JPS6224625A - Formation of pattern - Google Patents

Abstract

PURPOSE:To simplify the process and improve pattern resolution and accuracy by forming a pattern through irradiation with energy beam to a kind or several kinds of materials including a fluoride compound sequentially stacked on a substrate, forming a mask through adhesion of adhesive material only within a pattern or outside of pattern and then processing laminated material. CONSTITUTION:A silicon substrate 5 is coated with a lower layer resist 4 and then with a co-polymer of hexafuluorobutylmethacrylate and grycyzilmethacrylate as a polymer 6 including fluorine. Thereafter, it is baked. The substrate is them irradiated with electron beam as the energy beam 1 to form a latent image of pattern. Next, the substrate is placed on a rotatory coating apparatus, the adhesive material and then silicon substrate 5 are sequentially dried by high-speed rotation and thereafter etching is carried out by the reactive ion etching apparatus. By this operation, a pattern which is complementary to the original pattern is formed on the substrate 5. Thereby, the process is simplified, pattern-forming speed is improved, pattern resolution is also improved and a pattern having high dimensional accuracy may be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming fine patterns in semiconductor manufacturing and the like.

[Conventional technology]

The degree of integration of semiconductor integrated circuits has improved with the miniaturization of circuit patterns, and pattern forming techniques in the micron to submicron range are now required.

Although several methods have been proposed to form patterns in the submicron region, there are very few techniques that can be put to practical use. The reason for this is that, in practical terms, it is necessary to increase the pattern formation speed at the same time as high resolution and precision of the pattern, and it is not permissible to go through a very complicated process.

Conventionally, a multilayer resist method (for example, US Pat. No. 4,244,799) has been used as a method for forming patterns in the submicron region. Here, a three-layer resist, which is the most basic of the multilayer resist methods, will be described.

FIG. 3 shows a pattern formation process using a three-layer resist. 1 is an energy beam such as light, electron beam, ion, or X-ray. 2 is an energy $IK sensitive resist (
(generally referred to as an upper layer resist), 3 is an intermediate layer, and 4 is a lower layer resist.

Since the intermediate layer 3 serves as a mask when etching the lower resist layer, a material with high etch resistance, such as spin-on glass or silicone resin, is used. 5 is a substrate. When the upper resist 2 is irradiated with energy F11, the upper resist is decomposed and a low molecular weight polymer is generated. When this is immersed in a developer, the irradiated area will dissolve,
A pattern is formed on the upper resist 2. The sample was placed in a scheelite ion etching device and exposed to a CF, gas atmosphere! M.J.
When etching is performed in air using the upper resist 2 as a mask, the upper resist pattern is transferred to the intermediate layer 3.

Further, when etching is performed in a 0□ gas atmosphere using a reactive ion etching device using the mosquito intermediate layer 3 as a mask, the pattern of the intermediate layer 3 is transferred to the lower resist 4.

[Problem that the invention seeks to solve]

Compared to the single-layer resist method currently used in production lines, the above method has superior advantages in terms of: ■ coverage of substrate steps, ■ etching resistance for accumulator processing, and ■ resolution. On the other hand, dry etching must be performed twice using different gases, resulting in a disadvantage that the process becomes complicated. In addition, it is known that the resolution and dimension a of the pine that is generally formed improve as the upper layer resist becomes thinner, but in reality, it is usually 0.3 to 0.0 because of the dry etch resistance of the intermediate layer. 5 μm and slightly thin (not possible)
was there. Furthermore, while the intermediate layer is being etched using the upper resist pattern as a mask, the upper resist is also etched, making it difficult to maintain accurate dimensional accuracy of the pine. Also,
Intermediate ri! Since I3 serves as a mask for the lower resist 4, atoms that normally constitute the resist (for example, C, H,
atoms with higher density (e.g. O, Ge,
MO, etc.) are included. For this reason, when using a serpentine beam as the energy beam, there is a problem in that electrons backscattered by the intermediate layer deteriorate the resolution of the upper resist layer.

An object of the present invention is to simplify the pattern formation process and improve pattern resolution and pattern accuracy.

[Means for Solving the Problems] The present invention provides a method for forming a pattern using energy beams such as light, electron beams, ions, or a step of sequentially dipping seed materials; a step of irradiating a small layer of the laminated material with energy rays to form a pattern;
2. The fluorinated compound is characterized by comprising a step of selectively attaching an adhesive material only inside or outside the pattern, and a step of processing the laminated material using the adhesive material as a mask. Polyhexafluorobutyl methacrylate or poly 1,1 dimethyl 2,2#
It is desirable to use fluorine-containing polymers such as 3 s 3 tetrafluor a-propyl methacrylate or hexafluoroptyl methyl acrylate togelicidyl methacrylate copolymer.

Moreover, it is desirable to use a silicon compound as the layered material.

(Example 'J) The present invention utilizes the experimental fact that fluorine compounds with low surface energy and silicone resins have a marked lack of adhesion.

Hereinafter, embodiments of the present invention will be described in detail with reference to IEl[1 and FIG. 2. In addition, in these figures, the same reference numerals are given to the same elements as those shown in Figure 3.

An embodiment of the present invention is shown in FIG. AZ1350J (Shipley Co., Ltd.) was applied to the silicon substrate 5 as the lower resist 4.
1) was spin-coated to a thickness of 1.5 μm and baked at 200° C. for 3θ minutes. A hexafluorobutyl methacrylate and glycidyl methacrylate copolymer (this side slope is disclosed in Reference 1 under the name FRM-G) was spin-coated to the sample as the fluorine-containing polymer 6 to a thickness of 0,1 μm, and the mixture was coated at 140°C. Bake for 30 minutes. An phantom image of a pattern was formed by irradiating this with an electron beam as energy Ml.

(See Figure 1 (a)) FBM-G is an electron beam
I! is known to exhibit high sensitivity to In this example, an electron beam of 30KV is used, and 3 ttC/cm2
A pattern was formed with an irradiation dose of . When this is immersed for 60 seconds in a developer with a 1:1 mixing ratio of ethanol and inbutyl alcohol, the FBM-G of the part irradiated with the electron beam is
was fermented and a pattern was formed.

(F, 1 [see 6(b)ff1) Lower Wzvshi,
) AZ i 350 J has an electron beam sensitivity of several hundred μC/
Tan 2 F due to the extremely vomiting age and the effect of hard baking
The lower layer resist of the opening of BM-G did not change at all. Next, the sample is placed on a spin coating device and rotated at high speed (
3,000 rpm to 6,000 rpm), and silicone resin was dropped as the adhesive material 7. By this operation, as shown in Figure 1 0, silicone resin adhered only to the opening of FBM-G and did not adhere to all of FBM-G. The wettability and adhesion are significantly inferior to those of silicone resin and AZ1350J.
Fluorine-containing organic po-117 such as dimethyl 2,2,3.3 tetrafluoropropyl medacrylate (FPM; Reference 2 & Ishin), hexafluorobutyl medacrylate (FBM: see Reference 3), and Teflon.
Check what happens between - and silicone resin. The silicone resin is deposited at the opening of FBM-G to a thickness of approximately 0.1 μm. The sample was dried and then subjected to reactive ion etching (RIE) at a flow rate of 50
sccm (7) Using 0□ gas, power dense KO
, 3W and 7cm 2 for about 12 minutes. By this operation, the board 5 is cut into a shape as shown in FIG. 1(a).
A pattern complementary to the original pattern was formed on top. During the etching process, the silicone resin was hardly etched and the resist pattern was very well reflected on the upper resist pattern, making it possible to form a pattern with high dimensional accuracy.

In this example, an electron beam was used as the energy beam, but it is also possible to use an X-ray or an ion beam to form a full-length pine (pine) using a similar process. A pattern can be formed using a similar process.In addition, a single layer of fluorine-free polymer 11 is applied to the substrate, and after the pattern is formed on the polymer, silicone resin is applied to form a Kg contact silicon II resin balloon on the substrate. It is also possible to process the substrate using the silicone resin as a mask.

FIG. 2 shows an embodiment of KM2. AZ 1350J was spin-coated to a thickness of 1.5 μm as the lower resist 4 on the silicon substrate 5, and baked at 200° C. for 30 minutes. To this, FBM was spin-coated as a fluorine-containing resist 6. Apply the irises μm thick and heat at 140℃ for 30 minutes. Furthermore, on top of this, AZ1350J is applied at 0.1 as upper layer resist 2.
It was spin-coated to a thickness of μm and incubated at 90° C. for 30 minutes. The sample was transferred to 6o using a g-line (wavelength 436m) stepper.
Exposure with II & J/Saw 2, developer (MF 2412:)
f20 = 1: 1) for about 60 seconds to form a pattern, FBM resist is not sensitive to light, so
As shown in FIG. 2(b), the pattern is formed only on the upper resist layer. The silicone resin used in the above-mentioned example was applied as adhesive material 7 to this by spin-coating by hand as described above. As a result, as shown in FIG. 2(c), silicone resin was not deposited on all the pattern openings where the surface of the FBM resist was exposed, but only on AZ 1350J of the upper resist layer 2.
．． When the sample deposited to a thickness of about 2 μm was etched by RIE under the conditions described above, a resist pine identical to the original pattern as shown in FIG. 2(d) was formed on the substrate 5.

In this example, pattern formation by light exposure was shown, but the upper layer resist was an electron beam resist, such as polymethyl methacrylate (PMMA), a copolymer of phenyl methacrylate and megacrylic acid (φ-MAC), or chloromethylated polystyrene. It is obvious that the method can be applied to energy rays such as (CMS), or by using X-rays and other energy rays. Furthermore, according to the gist of the present invention, not only the more positive resist shown in FIG. The reverse process of applying the fluorine-containing polymer after forming the pattern may also be used.Furthermore, throughout the first and second examples, AZI350J resist was used as the lower layer material, but it is not limited to this.Lower layer material The role of A(f) is that any material can be used as long as it can transfer the pattern formed in the upper layer and can withstand substrate processing, so there is a wide range of selection. - Examples include CMS, φ-
It is clear that the effects of the present invention will not be impaired even if a resist such as MAC, 0FPR800 (Tokyo Ohkari Co., Ltd.) or a polyimide film or carbon film is used. Furthermore, in this embodiment, an electric furnace was used for solidifying and drying the resist, but it is also possible to use a known hot plate, microwave heater, or the like.

Further, although an example of spin coating is shown as a method for applying the adhesive material, it is possible to use other methods such as spray coating and dip coating.

(References: 1) H, Asakawe et al, 57m1)'),
on VLSI'l'erhno1. , P 88 (
1982) 01eo, Japan (References: 2) M, Kakuchi et PLl, J, Ele
ct, rochem, Soc,.

124, P, 1648 (1977) (References: 3
) Kp Murase et al, Proc, I
nt, Conf.

Microlithography, y, P 261
(1977) Paris, France [Effects of the Invention] As explained above, in the present invention, unlike the conventional three-layer resist method, there is no step of etching the intermediate layer using the upper resist as a mask, and the etching process is simply performed after patterning the upper layer. Since a mask pattern can be selectively formed by spin-coating the material, the process is simplified and the pattern formation speed is improved. Furthermore, since there is no need to etch the intermediate layer, the upper resist layer can be made sufficiently thin, improving the resolution of the pattern, and at the same time, it is possible to form a pattern with extremely high dimensional accuracy without any damage to the upper resist layer. In addition, since the adhesive material can be attached after forming the pattern on the upper layer resist, it not only has the advantage of widening the selection range of adhesive materials (but also under ideal conditions without considering the influence of the adhesive material when forming the upper layer pattern). It also has the advantage of being able to form high-resolution patterns.Furthermore, in the present invention, the original pattern can be turned into an inverted state or a layered state by a simple method as needed, that is, a negative or a positive pattern can be formed. However, there is also the advantage that the scope of application of the present invention is expanded.Furthermore, when referring to negative patterns, it is possible to use a positive pattern which generally has high resolution.
It has advantages such as being able to form a negative pattern with high grouping properties.

[Brief explanation of the drawing]

sg1 figures (a) to (d) are pattern forming process diagrams of the preferred embodiment of the present invention, FA2 figures (a) to (d) are pattern forming process diagrams of the second embodiment of the present invention, and The figure is a diagram of the pine forming process using the conventional three-layer resist method. l...Energy rays, 2.Old...Resist sensitive to energy rays, 3...Intermediate layer, 4...
... Lower layer resist, 5 ... Substrate, 6 ...
...Fluorine-containing polymer, 7... Adhesive material.

Claims (1)

[Claims] (1.) In pattern formation using energy beams such as light, electron beams, ions, or X-rays, one or more materials containing a fluorine compound in at least one layer are sequentially laminated on a substrate. a step of irradiating at least one layer of the laminated material with energy rays to form a pattern; a step of selectively adhering an adhesive material only within or outside the pattern; A pattern forming method comprising a step of processing a laminated material. (2.) As the fluorine compound, polyhexafluorobutyl methacrylate or poly 1,1 dimethyl 2,
The pattern forming method according to claim 1, characterized in that a fluorine-containing polymer such as 2,3,3 tetrafluoropropyl methacrylate or a copolymer of hexafluorobutyl methacrylate and glycidyl methacrylate is used. (3.) The pattern forming method according to claim 1 or 2, wherein a silicon compound is used as the adhesive material.