JPH02296245A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To reduce halation even when a photoresist pattern is formed on the surface of a substrate high in reflectance by incorporating at least one kind of specified hydroxyazobenzenecarboxylic acid derivatives in the photoresist. CONSTITUTION:The photoresist contains at least one kind of the hydroxyazobenzenecarboxylic acid derivatives represented by formula I in which one of R<1> - R<5> is -COOH and one of R<6> - R<10> is -OH, and the other is H or alkyl, thus permitting absorption of line i and line h to be made more than the case of executing lithography alone, accordingly, exposure light to be attenuated even when the resist pattern is formed on the surface of the substrate made of the material having high reflectance, and halation to be lowered.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a photosensitive composition suitable for use in forming a pattern on a substrate having high reflectance, and particularly to a photosensitive composition suitable for forming a pattern on a substrate having high reflectance.
The wavelength is 365 (nm)) or the h-line (the wavelength is 405 (nm)
A photosensitive composition capable of forming a high-definition pattern on the above-mentioned substrate using the light of (m)).

(Conventional technology) As semiconductor devices become more highly integrated and faster, the demand for microfabrication technology used in their manufacturing increases. It's getting tougher. Among these microfabrication techniques, the resist process technique in particular is a fundamental technique for manufacturing semiconductor devices, and therefore it is necessary to obtain a resist pattern of desired dimensions.

Normally, in the manufacture of semiconductor devices, photolithography steps and etching steps are repeated many times in order to fabricate various semiconductor elements on a substrate. At this time, film formation and resist pattern formation are performed using a substrate on which semiconductor elements have already been formed as a base.

It is difficult to deposit a photoresist with a uniform thickness on a base having a step caused by the semiconductor element, making it difficult to perform highly accurate patterning. In addition, the surface of this base is made of a material with high reflectance (for example, aluminum (/
(19), the exposure light is reflected on the side surface of the step mentioned above. For this reason, poor resolution of the resist pattern, so-called halation, occurs, making high-definition pattern thinning even more difficult.

Conventionally, as a technique capable of reducing the above-mentioned halation, for example, as disclosed in JP-A-63-136040, a photosensitive composition containing a photoresist blended with a strong pigment that absorbs exposure light has been used. Something was being done.

According to this publication, curcumin, which is a diketone pigment, is used as the above-mentioned pigment, and the 9-ray (wavelength is 43
It is effective as a photosensitive composition having a sensitivity to 5.8 (nm)).

(Problems to be Solved by the Invention) However, most of the dyes added to conventionally known photoresists for reducing halation are effective for 9-line radiation. For this reason, dyes that absorb i- and h-lines have been discovered, which are effective for increasing the definition of resist patterns.When forming resist patterns on substrates with high reflectance, it is necessary to achieve sufficient resolution. There was a problem in that there was no known photosensitive composition that could be used.

In view of the above-mentioned conventional problems, an object of the present invention is to reduce halation, which is suitable for use in photolithography technology using i-line and h-line. The object of the present invention is to provide a photosensitive composition capable of forming a desired high-definition resist pattern.

(Means for solving the problem) In order to achieve this objective, the inventors of this application:
We conducted extensive research on various compounds. As a result, this invention was completed by focusing on hydroxyazobenzenecarboxylic acid derivatives.

Therefore, according to the photosensitive resin composition of the present invention, either the following general formula (I) ρ7 or an alkyl group is represented in the photoresist. ) is characterized in that it contains at least one type of hydroxyazobenzenecarboxylic acid derivative represented by the following.

Examples of the hydroxyazobenzenecarboxylic acid derivatives mentioned herein include compounds shown in the following structural formulas (1) to (2).

(However, in -Funenin (I), any one group from 81 to R5 represents a carbonyl group (-COOH), and any one group from B6 to RIO represents a hydroxyl group (-Ko). In addition, other groups have a hydrogen atom structure 2〇 Structural formula
Various hydroxyazobenzenecarboxylic acid derivatives represented by are commercially available and easily available.

In addition, there are various types of photoresists suitable for blending such hydroxyazobenzenecarboxylic acid derivatives. For example, in the case of a positive resist, naphthoquinone cyatosulfonic acid ester is added to a cresol novolac resin. Examples of negative resists include those in which a hisazide compound is added to polyvinylphenol resin, and those in which naphthoquinone cyacytosulfonic acid is directly introduced into cresol novolak resin by esterification.

Specific examples of photoresists suitable for the photosensitive composition according to the present invention include 'TSMR-V3J, 'TSMR-VIJ, manufactured by Tokyo Ohka Kogyo ■;
'TSMR-8800J, 'TSMR-8900J
'TSMR-365iB, +, '0FPR-500
0J, '0FPR-800J ■ rPR1024MB manufactured by East McDermitt.

■'RI-7000PJ, 'RD-200ONJ' made by Hitachi Chemical ■'MP-2400' made by Sibley ■'AZ-2400J, 'AZ-5214' made by Hoechst ■'FSMRJ made by Fuji Pharmaceutical Co., Ltd. (All of the above (trade name), or any other photoresist may be used as long as it is inert to the hydroxyazobenzenecarboxylic acid derivative to be blended.

In carrying out the present invention, in the photosensitive composition,
- It is preferable that the amount of the hydroxyazobenzenecarboxylic acid derivative of Shipman (I) is within the range of 0.1 to 10 (wt%) based on the solid content of the photoresist.

The lower limit of this preferred amount is the value necessary to exhibit the halation reduction effect, and the upper limit of the amount is the value necessary to avoid deterioration of the shape of the resist pattern, generation of bridges, scum, etc. It is.

In general, the photosensitive composition according to the present invention may contain one of the hydroxyazobenzenecarboxylic acid derivatives represented by the above-mentioned general formula CI), or may contain two or more of them at the same time. good.

(Function) According to the structure of the photosensitive composition of the present invention, by blending a predetermined amount of the above-mentioned hydroxyazobenzenecarboxylic acid derivative, the i-line and h-line Line absorption increases. For this reason, even if the surface of the base on which the resist pattern is to be formed is made of a material with high reflectance, the exposure light is absorbed by the above-mentioned dyes and is attenuated, making it difficult to reduce halation. can.

(Examples) Examples of the photosensitive composition according to the present invention will be described below with reference to the drawings. It should be noted that the numerical conditions, equipment used, chemicals used, etc. described in the following examples are merely illustrative, and it is understood that this invention is not limited to the specific conditions described below. I want to be

Prior to describing Examples of the photosensitive composition of the present invention, one example of the results of measuring the absorption characteristics of the compound represented by -Funenin (I) will be described. In the following explanation, 2-(4-hydroxyphenylazo)-benzoic acid (hereinafter sometimes simply referred to as HABA) shown in the above-mentioned structural formula (2) will be used as an example of a series of compounds represented by this -shipman.

) will be explained regarding the results of spectrum measurement.

This spectrum measurement was performed by preparing a coating solution containing HA8A7j described above, applying this solution to a quartz substrate,
This was done by forming a film.

The preparation of this coating solution will be explained below.
As the binder resin for forming the film, Vylon 200J (polyester resin manufactured by Toyobo Co., Ltd., trade name), which is substantially transparent from the visible range (about 700 (nm)) to around 250 (nm), was used.Coating The solution is
Prepared by dissolving this binder resin 120 (mq) and HABA (manufactured by Tokyo Kasei ■) 30 (mq) in methyl cellosolve acetate 1 (mβ), and filtering this through a membrane filter with a pore size of 0.2 (Llm). did.

The sample for measurement was prepared by applying the above-mentioned coating solution onto the surface of a quartz substrate with a thickness of 0.9 mm using a spin coating method (rotation speed: 2,000 (r, p, m, )), and drying. Obtained by letting. When the film thickness of the dry film formed on such a sample was measured using "Kristetub" (manufactured by Rank Taylor Hobson, trade name), it was found to be approximately 0.44 (
um).

Roughly speaking, the spectrum measurement was carried out using an ultraviolet-visible spectrophotometer rU-3400 manufactured by Hitachi, Ltd.
The experiment was carried out for wavelengths in the range of 0 (nm).

In Figure 1, the horizontal axis shows wavelength (nm), and the vertical axis shows transmittance (nm).
%) and is a characteristic curve diagram showing the results of the above-mentioned spectrum measurement.

As can be understood from this figure, the wavelength at which the absorption maximum of HABA shown in the above-mentioned structural formula (2) occurs is 387 (nm), and the transmittance at this wavelength was approximately 14.2 (%).

In addition, the transmittance at 365 (nm), which corresponds to the h-line, is 22
．． 2 (%), and the transmittance at 405 (nm) corresponding to the h-line was 20 (%).

As can be understood from this measurement result, this HABA is
It absorbs about 80% of the light that is half of the line and h-line. For this reason, HABA! It has been found that halation can be reduced by blending it into a photosensitive composition.

Next, the results of forming a resist pattern on the surface of a base having a high reflectance using the photosensitive composition obtained by blending the above-mentioned HABA will be explained.

The photosensitive composition according to this example is the above-mentioned r TSM
R-365if3+ (Solid content is 3.5 (wt%))
0.0 (ml2) of HABA in photoresist. +5 (9
) was prepared by dissolving and filtering through the membrane filter described above.

Next, the base material used in this patterning test will be explained with reference to the drawings.

FIG. 2(A) is a schematic cross-sectional view of the base, and FIG. 2(B) is an explanatory diagram showing the base in a plan view.

This base 11 has a diameter of 5 (inches) (1 inch is approximately 2
．． 54 (cm)) is used as the substrate 13, and the surface of the substrate 13 has a high g6. OO'O(λ) step 15% BPSG
(:Bor.

Phospho 5ilicate Glass). Furthermore, the upper side of the substrate 13 in this state has a thickness of 9,000 mm as a component having a high reflectance.
An aluminum film 17 is deposited to obtain a base 11 for use in the test. In addition, the step 15 is made by CVD method.
After depositing PSG, patterning was performed by photolithography, and sputtering was used to deposit the aluminum film 17.

Next, the procedure of a pattern printing test using the Photosensitive 1 composition prepared according to the above-mentioned procedure will be explained.

First, the substrate 11 described above is subjected to a Debite raying treatment at a temperature of about 200 CG for 60 seconds, and then exposed to hexamethyldisilazane vapor at a temperature of 25 (℃) for 60 seconds. Brimer treatment was performed by this.

Thereafter, the above-mentioned photosensitive composition is applied to the surface of the base 11 which has been subjected to such treatment by a spin coating method, and then the photosensitive composition 18 (
A film of um) was formed.

Furthermore, 90 ('
Soft bake at temperature C) for 60 seconds,
This was used as a sample for exposure.

In this patterning test, a plurality of the above-mentioned exposure samples were prepared, and an i-line reduction projection exposure apparatus rRA-101VLn J (manufactured by Hitachi, Ltd., trade name) (numerical aperture NA, 0. 42), the line formed is in the direction (
Exposure was carried out at various exposure doses so as to extend in the direction indicated by P in Figure 2 (CB). In this exposure, a chrome mask having lines and spaces of various dimensions was used.

After this exposed sample was baked for 60 seconds at a temperature of 0 (℃), it was baked using a metal-free alkaline developer 'NMD-WJ (concentration 2.38 (%)) (Tokyo Ohka Kogyo Co., Ltd.). Developed for 60 seconds using the paddle method.

Regarding the developed sample thus obtained, the formation state of the resist pattern was observed by microscopic observation, and the dimensions of the pattern were measured using an SEM length measuring machine rS-6000J (trade name, manufactured by Hitachi, Ltd. Measurements were made.

As a result, by using the photosensitive composition according to this example, the line and
A space can be formed, and the dimensional difference between the resist pattern formed on the step 15 and the resist pattern formed in the portion corresponding to between the steps 15 is 0.0.
It was very small, about 2 (Ll m).

In addition, for the purpose of comparison with the photosensitive composition according to this example, except that it was prepared without blending HABA,
A photosensitive composition having the same composition as above was prepared and a patterning test was conducted under consistent conditions.

As a result, when the photosensitive composition according to the comparative example was used, 0
．． Resist patterns with lines and spaces of up to 6 (μm) could be formed without breakage, but patterns with lines and spaces of 0.5 (un) were only partially resolved. However, a rupture occurred. Also, 0
．． The dimensional difference between the steps 15 and 15 in the resist pattern having a line and space of 6 (μm) was also as large as 1 (un), which is five times that of the example.

As can be understood from the results of these patterning tests, when forming a resist pattern on a substrate with high reflectance, halation can be reduced by using the photosensitive composition of the present invention, resulting in high precision and It was possible to form a resist pattern. Further, the hydroxyazohexicacarboxylic acid derivatives represented by -Funenin (I), including HABA used herein, are soluble in alkaline aqueous solutions widely used as developers.

Therefore, the above-mentioned upper limit of the compounding amount of the derivative is 1
In photosensitive compositions prepared with more than 0 (wt%), scum (residue) similar to that seen with compounds insoluble in alkaline aqueous solutions conventionally blended for the purpose of reducing halation may occur. did.

Furthermore, when the blending amount of the hydroxyazobenzenecarboxylic acid derivative was less than the amount (VO, IC weight %), the halation reduction effect disappeared.

In addition, FIG. 1 referred to in the above examples shows only the measurement results of a coating solution prepared without the influence of light (corresponding to the photosensitive composition before exposure).

However, at least in the wavelength range corresponding to the i-line and h-line, a substantial change in transmittance is observed even in the photosensitive composition after exposure to these lights. −
IA [IA functioned effectively.

In addition, in the series of measurements and tests mentioned above, the structural formula ■
Although the HABAu shown in the above example is given, similar effects can be obtained even if the photosensitive composition is prepared by blending other hydroxyazobenzenecarboxylic acid derivatives within a suitable amount and using other photoresists. You can expect it.

(Effects of the Invention) As is clear from the above explanation, the photosensitive composition according to the present invention has the above-mentioned general formula % formula % Contains a fixed amount. For this reason, 1 line or h
The property of absorbing exposure light such as lines, which is advantageous for forming resist patterns with high accuracy, is enhanced, and even when a resist pattern is formed on the surface of a base having a high reflectance, it is possible to reduce halation.

Therefore, by using the photosensitive composition of the present invention, it becomes possible to form patterns with higher precision in photolithography technology, where wavelengths are increasingly becoming shorter.

[Brief explanation of drawings]

FIG. 1 is a characteristic curve diagram showing transmittance (%) on the vertical axis and wavelength (nm) on the horizontal axis, in order to explain the invention in detail. FIG. 2 (A) and CB) show the following: FIG. 2A is a schematic cross-sectional view of the substrate, and FIG. 2B is a schematic plan view of the substrate. It is. 11... Base (having high reflectance) 13... Substrate, 15... Step (of BPSG film) 17... Aluminum film.

Claims (2)

[Claims] (1) The photoresist has the following general formula (I) ▲mathematical formula, chemical formula, table, etc.▼・・・(I) One of the groups represents a carbonyl group (-COOH), and one of the groups from R^6 to R^1^0 represents a hydroxyl group (-OH), and the other groups represent a hydrogen atom or an alkyl group. A photosensitive composition comprising at least one hydroxyazobenzenecarboxylic acid derivative represented by the following formula. (2) The amount of the hydroxyazobenzenecarboxylic acid derivative in the photosensitive composition according to claim 1 is 0.1 to 10 (wt%) based on the solid content of the photoresist.
) A photosensitive composition characterized by having a value within the range of