JPH09107129A - Semiconductor device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a compact and high-performance semiconductor device by easily fabricating the semiconductor device in an arbitrary shape. SOLUTION: A semiconductor device consists of a flexible film-shaped insulation substrate 2 such as polyimide and Teflon and a semiconductor 3 for thermoelectric conversion being formed on the entire surface of its single surface and the semiconductor 3 is fabricated by rolling the film-shaped insulation substrate 2. The semiconductor 3 is either a P-type thermoconversion semiconductor or N-type thermoconversion semiconductor in ultra-lattice structure by an ultra-thin film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device formed on a flexible film-like insulating substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art A thermoelectric conversion element is the most typical example of a power device that requires a multilayer structure to be formed. This thermoelectric conversion element is a mutual conversion element of heat and electricity with no moving parts. When dissimilar metals are joined at two places to form an electric circuit, and a direct current is applied, heat is generated at one joint and endothermic phenomenon is caused at the other. When the thermoelectric cooling is generated, and one of the joints is heated and the other is cooled, an open circuit voltage corresponding to the temperature is generated between the open terminals to reversibly generate thermoelectric power.

FIG. 8 generally shows a thermoelectric conversion module using a bulk thermoelectric conversion element. FIG.
, 71 and 72 are metal plates, 73 is an N-type semiconductor, 7
4 is a P-type semiconductor, 75 and 76 are terminals, and 77 is a substrate. This thermoelectric conversion module shows a thermoelectric device in which P-type semiconductors and N-type semiconductors are alternately electrically connected in series and thermally arranged in parallel. When a voltage is applied to the electrode terminals 75 and 76 of this thermoelectric device, one of the metal plates 71 and 72 is heated and the other is cooled. The following steps are taken as a method of manufacturing such a semiconductor device.

The P-type and N-type semiconductors are respectively subjected to composition adjustment, mixing, firing, and heat treatment to form a bulk-shaped thermoelectric conversion element, which is cut into a predetermined size to form a P-type semiconductor chip, An N-type semiconductor chip is manufactured. The shape of this thermoelectric conversion element is generally a prism.
This thermoelectric conversion element is a P-type semiconductor chip via electrodes,
N-type semiconductor chips are alternately connected in series by solder to form one unit. In addition, a plurality of series units may be connected in parallel to form one module depending on the electrode connection method. When this is used as a thermoelectric cooling element, if a negative voltage is applied to the P-side terminal and a positive voltage is applied to the N-side terminal, the electrode side on the upper surface of the unit in FIG. 8 becomes the heat absorbing surface and the electrode on the lower surface of the unit becomes the heat generating surface. Although not shown, a heat exchanger is usually installed to cover the upper and lower electrode surfaces via an electrode insulating substrate to improve the performance of the element by reducing the temperature difference between the high temperature and the low temperature of the element. .

Further, Japanese Patent Application Laid-Open No. 62-177985 discloses a thermoelectric conversion module having a laminated structure using a thin film thermoelectric conversion element. FIG. 9 shows the configuration of the main part thereof, (A) is a sectional view of the element substrate, (B) is a sectional view of the layers,
(C) has shown the cross section of the completed thermoelectric conversion element.
In FIG. 9, 81 is a glass substrate, 82 is a Ni metallized film, 83 is a P-type thermoelectric film, 84 is an N-type thermoelectric film, 85 is an element substrate, 86 is an adhesive, 87 is a conductive paste, 88 is a Cu plate, 89 indicates an adhesive and 90 indicates an electrode. This operation is similar to the case of the bulk thermoelectric conversion module described above, but in this case, the thin film (2 μm) is laminated, so that the module thickness is about 30 mm even if 50 layers are laminated. Have been described.

Further, Japanese Patent Laid-Open No. 2-198181 describes a manufacturing method by the Roll To Roll method.
In this manufacturing method, a P-type semiconductor and an N-type semiconductor are formed on an insulating film while controlling the deposition / non-deposition of a doping element with a shutter.
Alternate mold semiconductors are created in the same plane to form the structure as shown in FIG.

[0007]

A power device such as the thermoelectric conversion element as described above may require a multilayer structure in order to improve the performance. However, in the case of bulk-shaped or thin-film-shaped semiconductor elements, there is a defect that the area and volume are increased by stacking and the applicable range is narrowed and mechanical strength is weakened. In particular, Ro
A semiconductor element having a film substrate manufactured by the ll to roll method has a lower mechanical strength, and thus is more easily damaged than a semiconductor element formed on a rigid substrate.

The semiconductor element having such a laminated structure generally has a prismatic shape, and it has been difficult to arbitrarily change the shape. Therefore, for example, the shape of the semiconductor element cannot be set according to the shape of the thermoelectric conversion module described above, and the degree of freedom of the shape of the thermoelectric conversion module is extremely low.

Further, in the bulk and thin film thermoelectric conversion elements as described above, it is difficult to improve the performance even with a laminated structure, and the efficiency of thermoelectric conversion cannot be improved. The reason will be described below. The performance of the thermoelectric conversion element is represented by the performance index Z, and the larger Z is, the higher the performance of the thermoelectric conversion device is. FIG.
Shows the relationship between the temperature and Z of various typical thermoelectric materials.
In the figure, (A) is the material of the P-type thermoelectric conversion semiconductor,
(B) is a characteristic diagram of a material of an N-type thermoelectric conversion semiconductor. (Kinichi Uemura, Isao Nishida: "Thermoelectric semiconductor and its utility", 1988, p36). According to FIG. 10, there is an optimum temperature use range depending on the material, and if a thermoelectric cooling element is used at a temperature level (about 300 K) of a general air conditioner or a refrigerator, a chalcogenite-based material such as Bi, Te, Sb, Se, etc. The compound material of is most suitable. Even in the case of these materials, the figure of merit is about 2.5 × 10 ⁻³ (1 / K), and the dimensionless figure of merit ZT obtained by multiplying this by the operating temperature is the material mainly used for thermoelectric power generation at high temperature. Including the above, the current situation is about ZT≈1. Therefore, even if the bulk-shaped and thin-film-shaped thermoelectric conversion elements are stacked, the dimensionless figure of merit ZT does not change, and an effective effect on the efficiency of the thermoelectric conversion elements cannot be obtained.

In view of the above-mentioned problems, an object of the present invention is to propose a semiconductor device in which semiconductors can be easily laminated in an arbitrary shape, which is compact and whose performance can be improved, and a manufacturing method thereof.

[0011]

The present invention comprises a flexible film-like insulating substrate and a semiconductor formed on one surface of the film-like insulating substrate. The film-like insulating substrate is wound to stack semiconductors. A semiconductor element having a structure. In this semiconductor element, the semiconductor has a superlattice structure of an ultrathin film made of a semiconductor material for thermoelectric conversion.

According to another aspect of the present invention, a semiconductor is formed on one surface of a flexible film-like insulating substrate, and then the film-like insulating substrate is wound with a roll to laminate the semiconductors to manufacture a semiconductor element. A method of manufacturing a semiconductor element, characterized in that a roll having the same shape as that of the semiconductor element having the above shape is used.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Recently, for a crystal material of Bi ₂ Te ₃ , a theoretical consideration that the dimensionless figure of merit ZT reaches about 7 times that of a bulk material due to a two-dimensional quantum well structure by a superlattice (LDHicks, “Effect of quantum-well stracture
s on the thermoelestric figure of merit ", 1994), in which phonon conductivity is reduced by phonon confusion at the superlattice interface, and electron-phonon interaction is caused by the binding effect of electrons in quantum wells. The main factor is the improvement in electrical conductivity, which is the result of calculation of the thickness of the unit cell layer and the dimensionless figure of merit ZT according to this document.
Shown in The result varies depending on the crystal surrounding of Bi ₂ Te _{3 in} the current direction. For example, the effect appears when the film thickness is 40 angstroms or less on the a ₀ -b ₀ plane, and the film thickness is reduced to about 10 angstroms on the a ₀ -c ₀ plane. Results are shown that yield about 7 times the bulk Z. The superlattice structure is composed of, for example, a quantum well laser and has been put into practical use. However, it is formed in a minute portion of a laser light emitting element, and MBE
It is produced as a product realized by ultra-precision film formation by (Molecular Beam Epitaxy).

Therefore, the present inventors believe that the same effect can be obtained by the ultrathin film from the principle of improving the figure of merit by the superlattice, and form a semiconductor material having the ultrathin film on a flexible film-like insulating substrate. , A semiconductor roll chip in which they are wound and laminated is devised. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 2 is a constitutional view showing a first embodiment of a semiconductor roll chip which is a semiconductor element according to the present invention. (A) is a partial cross-sectional perspective view showing a semiconductor roll chip, and (B) is an enlarged view of the cross-sectional part a. This semiconductor roll chip 1 is a cylindrical semiconductor element for thermoelectric conversion, and includes a flexible film-like insulating substrate 2 made of a polymer material such as polyimide or Teflon, and a semiconductor for thermoelectric conversion formed on one entire surface thereof. 3 and has a structure in which the semiconductor 3 is laminated by winding the film-shaped insulating substrate 2 into a cylindrical shape. The semiconductor 3 is an ultra-thin P-type heat conversion semiconductor or an N-type heat conversion semiconductor. Although not shown, the end of the semiconductor roll chip 1 is fixed with a heat-resistant tape such as polyimide or Teflon to prevent the roll from unraveling. Since such roll holding means is common in the manufacture of capacitors and the like, detailed description thereof will be omitted.

FIG. 3 is a block diagram showing a semiconductor device manufacturing apparatus according to the first embodiment. In FIG. 3, 11 is a flexible film insulating substrate, 12 is a first winding roller, 13 is a second winding roller, 14 is a thin film thermoelectric conversion semiconductor forming device, 15 is a molecular beam source furnace, 16 is a crucible, and 17 is Target heating heater, 18 is a target, 19 is a substrate heating heater, 20 is a substrate temperature sensor, 21 is a mask, 22 is a shutter, 23 is a film thickness meter, 24 is a vacuum container,
Reference numeral 25 denotes an evacuation device.

The shapes and dimensions of each component are shown below. The flexible film-like insulating substrate 1 has no problem as long as it is an insulating substance having a flexible property and a low thermal conductivity, and for example, polyimide is used as described above. Here, it is assumed that the polyimide substrate has a width of about 10 mm and is wound around the second winding roller 13. One end of this film-like insulating substrate 11 is attached to the first winding roller 12, and after film formation, although not shown in the drawing, drive the motor of the first winding roller 12 outside the vacuum container. It is to be wound up by. here,
Since the insulating substrate 11 serves as a heat flow path from the heat generating surface to the heat absorbing surface, it is preferable that the thickness of the substrate is as thin as possible and the thermal conductivity is small.

Regarding the thin-film thermoelectric conversion semiconductor forming device 14, a single vapor deposition machine using alloy materials, a multi-source vapor deposition machine capable of depositing single materials simultaneously or in multiple layers, sputtering, CV.
Various methods such as D can be considered. However, in the present technology, in order to form a single crystal as a thin film of about 40 angstrom, film formation by an apparatus such as MBE (Molecular Beam Epitaxy) can be considered. Here, since the detailed description of the device such as the MBE is complicated, the main part will be described.

First, the molecular beam source furnace 15, which is a vapor deposition source, will be described. This molecular beam source reactor 5 is a PBN (Pyrolytic Born N
The main elements are a crucible 16 made of iteride) and a target heating heater 17 made of tungsten. Although not shown in the drawing, the molecular beam source furnace 15 is protected by a heat seal made of tantalum, and a W-Re (5-26%) thermocouple is arranged. This molecular beam source furnace 15 has a target 1
8 (chalgogenite type) is inserted and evaporated (about 500
° C).

Next, a halogen lamp heater or the like is used as the substrate heating heater 19 to heat the substrate 11 to about 250.degree. The substrate sensor 20 controls the substrate heater 19 using a chromel-alumel thermocouple. Mask 21
Is made of stainless steel and is about 15 mm (width) x 15 mm (length) x 0.3 mm (thickness) with 10 mm in the center.
There is a hole of × 10mm. In addition, the mask 21 is brought into close contact with the substrate by a motor (not shown) during film formation. The shutter 22 is made of stainless steel and is opened and closed by compressed air (5 kg / cm ² ) by a hose not shown in the figure.

The film thickness meter 23 is a reflection high-energy electron diffraction (RHEE)
D) A device or the like is conceivable. Based on the information of this device, the other first and second take-up rollers 12 and 13, the mask 2
1, the shutter 22 and the like are controlled. The vacuum container 24 is made of glass. The evacuation device 25 is composed of a turbo molecular pump, a diffusion pump, and an oil rotary pump.

Next, the operation of this manufacturing apparatus will be described.
The thin-film thermoelectric conversion semiconductor manufacturing apparatus is installed in a vacuum apparatus, the film-shaped insulating substrate 11 is set in a state of being wound around the second winding roller 13, and one end is the first
It is in a state of being attached to the take-up roller 12. Into the molecular beam source furnace 16 of the thin film thermoelectric conversion semiconductor forming apparatus 14, for example, a material target 18 of a P-type thermoelectric conversion semiconductor or an N-type thermoelectric conversion semiconductor whose main component is a chalcogenite-based material such as Bi, Sb or Te is inserted. Then, the inside of the vacuum container 24 is made into a vacuum state of 10 ⁻⁸ Torr or less by the vacuuming device 25, and unnecessary gas such as the substrate material in the vacuum container 24 is discharged. After performing sufficient gas discharge, the heater 19 for heating the substrate
Then, the target heating heater 17 is energized to heat the evaporation source and the substrate to about 500 ° C. and 250 ° C., respectively. Further, each heater is controlled by each sensor.

After the predetermined conditions are reached, the mask 21 is brought into close contact with the flexible film-like insulating substrate 11 and the shutter 22 is opened. The evaporated thermoelectric conversion material forms a semiconductor on the film-shaped insulating substrate 11 through the mask 21. The thin film thickness formed by the film thickness meter 23 is measured, and when the desired film thickness (about 40 Å) is reached, the shutter 22
Closed and the mask 21 is lowered. Then, the first winding roller 12 is rotated to align the next vapor deposition surface with the mask 21,
The above operation is repeated to form a thin film thermoelectric conversion semiconductor on the flexible film-like insulating substrate. By continuously performing this step, cylindrical P-type and N-type thin film thermoelectric conversion semiconductor roll chips can be produced.

FIG. 4 shows a thermoelectric conversion module using the semiconductor element of the first embodiment. In the figure, 26 is a P-type thin film thermoelectric conversion semiconductor roll chip, 27 is an N-type thin film thermoelectric conversion semiconductor roll chip, and 28 and 29 are ceramic substrates.

This module is manufactured by arranging the thin film thermoelectric conversion semiconductor roll chip 26 with a solder paste or the like on a substrate on which an electrode pattern of ceramic or the like is patterned, as in the case of a module using a conventional bulk thermoelectric conversion element. Two
7 is brought into contact with the electrode by heat treatment. By this step, a thermoelectric conversion module is formed using thin-film thermoelectric conversion semiconductor roll chips 26, 27 having the same shape as a conventional thermoelectric conversion module using a bulk thermoelectric conversion element and utilizing the characteristics of an ultrathin film. You can

Although an example of an apparatus such as MBE is shown here, an ultra-thin film can be formed by using a conventional vacuum vapor deposition machine or the like. It is said that it is difficult to form an ultra-thin film on a conventional vacuum vapor deposition machine due to an island phenomenon or the like, but this problem can be solved by the method described below. That is, the mask shape (the portion on which the semiconductor material is deposited) is reduced, the first winding roller 12 is continuously operated, and the thermoelectric conversion material is continuously deposited on the flexible film-shaped insulating substrate 11, so that the flexible film is uniformly formed. An ultrathin film can be formed on the insulating substrate 11.

(Second Embodiment) FIG. 5 shows a second embodiment of a semiconductor roll chip which is a semiconductor element according to the present invention. (A) of the figure is a partial cross-sectional perspective view of the semiconductor roll chip, and (B) is an enlarged view of the cross-sectional part b. The semiconductor roll chip 31 is a triangular prism-shaped thermoelectric conversion element, and like the first embodiment, a flexible film-like insulating substrate 32 such as polyimide or Teflon.
And a semiconductor 32 for thermoelectric conversion formed on the entire surface of one side thereof
And has a structure in which the semiconductor 32 is laminated by winding the film-like insulating substrate 32. Although not shown, the end of the semiconductor roll chip 31 is fixed with a heat-resistant adhesive tape such as polyimide or Teflon to prevent the roll from unraveling. Electrodes for connection are formed by paste solder 34 on both end faces of the triangular shape.

FIG. 6 is a block diagram showing a semiconductor device manufacturing apparatus according to the second embodiment. This manufacturing apparatus is the same as that of FIG. 3 except for the shapes of the first and second take-up rollers 12 and 13 and the installation of the electrode paste preparation apparatus 35, and therefore only the differences will be described. .

First and second take-up rollers 12, 13
The shape of the thin film thermoelectric conversion semiconductor roll chip after completion is made into a triangular prism by using a triangular shape as shown in FIG. Further, the electrode paste preparation device 35 is for applying paste solder, and the flexible film-shaped insulating substrate 11 can be formed by a solder application roller or the like.
Apply solder to both ends (about 1-2 mm). afterwards,
By performing the steps described in the first embodiment, triangular columnar P-type and N-type thin film thermoelectric conversion semiconductor roll chips can be produced.

In the above operation, the gas generated from solder or the like in the vacuum device 24 during the preparation of the electrode paste may affect the production of the thin film thermoelectric conversion semiconductor roll chip. In such a case, while forming either the electrode paste or the thin film thermoelectric conversion semiconductor on the flexible film-shaped insulating substrate 11,
It is wound by either of the first and second winding rollers 12 and 13. After the film is formed to a predetermined length, the take-up rollers of the first and second take-up rollers 12 and 13 different from those described above are rotated in the opposite direction, and the remaining paste of the electrode paste or the thin film thermoelectric conversion semiconductor is removed. By depositing one of them, a thin film thermoelectric conversion semiconductor roll chip with a thin film electrode can be prepared. The subsequent fabrication of the thin film thermoelectric conversion module is as described above. Further, the electrode production is not limited to the above-mentioned means, and may be performed by an ordinary vapor deposition machine or the like.

By continuously performing this step, triangular prism P-type and N-type thin film thermoelectric conversion semiconductor roll chips can be produced. FIG. 7 shows an embodiment of a thermoelectric conversion module showing the structure of the present invention. In FIG. 7, 36 is a P-type thin film thermoelectric conversion semiconductor roll chip, 37 is an N-type thin film thermoelectric conversion semiconductor roll chip, and 38 and 39 are ceramic substrates.

As can be seen from FIG. 7, the thin film thermoelectric conversion module formed by the pair of triangular prism type P-type and N-type thin film thermoelectric conversion semiconductor roll chips 36 and 37 can form a triangular type, and can be formed in a conventional square column type. The thermoelectric conversion semiconductor roll chips can be arranged more efficiently, and a large number of thermoelectric conversion semiconductor roll chips of other shapes can be arranged in a high density in the same triangular module, which can be improved in capability.

As described above, by using a roll having the same shape as the semiconductor roll chip having a desired shape, this semiconductor roll chip can be easily manufactured, and a large number of the semiconductor roll chips can be arranged in high density in accordance with the shape of the thin film thermoelectric conversion module. The most optimal shape that can be improved and can be improved can be selected.
Particularly, semiconductor roll chips of triangular prism type, quadrangular column type, hexagonal column type and the like have good meshing when arranged, and can be efficiently arranged with high density, and a compact thin film thermoelectric conversion module can be formed.

In the above-mentioned embodiments, the semiconductor element for thermoelectric conversion has been described in detail, but the present invention is not limited to the semiconductor element for thermoelectric conversion and can be applied to a semiconductor element having a laminated structure used for a power device. . In the case of a semiconductor device whose performance can be improved by the laminated structure of thin films, the structure in which the film-like substrates are laminated by rolling has an effect that it can be easily manufactured and mechanical strength is not deteriorated. Useful for.

[0035]

According to the present invention, a semiconductor is formed on one surface of a flexible film-like insulating substrate, and the film-like insulating substrate is wound to laminate the semiconductors, whereby a laminated structure can be easily formed and mechanical strength is also increased. It is not inferior to the one without a laminated structure. Moreover, since the film-shaped substrate is used, the shape of the semiconductor element can be easily set, and when assembling a module in which a large number of semiconductor elements are arranged,
A semiconductor element having an optimum shape can be used according to the module shape. If the semiconductor is a superlattice structure having an ultrathin film and having a thermoelectric conversion function, a laminated structure can significantly improve the heat conversion performance based on the principle of performance index improvement by the superlattice.

According to another invention, a flexible film-like insulating substrate is run to form a semiconductor on one surface of the film-like insulating substrate, and then the film-like insulating substrate is wound with a roll to laminate semiconductors. A semiconductor element having a desired shape can be manufactured very easily and efficiently because a semiconductor element having a desired shape and a roll having the same shape are used.

[Brief description of the drawings]

FIG. 1 is a relationship diagram between a film thickness of a unit lattice layer and a calculation result of a dimensionless figure of merit.

FIG. 2A is a configuration diagram showing a first embodiment of a semiconductor roll chip which is a semiconductor element according to the present invention,
(B) is an enlarged view of the arrow a in (A).

FIG. 3 is a configuration diagram showing a semiconductor roll chip manufacturing apparatus of the first embodiment.

FIG. 4 is a configuration diagram showing a thin-film thermoelectric conversion module using the semiconductor roll chip of the first embodiment.

FIG. 5A is a configuration diagram showing a second embodiment of a semiconductor roll chip which is a semiconductor element according to the present invention,
(B) is an enlarged view of the arrow b in (A).

FIG. 6 is a configuration diagram showing an apparatus for manufacturing a semiconductor roll chip according to a second embodiment.

FIG. 7 is a configuration diagram showing a thin film thermoelectric conversion module using the semiconductor roll chip of the second embodiment.

FIG. 8 is a configuration diagram of a thermoelectric conversion module using a conventional bulk material.

9A to 9C are configuration diagrams of a conventional thin film thermoelectric conversion module.

10 (A) and 10 (B) are graphs showing the relationship between the temperature and the figure of merit of various typical thermoelectric conversion materials.

[Explanation of symbols] 1 semiconductor roll chip 2 film-like insulating substrate 3 semiconductor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuaki Minato 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Shigeo Harada 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka (72) Inventor Yoshihiro Yamamoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) In-house, Takashi Tomita 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture

Claims (3)

[Claims] 1. A flexible film-like insulating substrate,
A semiconductor device comprising a semiconductor formed on one surface of the film-like insulating substrate, and a structure in which the film-like insulating substrate is wound to stack the semiconductors. 2. The semiconductor element according to claim 1, wherein the semiconductor has a superlattice structure of an ultrathin film made of a semiconductor material for thermoelectric conversion. 3. A semiconductor device is manufactured by forming a semiconductor on one surface of a flexible film-like insulating substrate, and then winding the film-like insulating substrate with a roll to laminate the semiconductors to produce a semiconductor device, in which case a semiconductor device having a desired shape. A method of manufacturing a semiconductor device, which uses a roll having the same shape as that of 1.