JPS61118745A - Light nd radiation sensitive organic polymer - Google Patents

Abstract

PURPOSE:To obtain a light and radiation sensitive org. polymer adapted to formation of a micropattern and superior in etchability by imparting Si-Si bonds and + or --electron conjugated org. groups to the principal chain of the polymer. CONSTITUTION:The light and radiation sensitive org. polymer obtained by condensing, e.g., p-bis(chloromethylphenylsilyl)benzene with methylphenyldichlorosilane in toluene in the presence of metallic sodium is represented by formula I in which R1 is a divalent pi-electro conjugated org. group, such as -CH=CH2, -Capprox.=C-, phenylene, or the like; each of R2-R5 is a monovalent org. group, such as 1-6C hydrocarbon group, -CH=CH2, or phenyl; and n, m are each 1-100, preferably, m/n=0.2-2.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to light- and radiation-sensitive organic polymer materials;
This invention relates to a radiation-sensitive organic polymer material with excellent dry etching resistance suitable for forming fine/arm turns.

Microfabrication technology using photoetching is used to manufacture electronic components such as semiconductor devices and integrated circuits.For example, a photoresist layer is formed by coating/coating photorenost on silicon single crystal phenol. ,
Layer a mask with the desired yarn on top of it, expose it,
In the above-mentioned microfabrication technology, which involves developing and rinsing to form an image, and etching to form lines and holes several micrometers wide, the product accuracy is largely determined by the performance of the photoresist, such as the resolution on the substrate, It depends on the degree of photosensitivity, adhesion to the substrate, resistance to etching, etc.

There are two types of photoresists: negative-shaped resists in which exposed areas become insolubilized, and positive resists in which exposed areas become soluble. In general, negative resists have excellent sensitivity but poor resolution, making them unsuitable as resists for microfabrication. On the other hand, although I-type resists have excellent resolution, they are inferior in sensitivity and resistance to etching2, and improvements in these characteristics are desired. It is required to form a t4 turn with a width of 1 μm or less for the purpose of improving the overall performance. In this case, high-speed electron beams, X-rays, or ion beams are used instead of light.

Energy radiation is used in lithography.

However, even in high-energy lithography, it is known that positive-tone radiation-sensitive organic polymer materials are superior to negative-tone radiation-sensitive organic polymer materials in terms of resolution, but inferior in sensitivity. It is strongly desired that negative resist materials have improved resolution, while positive resist materials are strongly desired to have improved sensitivity.

With the miniaturization of wiring in semiconductor devices, etc., dry etching is increasingly being adopted in place of the conventional wet etching for etching the underlying layer after quarter-turning the resist layer. Therefore, resist materials are required to have strong resistance to dry etching. However, conventional resist materials, regardless of whether they are positive or negative, do not necessarily have sufficient resistance to dry etching, and their characteristics Improvement is strongly desired fi [M, J, B
ovd@n and L, F, Thompson
: 5solid 5tate Technology
, 22.

72 (1979)) [Object of the Invention] The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to have high sensitivity to high-energy radiation such as light, electron beams, and X-rays; Another object of the present invention is to provide a light- and radiation-sensitive material having excellent resistance to dry etching.

[Summary of the invention]

In order to achieve the above objectives, we investigated various materials that are thought to have light and radiation sensitivity and have excellent resistance to dry etching. We found that polymeric materials with valent π-electron conjugated organic groups are good.9.

That is, when the above-mentioned polymeric material is subjected to turn formation by photolithography, exposed portions are efficiently solubilized in a developer by ultraviolet irradiation, resulting in a di-type photoresist. Even when the photoresist film was formed in this way and the photoresist film was irradiated with oxygen glazma, no film deterioration was observed, indicating that the polymeric material had excellent resistance to oxygen glazma.

The light sources used for ultraviolet irradiation include ultra-high pressure mercury lamps and xenon lamps, which have traditionally been used in photoetching technology.
In addition, the above-mentioned polymeric materials can be used as radiation-sensitive resist materials by inducing cross-linking reactions or decomposition reactions by irradiation with high-energy radiation such as electron beams and X-rays. The resist film formed with four turns has extremely high resistance to dry etching.

Next, materials used in the present invention will be explained.

The light- and radiation-sensitive organic polymer material used in the present invention has the general formula (1)% formula% (Tomodashi, in the general formula (1), R1 is a divalent π-electron conjugated organic group, R1+ R, e R4 and Rs represent monovalent organic groups, and i and m represent integers from 1 to 100. R, is =C)l=c)I+, -(:
=C-.

Examples include. Here, the bonding position with the silicon system is arbitrary, and a substituent may be attached.

a, l a3+ R4 and R in general formula (1) are -Cn)I2 n +1 preferably n ~1-6 *
%CH4)n CH=C)I, preferably rs=1~
6. (-CH'2+nPh preferably n=1 to 6, -
CI(=CI(2, -Ph, etc.). Here, the alkyl group, vinyl group, and phenyl group may have a substituent. 1. Rt * B,, s tR4 and L, From the viewpoint of solubility of the polymeric material, it is desirable that the polymeric material be composed of two or more types of organic groups.The polymeric material used in the present invention can be synthesized by various methods.

When using the light- and radiation-sensitive organic polymer material of the present invention for pattern formation of semiconductor devices, for example, the above-mentioned polymer material may be dissolved in a common organic solvent such as toluene. Ru. The above-described polymeric material solution (resist solution) is spin-coated onto an element substrate, and then prebaked under appropriate temperature conditions and irradiated with light or radiation in desired turns. After irradiation, the irradiated area is selectively dissolved or insolubilized using a toluene-isoglobil alcohol mixed solvent or a liquid solution made of toluene, etc., to form a positive resist mother turn or negative resist pattern. Resist T! You get a turn.

[Embodiments of the invention]

The present invention will be explained below with specific synthesis examples and examples.Synthesis Example 1. Synthesis of Polymeric Material (2) A 10014 Mitsulo flask equipped with a Herssie Perk stirrer, condenser, addition funnel, and thermometer was degassed and A:
Replace with r. , dried under Ar flow, nine tornine 30a
j and sodium 5. Of (0,27f atom)
7 Las jlC1p-bis(chloromethylphenylsilyl)benzene 10.0f (25.8m mot), methylphenyldi(chlorosilane 4.93t (2
5,8 m mot) and 5 d of toluene are placed in the dropping funnel. After heating the toluene in the flask and melting the sodium, fine particles of sodium are obtained by stirring at high speed.After cooling the flask to room temperature, a small amount of the monomer solution is added dropwise. Heat the flask from room temperature to less than
After dropping, continue to ripen under the same conditions, but when the sodium dispersion breaks out into large chunks, heat the flask to 90-100℃ to disperse the sodium, and then heat the flask to 90-92℃. Continue to mature. A maturing time of 1 hour or more is required.

After the reaction is completed, the reaction mixture is poured into methanol to remove excess sodium and precipitate the polymer. After filtration, the polymer is dissolved in tetrahydrofuran and added dropwise to water; n) The IJum salt is dissolved in water. 1. Wash the filtered polymer with methanol and dry under reduced pressure. Through the above steps, polymer material (2) was obtained with a yield of 96%.

The properties and instrumental analysis results of the obtained polymer are shown below.

Weight average molecular weight: 21.000 Melting point: 127-134°C Thermogravimetric analysis (in air): 400'CNMR spectrum (60MHz, COD@, CH2CLzδ5
．． 33):'J1.50. δ1,61 (br, 5X2
): δ8.13. δ8.40(br,sX2)m/n
== 0.67 (NMR; x, from vector) IR spectrum/van: aoso, aooo,
2960.

1430, 1380, 1250, 1125, 1
105, 785.

775, 740, 700, 505UV spectrum (C) IC6s): λwax 257 nm.

Synthesis example 2. Synthesis of polymeric material (3) In the same manner as in Synthesis Example 1, % p-bis(chloromethylphenylsilyl)benzene 10.0f (2,5,8 mmol)
) &(trimethyldichlorosilane 3.33P(25,8
m mot), and sodium 5.0f (0,22f
A polymer material @ (3) was obtained from 901% yield.

The properties and instrumental analysis results of the obtained polymer are shown below.

Weight average molecular weight: 18.000 Melting point: 97-104°C Thermogravimetric analysis (in air): 420'CNMR spectrum (60MHz * Cs D @ + CH2CZ @
δ5.33): δ1.00 to 1.66 (m) δ
8.11. δ8.40 (br, sX2) m/n z O
,40 (from NMR spectrum)! R spectrum/ν(
! II: 3070, 3050, 291G.

, 1435 , 1255 , 1135 , 1105 ,
790, 780, 740°705, 520 υV spectrum A/ (CHCLB): λmal 2
57nm synthesis example 3. Synthesis of polymeric material (4) In the same manner as in Synthesis Example 1, p-bis(chlorodimethylsilyl)benzene 6.58F (25.0m mot), methylphenyldichlorosilane 4.78F (25.0m mot)
t), and sodium 4.60fC0,20t at
Polymer material (4) was obtained with a yield of 66%.

The obtained 4'J mama-property and equipment analysis results are shown below.

Weight average molecular weight: 22.000 Melting point: 95-9 Thermogravimetric analysis: 40■ NMR spectrum (60MHz, C6D@, C
4C4eδ5.33):δ1.33 (br, s)δ
8.11, δ8.35 (br, sX2) m/n =
1.56 (from NMRx vector) IR spectrum/
ν trust: 3050, 2960, 2900.

1435 , 1385 , 1255 , 1135 , 1
105, 845.

825, 790, 770, 740, 710,
660, 510.

υVx pects, (CHCLs): λmax26
8nm Example 1゜Polymer material (2) was dissolved in toluene, 10% by weight.
A 0.28 μm thick/IJ film was formed on a 1"l silicon film by spin coating. Next, it was baked at 100°C for 30 minutes, and a 500 W xenon film was passed through the quartz film. Mercury run f (irradiation intensity: 12m W/Cl1l at 254nm)
) and 9. After irradiation, it was immersed in a mixed solvent of toluene and isopropyl alcohol (1:5 by vow) for 15 seconds and developed.

The irradiated area was solubilized by rinsing with ethyl cellosolve for 15 seconds and isopropyl alcohol for 15 seconds, resulting in exposure to light below 310 nm.

A positive resist/# turn was obtained after approximately 2 seconds of irradiation.

The resistance to oxygen plasma of the resist film formed in this way for 14 turns is shown in Figure 1. Even when left in oxygen plasma, no film deterioration was observed, confirming that the resist film has extremely high dry etching resistance. Chilled. For reference, 2 shows the oxygen plasma resistance of polyimide resin, which is one of the materials with excellent dry etching resistance.
The film reduction rate is 200X/min. Also,
This resist also has excellent resolution, and a line of 1 μm could be resolved by contact exposure.

・Example 2゜Same as Example 1, 0.15μ of polymer material (3)
A coating film of m thickness was formed on a silicon wafer. Next, under the same conditions as in Example 1, after light irradiation, the irradiated area was developed by immersing it in a mixed solvent of ethylcelonorbu-isopropyl alcohol (7:3 byvot) f& for 15 seconds, and then rinsing with isopropyl alcohol for 15 seconds to remove the irradiated area. was solubilized. As a result, it is exposed to light of 300 nm or less,
After about 16 seconds of irradiation, an I-shaped resist film and turns were obtained.

Similar to polymer material (2), this material did not peel off at all in oxygen plasma and exhibited extremely high dry etching resistance. It also had excellent resolution, and a 1 μm line could be resolved by contact exposure.

Example 3: In the same manner as in Example 1, 0.16μ of polymer material (4)
A coating film of m thickness was formed on a silicon wafer. Next, under the same conditions as in Example 2, light irradiation and development were performed to solubilize the irradiated areas. As a result, a positive resist mother turn was obtained by exposure to light of 305 nm or less and irradiation for about an additional second.

Similar to the polymer material (2), the material (4) also showed extremely high dry etching resistance without any film loss in oxygen plasma. It also has excellent resolution, with a resolution of 191 μm for close exposure.
A friend who can resolve lines.

Example 4゜Same as Example 1, 0.20μ of polymer material (3)
It is possible to form a m-thick a film on a silicon wafer. Next, the film was irradiated with an electron beam at an accelerating voltage of 20 KV under vacuum, developed by immersion in toluene for 1 minute, and then rinsed with ino-7'o-pyl alcohol. A negative resist pattern was obtained.

After forming a number of turns in this manner, the resistance to oxygen plasma of the Lennost film was examined. As with the results of Example 1, no film burrs were observed, and it was confirmed that the film had extremely high dry etching resistance. It was. 4 In addition, the resolution was excellent and a 191 μm line could be resolved by electron beam irradiation Example 5.6° In the same manner as in Example 4, 0.18 μm line of polymer material (3)
3 X 10-'C/cm" for a m-thick coating, and I X 10-'C for a 0.20-μm thick coating of polymer material (4).
A negative resist turn was obtained with an electron beam irradiation dose of /;-@''.

In addition, the film showed extremely high In)" re-etching resistance without any film damage even when exposed to oxygen plasma, and also had excellent resolution, and a line of 1 μm could be resolved by electron beam irradiation.

〔Effect of the invention〕

As is clear from the above description, when the light- and radiation-sensitive organic polymer material according to the present invention is used as a resist material, it can be used as a resist with particularly excellent resistance to dry etching. As a result, it is possible to form fine I-turns with extremely high precision, which can be put to practical use in manufacturing ultra-fine semiconductors and the like. As mentioned above, the light- and radiation-sensitive organic polymer material according to the present invention will be extremely useful.

[Brief explanation of the drawing]

The figure shows the oxygen plasma resistance of the resist film, in which the amount of film reduction of the resist film is plotted against the oxygen plasma etching time.

Claims (1)

[Claims] 1. General formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (However, in general formula (1), R_1 is a divalent π-electron conjugated organic group , R_2, R_3, R_4 and R_5 represent monovalent organic groups, and n and m represent integers from 1 to 100. Molecular materials. 2. In claim 1, R_1 in general formula (1) is a phenylene group, (R_2, R_3, R_4, R
The combination of _5) is (phenyl group, methyl group, phenyl group, methyl group), (phenyl group, methyl group, methyl group, methyl group), or (methyl group, methyl group, phenyl group, methyl group), m A light- and radiation-sensitive organic polymer material, characterized in that /n is 0.2 to 2.