JP6086781B2 - Method for manufacturing organic semiconductor element - Google Patents

Description

  The present invention relates to a method for manufacturing an organic semiconductor element such as a thin film transistor using an organic semiconductor material.

  So-called printing electronics (printed electronics) is known, which uses conductive ink, semiconductor ink, insulating ink, and the like to produce semiconductor elements such as electronic circuits and devices using printing techniques such as gravure offset printing and inkjet. It has been.

Conventionally used semiconductor device manufacturing by photolithography is to form a material layer or a photoresist layer for forming a wiring pattern or the like on the entire surface, pattern the photoresist layer, and then remove unnecessary portions by etching. Is done. Therefore, expensive materials such as gold are wasted and the material cost is increased.
On the other hand, in the printed electronics using printing, since the wiring and the like are formed only in necessary portions, the material cost is not wasted and the environmental harmony is high. Printing is highly productive and can be easily applied to a large area, and is advantageous in terms of production costs other than material costs.
Utilizing such advantages, development of circuits and thin-film transistors (TFTs) that use printed electronics has become particularly active.

On the other hand, photolithography can form a fine pattern. For example, formation of a pattern having a minimum unit such as a line spacing or a line width of 20 nm has been developed.
On the other hand, a pattern of about 100 μm such as a comb-shaped wiring of a solar cell is usually formed by printed electronics. In addition, even with new technology, a pattern of about 50 μm corresponding to the electrode formed on the outer peripheral portion of the smartphone touch panel has been tried. Furthermore, recently, printed electronics capable of forming a fine pattern using gravure offset printing has been announced, but this is still about 10 μm.

On the other hand, as a technique capable of forming a fine pattern other than photolithography, a method of cutting a wiring with a laser beam is known.
For example, in Patent Documents 1 to 3, a wiring pattern is formed on an insulating layer or the like, and the wiring pattern is cut with a laser beam of a pulse wave (pulse driving), thereby providing a source electrode and a drain electrode of the TFT. It is described to form.
In a semiconductor element such as a TFT, if the distance between the source electrode and the drain electrode is long, it takes time for carriers such as electrons and holes to move, and the response speed of the semiconductor element becomes slow. Therefore, in order to improve the performance of the semiconductor element, it is necessary to shorten the distance between the source electrode and the drain electrode. If it is the process which uses a laser beam, it can respond suitably also to such a fine process.

  Therefore, semiconductor elements with fine patterns, such as TFTs with narrow source and drain electrodes, can be manufactured at low cost and with high productivity by combining semiconductor element manufacturing with printed electronics and laser beam processing. There is a possibility of becoming.

JP 2003-309266 A Special table 2009-508321 gazette JP 2012-54510 A

By the way, an organic semiconductor film (organic semiconductor layer) made of an organic semiconductor material can be formed using a paint obtained by dissolving an organic semiconductor material in a solvent such as toluene.
For this reason, the organic semiconductor film can be easily applied to printed electronics, and development using organic semiconductor materials is actively performed in printed electronics.

Here, according to the study of the present inventor, in the manufacture of the semiconductor element for forming the organic semiconductor film, the above-described processing of the wiring pattern by the laser beam is performed by the source electrode and the drain as shown in Patent Documents 1 to 3. It can be suitably used for manufacturing a so-called bottom contact type semiconductor element in which an organic semiconductor layer is formed on an electrode.
However, when manufacturing a so-called top contact type semiconductor device having a source electrode and a drain electrode on an organic semiconductor film, the processing of a wiring pattern by a laser beam is often used, and defects in the organic semiconductor film or electrodes Various inconveniences such as poor insulation between them occur.

  An object of the present invention is to solve such problems of the prior art, and in the manufacture of top contact type organic semiconductor elements, defects are eliminated by utilizing the technology of printed electronics and processing by a laser beam. An object of the present invention is to provide an organic semiconductor element manufacturing method capable of manufacturing an organic semiconductor element having a fine pattern, such as a TFT having a small gap between a source electrode and a drain electrode, without causing occurrence.

  In order to achieve such an object, in the method for manufacturing an organic semiconductor element of the present invention, an organic semiconductor film made of an organic semiconductor material is formed on a substrate, and at least a part thereof is positioned on the organic semiconductor film. Thus, at least one of the line width and the line made of a conductive material is formed into a pattern having a size of 20 μm or more, and the pattern on the organic semiconductor film is further transformed into an organic semiconductor by a continuous wave electromagnetic beam having a spot diameter of 2 μm or less Provided is a method for manufacturing an organic semiconductor element, wherein a part of a pattern on an organic semiconductor film is removed by scanning a plurality of times at a scanning interval equal to or less than the diameter of an electromagnetic beam on the surface of the film.

In such a method for producing an organic semiconductor element of the present invention, the energy density of the electromagnetic beam on the surface of the organic semiconductor film is preferably 20000 mJ / cm ² or less.
The scanning speed of the electromagnetic beam on the surface of the organic semiconductor film is preferably 0.2 m / sec or more.
Further, it is preferable that the electromagnetic beam is collected by a lens having an aperture ratio of 0.2 or more.
The thickness of the organic semiconductor film is preferably 5% or more of the focal depth of the electromagnetic beam.
Moreover, it is preferable that the removal amount of the pattern on the organic semiconductor film is less than 20 μm.
Moreover, it is preferable that the organic-semiconductor material used as an organic-semiconductor film is a low molecular weight organic-semiconductor material.
In addition, the scanning interval of the electromagnetic beam on the surface of the organic semiconductor film is preferably 90% or less of the diameter of the electromagnetic beam on the surface of the organic semiconductor film.
Moreover, it is preferable that the thickness of a pattern is 1-100 nm.
The electromagnetic beam preferably has a focal point on the surface of the organic semiconductor film.
Furthermore, the pattern is preferably formed by printing.

According to the present invention, in the manufacture of an organic semiconductor element having an organic semiconductor film made of an organic semiconductor material, a large pattern of 20 μm or more such as a wiring pattern is formed using a printing technique or the like, and then a laser is formed. A part of this large pattern is removed by an electromagnetic beam such as a beam to prevent fine patterns such as the gap between the source electrode and the drain electrode from damaging or deteriorating the organic semiconductor film, and remaining unnecessary patterns. While forming.
Therefore, according to the method for manufacturing an organic semiconductor element of the present invention, it is possible to manufacture an organic semiconductor element in which a fine pattern is formed with high productivity while suppressing the occurrence of defects.

(A)-(C) are the conceptual diagrams for demonstrating an example of the manufacturing method of the organic-semiconductor element of this invention. (D) And (E) is a conceptual diagram for demonstrating an example of the manufacturing method of the organic-semiconductor element of this invention. (A) And (B) is a conceptual diagram for demonstrating an example of the manufacturing method of the organic-semiconductor element of this invention.

1 and 2 conceptually show an example of a method for manufacturing a semiconductor device of the present invention.
The method for producing a semiconductor element of the present invention (hereinafter also simply referred to as “the production method of the present invention”) comprises an organic semiconductor film and a conductive material by printing or the like on the surface of a substrate, and at least a part of the organic element is organic. A pattern located on the semiconductor film is formed, and a part of the pattern on the organic semiconductor film is removed by scanning with an electromagnetic beam a plurality of times.

  As shown in FIG. 1 and FIG. 2, in this example, a substrate 10 in which a thermal oxide film as an insulator layer 14 is formed on the surface of a Si (silicon) substrate 12 is used as the substrate 10. After forming the organic semiconductor film (organic semiconductor layer) 18 on the surface, a wiring pattern 20 passing over the organic semiconductor film 18 is formed, and the wiring pattern 20 on the organic semiconductor film 18 is irradiated with the laser beam L a plurality of times. The wiring pattern 20 is cut by scanning.

As described above, in the illustrated example, the substrate 10 is formed by forming a thermal oxide film as the insulator layer 14 on the Si substrate 12.
In the manufacturing method of the present invention, the substrate may be a metal other than silicon on which an insulator layer is formed, a metal such as silicon on which an insulator layer is not formed, ceramic, glass, plastic, etc. A plate-like material (sheet-like material / film) made of various materials can be used. Alternatively, the plate-like object may be used as a support, and a gate electrode may be formed on the surface thereof, and the support and the gate electrode may be covered to form an insulator layer.

  That is, in the present invention, in a manufacturing process of a so-called top contact type semiconductor element, in which a source electrode and a drain electrode are formed on an organic semiconductor film, an organic semiconductor film is formed on the surface, and then a wiring is formed. Various objects on which a pattern made of a conductive material such as is formed can be used as a substrate.

  As shown in FIGS. 1A and 1B, the manufacturing method of the present invention forms the organic semiconductor film 18 on the surface of the substrate 10 (the surface of the insulator layer 14).

The organic semiconductor film 18 is a film made of a known organic semiconductor.
In the manufacturing method of the present invention, as the organic semiconductor material for forming the organic semiconductor film 18, various known organic semiconductor materials used as the organic semiconductor film in the manufacture of the organic semiconductor element can be used.
Specifically, pentacenes such as 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS pentacene), tetramethylpentacene, perfluoropentacene, and acenes such as anthracene, TES-ADT, diF-TES-ADT, etc. Anthradithiophenes, DPh-BTBT, benzothienobenzothiophenes such as Cn-BTBT, dinaphthothienothiophenes such as Cn-DNTT, dioxaanthanthrenes such as perixanthenoxanthene, rubrenes, C60, PCBM And phthalocyanines such as copper phthalocyanine and fluorinated copper phthalocyanine, polythiophenes such as P3RT, PQT, P3HT, and PQT, and polythienothiophenes such as PBTT.

In the production method of the present invention, it is preferable to use a low molecular weight organic semiconductor material.
By using a low molecular weight organic semiconductor material in the production method of the present invention, the interaction between molecules is strong, which is preferable in terms of semiconductor characteristics such as mobility.

  In addition, the organic semiconductor film 18 is preferably polycrystalline or single crystal in that high mobility can be obtained.

The organic semiconductor film 18 may be formed by a known method.
Specifically, the above-mentioned printing electronics (printing) such as coating methods using paints in which organic semiconductor materials are dissolved in a solvent, gravure printing, offset printing, stencil printing, screen printing, gravure offset printing, transfer printing, ink jet printing, etc. Examples of various printing techniques used in Ted Electronics). Note that a method of forming a pattern on an adherend through an opening mask having an opening corresponding to a pattern to be formed, for example, by a film forming means such as vacuum deposition is also considered as a kind of stencil printing.

The thickness of the organic semiconductor film 18 may be appropriately determined according to the shape and size of the organic semiconductor film 18 and the type and size of the organic semiconductor element to be manufactured.
Here, in the manufacturing method of the present invention, the thickness of the organic semiconductor film 18 is preferably 5% or more of the focal depth of the laser beam L for removing the wiring pattern 20. This will be described in detail later.

In the manufacturing method of the present invention, after the organic semiconductor film 18 is formed, a wiring pattern 20 made of a conductive material is then formed as shown in FIG.
In the present invention, the wiring pattern 20 has a pattern in which at least a part is located on the organic semiconductor film 18 formed previously. In the example shown in FIG. 1 and FIG. 2, it is formed on the substrate 10 (insulator layer 14) so as to cross over the organic semiconductor film 18.

In the present invention, as the pattern made of a conductive material, at least a part of the pattern such as an electrode pattern, a resistance pattern, an organic semiconductor pattern, a capacitor pattern, etc. is formed on the organic semiconductor film 18 in addition to the illustrated wiring pattern. If it is possible, various patterns made of various conductive materials can be used.
In addition, the manufacturing method of the present invention can be used not only for manufacturing a conductive material but also for manufacturing an organic semiconductor element in which an insulator pattern using an insulating material is formed on the organic semiconductor film 18.

In the manufacturing method of the present invention, such a wiring pattern 20 (pattern) is a large (coarse) pattern that does not require fineness among patterns formed on an organic semiconductor element.
Specifically, at least one of the line width and the line is a pattern of 20 μm or more. Preferably, at least one of the line width and the line is a pattern of 30 μm or more.

Therefore, the wiring pattern 20 is formed by the gravure printing, the offset printing, the stencil printing, the screen printing, the gravure offset printing, the transfer printing, the ink jet, etc., which are exemplified in the case of forming the organic semiconductor film 18 previously. Various printing techniques used in printing electronics are preferably used.
By forming the wiring pattern 20 by printing, it is possible to form the wiring pattern 20 with high productivity, without waste of materials, at low cost, and suitable for a large area.
In the manufacturing method of the present invention, the wiring pattern is not limited to being formed by printing, and various known forming methods such as vapor deposition can be used.

  As the material for forming the wiring pattern 20, various known materials can be used as long as they are conductive materials such as gold, silver, and copper that can ensure necessary conductivity.

In addition, the thickness of the wiring pattern 20 may be appropriately determined according to the line width and line spacing of the wiring pattern to be formed, the type and size of the organic semiconductor element to be manufactured, and the like.
Here, according to the study of the present inventors, the thickness of the wiring pattern 20 is preferably 1 to 100 nm, and particularly preferably 5 to 30 nm.
By setting the thickness of the wiring pattern to this thickness, it is preferable from the standpoint that reliable processing with a laser beam L having a spot diameter of 2 μm or less, which will be described later, is possible, and the shape of the pattern edge is clean.

After the wiring pattern 20 is formed in this way, a part of the wiring pattern 20 formed on the organic semiconductor film 18 by the laser beam L irradiated from the optical system 24 is then used as shown in FIG. 2E, a gap 20a is formed, a source electrode 20b and a drain electrode 20c are formed on the organic semiconductor film 18, and a top contact type semiconductor element (TFT (thin film transistor) is formed. )) 26 is manufactured.
In this semiconductor element 26, the silicon substrate 12 serves as a gate electrode.

  In the present invention, as long as the optical system 24 can irradiate the laser beam L having a spot diameter of 2 μm or less, the light source of the laser beam L, the lens for the light source to focus the laser beam L, the laser beam L Various well-known laser beam irradiation apparatuses configured by combining mirrors for adjusting the optical path of the laser beam can be used.

As described above, in order to improve the performance of the organic semiconductor element, it is necessary to narrow the space between the source electrode and the drain electrode. However, in printing, for example, such fine processing such as forming the source electrode and the drain electrode with a gap of 5 μm is difficult.
On the other hand, as shown in Patent Documents 1 to 3, first, by forming a wiring pattern (metal layer to be an electrode) and processing the wiring pattern using a laser beam, the source electrode and the drain electrode A narrow gap can be formed. For example, Applied Physics Express 2 (2009) 126502 uses a laser processing apparatus (NEO1000 manufactured by Palestec Corporation) that uses a semiconductor laser with a wavelength of 405 nm and a lens with an aperture ratio (NA) of 0.5. It has been shown that it can.

Here, in the manufacturing method of the present invention, a laser beam L having a spot diameter of 2 μm or less is used, and the laser at this position on the surface of the organic semiconductor film 18 (interface between the organic semiconductor film 18 and the wiring pattern 20) is used. By scanning the processing position of the wiring pattern 20 a plurality of times at a scanning interval equal to or less than the beam diameter of the beam, the wiring pattern 20 is removed by the laser beam L to form a gap 20a.
Since the light intensity distribution of the beam spot is not uniform at the focal point of the laser beam L, the spot diameter is defined by the intensity of 1 / (e ² ) in the present invention. That is, in the present invention, if the wavelength of the laser beam is λ and the aperture ratio of the lens is NA,
Spot diameter = (0.82 × λ) / NA
It becomes.
The scanning interval of the laser beam L is the interval between the centers of the laser beams L on the surface of the organic semiconductor film 18. That is, in the present invention, scanning with the laser beam L is performed by overlapping the laser beam L on the surface of the organic semiconductor film 18.

In the illustrated example, as an example, as shown in FIGS. 2D and 2E, the wiring pattern 20 extending in the direction of the arrow y on the organic semiconductor film 18 is indicated by a broken line in FIG. As shown, the laser beam L is scanned in the x direction orthogonal to the y direction. When one scan is finished, the substrate 10 and the optical system 24 are moved relative to each other in the y direction by a predetermined scanning interval equal to or smaller than the beam diameter on the organic semiconductor film 18, and the laser beam L is moved again in the x direction. To scan. This scanning of the laser beam L is repeated according to the size of the gap 20a.
As a result, the wiring pattern 20 is two-dimensionally scanned with the laser beam L, and the wiring pattern 20 at the scanned position is removed to form the gap 20a.

In the manufacturing method of the present invention, after forming a large wiring pattern 20 using a printing technique or the like, a plurality of laser beams L overlapped by such a small continuous wave laser beam L having a spot diameter of 2 μm or less. The wiring pattern 20 is removed by scanning once.
Thereby, the organic semiconductor film 18 is not damaged by the laser beam L, and the wiring pattern 20 is surely removed, so that the semiconductor element 26 that has been subjected to fine processing with high productivity can be obtained with high yield. Can be manufactured.

In the formation of the gap of the wiring pattern by the laser beam as shown in the above-mentioned Patent Documents 1 to 3, it is most efficient to perform the processing with the laser beam having a beam diameter corresponding to the gap to be formed. For example, in order to form a gap of 5 μm in the wiring pattern, it is most preferable to form a gap in the wiring pattern by a single scan using a laser beam having a beam diameter of 5 μm at the interface between the wiring pattern and the lower layer. Efficient.
Further, in order to perform processing using the power of the laser beam efficiently, it is preferable to perform processing by positioning the focal point of the laser beam at the interface between the wiring pattern to be processed and the lower layer.
In addition, processing using such a laser beam is usually performed with a laser beam of a pulse wave that provides a large output, as shown in Patent Documents 1 to 3.

  However, when such laser beam processing is used for manufacturing a top contact type organic semiconductor element, the organic semiconductor film is often damaged, and an organic semiconductor element that operates properly cannot be manufactured in many cases. .

As described above, the spot diameter of the laser beam is “spot diameter = (0.82 × λ) / NA”. On the other hand, the depth of focus of the laser beam is “depth of focus = (λ / NA ² )”. That is, a laser beam with a large spot diameter has a deep focal depth.
Within the focal depth of the laser beam, the light intensity of the laser beam is strong. In particular, the region of about 10% centered on the focal point has a high light intensity.
On the other hand, in the organic semiconductor element 26, the thickness of the organic semiconductor film 18 is usually about 5 to 500 nm, and the thickness of the wiring pattern 20 is about 10 to 100 nm.

Therefore, in the manufacture of the top contact type organic semiconductor element 26 having the organic semiconductor film 18 under the wiring pattern 20 to be the source electrode 20b and the drain electrode 20c, the depth of focus having a spot diameter corresponding to the gap 20a to be processed is deep. When the gap 20a is processed with a laser beam, not only the wiring pattern 20 but also the organic semiconductor film 18 is removed.
If scanning is performed with a pulsed laser beam, continuous processing cannot be performed, and the wiring pattern 20 to be removed remains. Although this inconvenience can be avoided by narrowing the pulse width to a laser beam close to a continuous wave, an output peak occurs during irradiation with each pulse, so the organic semiconductor film 18 is also removed.
If the organic semiconductor film 18 is removed together with the wiring pattern 20, the organic semiconductor element naturally does not operate and becomes a defective product. Conversely, if the wiring pattern 20 to be removed remains, the organic semiconductor element will be short-circuited.

In contrast, in the manufacturing method of the present invention, the wiring pattern 20 is formed by scanning a plurality of times using a continuous wave laser beam L having a spot diameter of 2 μm or less, that is, a continuous wave laser beam L having a shallow focal depth. By removing, the gap 20a is formed.
Therefore, although the processing efficiency by the laser beam L is reduced, the organic semiconductor film 18 is removed by leaving the organic semiconductor film 18 in the vicinity of the interface with the insulator layer 14 through which charges mainly pass, and the organic semiconductor that operates properly. The element 26 can be manufactured. In addition, according to the laser beam L having a spot diameter of 2 μm or less, finer processing is possible.
Further, even if the laser beam L has a small spot diameter, the scanning interval in the y direction is set to be equal to or smaller than the diameter of the laser beam L on the surface of the organic semiconductor film 18, and the laser beam L is overlapped on the surface of the organic semiconductor film 18. Since the scanning is performed, the wiring pattern 20 can be surely removed at the position where the gap 20a is formed, and there is no inconvenience such as a short circuit.
Further, as described above, since the large wiring pattern 20 can be formed by a method with high productivity such as printing, the organic semiconductor element 26 subjected to such fine processing can be manufactured with high productivity. .

In the manufacturing method of the present invention, the spot diameter of the laser beam L may be 2 μm or less, more preferably 1.3 μm or less, and particularly preferably 0.7 μm or less. In addition, it is preferable that the spot diameter corresponds to the depth of focus corresponding to the thickness of the organic semiconductor film 18 described later.
By setting the spot diameter of the laser beam L in the above range, it is preferable in that the organic semiconductor film 18 can be more reliably prevented from being damaged, and the finer wiring pattern 20 can be processed.

In the manufacturing method of the present invention, the laser beam L can be used in various types of continuous wave that can remove the wiring pattern 20 by ablation, sublimation, evaporation, or the like.
Specific examples include a 405 nm laser beam, a 650 nm laser beam, and a 780 nm laser beam by a semiconductor laser.
Further, in the manufacturing method of the present invention, in addition to these laser beams, it is also possible to use an electromagnetic beam or the like obtained by condensing light from a light source such as an LED with a pinhole and an optical lens. However, a laser beam is preferably used in terms of increasing the energy density.

The laser beam L is preferably collected by a lens (including a combined lens) having an aperture ratio (NA) of 0.2 or more. That is, the optical system 24 preferably collects the laser beam L with a lens having an aperture ratio of 0.2 or more. Among these, the laser beam L is more preferably collected by a lens having an aperture ratio of 0.3 or higher, more preferably focused by a lens having an aperture ratio of 0.4 or higher, and an aperture ratio of It is even more preferable that the light is condensed by a lens of 0.5 or more, and it is particularly preferable that the light is condensed by a lens having an aperture ratio of 0.75 or more.
By focusing the laser beam L with a lens having an aperture ratio of 0.2 or more, processing with the laser beam L having a spot diameter and a focal depth suitable for removing the wiring pattern 20 is possible. This is preferable in that a fine pattern can be formed by preventing damage to the film 18.

The laser beam L is preferably energy density of 20000 mJ / cm ² or less at the surface of the organic semiconductor film 18, in particular, 5000 mJ / cm ² or less, preferably among them 2000 mJ / cm ² or less.
By setting the energy density on the surface of the organic semiconductor film 18 to 20000 mJ / cm ² or less, it is preferable in terms of more suitably preventing the organic semiconductor film 18 from being removed.

The energy density of the laser beam L on the surface of the organic semiconductor film 18 only needs to be equal to or higher than the energy density at which the wiring pattern 20 can be removed by ablation or the like.
Here, according to the study of the present inventor, in order to enable reliable removal of the wiring pattern 20, the energy density of the laser beam L on the surface of the organic semiconductor film 18 is preferably 100 mJ / cm ² or more, and 200 mJ. / Cm ² or more is more preferable.

The focal position of the laser beam L may be set to a position where the wiring pattern 20 can be removed by the laser beam L, but is preferably set to a range half the focal depth from the surface of the organic semiconductor film 18. It is preferable that the surface of the semiconductor film 18 and the focal point of the laser beam L coincide.
Setting the focal point of the laser beam L at this position is preferable in that the wiring pattern 20 can be removed efficiently using the power of the laser beam L.

  Here, in the manufacturing method of the present invention, the thickness of the organic semiconductor film 18 is preferably 5% or more of the focal depth of the laser beam L.

In the present invention, the spot diameter of the laser beam L is “(0.82 × λ) / NA” defined by “1 / e ² ”. The laser beam L has a distribution in light intensity among the spot diameters. Particularly, the light intensity is strong in an area of about 10% of the center. For example, in the case of a laser beam L having a wavelength of 405 nm collected by a lens having an aperture ratio of 0.85, the spot diameter is 391 nm, and the light intensity is particularly strong in a region having a central diameter of about 39 nm.
Similarly, the light intensity of the laser beam is strong within the depth of focus of the laser beam L, but the light intensity is also distributed within the depth of focus, and in particular, the light intensity is about 10% around the focus. Is strong. If the laser beam L is the same as described above, the depth of focus is 561 nm, and the light intensity is particularly strong in the region of about 56 nm centered on the focus.

Here, as described above, it is preferable that the surface of the organic semiconductor film 18 and the focal point of the laser beam L coincide with each other in order to efficiently remove the wiring pattern 20.
At this time, as conceptually shown in FIG. 3A, if the high-intensity region Ld having a focal depth of 10% centered on the focal point of the laser beam L includes the organic semiconductor film 18, the organic semiconductor film 18 There is a possibility that the laser beam L having a high light intensity is irradiated over the entire region in the thickness direction, resulting in alteration or destruction.
For example, in the above example, the high-intensity region Ld having a focal depth of 10% centered on the focal point of the laser beam L is about 56 nm, so that the organic semiconductor film 18 is organic when the thickness is 28 nm or less. There is a possibility that the entire region in the thickness direction of the semiconductor film 18 is exposed to the laser beam L having a high light intensity, resulting in alteration or destruction.

On the other hand, when the thickness of the organic semiconductor film 18 is set to 5% or more of the focal depth of the laser beam L, as conceptually shown in FIG. The upstream side in the traveling direction of the beam L) may be exposed to the high-intensity region Ld to cause alteration or the like. However, in the vicinity of the interface with the lower insulator layer 14, it is exposed to a laser beam with high light intensity. It will not be altered or destroyed.
For example, in the above-described example, if the thickness of the organic semiconductor film 18 exceeds 28 nm, for example, 30 nm, the region of 2 nm near the interface with the lower insulator layer 14 has a high light intensity. It is not exposed and will not be altered or destroyed.

In the organic semiconductor element 26, the electric charge passes between the source electrode 20 b and the drain electrode 20 c mostly in the vicinity of the interface between the organic semiconductor film 18 and the insulator layer 14. Therefore, the organic semiconductor element 26 operates properly unless alteration or destruction occurs in this portion.
That is, by setting the thickness of the organic semiconductor film 18 to 5% or more of the focal depth of the laser beam L, the organic semiconductor film 18 is prevented from being altered or broken in the vicinity of the interface with the insulator layer 14 and more stable. Thus, the organic semiconductor element 26 that operates properly can be manufactured.
In other words, in the manufacturing method according to the present invention, the laser beam L having a spot diameter corresponding to 5% or less of the depth of the organic semiconductor film 18 is used in accordance with the thickness of the organic semiconductor film 18. It is preferable to remove the pattern 20.

For example, in the case of a laser beam L having a wavelength of 405 nm collected by a lens having an aperture ratio of 0.85, 10% of the spot diameter is 39 nm and 5% of the focal depth is 28 nm. The thickness is preferably 30 nm or more, more preferably 45 nm or more, and particularly preferably 60 nm or more.
Further, in the case of the laser beam L having a wavelength of 650 nm collected by a lens having an aperture ratio of 0.65, 10% of the spot diameter is 82 nm and 5% of the focal depth is 77 nm. The thickness is preferably 80 nm or more, more preferably 120 nm or more, and particularly preferably 160 nm or more.
Further, in the case of a laser beam L having a wavelength of 780 nm collected by a lens having an aperture ratio of 0.55, 10% of the spot diameter is 116 nm and 5% of the focal depth is 129 nm. The thickness is preferably 130 nm or more, more preferably 195 nm or more, and particularly preferably 260 nm or more.

  That is, it is more preferable that the thickness of the organic semiconductor film 18 is more than 5% of the focal depth of the laser beam L, and above all, 1.5 times or more of 5% of the focal depth of the laser beam L. In particular, it is preferable to be at least twice as much as 5% of the focal depth of the laser beam L.

As described above, in the manufacturing method of the present invention, the scanning of the laser beam L in the x direction is performed a plurality of times in the y direction by overlapping the laser beam on the surface of the organic semiconductor film 18, thereby wiring. The pattern 20 is removed to form a gap 20a.
This scanning may be performed by moving the substrate 10, may be performed by moving the optical system 24, may be performed by moving both, and may be performed using an optical deflector. Also good.
Further, during scanning of the laser beam L in the x direction, the optical system 24 turns on the laser beam L only on the wiring pattern 20 to be processed and turns off (reduces the beam intensity) at other positions. The laser beam L is modulated.

Here, the scanning speed of the laser beam L (the linear velocity of the laser beam L) may be appropriately set according to the intensity of the laser beam L, the thickness of the wiring pattern 20 to be removed, and the like. Here, according to the study of the present inventor, the scanning speed of the laser beam L is preferably 0.2 m / sec or more, and more preferably 1 m / sec or more.
By setting the scanning speed to 0.2 m / sec or more, it is preferable in that the energy density of the laser beam L can be prevented from becoming higher than necessary, and alteration of the organic semiconductor film 18 can be prevented more reliably. .

The scanning interval of the laser beam L on the surface of the organic semiconductor film 18 may be equal to or less than the diameter of the laser beam L on the surface of the organic semiconductor film 18, but is preferably 90% or less, and 80% or less of the diameter of the laser beam L. Is more preferable.
By setting the scanning interval of the laser beam L on the surface of the organic semiconductor film 18 to 90% or less of the diameter of the laser beam L on the surface of the organic semiconductor film 18, the laser beam L can be more reliably formed on the surface of the organic semiconductor film 18. It is preferable in that the scanning can be performed in an overlapping manner, and the wiring pattern 20 in the region that becomes the gap 20a can be more reliably removed.

  In the manufacturing method of the present invention, the size of the wiring pattern 20 to be removed by the laser beam L, that is, the fine processing pattern such as the gap 20a between the source electrode 20b and the drain electrode 20c has a line spacing of less than 20 μm. preferable.

  As mentioned above, although the manufacturing method of the organic-semiconductor element of this invention was demonstrated in detail, this invention is not limited to the above-mentioned example, Even if various improvements and changes are performed in the range which does not deviate from the summary of this invention. Of course it is good.

  Hereinafter, the specific example of this invention is given and the manufacturing method of the organic-semiconductor element of this invention is demonstrated in detail.

[Example 1]
As a substrate, an n-type Si substrate having a diameter of 4 inches and a thickness of 0.5 mm, on which a thermal oxide film (insulator layer) having a thickness of 300 nm is formed, was prepared.
The surface of this insulator layer was irradiated with UV light to improve paintability.

  On the other hand, TIPS pentacene was dissolved in toluene to prepare a coating solution. The concentration of TIPS pentacene in the coating solution was 1% by mass.

The prepared coating solution was applied to the surface of the insulator layer by spin coating at 1000 rpm.
Next, by drying the coating solution, an organic semiconductor film having a thickness of 300 nm was formed on the surface of the substrate (insulator layer).

  On the organic semiconductor film (TIPS pentacene film) thus formed, gold having a thickness of 10 nm × 5 mm was deposited as a wiring pattern by vacuum deposition through a metal mask adhered to the organic semiconductor film. .

A wiring pattern is removed by ablation by scanning the wiring pattern with a laser beam using a laser processing apparatus (NEO1000 manufactured by Pulse Tech Co., Ltd.) to form a gap of 5 μm, as shown in FIG. A top contact type organic semiconductor element (TFT) having a configuration was manufactured. That is, the distance between the source electrode and the drain electrode is 5 μm.
In this organic semiconductor element, the Si substrate serves as the gate electrode.

The laser beam was a continuous wave, the wavelength was 405 nm, and the output was 10 mW. The aperture ratio was 0.85, and the spot diameter was 391 nm. Therefore, 5% of the focal depth of the laser beam L is about 28 nm.
The focal point of the laser beam L was matched with the surface of the organic semiconductor film (that is, the diameter of the laser beam on the surface was 391 nm). The scanning speed of the laser beam L on the surface of the organic semiconductor film was 0.6 m / sec, and the scanning interval was 300 nm.
The energy density on the surface of the organic semiconductor film is shown in the following table.

[Example 2] to [Example 8]
Except for setting the scanning speed of the laser beam to 1 m / sec (Example 2),
Example 3 except that the laser beam output was set to 5 mW
Example 4 except that the laser beam output was 20 mW and the scanning speed was 2 m / sec.
By changing the setting when applying the coating liquid, the thickness of the organic semiconductor film was changed to 200 nm (Example 5),
By changing the setting when applying the coating solution, the thickness of the organic semiconductor film was changed to 100 nm (Example 6),
The output of the laser beam was set to 20 mW, the scanning speed was set to 2 m / sec, and the setting for applying the coating liquid was changed to change the thickness of the organic semiconductor film to 60 nm (Example 7).
An organic semiconductor element was prepared in the same manner as in Example 1 except that the scanning speed of the laser beam was 1 m / sec and the deposition time was changed to change the wiring pattern thickness to 30 nm (Example 8). Was made.

[Comparative Example 1] to [Comparative Example 5]
Except that the scanning interval of the laser beam was 800 nm (Comparative Example 1),
The laser beam scanning interval was set to 600 nm, and the vapor deposition time was changed to change the wiring pattern thickness to 20 nm (Comparative Example 2).
The laser beam was changed to a pulse wave with a duty of 50% (Comparative Example 3).
Except that the scanning speed of the laser beam was 1 m / sec and the scanning interval was 500 nm (Comparative Example 4),
An organic semiconductor element was produced in the same manner as in Example 1 except that the scanning interval of the laser beam was changed to 600 nm (Comparative Example 5).
The following table shows the spot diameter, output, scanning speed, scanning interval, energy density (density) on the surface of the organic semiconductor film, and thickness (film thickness) of the organic semiconductor film 18 of the laser beam L.

<Measurement of mobility>
The field effect transistor (FET) was evaluated by connecting each electrode of each organic semiconductor element thus produced and each terminal of a manual prober connected to Agilent Technologies 4155C. Specifically, the field effect mobility ([cm ² / V · sec]) was calculated by measuring the drain current-gate voltage (Id-Vg) characteristics.
As a result, Example 1 is 1 × 10 ⁻³ ; Example 2 is 2 × 10 ⁻³ ; Example 3 is 1 × 10 ⁻³ ; Example 4 is 2 × 10 ⁻³ ; ^-3 ; Example 6 was 1 × 10 ⁻³ ; Example 7 was 6 × 10 ⁻⁴ ; Example 8 was 1 × 10 ⁻⁴ ;
On the other hand, in Comparative Examples 1 to 5, the organic semiconductor element did not operate and the mobility could not be measured (impossible).
The results are also shown in the table below.

As shown in the above table, the semiconductor element (TFT) produced by the manufacturing method of the present invention appropriately removes the wiring pattern by scanning the laser beam without causing destruction or alteration of the organic semiconductor film, Since the source electrode and the drain electrode can be formed, both have good mobility.
On the other hand, in Comparative Example 1, Comparative Example 2, Comparative Example 4 and Comparative Example 5, since the scanning interval of the laser beam is larger than the spot diameter, the wiring pattern remains, short-circuits, and the organic semiconductor The device did not work.
Further, in Comparative Example 3, since the wiring pattern was removed with a laser beam of a Halus wave instead of a continuous wave, the wiring pattern remained in a broken line shape in the scanning direction, and the organic semiconductor film was altered, The organic semiconductor device did not work.
From the above results, the effects of the present invention are clear.

  It can be suitably used for manufacturing an organic semiconductor element using an organic semiconductor material such as TFT.

DESCRIPTION OF SYMBOLS 10 Substrate 12 Si substrate 14 Insulator layer 18 Organic semiconductor film 20 Wiring pattern 24 Optical system 26 Organic semiconductor element

Claims (10)

An organic semiconductor film made of an organic semiconductor material is formed on the substrate,
Forming a pattern in which at least one of the line width and the line is made of a conductive material so that at least a part is located on the organic semiconductor film is 20 μm or more,
Further, by scanning the pattern on the organic semiconductor film with a continuous wave electromagnetic beam having a spot diameter of 2 μm or less at a scanning interval equal to or less than the diameter of the electromagnetic beam on the surface of the organic semiconductor film, Removing a part of the pattern on the organic semiconductor film , and
The method of manufacturing an organic semiconductor element , wherein the thickness of the organic semiconductor film is 5% or more of the focal depth of the electromagnetic beam . ^{2. The} method of manufacturing an organic semiconductor element according to claim 1, wherein the energy density of the electromagnetic beam on the surface of the organic semiconductor film is 20000 mJ / cm ² or less.   The method of manufacturing an organic semiconductor element according to claim 1, wherein a scanning speed of the electromagnetic beam on the surface of the organic semiconductor film is 0.2 m / sec or more.   The method of manufacturing an organic semiconductor element according to claim 1, wherein the electromagnetic beam is collected by a lens having an aperture ratio of 0.2 or more. The method for manufacturing an organic semiconductor element according to claim 1 , wherein a removal amount of the pattern on the organic semiconductor film is less than 20 μm. The method for producing an organic semiconductor element according to claim 1 , wherein the organic semiconductor material to be the organic semiconductor film is a low molecular weight organic semiconductor material. The organic semiconductor element manufacturing method according to any one of claims 1 to 6 , wherein a scanning interval of the electromagnetic beam on the surface of the organic semiconductor film is 90% or less of a diameter of the electromagnetic beam on the surface of the organic semiconductor film. Method. The method for producing an organic semiconductor element according to claim 1 , wherein the pattern has a thickness of 1 to 100 nm. The method of manufacturing an organic semiconductor element according to claim 1 , wherein the electromagnetic beam has a focal point on a surface of the organic semiconductor film. The manufacturing method of the organic-semiconductor element of any one of Claims 1-9 which forms the said pattern by printing.

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