JPH01166555A - Semiconductor element - Google Patents

Abstract

PURPOSE:To improve thermal stability, durability and workability by alternately laminating a thin organic polymer film and a thin inorganic film on a substrate to construct a periodic laminated structure, and forming the laminated structure in a superlattice structure of the repetition of a heterojunction. CONSTITUTION:A metal (base electrode) 9, a monolayer lamination 10, metal 11, a monolayer lamination 12 and metal (upper electrode) 13 are laminated on a substrate 2 to construct a periodic laminated structure, thin organic polymer films having insulation and thin inorganic films having conductivity or semiconductivity which are alternately laminated have a heterojunction, and the laminated structure has a superlattice structure of the repetition of the heterojunction. With this structure, mechanical strength, solvent resistance and heat resistance are improved, a preferable heterojunction is easily obtained, and the heterojunction is repeated thereby to construct an artificial periodic structure and a superlattice structure having high degree of freedom of materials.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to organic semiconductor devices.

More specifically, the present invention relates to a semiconductor element composed of an organic polymer and an inorganic composite material, and particularly to a semiconductor element having a superlattice structure in which a potential barrier formed by an organic polymer material repeats two or more times in the main current direction.

[Background field]

In recent years, in the fields of semiconductor technology and optical technology, with the high precision and fineness of processing, especially film formation technology, it has become possible to create semiconductor heterojunction interfaces that are of extremely high quality both electrically and optically. Ta. A structure in which different semiconductors are stacked in layers using this method to create a long-period structure is called a semiconductor heterostructure superlattice, and its physical properties (high mobility, negative resistance, etc.) resulting from its electronic structure have attracted attention. Many research institutes are attempting to put it to practical use in semiconductor devices.

[Problem that the invention seeks to solve]

Conventionally, the above studies have been conducted using GaA, which is relatively easy to handle.
Progress has been limited to inorganic materials such as S and Si. In addition, most of the thin films are formed using molecular beam epitaxy, which means that the manufacturing process is complex and requires processing under extreme conditions such as ultra-high vacuum and high temperatures, and the manufacturing equipment itself is large-scale. It becomes. Furthermore, since it is an inorganic material, there is also the problem that there is a low degree of freedom in material selection.

On the other hand, organic materials, on the other hand, are inexpensive, easy to manufacture, and highly functional, and semiconductor devices using organic materials such as fatty acid 9 dyes have recently been actively developed.

However, at present, when semiconductor elements are formed using low-molecular organic compounds such as fatty acid 1 dyes, there are problems such as insufficient thermal stability, durability, and processability.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel semiconductor device that solves the above-mentioned problems.

[Means and effects for solving the problems] The present inventors have solved the conventional problems as described above (as a result of intensive research, a heterojunction obtained by laminating organic polymeric materials and inorganic materials) has been proposed. and the heterostructure superlattice improves the thermal stability of semiconductor devices,
durability.

It has been found that it is extremely promising for improving processability and as a component of semiconductor devices. The present invention generally has high insulating properties (
By alternately laminating organic polymer thin films exhibiting conductivity (or semi-insulating) and inorganic thin films exhibiting conductivity (or semi-conductivity),
We focused on the fact that it is possible to easily realize a periodic structure of electric potential in which the potential barrier is 2 and the recovery ball is repeated preferably 2 to 20 times, especially 2 to 10 times, and in particular, the repetition width (organic high We expect that nonlinear current-voltage characteristics, etc., similar to conventionally known superlattice semiconductor devices formed only from inorganic materials will be exhibited when the thickness of the molecular thin film or the thickness of the inorganic thin film is extremely small. This is an attempt to achieve this goal. Furthermore, a new semiconductor element having an amplification function and the like has been realized using such characteristics. still,
In the present invention, the above-mentioned "extremely small" refers to the range of several angstroms to several 1 angstroms.
00 people, more preferably 10 Å to 1
This refers to the range of 00 people.

In the present invention, applicable materials are extremely wide-ranging, including inorganic thin films and organic polymer thin films. Since most of the currently known organic polymer materials exhibit insulating or semi-insulating properties, they satisfy the requirements for materials forming potential barriers in the present invention. on the other hand,
There are countless inorganic materials that have higher conductivity than organic materials. Au, Ag, Af, Ni
, Pt and other metals and alloys, graphite and Si
(Single crystal, polysilicon.

amorphous) and silicide.

palladium silicide), GaAs, GaP, CdS.

There are many materials including semiconductors such as CdBe, and their application to the present invention can be considered.

In particular, in the present invention, semiconductor materials containing elements selected from Group B of the long periodic table (C, Si, Ge), elements selected from Group IIB (Ga), and elements selected from Group VB (A
S, P) or an element selected from Group IIB (Cd) and an element selected from Group VIB (S.

Semiconductor materials containing Be) can be used.

The band gap formed at the heterojunction interface between the organic thin film and the inorganic thin film used in the present invention is usually 0.1 eV to several eV.
It is V.

As a method for forming an element using such a material, the object of the present invention can be sufficiently achieved by conventionally known thin film technology. especially,
In the present invention, since the element contains an organic polymer material, it is preferable to employ a method that can form a film under conditions of 300° C. or lower. For example, a vacuum evaporation method and a sputtering method can be cited as suitable inorganic thin film layer forming methods for use in the present invention. On the other hand, regarding the formation of organic thin film layers, it is possible to specifically apply methods such as vapor deposition and electrolytic polymerization, but the Langmuir-Prodgett method (LB method) proposed by Langmuir et al. is extremely suitable.

According to this LB method, a monomolecular film of an organic compound having a hydrophobic site and a hydrophilic site in one molecule or a cumulative film thereof can be easily formed on a substrate, and has a thickness on the order of a molecule. , and can stably supply a uniform and homogeneous ultra-thin organic film over a large area.

The LB method is a molecule with a structure that has a hydrophilic site and a hydrophobic site, and when the balance between the two (amphiphilic balance) is maintained appropriately, the molecule has a hydrophilic group on the water surface. This is a method of creating a monomolecular film or a cumulative film thereof by utilizing the fact that the monomolecular layer forms downward.

Groups constituting the hydrophobic moiety generally include various hydrophobic groups such as widely known saturated and unsaturated hydrocarbon groups and condensed polycyclic hydrocarbon groups. It constitutes a hydrophobic part.On the other hand, the most typical constituent elements of the hydrophilic part include hydrophilic groups such as carboxyl groups, sulfonic acid groups, and quaternary amino groups.

Molecules with a good balance of these hydrophobic groups and hydrophilic groups can form a monolayer on the water surface. Since a monomolecular cumulative film also exhibits insulating properties, it can be said to be an extremely suitable material for the present invention.

Examples include the following molecules.

(1) Addition polymer 1) Polyacrylic acid V plate 2) Polyacrylic acid ester R.

3) Acrylic acid copolymer Boku! 4) Acrylic ester copolymer 5) Polyvinyl acetate Ze1 OCOCR.

6) Vinyl acetate copolymer Vl [u] Condensation polymer 3) Polycarbonate (III) Ring-opening polymer l) Polyethylene oxide -1-0-CH-CH2-)- Here, R1 is a group having the above-mentioned σ electron level It is a long-chain alkyl group introduced to facilitate the formation of a monomolecular film on the water surface, and its carbon number n is 5≦n≦
30 is preferred.

Further, R2 is a short-chain alkyl group, and the number of carbon atoms n is l≦n<
It is 4. The degree of polymerization m is preferably too<m<5000.

The compounds mentioned above as specific examples are only basic structures,
Needless to say, various substituted forms of these polymers are also suitable in the present invention.

It goes without saying that any polymer material other than those mentioned above is suitable for the present invention as long as it is suitable for the LB method.

For example, biological materials (such as bacteriorhodopsin and cytochrome C) and synthetic polypeptides (such as PBLG), which have been actively researched in recent years, can also be applied. Such amphiphilic molecules form a monomolecular layer on the water surface with the hydrophilic groups facing downward. At this time, the monomolecular layer on the water surface has the characteristics of a two-dimensional system, and when the molecules are sparsely dispersed, the two-dimensional ideal gas equation is expressed between the area A per molecule and the surface pressure π.
π A=kT holds true, resulting in a "gas film". Here, k is Portzmann's constant and T is absolute temperature. If A is made sufficiently small, the intermolecular interaction becomes stronger, resulting in a two-dimensional solid "condensation film (or solid film)." The condensed film can be transferred layer by layer onto the surface of arbitrary objects having various materials and shapes, such as glass and resin. Using this method, a monomolecular film or a cumulative film thereof can be formed and used as a potential barrier layer for a semiconductor device according to the present invention.

As a specific manufacturing method, for example, the method shown below can be mentioned.

The desired organic compound is dissolved in a solvent such as chloroform, benzene, acetonitrile, dimethylacetamide, or the like.

Then, using a suitable device as shown in Figure 3 of the accompanying drawings,
The solution is developed on an aqueous phase 1 to form a developed layer 1 of an organic compound.
1 is formed into a film.

Next, a partition plate (or float) 3 is provided to prevent this spread layer 11 from freely diffusing and spreading too much on the aqueous phase l, and the area of the spread layer 11 is restricted to control the aggregation state of the film substance. Obtain the surface pressure π proportional to the collective state. By moving the partition plate 3, the area of the spread layer 11 is reduced to control the state of aggregation of the film material, gradually increasing the surface pressure, and setting the surface pressure π suitable for film production. While maintaining this surface pressure, the monomolecular film 4 of the organic compound is transferred onto the substrate 2 by gently raising or lowering the clean substrate 2 vertically. Such a monomolecular film 4 is a film in which molecules are arranged in an orderly manner as schematically shown in FIG. 4(a) or FIG. 4(b).

The monomolecular film 4 is manufactured as described above, and by repeating the above operations, a desired cumulative number of films can be formed. In addition to the above-mentioned vertical dipping method, methods such as a horizontal deposition method and a rotating cylinder method can also be used to transfer the monomolecular film onto a substrate.

The horizontal deposition method is a method in which the monomolecular film 4 is transferred by bringing the substrate 2 into horizontal contact with the water surface, and the rotating cylinder method is a method in which the cylindrical substrate 2 is rotated on the water surface to transfer the monomolecular film 4 onto the substrate 2. This is a method of transferring it to the surface.

In the above-mentioned vertical immersion method, when the substrate 2 having a hydrophilic surface is lifted out of water in a direction across the water surface, a monomolecular film 4 of an organic compound is formed with the hydrophilic groups of the organic compound facing toward the substrate 2.
is formed on the substrate 2 (FIG. 4-b). When the substrate 2 is moved up and down as described above, the monomolecular films 4 are stacked one by one in each step, forming a cumulative film 5. Since the direction of the film-forming molecules is reversed between the pulling process and the dipping process, this method forms a Y-side film in which the hydrophobic groups of the organic compound face each other between each layer of the monomolecular film 4 (the fifth Figure-a-)
.

On the other hand, in the horizontal deposition method, a monomolecular film 4 with the hydrophobic groups of the organic compound facing the substrate 2 is formed on the substrate 2 (FIG. 4-a). In this method, even if the monomolecular film 4 is accumulated, there is no change in the direction of the film-forming molecules, and an X-shaped film is formed in which the hydrophobic groups face the substrate 2 in all layers (No. 5
Figure-b-). On the contrary, in all layers the hydrophilic groups are connected to the substrate 2.
The cumulative film 5 facing the side is called a Z-type film (Fig. 5-c)
-).

The method of transferring the monomolecular film 4 onto the substrate 2 is not limited to the above method (when a large-area substrate is used, a method of extruding the substrate 2 from a roll into an aqueous phase may also be adopted). In addition, the substrate 2 of the hydrophilic group and hydrophobic group described above
As a general rule, the direction toward the substrate 2 can be changed by surface treatment of the substrate 2, etc. 1. As described above, the potential barrier layer consisting of the monomolecular film 4 of the organic compound or the cumulative film 5 of the organic compound is directed to the substrate. It is formed.

In the present invention, the substrate 2 for supporting the thin film laminated with the above-mentioned inorganic and organic materials is metal.

Glass, ceramics, plastic materials, etc.:
Furthermore, biomaterials with extremely low heat resistance “1” may be used.
can also be used.

The substrate 2 as described above may have any shape, preferably a flat plate, but is not limited to a flat plate at all.

That is, the above-mentioned film forming method has the advantage that the film can be shaped according to the shape of the surface of the substrate 2, regardless of the shape.

[Example 1] A 9-layer monomolecular cumulative film 1 of metal (base electrode) was prepared by the following procedure.
0/Metal 11/Single molecule cumulative film 12/Metal (upper electrode) 1
A sample (Fig. 1) having the structure No. 3 was prepared. At this time, the number of layers of the monomolecular cumulative films 10 and 12 on both sides sandwiching the intermediate metal layer 11 was made equal (in the figure, 41 and 42 represent extraction electrodes). First, hexamethyldisilazane (HMD
Cr was deposited to a thickness of 500 mm as an undercoat layer by vacuum evaporation method on a glass substrate (#7059 manufactured by Corning Inc.) which had been hydrophobically treated by leaving it in saturated steam of S2 for one day and night, and then Au was deposited by the same method ( Film thickness: 1000), width: 1mm
A striped base electrode was formed. A polyimide cumulative film 10 was formed by the LB method using such a substrate as a carrier.

Next, details of the cumulative film production method will be described.

Polyamic acid (molecular weight approximately 200,000) at a concentration of I x 10
-''% (vol/vol) dimethylacetamide solution was spread on an aqueous phase of pure water at a water temperature of 20°C to form a monomolecular film on the water surface.The surface pressure of this monomolecular film was set to 25%.
mN/m, and while keeping this constant, the substrate was immersed and pulled up at 5 mm/min in the direction across the water surface to accumulate a Y-type monomolecular film. By repeating such operations, 18.24.30°36,4
Five types of cumulative films with zero layers were formed. Furthermore, these films are
Polyimide was obtained by heating at 00°C for 10 minutes. Next, a dot-like pattern of Au (diameter l) was formed on the film surface.
The intermediate metal layer 11 was formed by vapor-depositing φ, film thickness: 80 mm).

Next, a polyimide cumulative film was formed as above (18, 24, 30, 36°, 40 layers (cumulative film 12) in the same manner), and then Au (diameter 2φ, film thickness 100) was used as the upper electrode 13.
0 people) were deposited.

The sample prepared as described above was placed in a cryostat (vacuum container), and current characteristics (1 characteristic) were measured when a voltage was applied between the upper and lower electrodes at low temperature (77°K).

As a result, the V of monomolecular cumulative film, 18-layer and 24-layer samples
In the I characteristic, in addition to waiting for the maximum around 1 to 2 volts,
A convex characteristic curve was observed, confirming that the sample exhibited negative resistance. FIG. 2 clarifies the V■ characteristics when a sample with four monomolecular cumulative layers is used.

[Examples 2 to 6] Samples having the same structure as in Example 1 were prepared. At this time, molecules 1 or 2 shown below were used as constituent molecules of the monomolecular cumulative film (potential barrier layer). The formation of a monolayer and its cumulative conditions and processes are such that the surface pressure is 15 mN/m.
The procedure was exactly the same as in Example 1 except that the cumulative speed was 3 mm/min. However, each layer 10 sandwiched between the metal layers was a cumulative film of 4 layers and 8 layers, respectively.

↓ Polyisobutyl methacrylate (molecular weight approx. 500,000) H3 Tobi\ H3 2 Poly-α-n-hexadecyl acrylic acid (molecular weight approx. 3
00,000) O2H Further, the base electrode 9 and the upper electrode 13 were also formed in the same manner as in Example 1.

The intermediate metal layer 11 sandwiched between the monomolecular cumulative films has A7! for each sample. , Au, Ni and Pt were used.

However, the thickness of each film was 50, and the method shown in the table below was used for forming the film. All such formation methods are conventionally known,
Since this technology is already established, a detailed explanation of its procedures will be omitted.

However, conditions to be kept in mind in the present invention are shown below.

B. AA (sputtering method); Example 5 Specifically, a magnetron sputtering method was used to reduce damage to the film.

Ar positive bioions were used, the gas pressure was 2×10 −3 Torr, the target voltage was 250 V, and the target current was adjusted so that the film formation rate was 2 persons/sec.

Pt (electron beam method); Example 6 When heating the target (Pt20φ10t), splashes (flying in the form of particles) are more likely to occur than with other metals, so the electron beam output was reduced and the film formation rate was reduced to 0. It was necessary to lower the number to .05 people/S.

Regarding the samples prepared as described above, the Vl characteristics were measured in the same manner as in Example 1, and the results shown in the table below were obtained.

2 I AI! Resistance heating (vapor deposition) method 03 2 N i /
IQ4 // A 7! ,,
05 ” Aj7 Sputtering method 06 〃 Pt Electron beam heating (evaporation) method △As indicated by O in the table, negative resistance was observed for most of the samples. The reason why the voltage is about several volts in the samples is considered to be because the structural parameters such as the film thickness of each layer are almost the same even in different samples.However, in Example 6, the 12 samples made under the same conditions Corrosion resistance was observed in only two samples, and no significant negative resistance was observed (indicated by △ in the table).

This is considered to be due to the fact that it was difficult to obtain a uniform thin film of approximately 50 layers for Pt.

[Example 7] One of the samples prepared in Example 4 was selected, and an electric circuit shown in FIG. 6 was constructed. In FIG. 6, 61 is a sample forming a two-terminal element, 62 is a DC bias voltage source Vo, and 63 is a sample forming a two-terminal element.
is the input signal source V,. In detail, a low frequency oscillator was used. Further, 64 is a load resistor, which is a metal film type resistor of 300Ω. Note that the potential generated in the load resistance was observed with an oscilloscope (input resistance IMΩ) connected to both ends thereof.

First, the output of the input signal source vIn14 was set to zero, and the DC bias voltage source VB13 was set to a voltage at which the sample 61 exhibited negative resistance, specifically, 2.2V. After Sun Tzu, the input signal source V In 63 has a peak value of 50 mV.

When a sine wave with a frequency of IKHz was applied, the resistor 64
The same (1 KHz) sine wave with a peak value of about 85 mV was obtained at both ends of the sample 61. In other words, it was shown that the sample 61 functions as an amplification element.

Incidentally, as long as the frequency was changed up to I MHz, the amplification factor hardly changed.

[Example 8] A sample having exactly the same configuration as in Example 4 was prepared.

However, at this time, an external lead electrode was provided on the intermediate metal layer 11 sandwiched between the monomolecular stacked films. Specifically, the device configuration shown in FIG. 7 was made. This could be formed by the same method as in Example 4, except that the mask pattern during metal vapor deposition was replaced.

Next, in the sample, probes were set up in areas 7 and 72.73 to make contact with the upper electrode 13, intermediate electrode 11, and lower electrode 9, respectively. At this time, in particular in region 72, contact was made by pushing the probe strongly (needle force > 50 mg) so as to break through the monomolecular cumulative film layer. Further, the probe includes an ammeter 81 and a bias voltage VB.
The electric circuit shown in FIG. 8 was assembled by connecting the direct current power supply 62 for signal source V in and the direct current 6β for signal source Vin. Next, while keeping the output of the DC power source 63 for signal source V in at Ov, the output of the DC power source 62 for bias voltage VB was set so that the maximum current flows.

At this time, VB was approximately 4=-4.

When the current flowing through the circuit was measured when V In was varied by 250 mV under the conditions obtained as follows, the results shown in FIG. 9 were obtained. This result shows that the three-terminal element functions as a voltage-controlled current amplification element. Of course, the amount of current varies greatly depending on the applied voltage, indicating that it can also be applied as a switching element.

[Example 9] In the region sandwiched between the upper and lower electrodes of Example 8, a potential barrier layer (a monomolecular cumulative film was used in Example 8)
A three-terminal element having a structure in which the process is repeated two or more times, specifically, four times in this example, was created. The first outline of the cross-sectional structure
This is shown in Figure 0 (c). Base metal layer 9, upper metal layer 13, and monomolecular cumulative films 10a, 10b.

10c, 12, and intermediate metal layers 11a, llb, and llc were formed under the same conditions as in Example 8. However, after repeating the formation of the monomolecular cumulative film layer/metal layer three times, the uppermost monomolecular cumulative film layer was formed. In addition, in order to ensure contact with the intermediate metal layer, a part of the laminated film including the monomolecular cumulative film is peeled off (peeled part 101) L, and lead-out electrode metals 100a and 1o00b are injected into the same area. I took a method. The situation and procedure are shown in Figure 10a.

Shown in b and c. Specifically, M having a desired shape.

A manufactured mask (t = 0.1) was placed in close contact with the sample, and this was placed in a vacuum chamber of a high-frequency ion brating device that has both a gas inlet and an electron beam evaporation source. Introduced high frequency power (13,
The resulting Ar'' ion beam 102 was accelerated at 100 eV and irradiated from above the sample for 10 minutes to etch the area not covered by the mask.The substrate temperature was set at room temperature. Furthermore, without taking out the sample from the vacuum container, the inside of the container was kept in vacuum again (2 x 10-'Torr), and this time an emission current of 600 mA was applied using an electron beam evaporation source.

AI under the condition of acceleration voltage 10KV! evaporated (thickness: 500
person). After this, the upper electrode was formed.

Regarding the device obtained as described above, the current-voltage characteristics at a constant bias J were observed in exactly the same manner as in Example 8.
It was confirmed that it has an amplification function.

In the examples described above, the LB method was used to form the potential barrier layer, but the LB method is not limited to any film formation method that can create an extremely thin (uniform insulating or semiconductive organic thin film). Specific examples of methods that can be used include vacuum evaporation, electrolytic polymerization, and CVD, expanding the range of usable organic materials.

In addition, as already mentioned for the conductive layer surrounded by potential barriers, any film formation method that can create a uniform thin film on the organic thin film layer can be used, and is limited to vacuum evaporation and sputtering. It's not a thing.

Further, the present invention does not limit the material of the substrate or the shape of 3 in any way.

〔Effect of the invention〕

■ Because it uses polymer as an organic material, it has excellent mechanical strength, solvent resistance, and heat resistance.

(2) By alternately laminating inorganic materials and organic polymer materials, a good heterojunction with extremely rapid compositional changes was easily obtained.

■ Artificial periodic structures and superlattice structures could be constructed by repeating such heterojunctions. At this time, it was shown that the material has a higher degree of freedom than conventional superlattice elements made only of inorganic materials.

■ Since the organic polymer material layer is formed by accumulating monomolecular films, film thickness control on the order of molecules (several angstroms to tens of angstroms) can be easily achieved.

Since it has excellent controllability, it has high reproducibility when forming elements and is highly productive.

(2) As a result, desired nonlinear current-voltage characteristics (negative resistance) were observed in the device having a superlattice structure.

(2) We proposed new two-terminal and three-terminal devices having heterojunctions of inorganic and organic polymeric materials, and furthermore showed that such devices can provide good amplification and switching characteristics.

■ Since such devices do not require processing under extreme conditions such as high temperatures compared to conventional superlattice devices made only of inorganic materials, devices with high affinity with living organisms such as molecular electronics and bioelectronics will be provided in the future. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a semiconductor device of the present invention, and FIG. 2 is a characteristic diagram showing its VI characteristics. FIG. 3 is a diagram schematically showing a method of forming the potential barrier layer of the present invention by the LB method. FIGS. 4(a) and (b) are schematic diagrams of a monomolecular film, and FIGS. 5(a), (b), and (c) are schematic diagrams of a cumulative film. FIG. 6 is an electrical circuit diagram of a measuring instrument used when measuring the Vl characteristics of the present invention. FIG. 7(a) is a plan view of another semiconductor device of the present invention, FIG. 7(b) is a cross-sectional view taken along line A-A', and FIG. 8 is a plan view of another semiconductor device of the present invention. FIG. 9 is a characteristic diagram showing the Vl characteristics at that time. FIGS. 1O (a), (b) and (c) are cross-sectional views showing a process for producing another semiconductor device of the present invention. Application ε pressure activation 3 Figure 5 Between (cL) (bn (Q) Figure 8 vryt, anti-Vin

Claims (21)

[Claims] (1) A semiconductor device comprising a substrate and a periodic laminated structure in which organic polymer thin films and inorganic thin films are alternately laminated. (2) The semiconductor device according to claim 1, wherein the organic polymer thin film and the inorganic thin film have a heterojunction, and the periodic stacked structure forms a superlattice structure by repeating the heterojunctions. . (3) The semiconductor device according to claim 1 or 2, wherein the organic polymer thin film has insulating properties, and the inorganic thin film has conductivity or semiconductivity. (4) The semiconductor device according to claim 1, wherein the periodic laminated structure is arranged between a pair of electrodes. (5) The semiconductor device according to claim 1, wherein the inorganic thin film is a thin film formed by a vapor deposition method or a sputtering method. (6) The semiconductor device according to claim 5, wherein the vapor deposition method is a vapor deposition method using an electron beam heating method. (7) The semiconductor device according to claim 1, wherein the organic polymer thin film is an organic polymer thin film having a hydrophilic site and a hydrophobic site within the molecule. (8) The semiconductor device according to claim 1, wherein the number of heterojunction interfaces is 2 to 20. (9) The semiconductor device according to claim 1, wherein the number of heterojunction interfaces is 2 to 10. (10) The semiconductor device according to claim 1, wherein the organic polymer thin film has a thickness of several angstroms to several hundred angstroms. (11) The semiconductor device according to claim 1, wherein the organic thin film has a thickness of 10 Å to 100 Å. (12) The semiconductor device according to claim 1, wherein the inorganic thin film has a thickness of several angstroms to several hundred angstroms. (13) The semiconductor device according to claim 1, wherein the inorganic thin film has a thickness of 10 Å to 100 Å. (14) The semiconductor device according to claim 1, wherein the inorganic thin film is a thin film formed of a metal or an alloy. (15) The semiconductor device according to claim 14, wherein the metal or alloy is Al, Ag, Au, Ni, or Pt. (16) The inorganic thin film is a substance containing an element selected from Group IVB of the long periodic table, a substance containing an element selected from Group IIIB, an element selected from Group VB, or a substance selected from Group IIB. The semiconductor device according to claim 1, which is a thin film formed of a substance containing an element and an element selected from Group VIB. (17) The semiconductor device according to claim 16, wherein the element selected from Group IVB is C or Si. (18) The semiconductor device according to claim 16, wherein the element selected from Group IIIB is Ga, and the element selected from Group VB is As or P. (19) The element selected from Group IIB is Cd, and the V
17. The semiconductor device according to claim 16, wherein the element selected from Group IB is S or Be. (20) The semiconductor device according to claim 1, wherein the inorganic thin film is a thin film formed of silicide. (21) The semiconductor device according to claim 20, wherein the silicide is nickel silicide or palladium silicide.