed, it no longer reacts with oxygen plasma. For this reason, the remaining second material 63 area changed SiO ₂ 65
Serves as a mask and protects the first material 62 thereunder. On the other hand, since the first material 62, which is not covered with the SiO ₂ 65, contains C as a main component, it reacts with oxygen plasma and is etched. For this reason, the non-irradiated portion of the energy beam 64 remains, and a positive resist pattern is obtained as shown in FIG.

During this oxygen plasma treatment, the incident direction of oxygen ions is vertical to the substrate due to the high frequency electric field. Therefore, anisotropic etching is realized, and the pattern shape after formation becomes good. During the anisotropic etching of the first material 62, the etching in the lateral direction may slightly progress. This causes a pattern dimension variation, but can be reduced by adjusting the etching conditions.

The advantages of this method are as follows. Generally, when forming a fine pattern, it is necessary to reduce the film thickness of the pattern forming material in order to improve the resolution. Since the film thickness of the surface adsorption layer is basically equivalent to a single molecule or several molecules, the film thickness is as thin as several nm at most. Therefore, very high resolution can be expected in microfabrication using this ultrathin film. Also, the problem of surface absorption when using ultraviolet rays of short wavelength can be avoided because the ultrathin film is used.

In addition to this, in forming the second material, a method of introducing the second material into the first material by diffusion may be adopted. Then, as the method for removing the second material, ablation or laser-induced reaction can be used in addition to desorption.

In the present invention, since the conventional spin coating method is not used for introducing the second material to be patterned, even if the substrate or the first material has irregularities, the second material is faithfully adhered to the surface shape. Is formed, and the film thickness can be constant (conformal). Therefore, the variation of the pattern dimension due to the variation of the film thickness is suppressed.

As described above, since the present invention is the direct processing by the energy ray irradiation, the step of etching with the halogen gas as in the known example is unnecessary, the resolution is high, and the step can be simplified. It is suitable for cost reduction.

[0027]

【Example】

Example 1 First, as shown in FIG. 1A, a cyclohexanone solution of cresol novolac 12, which is a polymer resin containing C as a main component as a first material, was prepared, for example, with a diameter of 4
Spin coating on an inch silicon substrate 11. Here, the treatment is performed at 2,000 rpm for 1 minute, and then heat treatment is performed at 100 ° C. for 2 minutes in order to scatter the solvent to form a thin film of cresol novolac 12 to a thickness of 300 nm, for example. As the cresol novolac 12, for example, a known weight average molecular weight of 6,000 and a known polydispersity of 1.5 were used. Here, the processing dimension and the film thickness may be approximately the same, and when the pattern includes a portion whose target processing dimension of width or length is 300 nm or less, the film thickness is preferably 300 nm or less.

Then, as shown in FIG. 1 (b), a hexamethyldisilazane 13 layer as a second material is formed on the cresol novolac 12 by surface adsorption. The substrate temperature is set to, for example, 50 ° C., and the entire silicon substrate 11 is set by a vacuum pump in an atmosphere reaching 10 −1 Pa (Pascal). Hexamethyldisilazane 13 gas is allowed to flow at a flow rate of, for example, 30 ml / min for 1 minute, so that the surface of cresol novolac 12 is adsorbed by one layer. Here, cresol novolac 12
Alternatively, surface adsorption is realized by chemisorption in which hexamethyldisilazane 13 is chemically bonded to the hydroxyl group contained in the surface-adsorbed water of cresol novolac 12.

When the electron beam 14 is used as the energy beam, the above-mentioned silicon substrate 11 is installed in a known electron beam drawing apparatus, and the electron beam 1 is selectively selected according to a desired pattern.
Irradiate 4. The acceleration voltage of the electron beam is, for example, 20 kV
The dose is, for example, 10 μC / cm ² . Since the adsorption energy of hexamethyldisilazane 13 on the surface of cresol novolac 12 is as low as about 2 meV,
As shown in (c), the hexamethyldisilazane 13 in the irradiated portion of the electron beam 14 is desorbed and removed by the energy of the accelerated electron beam. The accelerating voltage is not limited to 20 kV, and generally, the lower the accelerating voltage is, the more the desorption reaction proceeds at a low irradiation amount, that is, the highly sensitive reaction.

Subsequently, the entire silicon substrate 11 is placed in a vacuum container having a well-known parallel plate type electrode, and oxygen plasma treatment is performed. After decompressing with a vacuum pump, oxygen gas was introduced to a pressure of 100 Pa, for example, 13.
Power of 50 W at a frequency of 56 MHz is supplied by a high frequency power source. Here, the upper electrode is grounded and high frequency power is applied to the lower electrode. Here, for example, discharging is performed for 15 minutes. Hexamethyldisilazane 13 reacts with oxygen in oxygen plasma to form SiO ₂ 15. Once SiO ₂ 15 is formed, it no longer reacts with oxygen plasma. Therefore, the remaining hexamethyldisilazane 13 region serves as a mask to protect the cresol novolac 12 thereunder. On the other hand, the cresol novolac 12 not covered by the hexamethyldisilazane 13 is C
Since the main component is, the oxidation reaction with oxygen plasma proceeds and etching is performed. Due to the high frequency electric field, the incident direction of oxygen plasma is vertical. Therefore, anisotropic etching proceeds with the portion not irradiated with the electron beam 14 remaining, and a positive resist pattern is obtained as shown in FIG. 300 nm
When the pattern No. was formed, it was possible to realize highly accurate processing in which the variation from the design dimension was within 10 nm in total.

The first material to be etched by oxygen plasma is not limited to cresol novolac, but is mainly composed of phenol resin such as propylphenol novolac and polyvinylphenol, vinyl polymer resin such as polymethylmethacrylate, and C such as polyimide. Polymer resin,
Alternatively, a mixed system of two or more thereof may be used.

In the embodiment, an electron beam was used as the energy beam, but other than that, a particle beam such as an ion beam,
Similar effects can be obtained by using electromagnetic waves such as ultraviolet rays, X-rays and gamma rays.

In the above embodiment, the case where hexamethyldisilazane is used as the second material has been described.
In addition, the same effect can be obtained by using a silicon-containing compound generally called a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, and vinyltriacetoxysilane.

(Embodiment 2) In Embodiment 1, the case of removing the second material by desorption was explained, but here, the case of removing it by ablation and laser-induced reaction will be explained.

As shown in FIG. 2A, a solution of polymethylmethacrylate 22 which is a polymer resin containing C as a main component as a first material in a solution of 2-ethoxyethyl acetate is used, for example, on a silicon substrate having a diameter of 4 inches. 21 is spin coated. Here, the treatment is performed at 1,000 rpm for 1 minute, and thereafter, heat treatment is performed at 170 ° C. for 20 minutes in order to scatter the solvent, and for example, a polymethylmethacrylate 22 thin film is formed to a thickness of 200 nm. This polymethylmethacrylate 22 has, for example, a known weight average molecular weight of 30.
A known polydispersity index of 2.4 was used.

Then, as shown in FIG. 2B, a hexamethyldisilazane-containing layer 23 is formed as a second material on the surface portion of the polymethylmethacrylate 22 by diffusion. The substrate temperature is set to, for example, 180 ° C., and the entire silicon substrate 21 is set to 10 −2 Pa by a vacuum pump.
Install in an atmosphere that has reached (Pascal). Hexamethyldisilazane-containing layer 23 having a thickness of about 20 nm is formed on the surface of polymethylmethacrylate 22 by diffusing hexamethyldisilazane gas at a flow rate of 20 ml / min for 5 minutes. The thickness of the contained layer can be controlled by the conditions. Generally, the higher the substrate temperature and the longer the gas introduction time, the thicker the contained layer. Here, since the boiling point of hexamethyldisilazane is 126 ° C. or higher and the temperature is higher than the glass transition point of polymethylmethacrylate, diffusion into polymethylmethacrylate occurs instead of surface adsorption.

Then, for example, far-ultraviolet light having a wavelength of 248 nn is used as the energy ray. This far ultraviolet light is an excimer laser generated by stimulated emission from excitons (heteroexcimer) KrF of krypton (Kr) and fluorine (F ₂ ). Here, when the energy density of the excimer laser is high, ablation occurs. For example, the energy (fluence) per pulse is 300 mJ / cm ²
The KrF excimer laser of. At this time, 10 nm of hexamethyldisilazane-containing layer 23 was etched per pulse. Therefore, the hexamethyldisilazane-containing layer 23 is removed by ablation with two pulse incidence. Here, four pulses of the excimer laser 24 were incident through a mask in which a required pattern was formed, and as shown in FIG. 2C, the hexamethyldisilazane-containing layer 23 was selectively removed completely. At this time, as shown here, the polymethyl methacrylate 22 may be partially removed by ablation.

Subsequently, the entire silicon substrate 21 is put into a vacuum container having a well-known parallel plate type electrode, and oxygen plasma treatment is performed. After decompressing with a vacuum pump, oxygen gas is introduced up to a pressure of 100 Pa.
Power of 50W at a frequency of 3.56MHz is supplied from a high frequency power supply. Here, the upper electrode is grounded and high frequency power is applied to the lower electrode. For example, discharging is performed for 10 minutes. Hexamethyldisilazane on the surface of the hexamethyldisilazane-containing layer 23 reacts with oxygen in oxygen plasma to form SiO ₂ 25. Once SiO ₂ 25 is formed, it no longer reacts with oxygen plasma. Therefore, the remaining region of the hexamethyldisilazane-containing layer 23 serves as a mask to protect the polymethyl methacrylate 22 thereunder. On the other hand, the polymethylmethacrylate 22 which is not covered with the hexamethyldisilazane-containing layer 23 is etched due to the progress of oxidation reaction with oxygen plasma. Due to the high-frequency potential, the incident direction of oxygen plasma is vertical. Therefore, anisotropic etching proceeds with the non-irradiated portion of the excimer laser 24 remaining, and a positive resist pattern is obtained as shown in FIG. 2D. When a 200 nm pattern was formed, it was possible to realize highly accurate processing in which the variation from the design dimension was within 10 nm in total.

The first material which can be etched by oxygen plasma is not limited to polymethylmethacrylate, and phenol resins such as cresol novolac and propylphenol novolac, vinyl polymer resins such as polystyrene,
It may be a polymer resin containing C as a main component such as polyimide, or a mixed system of two or more thereof.

In the embodiment, the case of the excimer laser which is far ultraviolet rays as the energy ray has been described, but the same effect can be obtained by using a particle beam such as an ion beam or an electromagnetic wave such as an X ray or a gamma ray. A known "phase shift mask" that improves resolution by using phase information may be used as a mask required when electromagnetic waves are used as energy rays.

Further, in the embodiment, the case where hexamethyldisilazane is used as the second material has been described, but the present invention is not limited to this. In addition, the same effect can be obtained by using a silicon-containing compound generally called a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, and vinyltriacetoxysilane.

In the embodiment, the case where ablation is used as the method for processing the second material has been described, but the pattern may be formed by laser-induced reaction with a laser having a low energy density (low fluence).

Example 3 In the above example, the first material was formed by a known wet spin coating method, but the present invention is not limited to this.

For example, a silicon substrate is installed in a well-known parallel plate type plasma generator. After reducing the pressure with a vacuum pump, for example, xylene gas is introduced at a room temperature so as to have a pressure of 50 Pa. And, for example, 13.56 MH
A power of 0.5 W / cm ² at a frequency of z is supplied by a high frequency power source. Here, the upper electrode is grounded, and the lower electrode, whose substrate is grounded, is applied with a DC potential of -4V. As a result, xylene plasma is generated and xylene is decomposed, and an amorphous (amorphous) carbon (C) film grows on the silicon substrate. After discharging for 5 minutes, an amorphous C film having a film thickness of 300 nm was obtained. Here, a substantially flat film could be obtained even when the silicon substrate includes a step.

Then, the positive type pattern of the amorphous C film formed here can be realized by performing the formation of the second material film, the energy irradiation, and the oxygen plasma treatment described in the first or second embodiment.

In the spin coating method, the shape of the formed film is greatly affected by the shape of the substrate step. On the other hand, according to the present dry method, it is possible to form a flat film regardless of the substrate step, or to form a film having a shape faithfully following the substrate step, depending on the conditions. Therefore, when it is necessary to control the first film shape, a dry film forming method is desirable.

In the examples, xylene was used as the supply gas, but hexamethyldisilazane,
The same effect can be obtained by using a gas containing C as a main component such as benzene, styrene, toluene and butadiene.

[0048]

According to the present invention, since dry development using oxygen plasma is used, anisotropic etching is realized,
This has a great effect in forming a pattern having high dimensional controllability, and has a great effect in reducing the process cost because the dry development mask formed to have a constant film thickness is formed by direct processing.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention using surface adsorption.

FIG. 2 is an explanatory diagram of an embodiment of the present invention using ablation.

FIG. 3 is an explanatory diagram of a conventional wet development method.

FIG. 4 is an explanatory diagram of a conventional dry development method.

FIG. 5 is an explanatory diagram of a conventional dry development method.

FIG. 6 is an explanatory diagram of the principle of the present invention.

[Explanation of symbols]

11 ... Silicon substrate, 12 ... Cresol novolac, 1
3 ... Hexamethyldisilazane, 14 ... Electron beam, 15 ... S
iO ₂ .

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01L 21/3065 21/31 H01L 21/30 573 21/302 H 21/31 C (72) Inventor Shinji Okazaki 1-280, Higashi Koigokubo, Kokubunji City, Tokyo Central Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] 1. A pattern forming method for forming a pattern on a substrate, the step of forming a first material on the substrate, the step of forming a second material on the surface of the first material, the second Of the second material by directly irradiating the second material with energy rays, and removing the first material portion which is not covered by the second material, which appears as a result of the direct processing. In the pattern forming method, the step of forming the second material on the surface portion of the first material is at least surface adsorption or diffusion of the second material to the surface portion of the first material. And a pattern forming method. 2. The pattern forming method according to claim 1, wherein the step of directly processing the second material is at least one of desorption, ablation, and laser-induced reaction. 3. The pattern forming method according to claim 1, wherein the energy beam is at least one of a particle beam such as an electron beam and an ion beam, and an electromagnetic wave such as an ultraviolet ray, an X-ray and a gamma ray. 4. The pattern forming method according to claim 1, wherein the step of removing the first material portion which is not covered with the second material on the substrate is etching by oxygen plasma treatment. 5. The pattern forming method according to claim 4, wherein during the oxygen plasma treatment, the second material reacts with the oxygen plasma to change into a material having etching resistance to the oxygen plasma. 6. The pattern forming method according to claim 5, wherein the second material is a silane coupling material.