JP3198453B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same. More specifically, the present invention relates to a semiconductor device using a metal oxide and a method for manufacturing the same.

[0002]

2. Description of the Related Art In the case of pure metal oxide, 3 to 4 eV
And has a large band gap, and thus exhibits properties as an insulator. However, when an oxygen vacancy exists, a donor level is generated, and the semiconductor shows n-type semiconductor conductivity. Since a metal oxide has a large band gap as described above, it can be expected to be used as a diode having high withstand voltage characteristics if an appropriate carrier for flowing a current is generated by an oxygen defect.

As a semiconductor device using a metal oxide as a channel, the 11th ferroelectric application conference lecture proceedings, p.
27-p28 (Reference 1). That is, in this document 1, magnesium oxide (MgO)
In a thin film transistor using strontium titanate (SrTiO ₃ ) as a channel formed thereon by a laser ablation method, niobium (Nb) is used as an ohmic metal, and argon (Ar) ions are implanted into an ohmic formation region to remove oxygen defects. Making a forming career. The characteristics of the obtained semiconductor device are such that a current of 100 nA is obtained for a gate width of 20 μm.

Further, among semiconductor devices using metal oxides, utilization as semiconductor devices using the insulating properties and high dielectric constant properties of metal oxides is described in, for example, Nikkei Microdevices, p111-p116, January 1992. Monthly issue (Reference 2)
And Japanese Patent Application Laid-Open No. 5-267565 (Document 3). That is, in Reference 2, Ba _0.5 Sr _0.5 TiO ₃ formed by magnetron sputtering on a Si substrate is used, and Pt / Ta, which is less deteriorated by the heat process, is used for the lower electrode that receives the high-temperature heat process of the metal oxide. A capacitor for DRAM using TiN for the upper electrode is described. On the other hand, Literature 3 describes a capacitor using Ba _0.7 Sr _0.3 TiO ₃ formed by a sol-gel method for a dielectric, using Pt / Ti for the lower electrode and Pt for the upper electrode.

[0005] Further, Document 2 reports that when heat treatment is performed at 500 ° C. or higher, a reaction occurs in the Pt / Ti electrode, resulting in a decrease in reliability.

[0006]

In Document 1, which uses a metal oxide as a thin film transistor as a channel, an n ⁺ layer is formed by implanting Ar ions into a portion in contact with an electrode to form an oxygen defect. However, the channel SrTiO ₃ has sufficient oxygen vacancies,
That is, it is considered that no practical current flows because no carrier is formed.

The device of Document 1 has a horizontal structure in which metal electrodes are provided at both ends of a metal oxide film. The distance between the metal oxides in the direction in which current flows is long, and current does not easily flow. In fact, the current passing through the metal oxide film in this example is about 100 nA for a gate width of 20 μm, and a practical current (〜mA) as a device has not been obtained.

In the conventional example of a semiconductor device using a metal oxide as a high dielectric, that is, in References 2 and 3, when used as a capacitor, the high dielectric constant characteristics of the metal oxide are used. For example, the electric charge stored in the memory of the DRAM disappears, and the characteristics as a capacitor deteriorate. For this reason, as in Reference 2,
In order to promote perovskite-type crystallization, a method of promoting crystallization by sputtering at 650 ° C. or a high-temperature oxygen treatment at 700 ° C. or more as described in Reference 3 to reduce the leakage current of the metal oxide. I do.

However, high-temperature sputter deposition,
Since high-temperature baking in oxygen is necessary, the process temperature cannot be matched with a semiconductor element such as Si or GaAs that requires low-temperature processing. For this reason, as described in Reference 2, Pt / T
In the conventional process in which a is used as an electrode or an FET is first formed, the multilayer wiring of the IC can be used as the upper and lower electrodes of the capacitor. For this reason, it is necessary to form an electrode for a capacitor in a separate process. Such a significant change in the electrodes and processes causes an adverse effect on the electrode material (reduced reliability) and a significant increase in manufacturing cost.

As described above, in the conventional technology, when a metal oxide is used as a semiconductor material, sufficient oxygen vacancies are not easily formed in the metal oxide, and the characteristics of the semiconductor layer capable of controlling and passing a current are reduced. It is difficult to use such an ohmic contact electrode, and the formation of the ohmic contact electrode has a problem that the process becomes complicated, such as the purpose of implanting Ar ions to form an n ⁺ layer.

When a metal oxide is used as an insulator having a high dielectric constant, a high-temperature treatment is required.
When the electrodes are formed on a semiconductor substrate such as s, there is a problem that the electrodes and the manufacturing process need to be changed, resulting in a decrease in reliability and an increase in manufacturing cost. Accordingly, an object of the present invention is to provide a semiconductor device that operates as a diode and a capacitor, using a metal oxide that can supply a practical current (up to mA) by forming a sufficient oxygen defect.

[0012]

Means for Solving the Problems Thus, according to the present invention, on a semiconductor substrate, and the lower wiring of any shape made of a metal which forms a metal oxide film and a Schottky contact having an oxygen defect, the Before formed on the lower wiring
A serial metal oxide film, affinity for oxygen is formed larger than a metal of a metal contained in the metal oxide film, said metal
Bei a vertical structure with the upper layer wiring and formed on the oxide film on the
And the metal oxide film is coated on the lower wiring.
The precursor solution consisting of the metal alkoxide
Water content by baking performed in the range of 300 ° C to 500 ° C in air
It must be formed by the sol-gel method using the solution.
And a semiconductor device characterized by the following.

Further, according to the present invention, (1) a semiconductor substrate
Metal oxide film with oxygen vacancies and Schottky
Lower layer of any shape composed of metal forming contact
Forming a wiring; (2) (a) a metal alcohol forming the metal oxide film;
A process for applying a precursor solution consisting of oxide on the lower wiring
Degree, then (b), the resulting coating film, 300 ° C. in air 50
Solge using hydrolysis by calcination performed at 0 ° C
Forming the metal oxide film by a step of subjecting to a metallization method
And (3) gold contained in the metal oxide film having an affinity for oxygen.
For forming upper layer wiring composed of metal larger than
Semiconductor having a vertical structure characterized by comprising:
A method for manufacturing a device is provided. The semiconductor substrate that can be used in the present invention is not particularly limited, and silicon, GaAs
s and the like. Although a lower wiring is provided on the semiconductor substrate, an insulating film such as silicon nitride or silicon oxide may be formed before the lower wiring. By forming the insulating film over the semiconductor substrate, it is possible to improve the consistency of a manufacturing process with another semiconductor device formed over the substrate.
The thickness of the insulating film is 300 to 5000 °.

Next, the lower wiring that can be used in the present invention is as follows:
It is made of a metal that forms a Schottky contact with a metal constituting a metal oxide film described later. Examples of the metal that can be used for the lower layer wiring include platinum, titanium, and tungsten. Of these, platinum is preferable. The thickness of the lower wiring is 500 to 20,000 °, and
Preferably, it is 2,000 °. Here, if the angle is smaller than 500 °, the wiring becomes high in resistance, which is not preferable.
If it is larger than Å, the step at the electrode edge becomes too large, which is not preferable. Further, the lower layer wiring does not necessarily need to be formed of one layer, and may be formed of two or more layers. For example, in the case of a two-layer structure, a laminate of titanium / platinum, aluminum / platinum, or the like may be used. Among them, a laminate made of titanium / platinum is preferable in consideration of the adhesion between the semiconductor substrate and the metal oxide film.
白金, and the platinum layer is 500-2000Å. In addition,
It is preferable that a platinum layer is formed on the upper surface of the lower wiring in contact with the metal oxide film. This is because the platinum layer is hardly oxidized and has a certain degree of adhesion to the metal oxide film. The method for forming the lower wiring is not particularly limited, and examples thereof include a sputtering method and a vacuum evaporation method. The lower wiring may be formed by a photolithographic method to obtain a desired shape.

Next, a metal oxide film having oxygen defects is formed on the upper wiring. Examples of the metal oxide that can be used in the present invention include Ba _x Sr _1-x TiO
₃ (0 ≦ x ≦ 0.7), SrTiO ₃ , BaMgF ₄ ,
LiNbO ₃ , LiTaO ₃ , CaBi ₄ Ti ₄ O ₁₅ ,
High dielectric constant materials such as KNbO ₃ and NaNbO ₃ can be used. Among them, Ba _x Sr _1-x TiO ₃ (0 <x ≦ 0.
7, especially 0.5 <x ≦ 0.7). Further, the thickness of the metal oxide layer is 1000 to 3000 °, and 2
It is preferably from 2,000 to 2500 °. Where 1
If it is smaller than 000 °, the breakdown voltage becomes extremely small, and if it is larger than 3000 °, cracks are generated due to stress at the time of formation. As a method for forming the metal oxide film, a sol-gel method is preferable. In this method, a precursor solution composed of an alkoxide of a metal constituting a metal oxide is applied by, for example, spin coating or the like, and 3
This is a method of forming a metal oxide film by firing at a low temperature of 00 to 500 ° C. When the firing temperature is lower than 300 ° C., the crystallization of the metal oxide film is not sufficient,
If it is higher, it is necessary to change the manufacturing process itself of the semiconductor device, and it is necessary to select a new wiring material, which undesirably decreases reliability and increases manufacturing cost. Under such forming conditions, a perfect crystal state (perovskite structure) is not obtained, but a material having a relative dielectric constant of 20 to 30 can be obtained. This value is 4 to 4 compared to SiN.
M with a dielectric constant of 6 times and a structure in which an insulator is sandwiched between metals
It can be used as IM (metal / insulator / metal) capacitor material. Further, the metal oxide film may be formed by a photolithographic method in order to obtain a desired shape.

Next, an upper wiring is formed on the metal oxide film. The upper wiring that can be used in the present invention is made of a metal having a higher affinity for oxygen than the metal constituting the metal oxide film described above. Examples of the metal that can be used for the upper wiring include titanium, platinum, gold, aluminum, and the like. Of these, titanium is preferable. The thickness of the upper layer wiring is 500 ° to 10 μm, and preferably 2 to 10 μm. Here, if the angle is smaller than 500 °, the resistance is increased, which is not preferable. Further, the upper layer wiring does not necessarily have to be formed of one layer, and may be formed of two or more layers. For example, when it is composed of two layers, a laminate of titanium / gold, platinum / gold, etc. is mentioned. When it is composed of three layers, it is titanium / platinum /
Laminated bodies of gold, tungsten / platinum / gold and the like can be mentioned.
Among these, a laminated body composed of titanium / gold or titanium / platinum / gold is preferable in consideration of the adhesive force between the semiconductor substrate and the metal oxide film.
000 °, the gold layer is 2-10 μm, while in the case of three layers, the titanium layer is 500-1000 °, the platinum layer is 1000-2000 °, and the gold layer is 2-10 μm. Preferably, the upper wiring has a titanium layer formed on a lower surface in contact with the metal oxide film. this is,
This is because the titanium layer can form titanium oxide by removing oxygen from the surface of the metal oxide film, form a high-concentration oxygen-deficient layer on the surface of the metal oxide film, and form an ohmic contact. The method for forming the upper wiring is not particularly limited, and examples thereof include a sputtering method and a vacuum evaporation method, and the upper wiring may be formed by a photolithographic method in order to obtain a desired shape.

The semiconductor device having a vertical structure according to the present invention can be used for capacitors, diodes, bypass capacitors and the like. For example, a lower layer wiring can be used as a capacitor by applying a DC negative bias relatively constant to the upper layer wiring within a range that does not destroy insulation. When the current flowing through the metal oxide film is suppressed while being fixed at a fixed DC negative bias, the metal oxide film exhibits characteristics as an insulator and operates as a capacitor with small loss. Note that the constant DC negative bias is -0.5 to-
10V is preferred. If the voltage is higher than -10 V, the insulation may be broken, which is not preferable. If the voltage is lower than -0.5 V, there are many restrictions on the circuit, which is not preferable.

In the above description, for simplicity, only one semiconductor device has been described as an example. However, two or more semiconductor devices may be simultaneously formed, or may be combined with another semiconductor device.

[0019]

According to the semiconductor device of the present invention, an arbitrary-shaped lower-layer wiring made of a metal forming a Schottky contact with a metal oxide and a metal oxide film having an oxygen defect are provided on a semiconductor substrate. Since a vertical structure having an upper wiring having an arbitrary shape composed of a metal having an affinity for oxygen larger than that of the metal contained in the metal oxide film is characterized, a high breakdown voltage element is formed on a semiconductor substrate. Thus, the integrated circuit can be operated together with other active elements formed on the substrate, and the performance of the integrated circuit can be improved.

Further, the lower wiring has a platinum layer on the upper surface in contact with the metal oxide film, and the upper wiring has a titanium layer on the lower surface in contact with the metal oxide film. A Schottky contact is formed between the oxide films, and an ohmic contact is formed between the upper wiring and the metal oxide film. Further, by changing the metal of the upper and lower wirings of the metal oxide film, a semiconductor device capable of flowing a current having a practical current density of 1 to 10 A / cm ² in the vertical direction is provided.

Further, the lower wiring is made of a laminate of titanium / platinum, and the upper wiring is made of titanium / gold or titanium / platinum / titanium.
Since it is made of a gold laminate, a semiconductor device having better characteristics can be obtained. The metal oxide is strontium barium titanate (Ba _x Sr _1-x TiO ₃ ; 0 ≦ x ≦ 0.
7), a semiconductor device having an improved relative dielectric constant as compared with a conventional device using an insulator such as SiN can be obtained.

Further, since silicon nitride or silicon oxide is interposed between the semiconductor substrate and the lower wiring,
The process matching with another semiconductor device on the semiconductor substrate is improved. Further, since the semiconductor device is used as a diode, a diode with a high breakdown voltage can be obtained.

Further, since the lower wiring is used as a capacitor by applying a constant DC negative bias relatively to the upper wiring within a range that does not destroy the insulation, the characteristics of the metal oxide film as an insulator are shown. A capacitor with low loss can be obtained. In addition, a constant DC negative bias is −0.5V to −0.5V.
Since the voltage is 10 V, a capacitor with less loss can be obtained.

Furthermore, since the diode and the capacitor manufactured in the same process are included as constituent elements in the circuit, the capacitor and the diode are formed in the same process. Further, the metal oxide film is formed by applying a precursor solution comprising an alkoxide of a metal constituting the metal oxide film onto the lower wiring, and then performing calcination in air at a temperature of 300 ° C. to 500 ° C. Formed by a sol-gel method using a
cm ² ) is maintained.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments, but the present invention is not limited to the embodiments. Example 1 The semiconductor device shown in FIG. 1 was formed. 1A is a plan view, and FIG. 1B is a cross-sectional view. In FIG. 1, 1 is a lower layer wiring made of platinum, and 2 is strontium barium titanate (B
a _x Sr _1-x TiO ₃ , x = 0.5 or 0.7), 3 is an upper wiring made of titanium, 4 is G
1 shows an insulating semiconductor substrate made of aAs.

First, a resist was applied on the insulating semiconductor substrate 4 by spin coating, and a rectangular space pattern of 110 μm × 150 μm was formed on the resist by photolithography. Titanium was deposited to a thickness of 2500 ° on the substrate 4 by a sputtering method, and a pattern of a 110 μm × 150 μm rectangular lower wiring 1 was formed by lift-off.

Next, strontium barium titanate (Ba _x Sr _{1 -x} TiO ₃ x = 0.5) is formed on the substrate 4.
Alternatively, a precursor solution composed of a metal alkoxide to be 0.7) was applied to a thickness of 2000 ° by spin coating. Thereafter, the substrate was dried in air at 150 ° C. for 15 minutes, and subsequently baked in air at 500 ° C. for 1 hour to form a metal oxide film 2. Next, a resist was applied on the metal oxide film 2 by a spin coating method, a part of the lower wiring 1 was exposed by etching, a hole for contact was formed, and an unnecessary portion of the metal oxide film was removed. The etchant was a 5% buffered hydrofluoric acid: hydrochloric acid: pure water (1: 1: 2) solution, and was etched by immersing it in this solution for 15 seconds.

Next, a resist was applied on the substrate 4 by spin coating, and a space pattern was formed on the resist by photolithography. By depositing platinum on the substrate 4 to a thickness of 2 μm by a sputtering method and forming a pattern of the upper wiring 3 by lift-off, FIG.
The semiconductor device as shown in FIG. The area where the lower wiring 1 and the upper wiring 3 were in contact with each other via the metal oxide film 2 was 100 μm × 100 μm.

Example 2 The semiconductor device shown in FIG. 5 was formed based on FIGS.
2A to 5A are plan views, and FIG. 2B is a cross-sectional view. 2 to 5, 1 to 4 are the same as in FIG. 1, 5 is a titanium layer, 6 is a platinum layer, 7 is a gold layer, and 8 is Si.
2 shows an insulating film made of N.

First, an insulating film 8 made of SiN was formed on the insulating semiconductor substrate 4 at a thickness of 2000 ° by the PCVD method. Next, 110 μm × 15
A rectangular space pattern made of a 0 μm resist is formed, a titanium layer 5 is deposited in a thickness of 500 ° by a sputtering method, and a platinum layer 6 is deposited in a thickness of 2000 ° in this order.
A pattern of a rectangular lower-layer wiring 1 of 0 μm × 150 μm was formed (see FIGS. 2A and 2B).

Next, a metal oxide film 2 was formed on the lower wiring 1 in the same manner as in Example 1. Note that x was set to 0.7 (see FIGS. 3A and 3B). Next, a pattern made of a resist was formed in the same manner as in Example 1, a titanium layer 5 was deposited at 500 ° by a sputtering method, a gold layer 7 was deposited in this order of 2 μm, and a pattern of the upper wiring 3 was formed by lift-off ( 4 (a) and (b).

Thereafter, the resist was removed to obtain a semiconductor device as shown in FIG. The area where the lower wiring 1 and the upper wiring 3 are in contact via the metal oxide film 2 is 1
It was 00 μm × 100 μm. FIG. 6 shows the structure of FIG.
4 is a graph showing the relationship between the voltage applied to the lower wiring 1 of the semiconductor device using Ba _0.7 Sr _0.3 TiO ₃ for the metal oxide film 2 and the current flowing through the semiconductor device from the lower wiring to the upper wiring 3.

As apparent from FIG. 6, -1 is applied to the lower wiring.
Even when 0 V is applied, almost no current flows, indicating good diode characteristics. Further, when a voltage was applied to the lower wiring for a long time in the range of −10 V or less, the current flowing through the high dielectric increased, resulting in dielectric breakdown. Example 3 The semiconductor device shown in FIG.
It was formed by repeating the same steps as in Example 2 except that a platinum layer 6 having a thickness of 100 ° was formed between the titanium layer 5 and the gold layer 7 and that the insulating film 8 was made of SiO ₂ .

FIG. 8 shows the structure of FIG.
Ba _0.5 Sr with thickness of 2000 ° C. performed at 0 ° C. for 1 hour
_In a semiconductor device using _0.5 TiO ₃ for the metal oxide film 2,
The voltage applied to the lower wiring 1 and the lower wiring 1 to the upper wiring 3
2 shows the relationship of the normalized current flowing through the semiconductor device. In FIG. 8, the dimensions of the upper wiring 3 are set to 20 μm × 10 μm to 200 μm.
It is changed to μm × 200 μm.

As is apparent from FIG. 8, the forward current is
It can be seen that it depends on the area of the upper wiring 3. Also,-
Apply DC bias to the lower electrode from 8 to -10V
Almost no reverse current flows, and a +2 to 3 V DC
When a bias is applied, a practical level of forward current (about 1 A)
/ Cm^Two) Flows. This is achieved by the present invention.
Semiconductor device operates as a diode with a high reverse breakdown voltage
It shows that it works. In addition, applied to the lower electrode
When the DC bias is fixed at -2 V, the current becomes 10 ^-6~ 1
0^-FourA / cm^TwoAnd shows good leak characteristics.

Embodiment 4 FIG. 9 shows an example of a circuit configuration when the semiconductor device of the present invention is used as a capacitor. A in FIG. 9 is a semiconductor device of the present invention including a lower wiring 1, a metal oxide film 2, and an upper wiring 3. The relative dielectric constant of 1 to 15 GHz when -5 V is applied to the lower wiring 1 is Ba _0.7 Sr _0.3
The case of TiO ₃ was 30, the case of Ba _0.5 Sr _0.5 TiO ₃ was 25, and the case of SrTiO ₃ was 20. The relative dielectric constant (100 to 100) originally obtained with these high dielectric metal oxides
300) was not obtained, but SiN was 5.6, SiO
Compared to ₂ being 4, capacitors made of these metal oxides were found to exhibit 4-7 times the capacitance. Therefore, when using SiN or SiO ₂ of the same thickness,
The capacitor area can be reduced to 1/4 to 1/7.

Embodiment 5 FIG. 10 shows an example of a circuit configuration when the semiconductor device of the present invention is used as a diode and a capacitor on the same substrate. Even with the same device structure, the capacitor and the diode can be formed at once, and the process can be simplified.

[0038]

According to the semiconductor device of the present invention, an arbitrary-shaped lower wiring made of a metal forming a Schottky contact with a metal oxide and a metal oxide film having an oxygen defect are sandwiched on a semiconductor substrate. Since the vertical structure having an upper wiring having an arbitrary shape composed of a metal having an affinity for oxygen larger than the metal contained in the metal oxide film is characterized, a high breakdown voltage element is formed on a semiconductor substrate. And can be operated together with other active elements formed on the substrate, so that the performance of the integrated circuit can be improved.

Also, the lower wiring has a platinum layer on the upper surface in contact with the metal oxide film, and the upper wiring has a titanium layer on the lower surface in contact with the metal oxide film. A Schottky contact can be formed between the oxide films, and an ohmic contact can be formed between the upper wiring and the metal oxide film. Further, by changing the metal of the upper and lower wirings of the metal oxide film, it is possible to provide a semiconductor device capable of flowing a current having a practical current density of 1 to 10 A / cm ² in the vertical direction.

Further, the lower wiring is made of a laminate of titanium / platinum, and the upper wiring is made of titanium / gold or titanium / platinum / titanium.
Since it is made of a gold laminate, a semiconductor device having better characteristics can be obtained. Further, when the metal oxide is strontium barium titanate (Ba _x Sr _{1 -x} TiO ₃ ; 0 ≦
x ≦ 0.7), it is possible to obtain a semiconductor device having an improved relative dielectric constant as compared with a conventional device using an insulator such as SiN.

Further, since silicon nitride or silicon oxide is interposed between the semiconductor substrate and the lower wiring,
The process matching with another semiconductor device on the semiconductor substrate is improved. Further, since the semiconductor device is used as a diode, a diode with a high breakdown voltage can be obtained.

Further, since the lower wiring is used as a capacitor by applying a DC negative bias relatively constant to the upper wiring within a range that does not destroy the insulation, the characteristics of the metal oxide film as an insulator are shown. A capacitor with low loss can be obtained. In addition, the constant DC negative bias is −0.
Since the voltage is 5 V to -10 V, a capacitor with less loss can be obtained.

Furthermore, since the diode and the capacitor manufactured in the same process are included in the circuit as constituent elements, the capacitor and the diode can be formed in the same process. Further, a metal oxide film is applied with a precursor solution comprising an alkoxide of a metal constituting the metal oxide film on the lower wiring, and then fired in air at 300 ° C to 500 ° C.
Formed by a sol-gel method utilizing hydrolysis, which is performed in the range of
An oxygen vacancy state of 10 A / cm ² ) can be maintained. Also, since firing can be performed at a low temperature,
The manufacturing process of other semiconductor devices formed on the semiconductor substrate is not significantly changed, and there is no need to select an electrode material that causes a reduction in reliability. Therefore, there is no problem of reliability deterioration and no increase in manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a schematic plan view and a cross-sectional view of a semiconductor device according to the present invention.

FIG. 2 is a schematic plan view and a cross-sectional view of a manufacturing process of the semiconductor device of the present invention.

FIG. 3 is a schematic plan view and a cross-sectional view of a manufacturing process of the semiconductor device of the present invention.

FIG. 4 is a schematic plan view and a cross-sectional view of a manufacturing process of the semiconductor device of the present invention.

FIG. 5 is a schematic plan view and a cross-sectional view of a semiconductor device of the present invention.

FIG. 6 is a graph showing the relationship between the current of the semiconductor device of the present invention and the voltage applied to the lower wiring.

FIG. 7 is a schematic plan view and a cross-sectional view of the semiconductor device of the present invention.

FIG. 8 is a graph showing a relationship between a current of the semiconductor device of the present invention and a voltage applied to a lower wiring.

FIG. 9 is a circuit configuration diagram when the semiconductor device of the present invention is used as a capacitor.

FIG. 10 is a circuit configuration diagram when the semiconductor device of the present invention is used as a diode and a capacitor on the same substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower wiring 2 Metal oxide film 3 Upper wiring 4 Semiconductor substrate 5 Titanium layer 6 Platinum layer 7 Gold layer 8 Insulating film A Semiconductor device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-299584 (JP, A) JP-A-5-267565 (JP, A) JP-A-4-221848 (JP, A) JP-A-4,221 167554 (JP, A) JP-A-6-188366 (JP, A) JP-A-56-79423 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 27/04 H01L 21 / 822 H01L 29/861

Claims (7)

(57) [Claims] 1. A lower wiring having an arbitrary shape formed of a metal which forms a Schottky contact with a metal oxide film having an oxygen defect on a semiconductor substrate, and a lower wiring formed on the lower wiring.
And the metal oxide film was made, affinity for oxygen is formed larger than a metal of a metal contained in the gold <br/> genus oxide film, an upper layer wiring formed on the metal oxide film Having a vertical structure having the metal oxide film,
Precursor consisting of metal alkoxide applied on layer wiring
Baking the body solution in the range of 300 to 500 ° C in air
Formed by sol-gel method utilizing hydrolysis by
A semiconductor device, which is a semiconductor device. Wherein said lower layer wiring has a platinum layer on the surface in contact with the metal oxide film, the upper layer wiring, have a titanium layer on the lower surface in contact with the gold <br/> genus oxide film 2. The semiconductor device according to claim 1, wherein: 3. The method according to claim 1, wherein the metal oxide film is made of barium strontium titanate (Ba _x Sr _{1 -x} TiO ₃ : 0 ≦ x ≦ 0.
3. The semiconductor device according to claim 1, wherein 4. A semiconductor device, wherein the semiconductor device is used as a diode, and the upper wiring, the metal oxide film, and
The lower wiring is an upper wiring of a diode, a metal oxide film.
And a semiconductor device according to any one claims 1 to 3 that corresponds with the lower wiring. 5. The method according to claim 1, wherein the semiconductor device is used as a capacitor.
The upper wiring of the semiconductor device, the metal oxide film and
The lower wiring is an upper wiring of a capacitor, a metal oxide film
Corresponding to the lower wiring and the lower wiring of the capacitor,
As long as the insulation is not destroyed,
5. A method according to claim 1 , wherein a constant negative DC bias is applied.
The semiconductor device according to any one of the above. 6. A constant DC negative bias is between -0.5V and
The semiconductor device according to claim 5, wherein the voltage is -10V. 7. A semiconductor substrate having an oxygen defect.
Metal that forms a Schottky contact with the metal oxide film
Ri forming a lower layer wiring of any shape configured, the metal constituting the (2) (a) the metal oxide film Arco
A process for applying a precursor solution consisting of oxide on the lower wiring
Degree, then (b), the resulting coating film, 300 ° C. in air 50
Solge using hydrolysis by calcination performed at 0 ° C
Forming the metal oxide film by a step of subjecting to a metallization method
And (3) gold contained in the metal oxide film having an affinity for oxygen.
For forming upper layer wiring composed of metal larger than
Semiconductor having a vertical structure characterized by comprising:
Device manufacturing method.