JP3218277B2 - Organic semiconductor and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic semiconductor having a polyacene skeleton structure obtained by laser ablation using an ultraviolet laser.

[0002]

2. Description of the Related Art In recent years, the production of organic polymer materials has been demanded in many industrial fields including the electronics industry. In particular, the electric conductivity is in the semiconductor or conductor region, and has properties as a p-type or n-type semiconductor like inorganic semiconductors such as silicon and germanium. Organic semiconductors or conductors that can be applied to semiconductors, transistors, or solar cells are desired. In order to meet such a demand, Japanese Patent Publication No. 44212/1994 discloses an insoluble and infusible substrate having a polyacene skeleton structure. This insoluble and infusible substrate has both p and n dopants.
It is expected in the electronics field because it can be pinged and has excellent heat resistance, chemical resistance, and oxidation resistance. However, since the organic semiconductor is synthesized using a thermal reaction, there are problems in, for example, forming an extremely thin layer of several μm, delicate pattern processing, joining of semiconductor layers having different electric conductivities, and the like. It was something to leave.

[0003]

In view of the above problems, the present inventors have made intensive studies and completed the present invention. An object of the present invention is to provide a conjugated system between carbon atoms. An object of the present invention is to provide an organic semiconductor which is an insoluble and infusible substrate having a developed polyacene skeleton structure. Another object of the present invention is to provide an organic semiconductor having an ultrathin organic semiconductor or a delicate pattern which can be easily manufactured. Still another object of the present invention is to provide an organic semiconductor having excellent heat resistance, chemical resistance, and oxidation resistance.

[0004]

Means for Solving the Problems The present inventors have completed the present invention by synthesizing an insoluble and infusible substrate having a polyacene skeleton structure using laser ablation using an ultraviolet laser. That is, the present invention
(1) Aromatic condensation polymer composed of carbon, hydrogen and oxygen
-Or (2) aromatics composed of carbon, hydrogen and oxygen
Heat-treated condensed polymer containing hydrogen atoms / carbon atoms
And a hydrogen atom / carbon atom ratio of 0.51 to 0 obtained by depositing fragments generated by ablation using an ultraviolet laser on the substrate with a substrate having an atomic ratio of 0.05 or more as a target. .05 and
And the electrical conductivity corresponding to it is 10 ^-8 S / cm or more and 10
An organic semiconductor characterized by being ² S / cm or less . Further, the present invention is directed to an ultraviolet laser targeting the substrate.
Fragmentation caused by laser ablation
Is different from the target obtained by depositing the target on the substrate.
The present invention relates to a method for manufacturing a semiconductor.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The aromatic condensed polymer comprising carbon, hydrogen and oxygen in the present invention is not particularly limited, but is a condensate of an aromatic hydrocarbon compound and an aldehyde. As the aromatic hydrocarbon compound, for example, so-called phenols such as phenol, cresol, and xylenol are preferable. For example,

Embedded image (Where x and y are each independently 0, 1 or 2
Methylene bisphenols represented by the formula: or hydroxy biphenyls or hydroxynaphthalenes. Of these, phenols, particularly phenol, are practically preferred. As the aromatic condensation polymer in the present invention, a part of the aromatic hydrocarbon compound having a phenolic hydroxyl group is replaced with an aromatic hydrocarbon compound having no phenolic hydroxyl group, such as xylene, toluene, or aniline. A modified aromatic condensation polymer, for example, a condensate of phenol, xylene and formaldehyde, or a modified aromatic polymer substituted with melamine or urea can also be used. Further, a furan resin is also preferable. As the aldehyde, aldehydes such as formaldehyde, acetaldehyde, and furfural can be used. Among them, formaldehyde is preferable. The phenol formaldehyde condensate may be any of a novolak type, a resol type or a mixture thereof.

The heat-treated product of the aromatic condensed polymer comprising carbon, hydrogen and oxygen in the present invention is preferably prepared by subjecting the aromatic polymer to a temperature of 200 ° C. to 800 ° C., preferably in a non-oxidizing atmosphere (including vacuum). ° C, more preferably 400 ° C
It is obtained by gradually heating to an appropriate temperature of ~ 600 ° C. The heat-treated aromatic condensed polymer composed of carbon, hydrogen and oxygen or the heat-treated aromatic condensed polymer composed of carbon, hydrogen and oxygen in the present invention has an atomic ratio of hydrogen atoms / carbon atoms of 0.05. Above, preferably 0.15 or more.

[0007] The insoluble and infusible substrate having a polyacene skeleton structure used in the present invention is an aromatic condensed polymer composed of carbon, hydrogen and oxygen, or an aromatic condensed polymer composed of carbon, hydrogen and oxygen. Which is obtained by depositing fragments produced by ablation using an ultraviolet laser on a substrate, targeting a substrate having an atomic ratio of hydrogen atoms / carbon atoms of 0.05 or more. . Ultraviolet ray used for ablation
The excimer laser is not particularly limited, but a rare gas-halogen excimer laser is generally used.
rF laser (193 nm), KrCl laser (22
2 nm), KrF laser (249 nm), XeCl laser (308 nm) and the like. The method of irradiating the ultraviolet laser is appropriately selected depending on the substrate to be irradiated, the insoluble and infusible substrate having a polyacene skeleton structure to be obtained, or the shape thereof. For example, the irradiation output is 1 mJ.
/ Cm ² -500 mJ / cm ² , irradiation time is 0.1 Hz
The irradiation power is advantageously from 10 mJ / cm ^{2 to} 100 mJ / cm ² , and the irradiation time is preferably from 0.5 Hz to 10 Hz and from 30 seconds to 2 hours. In this way, fragments generated by laser ablation are deposited on the substrate. The substrate used for this is not particularly limited, for example, glass, aluminum, copper, stainless steel, platinum, a metal plate such as gold, polypropylene, a film or plate of a polymer such as polyethylene, and a polyacene organic semiconductor obtained by a heat treatment method. It is selected according to the intended use. Then, the substrate for deposition can be heated to 40 ° C. to 500 ° C. for use.

The insoluble and infusible substrate having a polyacene skeleton structure of the present invention can be formed with a thickness of 10 μm or less.
Further, by repeating the ablation operation two or more times under different conditions, it is possible to produce semiconductor bonding films having different electric conductivities. The electric conductivity of the organic semiconductor is preferably 10 ⁻¹² S / cm or more and 10 ² S / cm or less.

The infrared absorption spectrum of the organic semiconductor of the present invention, when formed on various substrates as described above, can be measured by the ATR method. 1180 Kaiser-1
The absorption peak in the range of 280 Kaiser is the C—H of the aromatic ring.
Due to the in-plane vibration of the coupling, 1560 Kaiser to 1640
The peaks in the Kaiser range are due to deformation of the skeleton of the aromatic ring, and are irradiated with ultraviolet laser light from 1180 Kaiser to 12
Reduced absorption peak in the range of 80 Kaiser, or 15
Since an increase in peaks in the range of 60 to 1640 Kaiser is observed, the organic semiconductor of the present invention has developed a condensed aromatic ring, that is, 2 which constitutes a conjugated system of a benzene ring.
It is understood to have a polyacenic skeleton structure having a bond between carbon atoms as a main bond.

[0010]

The organic semiconductor of the present invention is made of an aromatic polymer or a heat-treated aromatic polymer as a starting material, and has an insoluble infusible material having a polyacene skeleton structure in which a conjugated system between carbon atoms is developed. An organic semiconductor that is a conductive substrate. According to the present invention, an organic semiconductor having a minute shape such as an ultrathin layer organic semiconductor, an organic semiconductor having a delicate pattern, and an ultrathin film that can be easily manufactured is provided.

[0011]

The present invention will be specifically described below with reference to examples.

Example 1 An excimer laser beam having a wavelength of 308 nm (XeCl) was irradiated for 60 minutes at an output of 20 mJplus ^{-1 using} a phenol resin plate having a thickness of 500 μm as a target in a chamber evacuated to about 10 ⁻² Torr. To ablate. A thin film was obtained by depositing fragments generated by ablation on a glass substrate. At this time, the substrate temperature was 20 ° C. The electrical conductivity of the thin film is 10 at room temperature.
^-8 S / cm and brownish color. FIG. 1 shows an SEM photograph of this thin film. If you look at this picture, the thickness is 0.5
It can be seen that an extremely dense thin film of μm is formed on the substrate. Results of X-ray diffraction measurement of this thin film 2
A fairly broad diffraction peak was shown around θ = 20 ° to 25 °, and the structure of the film was amorphous. Elemental analysis of this thin film revealed that the atomic ratio of hydrogen atoms / carbon atoms was 0.51.

Example 2 A phenol resin plate having a thickness of 500 μm was heat-treated at 500 ° C. in a nitrogen atmosphere to obtain an insoluble infusible substrate having an atomic ratio of hydrogen atoms / carbon atoms of 0.46. A thin film having a thickness of about 1 μm was obtained in the same manner as in Example 1 except that the insoluble infusible substrate was used as a target. The atomic ratio of hydrogen atoms / carbon atoms of the thin film was 0.38, and the electric conductivity was 2 × 10 ⁻⁵ S / cm.

[Brief description of the drawings]

FIG. 1 is an electron micrograph (20,000 ×) of the semiconductor thin film of the present invention obtained in Example 1.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Patent 2968179 (JP, B2) Japanese Patent Publication No. 1-44212 (JP, B2) Appl. Phys. Lett. , 65 (11), 12 September 1994, pp. 1370-1372 Appl. Phys. Lett. , 62 (9), 1 March 1993, pp. 1026-1028 (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 51/00 C08G 81/10 C23C 14/12 H01L 21/203

Claims (3)

(57) [Claims] 1. An aromatic compound comprising (1) carbon, hydrogen and oxygen
A condensation polymer or (2) an aromatic condensation polymer comprising carbon, hydrogen and oxygen
-Heat-treated product with an atomic ratio of hydrogen atoms / carbon atoms
Atomic ratio of hydrogen atoms / carbon atoms obtained by depositing fragments generated by ablation using an ultraviolet laser on a substrate, targeting at a substrate of 0.05 or more
Is 0.51 to 0.05, the corresponding electrical conductivity
Is an organic semiconductor, which is 10 ⁻⁸ S / cm or more and 10 ² S / cm or less . 2. The organic semiconductor according to claim 1, wherein the thickness of the organic semiconductor is 10 μm or less. 3. An aromatic compound comprising (1) carbon, hydrogen and oxygen
A condensation polymer or (2) an aromatic condensation polymer comprising carbon, hydrogen and oxygen
-Heat-treated product with an atomic ratio of hydrogen atoms / carbon atoms
A target using a substrate of 0.05 or more and an ultraviolet laser
Deposition of fragments generated by brazing on the substrate
How to produce an organic semiconductor different from the target
Law.