JPS5979249A - Pattern formation - Google Patents

Abstract

PURPOSE:To form both positive and negative patterns, by using a photosensitive compsn. contg. a bisazide compd. and an o-naphthoquinonediazide positive type resist. CONSTITUTION:The photosensitive compsn. as expressed by the formula (A is O, S, S2, SO2, or CH2 and X is H) contg. a bisazide compd. and an o-naphthoquinonediazide positive type resist is allowed to act as a positive type by irradiation of UV rays, but as a negative type by irradiation of excessive UV rays or far UV rays. A substrate is coated with said compsn. and a positive pattern is formed by imagewise exposing the coat to UV rays, developing it with a positive type developing soln., then, exposing its whole surface to far UV rays, and cross-linking it to form a heat and solvent resistant pattern. A negative type pattern is obtained by imagewise exposing it to far UV rays, exposing the whole surface to an amt. of UV rays forming a positive type, and develping it, or imagewise exposing it to an amt. of UV rays forming a negative type, then exposing the whole surface to an amt. of UV rays forming a positive type, and developing it.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pattern forming method, and more specifically, the present invention relates to a pattern forming method that is sensitive to two different types of radiation, and does not dissolve in a developer when irradiated with one radiation, but dissolves in a developer when irradiated with the other radiation. The present invention relates to a resist pattern forming method in which both negative and positive patterns can be formed by dissolving or by varying the amount of ultraviolet irradiation.

In recent years, with the miniaturization and higher integration of semiconductor integrated circuits,
Microfabrication technology is becoming increasingly sophisticated and complex, and the materials used for it are now being required to have more stringent characteristics than ever before, as well as new functions and characteristics. For example, in resists used in lithography, the types of radiation applied range from ultraviolet to deep ultraviolet, electron beams, and X-rays, and the process still being applied has evolved from wet to dry.

As it is put into practical use, the required properties and characteristics also increase, such as sensitivity and
Traditional items such as resolution, purity, and adhesion are not enough, and plasma resistance and heat resistance are also required.

New items such as solvent resistance and items that have not been a problem in the past are now being required, and there is a need to develop new substances and materials with new compositions that meet these requirements, as well as methods for forming patterns. ing.

In view of these circumstances, the inventors of the present invention have completed the present invention as a result of intensive research to develop an excellent resist with new functions and properties and a pattern forming method thereof.

That is, the present invention is sensitive to two different types of radiation irradiation, and does not dissolve in the developer when exposed to one type of radiation.
On the other hand, in the case of radiation irradiation, it may be due to dissolution in the developer,
Alternatively, to form a resist pattern that can form both negative and positive patterns depending on the amount of ultraviolet irradiation, first irradiate a radiation pattern with radiation that can form a negative resist pattern, and then apply a positive pattern. After irradiating the entire surface with radiation that can form a mold resist pattern,
In order to form a no-turn forming method which is characterized by forming a negative pattern and a positive pattern by developing, and a resist pattern capable of forming both negative and positive patterns, first, a positive pattern is formed. The present invention provides a pattern forming method characterized by selectively irradiating radiation capable of forming a type resist pattern, developing, and further irradiating the entire surface with radiation capable of forming a negative type resist pattern.

The resist used in the method of the present invention is as follows.

General formula (in the formula (7), A is o, s, s2.so2 or 1d:
Preferred examples include photosensitive compositions containing a bisazide compound represented by CH2 or a substituent (X is a hydrogen atom or a chlorine atom) and an O-naphthoquinone diazide positive resist in substantial amounts.

A bisazide compound (c) represented by the general formula (1) above.

Deep ultraviolet light with a spectral wavelength of 200 to 330 nm
V) A crosslinkable compound sensitive to radiation, for example 4
．． 4'-Diazidiphenyl ether, 4.4'-Diazidiphenyl sulfide, 4.4'-Diazidiphenylsulfoni/, 3.3'-Diazidiphenyl ethulfone, 4.4'-Diazidiphenylmethane, 3
．． 3'-dichloro-4,4 diazidodiphenylmethane.

Examples include 4.4'-diazide diphenyl disulfide, which may be used alone or in combination of two or more. still.

Among the bisazide compounds described in AiJ, 4,4'-diazide diphenyl sulfide is particularly preferred because it has high sensitivity as a negative type and has a [gamma] ratio and a resolution of [1].

However, the O-naphthoquinonediazide-based positive resist contained in the photosensitive composition is manufactured from a novolac resin obtained from formaldehyde and phenols, and an O-naphthoquinonediazide derivative, and has a spectral wavelength of 2.
A positive resist that is sensitized and solubilized by ultraviolet rays (UV) of 00 to 500 nm, and is commercially available, such as 0
FPR series (manufactured by Tokyo Ohka Kogyo Co., Ltd.), AZ series (manufactured by Hoechst), KPR series (manufactured by Kodak)
, HPR series (manufactured by Nto Chemical Co., Ltd.), Microposit (manufactured by Shipley Co., Ltd.), etc. can be used.

The mixing ratio of the O-naphthoquinonediazide positive resist and the bisazide compound represented by the general formula m is selected in consideration of the purpose of use and performance. Solid content of 1
0.00 parts by weight, the bisazide compound is 0.1 to 50 parts by weight.
The amount is preferably in the range of 10 to 20 parts by weight, more preferably 10 to 20 parts by weight.

Photosensitive composition fd used in the method of the present invention: exhibits positive-type properties when exposed to normal ultraviolet rays, but exhibits negative-type properties when exposed to excessive ultraviolet rays; on the other hand, when exposed to deep ultraviolet rays, it becomes an extremely sensitive negative resist. Become.

As a specific example, 0FPR-800 (manufactured by Tokyo Ohka Kogyo ■), which consists of a 0-naphthoquinonediazide-novolac positive resist solution, has 4.4'-diazide in its solid content. The following is added to the photosensitive composition of the present invention in which diphenyl sulfide is dissolved in 0% by weight (A), 5% by weight (B), 10% by weight (C), 15% by weight (D) or 20% by weight (E), respectively. Sensitivity curves obtained by exposure to ultraviolet rays and deep ultraviolet rays as described above are shown in FIGS. 1 and 2. That is, the photosensitive composition described above was applied onto a silicone layer using a spinner, and then dried in a dryer for 80 minutes.
Pre-bake for 30 minutes at a temperature of 5°C to obtain a film thickness of 1.
A 3 μm resist film is formed, and in the case of UV exposure, PLA-50 is applied via a glass step tablet.
After exposure with a 0F exposure machine (manufactured by Canon Co., Ltd.), in the case of deep ultraviolet exposure, use a quartz step tablet to expose with a PLA-520F exposure machine (manufactured by Canon Co., Ltd.), and then expose the entire surface with ultraviolet rays. After that, 0FPR consisting of an aqueous solution of tetramethylammonium hydroxide
-800 developer (NMI)-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was used for development at a temperature of 23° C. for 1 minute, and the remaining film rate at each step was measured to obtain a sensitivity curve.

As can be seen from these figures, the photosensitive composition used in the present invention first forms a Jf di-type pattern when exposed to normal ultraviolet rays, and forms a negative pattern when exposed to excessive ultraviolet rays. On the other hand, deep ultraviolet exposure forms a negative pattern. This is because the spectral sensitivity wavelength of a positive type naphthoquinone diazide resist is 200 to 500 nm and that of a negative type bisazide compound is 200 to 330 nm, whereas the irradiation wavelength of UV exposure is 280 to 600 nm.
1 The wavelength of far ultraviolet exposure is 200 to 330 nm. 1 The transmission wavelength of quartz and glass is 150 to 11000 nm, respectively.
and 300 to 11,000n, and the sensitivity of the positive naphthoquinonediazide resist to ultraviolet rays is sufficient.
(The sensitivity of negative-tone bisazide compounds is extremely low for UV radiation, while the sensitivity of positive-type naphthoquinone diazide resists is sufficiently low for deep ultraviolet rays.)
This is due to the sufficiently high sensitivity of the negative-type bisazide compound.

Next, one embodiment of the pattern forming method of the present invention will be described.
For example, the photosensitive composition described above is first applied to a substrate such as nonwoven fabric using a spinner or the like, and then dried to form a resist film having a thickness of 0.1 to 2 .mu.m.

Next, when forming a positive resist pattern, the resist film is exposed to ultraviolet rays through a glass mask or the like to form an image, and then an ordinary aqueous inorganic alkali solution or an organic alkali aqueous solution is used. A positive resist pattern is obtained by developing with a positive resist developer.Then, the entire surface is exposed to deep ultraviolet rays for crosslinking, thereby forming a heat-resistant and solvent-resistant positive resist pattern.

On the other hand, when forming a negative resist pattern, the resist film is exposed by irradiating far-violet lA rays through a quartz mask, etc., and then the amount of exposure to make it positive with ultraviolet rays is applied to the entire surface. When irradiated and then developed with the developer for positive resist described above, the areas exposed to both deep ultraviolet and ultraviolet rays do not dissolve in the developer, and the areas unexposed to deep ultraviolet rays and only irradiated with ultraviolet rays. is dissolved to form a negative resist pattern.

Another method for forming a negative resist pattern is to irradiate the resist film with ultraviolet rays through a mask in a large amount comparable to that of a negative resist, and then expose It is also possible to expose the entire surface to a dose that produces a positive resist, and then develop it with the above developer for positive resist.

A negative resist pattern can be formed.

According to the pattern forming method of the present invention, it is possible to form a positive type resist pattern, a negative type resist pattern, or both, which have excellent heat resistance and solvent resistance.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 oFpR-soo (manufactured by Tokyo Ohka Kogyo Co., Ltd.) consisting of a naphthoquinonediazide-novolak resist solution was
After adding and dissolving 15 parts by weight of 4.4'-diazide diphenyl sulfide to the solid content,
A photosensitive composition was prepared by filtering through a μm filter.

This composition was applied onto a silicon wafer using a spinner, and was then bre-baked in a dryer at 85° C. for 30 minutes to form a resist layer with a thickness of about 1.3 μm. This silicon wafer was exposed to ultraviolet rays for 10 seconds through a chromium test chart on a glass substrate using a Canon PLA-500F exposure machine, and then a developer for 0FPR-800 consisting of an aqueous solution of tetramethylammonium hydroxide was applied. using NMD-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C.
Developed for 1 minute. As a result, a positive resist pattern faithful to the test chart was obtained, and resolution down to 0.5 μm was possible.

Example 2 A silicon wafer on which a resist layer was formed in the same manner as in Example 1 was exposed to deep ultraviolet rays for 1 to 2 seconds using a PLA-500F exposure machine manufactured by Canon Inc. through a chromium test chart on a quartz substrate. Thereafter, the entire surface of the glass substrate without any pattern was exposed to ultraviolet light for io seconds. Next, development was performed in the same manner as in Example 1, and the result was 0.75
A negative resist pattern with resolution down to μm was obtained.

Example 3 Two silicon wafers which were patterned by exposure and development in the same manner as in Example 1 were prepared, and only one of them was entirely exposed to deep ultraviolet rays for 10 seconds. Separately, two sheets were patterned using 0FPR-800, which does not contain bisazide compounds.
Only one of the sheets was fully exposed to deep ultraviolet light for 10 seconds. This 4
A piece of silicon wafer was post-baked in a baking oven at 250°C for 20 minutes. The results are shown in the table.

As is clear from the table, using the photosensitive composition of the present invention,
The post-exposed pattern showed excellent heat resistance.

Example 4 Soricon sea urchin patterned in the same manner as in Example]
・The entire surface was exposed to deep ultraviolet rays for 10 seconds.

This resist pattern was less soluble in a good solvent such as methyl ethyl ketone than a pattern using only 0FPR-800, and had improved solvent resistance.

Example 5 A resist layer obtained in the same manner as in Example 1 was exposed to ultraviolet rays for 30 seconds to form a line-and-space pattern with a diameter of 2 μm through a chrome tester 1 on a glass substrate. Next, the silicone wafer was moved by a distance of 2 μm using an alignment device ff VC, and exposed to ultraviolet light for 30 seconds through the same chrome test chart. Thereafter, development was carried out in the same manner as in Example 1, and lines and spaces of 1 μm were obtained.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between exposure time and residual film rate when a photosensitive composition using the BAK of the present invention is irradiated with ultraviolet rays, and Figure 2 is a graph showing the relationship between exposure time and residual film rate when a photosensitive composition using the BAK of the present invention is irradiated with deep ultraviolet rays. It is a graph showing the relationship with the residual film rate. Patent applicant: Tokyo Ohka Kogyo Co., Ltd. Agent: Akira Agata

Claims (1)

[Claims] 1. It is sensitive to two different types of radiation irradiation, and does not dissolve in the developer when irradiated with one radiation, but dissolves in the developer when irradiated with the other radiation, or by reducing the amount of ultraviolet irradiation. In forming a resist pattern that can form both negative and positive patterns to some extent, a radiation pattern is first irradiated using radiation capable of forming a negative resist pattern, and then a positive resist pattern is formed. A pattern forming method characterized by forming a negative resist pattern by irradiating the entire surface with bright radiation and then developing. 2 The resist is a bisazide compound and O-naphthoquinonediazide-based positive resin represented by the general formula (A in the formula is an atom or substituent of o, s, s2.so2, or CH2, or a hydrogen atom or a chlorine atom). The method according to claim 1, wherein the photosensitive composition substantially contains: 3 The bisazide compound is 4,4-diazide diphenyl ether, 4,4'-diazide diphenyl sulfide, 4
．． 4'-Diazidiphenyl sulfone, 3.3'-Diazidiphenyl sulfone, 4.4'-Diazidiphenylmethane% 3,3L dichloro-4,4'-Diazidiphenylmethane, 4.4'-Diazidiphenyl disulfide The method according to claim 2, wherein at least one compound selected from the group consisting of: 4. Is it because it is sensitive to two different types of radiation exposure, and does not dissolve in the developer when exposed to one type of radiation, but dissolves in the developer when exposed to the other radiation? Alternatively, in forming a resist pattern that can form both negative and positive patterns depending on the amount of ultraviolet irradiation, first form a positive resist pattern. A pattern forming method characterized by irradiating the entire surface with radiation capable of forming a negative resist pattern. 5 A in the general formula C of the resist is O, S, S2, S02 or 0H2
O atom or substituent, X is a hydrogen atom or a chlorine atom)
5. The method according to claim 4, which is a photosensitive composition containing a bisazide compound represented by the formula and an O-naphthoquinonediazide positive resist. 6 The bisazide compound is 4,4'-diazide diphenyl ether + 4,4'-diazide diphenyl sulfide)"
, 4.4'-Diazidiphenylsulfone, 3
．． 3'-Diazidiphenyl sulfone, 4,4'-Diazidiphenylmethane, 3,3'-dichloro-4,4'
6. The method according to claim 5, wherein at least one member is selected from the group consisting of -diazidodiphenylmethane and 4,4'-diazidodiphenyldisulfide.