JP2017216445A - Film, method for manufacturing the same, laminate, and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxynitride film capable of film formation by a method excellent in productivity, having a high dielectric breakdown electric field, and suitable for an insulating film and a protective film of a device, and a manufacturing method of the same.SOLUTION: The film includes at least one metal element selected from In, Ga, Zn, Al, and Sn, an oxygen element, and a nitrogen element, and has an electric resistivity of 1×10Ωm or more at a time when an electric field of 0.1MV/cm is applied at temperature of 25°C.SELECTED DRAWING: None

Description

  The present invention relates to a film, a film manufacturing method, a laminate, and a semiconductor device.

  In recent years, metal oxides have been used in various devices. Many metal oxides are characterized by being transparent to visible light and having a band gap between the valence band and the conductor of 3 eV or more. As a rule of thumb, a material with a large band gap has a high electrical resistance and is suitable as an insulator. Such metal oxide insulators are used for insulating substrates, gate insulating films, protective films and the like of semiconductor devices.

Devices using SiO ₂ as an insulating film are well known. Since SiO ₂ has a large band gap of 9 eV and a dielectric breakdown electric field as large as 8 to 10 MV / cm, it is suitable for an insulating film and has been studied for many years. However, in order to obtain a high-quality SiO ₂ insulating film by the CVD method, it is necessary to go through a high-temperature process. Further, in order to manufacture the SiO ₂ film by the sputtering method, it is necessary to adopt RF sputtering because an insulator target is used. RF sputtering has a slow film formation rate and has a problem in mass productivity. Furthermore, when the SiO ₂ film is manufactured by the solution method, there is a problem that the dielectric breakdown electric field is reduced due to residual carbon caused by the solvent.

Al ₂ O _{3 is} also said to have a wide band gap of 6 eV to 8 eV, and a high dielectric breakdown electric field is expected. However, the sputtering method still uses RF sputtering due to the use of an insulator target, and there is a problem in mass productivity. In addition, the ALD method can obtain a high-quality Al ₂ O ₃ insulating film, but has a slower deposition rate than the sputtering method and has a problem in mass productivity.

  Patent Document 1 discloses a semiconductor material made of a metal oxynitride containing indium, gallium, and zinc. However, according to the present technology, the metal oxynitride layer is used as a semiconductor of a channel portion through which a current flows in a thin film transistor, and is not suitable as an insulating film that requires high electrical resistance.

  Patent Document 2 discloses a semiconductor device using an oxynitride containing indium, gallium, zinc, and nitrogen. However, in this configuration, the oxynitride is used only for each semiconductor layer. Further, although silicon oxynitride is used as the insulating layer, the addition ratio of nitrogen decreases the selectivity with the underlying semiconductor during wet etching, so that it is unsuitable as a main insulating film.

  Patent Document 3 discloses an optical semiconductor containing indium, gallium, zinc, oxygen, and nitrogen. However, it is used as an electrode in a photoelectrochemical cell and is not suitable as an insulating film that requires insulation.

  Patent Document 4 discloses a semiconductor film using an oxynitride containing indium, gallium, tin, and nitrogen. Similar to Patent Document 1, it is used as a semiconductor and is not suitable as an insulating film requiring high electrical resistance.

JP 2015-18929 A WO2015 / 118710 WO2011 / 108271 JP 2014-56945 A

  An object of the present invention is to provide an oxynitride film that can be formed by a method with excellent productivity, has a high dielectric breakdown electric field, and is suitable for an insulating film and a protective film of a device, and a manufacturing method thereof. It is.

  A metal oxide containing indium, gallium, zinc, or the like as a main component has a wide band gap of 3 eV or more and has a high dielectric breakdown electric field, so that application to an insulating film of a semiconductor device is expected. However, it has been used only as a semiconductor film until now.

Therefore, the present inventors have sintered metal oxides mainly composed of indium, gallium, zinc, etc., conventionally used for forming a semiconductor film in a sputtering atmosphere containing a gas containing nitrogen element. When a body target was used, it was found that an insulating film having a high dielectric breakdown electric field could be formed, and the present invention was completed.
Furthermore, since the metal oxide sintered body target is a target having a lower electric resistance than the SiO ₂ target and Al ₂ O ₃ target conventionally used as materials for insulating films, DC sputtering with a high film formation rate is possible. Yes, it can be expected to improve mass productivity.

According to the present invention, the following films, laminates, semiconductor devices, and methods for producing the films are provided.
1. It contains at least one metal element selected from In, Ga, Zn, Al, and Sn, an oxygen element, and a nitrogen element, and has an electric resistivity of 1 × 10 at a temperature of 25 ° C. and an electric field of 0.1 MV / cm. ^{7 A} membrane that is at least Ωm.
2. 2. The film according to 1, containing a Ga element.
3. Furthermore, the film | membrane of 2 containing In element.
4). Furthermore, the film | membrane of 2 or 3 containing Zn element.
A laminate comprising the film according to any one of 5.1 to 4.
The semiconductor device containing the film | membrane in any one of 6.1-4 as an insulating layer or a protective layer.
7). 7. The semiconductor device according to 6, wherein the insulating layer is provided on at least one side of the gate electrode.
8). Including a source electrode, a drain electrode, a semiconductor layer and a substrate,
The semiconductor device according to 6 or 7, wherein the protective layer is provided on at least the semiconductor layer among the source electrode, the drain electrode, and the semiconductor layer, and includes the protective layer, the semiconductor layer, and the substrate in this order.
9. A method for producing a film in which a sputtering target comprising an oxide sintered body containing at least one metal element selected from In, Ga, Zn, Al and Sn is sputtered by introducing a gas containing a nitrogen element,
The manufacturing method of the film | membrane in any one of 1-4 whose flow rate of the gas containing the said nitrogen element is 1 volume% or more and 100 volume% or less in the total flow volume of the gas to introduce | transduce.
10. 10. The method for producing a film according to 9, wherein a flow rate of the gas containing the nitrogen element in the total flow rate of the introduced gas is 2% by volume or more and 50% by volume or less.
11. The method for producing a film according to 9 or 10, wherein the gas to be introduced contains water, and a water flow rate in a total flow rate of the gas to be introduced is 0.1% by volume or more and 50% by volume or less.
12 The manufacturing method of the film | membrane in any one of 9-11 in which the said oxide sintered compact contains Ga element.
13. The manufacturing method of the film | membrane in any one of 9-12 whose ratio of Ga element to all the metal elements in the said oxide sintered compact is 50-100 atomic%.
14 The method for producing a film according to 12 or 13, wherein the oxide sintered body contains an In element.
15. The manufacturing method of the film | membrane in any one of 12-14 in which the said oxide sintered compact contains Zn element.
16. The manufacturing method of the film | membrane in any one of 9-15 in which the said oxide sintered compact contains In element, Ga element, and Zn element in the following atomic ratio range.
In / (In + Ga + Zn) = 0.001 to 0.998 Ga / (In + Ga + Zn) = 0.001 to 0.998 Zn / (In + Ga + Zn) = 0.001 to 0.998

  According to the present invention, it is possible to provide an oxynitride film which can be formed by a method with excellent productivity, has a high dielectric breakdown electric field, and is suitable for an insulating film and a protective film of a device, and a manufacturing method thereof.

It is a schematic sectional drawing which shows one Embodiment of a thin-film transistor. It is a schematic sectional drawing which shows one Embodiment of the thin-film transistor which has a protective layer. It is a schematic sectional drawing which shows one Embodiment of the thin-film transistor which has a protective layer of another form.

1. Film and Film Manufacturing Method A film according to one embodiment of the present invention (hereinafter referred to as a film of the present invention) includes at least one metal element selected from In, Ga, Zn, Al, and Sn, an oxygen element, and a nitrogen element And having an electric resistivity of 1 × 10 ⁷ Ωm or more when applied at a temperature of 25 ° C. and an electric field of 0.1 MV / cm.
The film of the present invention is an oxynitride film having a high electric resistivity of 1 × 10 ⁷ Ωm or more when applied at a temperature of 25 ° C. and an electric field of 0.1 MV / cm, and having an excellent breakdown electric field. It can be used as a protective film and insulating film for semiconductor devices.

A film manufacturing method according to an embodiment of the present invention (hereinafter referred to as a manufacturing method of the present invention) includes an oxide sintered body containing at least one metal element selected from In, Ga, Zn, Al, and Sn. The film of the present invention is manufactured by sputtering the sputtering target at a flow rate of a gas containing nitrogen element in the total flow rate of the introduced gas at 1 vol% or more and 100 vol% or less.
By adding a gas containing nitrogen element to the sputtering atmosphere, nitrogen element is introduced into the resulting film, and an oxynitride film having an excellent dielectric breakdown electric field is obtained.

In the prior art, for example, when an insulating film is to be manufactured by a sputtering method, an RF sputtering with a slow film formation rate must be used because an insulator target is used, and there is a problem in mass productivity. On the other hand, according to the manufacturing method of the present invention, it is not necessary to use an insulator target, and it is possible to form an insulating film by DC sputtering, which has a higher film formation rate than RF sputtering and is excellent in productivity. It becomes.
Moreover, in the manufacturing method of this invention, an insulating film can be manufactured with sputtering method using the target conventionally used for semiconductor film manufacture.

The principle that the film of the present invention becomes an insulating film, despite the sputtering of a target that has been conventionally used for manufacturing a semiconductor film, is presumed as follows.
A film obtained by sputtering a metal oxide sintered body tends to be non-stoichiometric and contains oxygen vacancies in the film. Leakage current flows through oxygen vacancies and the breakdown electric field decreases. Here, it is expected that by adding nitrogen to the atmosphere during sputtering, the film contains nitrogen, terminates oxygen vacancies, prevents leakage current, and improves the dielectric breakdown electric field. This is because the difference in electronegativity of the metal-nitrogen bond is smaller than that of the metal-oxygen bond and the covalent bond is strong, that is, the binding energy of nitrogen is stronger than that of oxygen.

The film of the present invention preferably contains a Ga element.
The film of the present invention preferably further contains an In element and / or a Zn element in addition to the Ga element.

The film of the present invention has an electric resistivity of 1 × 10 ⁷ Ωm or more, preferably 1 × 10 ¹⁰ Ωm or more, more preferably 1 × 10 ¹² when a temperature: 25 ° C. and an electric field: 0.1 MV / cm are applied. Ωm or more. When the electrical resistivity is less than 1 × 10 ⁷ Ωm, the semiconductor device has conductivity when used as an insulating film or a protective film of a semiconductor device, resulting in a decrease in dielectric breakdown. The upper limit of the electrical resistivity is not particularly limited, but when the electrical resistivity exceeds 1 × 10 ²² Ωm, an attoampere-class ammeter is necessary, and it is extremely difficult to evaluate the electrical resistivity.

  In the present invention, the electrical resistivity of the film means that a voltage was applied to a laminate in which the substrate, the film of the present invention, and the electrode were laminated in this order (hereinafter sometimes referred to as “substrate / film of the present invention / electrode”). In this case, the value obtained by measuring the leakage current and dividing the leakage current by the voltage and the film thickness of the film of the present invention. The obtained electrical resistivity is the electrical resistivity of the laminate, but the substrate and the electrode used in the present invention are conductive materials, and the electrical resistivity is much smaller than the film of the present invention. And the electrical resistivity of the electrode is negligible. Therefore, the electrical resistivity of the laminate can be made the electrical resistivity of the film of the present invention.

When the film of the present invention is used for a gate insulating film of a thin film transistor, the electrical resistivity of the gate insulating film can be obtained by applying a voltage between the source and drain electrodes and the gate electrode and measuring the leakage current.
When there is no structure in which the film of the present invention is sandwiched between electrodes or when it is used as a protective film, it can be measured by a four-probe method using a probe.

  The film of the present invention may be an amorphous film, a polycrystalline film, or a film in which these are mixed.

  The film thickness of the film of the present invention is usually 10 nm to 10 μm, preferably 50 nm to 3 μm, more preferably 100 nm to 1 μm. The film thickness can be appropriately selected so that a desired dielectric breakdown electric field can be obtained.

The dielectric breakdown electric field (Ec) of the film of the present invention can be determined as follows.
A power supply for applying a voltage to the substrate / film / electrode laminate of the present invention is prepared, and the applied voltage is increased from 0 V in 0.01 V steps at a temperature of 25 ° C., and the current increases rapidly to 10 A. A voltage obtained when the voltage reaches / cm ² is divided by the film thickness of the film of the present invention is defined as a dielectric breakdown electric field.

The dielectric breakdown electric field of the film of the present invention may be appropriately determined according to the characteristics and functions required of the film, but when used as an insulating film, it preferably exceeds 1.0 MV / cm, and is preferably 1.5 MV. More preferably, it exceeds / cm. There is no particular limitation on the upper limit of the dielectric breakdown electric field.
In addition, when the film of the present invention is used as an insulating film in a semiconductor device, it is desirable to have a higher breakdown electric field than the substrate and the semiconductor layer with which the film is in contact.

The relative dielectric constant of the film of the present invention may be appropriately determined according to the characteristics and functions required of the film. However, when used as an insulating film, it preferably exceeds 3.9, more preferably exceeds 10. preferable. There is no particular limitation on the upper limit of the relative dielectric constant of the film.
A material having a relative dielectric constant higher than SiO ₂ (ε _r = 3.9) is referred to as a High-k material, and the film thickness of the gate insulating film is maintained while maintaining the operation speed of the semiconductor device equivalent to the case where SiO ₂ is thinned. Can be thickened. Thereby, the leakage current of the gate can be greatly reduced, and the power consumption can be reduced.

この式より求めたε_rを比誘電率とする。 The relative dielectric constant (ε _r ) of the film of the present invention can be determined as follows.
An LCR meter is connected to the substrate / membrane / electrode laminate of the present invention, and the capacitance at a temperature of 25 ° C. is measured. If the obtained capacitance is C [F], the electrode area is S [m ² ], the insulating film thickness is d [m], and the vacuum dielectric constant is ε ₀ [F / m], the following equation is established.

_Let ε _r obtained from this equation be the relative dielectric constant.

  According to the manufacturing method of the present invention, an oxynitride insulating film can be obtained by DC sputtering an oxide sintered body target that is not an insulator in an atmosphere containing a nitrogen element-containing gas. By doing so, the deposition rate is greatly improved as compared with the case where an insulating film is manufactured by RF sputtering using an insulator target.

The flow rate of the gas containing nitrogen element in the total flow rate of the introduced gas is 1% by volume or more and 100% by volume or less, preferably 2% by volume or more and 50% by volume or less, more preferably 4% by volume or more and 12% by volume or less. It is.
Examples of the gas containing nitrogen element include N ₂ , NO, NO ₂ , N ₂ O, N ₂ O ₃ , N ₂ O ₄ , N ₂ O ₅ , and NH ₃ .

  Further, by introducing water, the oxidation of the formed film is promoted, and the insulating property of the obtained film is further improved. The water flow rate in the total flow rate of the gas to be introduced is from 0.1% by volume to 50% by volume, preferably from 1% by volume to 20% by volume.

The gas (sputtering atmosphere) introduced at the time of sputtering contains Ar, O ₂ , He, Ne, Xe, Kr, etc. generally used in the sputtering atmosphere, in addition to the gas containing nitrogen element and water. Also good. The sputtering conditions are not particularly limited, but the film may be formed at 0 to 300 ° C. and 0.1 to 10 Pa. Further, the treatment after the film formation is not particularly limited, but annealing at 0 to 300 ° C. for 10 to 120 minutes may be performed.

The sputtering target used in the production method of the present invention is composed of an oxide sintered body containing at least one metal element selected from In, Ga, Zn, Al, and Sn.
The sputtering target is preferably composed of an oxide sintered body containing Ga element, and the proportion of Ga element in all metal elements in the oxide sintered body is preferably 50 to 100 atomic%, and 60 to It is more preferably 100 atomic%, and further preferably 60 to 99 atomic%. By using a sputtering target made of a Ga-rich oxide sintered body, a Ga-rich film can be obtained. Ga-rich films have excellent dielectric breakdown characteristics. Similar effects can be obtained by using Al element, Sn element and lanthanoid (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu). .
Moreover, it is more preferable to consist of oxide sinter containing Ga element and In element and / or Zn element. In elements and Zn elements have the effect of facilitating DC sputtering.

In the case of a sputtering target composed of an oxide sintered body containing an In element, a Ga element, and a Zn element, the preferred atomic ratio ranges for each element are as follows.
In / (In + Ga + Zn) = 0.001 to 0.998, preferably 0.001 to 0.5, and more preferably 0.001 to 0.333.
Ga / (In + Ga + Zn) = 0.001 to 0.998, preferably 0.333 to 0.998%, more preferably 0.5 to 0.998.
Zn / (In + Ga + Zn) = 0.001 to 0.998, preferably 0.001 to 0.5, and more preferably 0.001 to 0.333.

  The oxide sintered body constituting the sputtering target used in the present invention may consist essentially of In, Ga and Zn, and optionally Al and Sn as metal elements. In this case, inevitable impurities may be included. For example, 70 atomic% or more, 80 atomic% or more, or 90 atomic% or more of the metal element of the oxide sintered body used in the present invention may be In, Ga, Zn, and optionally Al and Sn. . The oxide sintered body used in the present invention may contain only In, Ga, Zn, and optionally Al and Sn as metal elements.

Although the manufacturing method and physical property of the sputtering target used by this invention do not have a restriction | limiting in particular, An illustration is described below.
The purity of each raw material powder is usually 99.9% (3N) or higher, preferably 99.99% (4N) or higher, more preferably 99.995% or higher, particularly preferably 99.999% (5N) or higher. . If the purity of each raw material powder is less than 99.9% (3N), the semiconductor characteristics may be deteriorated due to impurities, appearance defects such as uneven color and spots may occur, and reliability may be reduced. is there.

Moreover, it is preferable to use the powder whose specific surface area of the oxide powder of each element is substantially the same. Thereby, it can pulverize and mix more efficiently. Specifically, the difference in specific surface area is preferably 5 m ² / g or less. If the specific surface area is too different, efficient pulverization and mixing cannot be performed, and oxide particles of the raw material powder may remain in the sintered body.

The mixed powder is mixed and ground using, for example, a wet medium stirring mill. At this time, the specific surface area after pulverization is increased to 1.0 to 3.0 m ² / g from the specific surface area of the raw material mixed powder, or the average median diameter after pulverization is adjusted to be 0.6 to 1 μm. It is preferable to do. By using the raw material powder thus adjusted, a high-density oxide sintered body can be obtained without requiring a calcination step at all. Moreover, a reduction process is also unnecessary.

In addition, if the increase in the specific surface area of the raw material mixed powder is less than 1.0 m ² / g or the average median diameter of the raw material mixed powder after pulverization exceeds 1 μm, the sintered density may not be sufficiently increased. On the other hand, if the increase in the specific surface area of the raw material mixed powder exceeds 3.0 m ² / g, or if the average median diameter after pulverization is less than 0.6 μm, contamination from the pulverizer during pulverization (impurity contamination amount) ) May increase.

Here, the specific surface area of each powder is a value measured by the BET method. The median diameter of the particle size distribution of each powder is a value measured with a particle size distribution meter. These values can be adjusted by pulverizing the powder by a dry pulverization method, a wet pulverization method or the like.
The raw material after the pulverization step is dried with a spray dryer or the like and then molded. For forming, a known method such as pressure forming or cold isostatic pressing can be employed.

  Next, the obtained molded product is sintered to obtain a sintered body. The sintering is preferably performed at 1350 to 1600 ° C. for 2 to 20 hours. If the temperature is lower than 1350 ° C., the density does not improve, and if it exceeds 1600 ° C., some elements evaporate, the composition of the sintered body changes, or voids (voids) are generated in the sintered body due to evaporation. Sometimes.

Sintering is preferably performed in an oxygen atmosphere by circulating oxygen or under pressure. Thereby, transpiration of some elements can be suppressed, and a sintered body free from voids (voids) can be obtained.
Since the sintered body manufactured in this manner has a high density and generates less nodules and particles during use, an oxide semiconductor film having excellent film characteristics can be manufactured.

  The oxide sintered body becomes a target by performing processing such as polishing. Specifically, the sintered body is ground by, for example, a surface grinder so that the surface roughness Ra is 5 μm or less. Further, the sputter surface of the target may be mirror-finished so that the average surface roughness Ra is 1000 angstroms or less. For this mirror finishing (polishing), a known polishing technique such as mechanical polishing, chemical polishing, mechanochemical polishing (a combination of mechanical polishing and chemical polishing) can be used. For example, polishing to # 2000 or more with a fixed abrasive polisher (polishing liquid: water) or lapping with loose abrasive lapping (abrasive: SiC paste, etc.), and then lapping by changing the abrasive to diamond paste Can be obtained by: Such a polishing method is not particularly limited.

  By bonding the obtained target to a backing plate, it can be used by being attached to various film forming apparatuses. Examples of the film forming method include a sputtering method, a PLD (pulse laser deposition) method, a vacuum deposition method, and an ion plating method. From the viewpoint of mass productivity, the DC sputtering method is preferable.

In addition, air blow, running water washing | cleaning, etc. can be used for the cleaning process of a target. When removing foreign matter by air blow, it is possible to remove the foreign matter more effectively by suctioning with a dust collector from the opposite side of the nozzle.
In addition to air blow and running water cleaning, ultrasonic cleaning and the like can also be performed. In ultrasonic cleaning, a method of performing multiple oscillations at a frequency of 25 to 300 KHz is effective. For example, it is preferable to perform ultrasonic cleaning by causing multiple oscillations of 12 types of frequencies at intervals of 25 KHz between frequencies of 25 to 300 KHz.

  The particle size of each compound in the oxide sintered body is preferably 20 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less. The particle size is an average particle size measured with an electron probe microanalyzer (EPMA). For the crystal grain size, for example, the mixing ratio of each powder of the metal oxide as the raw material, the particle size of the raw material powder, purity, heating time, sintering temperature, sintering time, sintering atmosphere, cooling time are adjusted. Can be obtained. If the particle size of the compound is larger than 20 μm, nodules may be generated during sputtering.

The density of the target is preferably 95% or more of the theoretical density, more preferably 98% or more, and particularly preferably 99% or more. If the density of the target is less than 95%, the strength is insufficient and the target may be damaged during film formation. In addition, performance may be uneven when a transistor is manufactured.
Here, the theoretical relative density of the target is the specific gravity of each oxide (for example, ZnO is 5.66 g / cm ³ , In ₂ O ₃ is 7.12 g / cm ³ , and ZrO ₂ is 5.98 g / cm ³ ). The density is calculated from the quantitative ratio, and the ratio with the density measured by the Archimedes method is calculated to obtain the theoretical relative density.

The bending strength of the target is preferably 8 kg / mm ² or more, more preferably 10 kg / mm ² or more, and particularly preferably 12 kg / mm ² or more. The target is required to have a certain level of bending force because a load is applied during transportation and mounting of the target, and the target may be damaged. If the target is less than 8 kg / mm ² , it cannot be used as a target. There is a fear. The bending strength of the target can be measured according to JIS R 1601.

In general, the bulk resistance of an oxide sintered body (target) used for manufacturing a semiconductor film is 1 × 10 ⁷ Ωm or less, preferably 1 × 10 ⁵ Ωm or less, more preferably 1 × 10 ² Ωm or less. More preferably, it is 10 Ωm or less.
The bulk resistance of the oxide sintered body can be measured based on the four-probe method using a resistivity meter (Made by Mitsubishi Chemical Corporation, Loresta).

In the manufacturing method of the present invention, since an oxide sintered body target that has been used for film formation of a semiconductor film can be used instead of an insulator target, DC sputtering can be performed at a higher film formation rate than RF sputtering. Excellent in mass production of insulating films and protective films.
When using an oxide sintered compact target having a relatively large bulk resistance, pulse DC sputtering can be used.

2. Laminated body and semiconductor device The laminated body which concerns on 1 aspect of this invention (henceforth the laminated body of this invention) is characterized by including the film | membrane of the said invention.
The film of the present invention can function as an insulating film, a protective film, or the like.

The laminate of the present invention refers to a structure in which the film of the present invention is provided on some support. When the said laminated body is comprised with a some layer, the film | membrane of this invention may be formed in the outermost layer, and may be formed between several layers.
The support may have a planar shape or a three-dimensional shape. Moreover, the film | membrane of this invention may be provided in the whole support body surface, and may be provided only in a part of support body surface.

  When the support is a substrate and the film of the present invention is provided in contact with the substrate, the material of the substrate is not particularly limited. For example, glass, plastic, metal, semiconductor, oxide, paper, cloth, ceramics, etc. Is mentioned.

In the laminate, when the film of the present invention is laminated with the electrode layer, the material of the electrode layer is not particularly limited as long as it can be formed on one or both sides of the oxide insulating layer made of the film of the present invention. Mo, Ti, Au, Ag, Al, and Cu can be suitably used.
The electrode layer may be composed of a plurality of layers. For example, the oxidation of the Mo electrode layer can be prevented by stacking the oxide insulating layer / Mo electrode layer / Au metal layer in this order.

  The film thickness of the electrode layer may be appropriately selected so as to obtain desired electrical characteristics, and is, for example, in the range of 10 nm to 10 μm, and preferably in the range of 100 nm to 3 μm.

In the laminate, when the film of the present invention is laminated with the semiconductor layer of the laminate, the material of the semiconductor layer is particularly limited as long as it can be formed on one or both sides of the oxide insulating layer made of the film of the present invention. However, Si, SiC, GaAs, GaN, Ga ₂ O ₃ , IGZO, AlN, diamond, or the like can be preferably used.
The semiconductor layer may be composed of a plurality of layers. For example, it can be laminated in the order of Si support substrate / SiC layer / oxide insulating layer.

  The film thickness of the semiconductor layer may be appropriately selected so that desired electrical characteristics can be obtained. For example, the film thickness is in the range of 10 nm to 2 mm, and preferably in the range of 20 nm to 100 μm.

  A semiconductor device according to one embodiment of the present invention (hereinafter referred to as a semiconductor device of the present invention) includes the film of the present invention as an insulating layer or a protective layer.

  The film of the present invention is an oxynitride film having an excellent dielectric breakdown electric field, and can be suitably used as an insulating film or a protective film in various semiconductor devices.

  The semiconductor device (element) is not particularly limited as long as the film of the present invention can be used as an insulating film and / or a protective film. For example, a transistor, a diode, a rectifier element, a photoelectric conversion element, a semiconductor integrated circuit , Light emitting diodes, varistors, thyristors, resistors, capacitors, and the like.

  A thin film transistor (TFT) which is one of semiconductor devices includes a gate electrode, a gate insulating film, an oxide semiconductor film in contact with the gate insulating film, and a source electrode connected to the oxide semiconductor film and separated by a channel portion And at least a drain electrode.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a thin film transistor.
The thin film transistor 1 has a gate electrode 20 sandwiched between a substrate 10 and an insulating film 30, and a semiconductor film 40 is stacked on the gate insulating film 30 as an active layer. Further, a source electrode 50 and a drain electrode 52 are provided so as to cover the vicinity of the end of the semiconductor film 40. A channel portion 60 is formed in a portion surrounded by the semiconductor film 40, the source electrode 50 and the drain electrode 52. The film of the present invention can be incorporated into a thin film transistor as a gate insulating film.

  The thin film transistor 1 in FIG. 1 is a so-called channel etch type thin film transistor, but the thin film transistor is not limited to a channel etch type thin film transistor, and an element configuration known in this technical field can be adopted.

  In the semiconductor device of the present invention, for example, a thin film transistor, it is preferable that the insulating layer made of the film of the present invention is provided on at least one surface of the gate electrode.

  In addition, the thin film transistor preferably includes a protective layer including the film of the present invention over at least a semiconductor layer among a source electrode, a drain electrode, and a semiconductor layer, and includes a protective layer, a semiconductor layer, and a substrate in that order.

  FIG. 2 is a schematic cross-sectional view showing an embodiment of a thin film transistor having a protective layer. 1 is different from the thin film transistor 1 of FIG. 1 in that a protective layer 70 is provided on the entire surface of the substrate 10 facing the surface on which the source electrode, the drain electrode, and the semiconductor layer are formed. The gate insulating film 30 and / or the protective layer 70 can be used.

FIG. 3 is also a schematic cross-sectional view showing an embodiment of a thin film transistor having another form of protective layer.
This is different from the thin film transistors 1 and 2 of FIGS. 1 and 2 in that the protective layer 72 is provided only on the semiconductor layer 40, but is otherwise the same.

Example 1
An n-type Si substrate (diameter 4 inches) having a resistivity of 0.1 Ωm was set in a sputtering apparatus (manufactured by ULVAC: MPS-6000C4), and a bulk resistance of 2.6 Ωm InGaZnO (In: Ga: Zn = 1: 1: 1 (atomic ratio)) a sputtering target made of an oxide sintered body was sputtered in a mixed gas atmosphere of DC 100 W, Ar, H ₂ O and N ₂ for 1000 seconds to form a 200 nm film. The flow rate of N ₂ in the mixed gas flow rate introduced during sputtering was 4% by volume, and the flow rate of H ₂ O in the mixed gas flow rate was 1% by volume.
Further, the obtained film was subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectroscopic analyzer (manufactured by ULVAC-PHI, Inc .: VersaProbell). As a result, In element, Ga element, Zn element, O element and N It was confirmed that the element was present.
The substrate was taken out and annealed in an electric furnace at 300 ° C. for 1 hour in air.
After this substrate was set in the sputtering apparatus together with Area Max again, Mo was deposited as an electrode at a thickness of 150 nm under the conditions of DC 100 W, Ar atmosphere, and 1200 seconds.

The element (Si / InGaZnON / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 2 × 10 ¹² Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 1.6 MV / cm, and the dielectric constant was 15.5.

Example 2
The device (Si / InGaZnON / Mo) was formed by the method described in Example 1 except that the flow rate of H ₂ O in the mixed gas flow rate was changed to 10% by volume in a mixed gas atmosphere of Ar, H ₂ O and N ₂ during sputtering. Got. Moreover, when X-ray photoelectron spectroscopy measurement was performed on the obtained film with an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI), In element, Ga element, Zn element, O element and N element were found to be present. Confirmed that it exists.

The element (Si / InGaZnON / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electric resistivity at the time of application was 4 × 10 ¹² Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 2.2 MV / cm, and the dielectric constant was 14.1.

Comparative Example 1
An element (Si / InGaZnO / Mo) was obtained by the method described in Example 1 except that a mixed gas atmosphere of Ar and H ₂ O was used during sputtering. The flow rate of H ₂ O in the introduced mixed gas flow rate at this time was 1% by volume. Further, when the obtained film was subjected to X-ray photoelectron spectroscopy measurement with an X-ray photoelectron spectroscopic analyzer (manufactured by ULVAC-PHI, Inc .: VersaProbell), In element, Ga element, Zn element and O element were present. It was confirmed.

About the obtained element (Si / InGaZnO / Mo), a semiconductor parameter analyzer (manufactured by Agilent: B1500) was used to measure the electrical resistivity. As a result, the temperature was 25 ° C. and the electric field was 0.1 MV / cm applied. The electrical resistivity was 5 × 10 ⁶ Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 1.0 MV / cm, and the dielectric constant was 15.5.

Example 3
As a sputtering target, a sputtering target made of an oxide sintered body of InGaZnO (In: Ga: Zn = 1: 3: 1 (atomic ratio)) with a bulk resistance of 1 × 10 ⁵ Ωm was used, and the atmosphere during sputtering was Ar. A film was formed in the same manner as in Example 1 except that the mixed gas atmosphere of O ₂ and N ₂ was changed to pulsed DC 100 kHz, and a device (Si / InGaZnON / Mo) was manufactured.
The flow rate of N ₂ in the mixed gas flow rate introduced during sputtering was 10% by volume, and the flow rate of O ₂ in the mixed gas flow rate was 1% by volume.
When a film obtained by sputtering was subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI), In element, Ga element, Zn element, O element and It was confirmed that N element was present.

The element (Si / InGaZnON / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 1 × 10 ¹² Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 2.5 MV / cm, and the dielectric constant was 13.0.

Comparative Example 2
A film was formed in the same manner as in Example 3 except that the atmosphere during sputtering was a mixed gas atmosphere of Ar and O ₂ , and an element (Si / InGaZnO / Mo) was manufactured.
The flow rate of O ₂ in the mixed gas flow rate introduced at the time of sputtering was 1% by volume.
When a film obtained by sputtering was subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI), In, Ga, Zn, and O elements exist. It was confirmed.

The element (Si / InGaZnO / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 9 × 10 ⁶ Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 1.5 MV / cm, and the dielectric constant was 13.5.

Example 4
As a sputtering target, a sputtering target made of an oxide sintered body of GaZnO (Ga: Zn = 9: 1 (atomic ratio)) with a bulk resistance of 1 × 10 ⁷ Ωm was used, and the atmosphere during sputtering was Ar, O _2, and An element (Si / GaZnON / Mo) was manufactured by forming a film in the same manner as in Example 1 except that the atmosphere was a mixed gas atmosphere of N ₂ and sputtering was performed at a pulse DC of 100 kHz.
The flow rate of N ₂ in the mixed gas flow rate introduced during sputtering was 10% by volume, and the flow rate of O ₂ in the mixed gas flow rate was 1% by volume.
The film obtained by sputtering was subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI). As a result, Ga element, Zn element, O element and N element were found to be present. Confirmed that it exists.

The element (Si / GaZnON / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C., and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 1 × 10 ¹² Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 4.5 MV / cm, and the dielectric constant was 10.1.

Comparative Example 3
A film was formed in the same manner as in Example 4 except that the atmosphere during sputtering was a mixed gas atmosphere of Ar and O ₂ , and an element (Si / GaZnO / Mo) was manufactured.
The flow rate of O ₂ in the mixed gas flow rate introduced at the time of sputtering was 1% by volume.
When a film obtained by sputtering is subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe all manufactured by ULVAC-PHI), there are Ga element, Zn element and O element. It was confirmed.

The element (Si / GaZnO / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 9 × 10 ⁶ Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 4.0 MV / cm, and the relative dielectric constant was 10.2.

Example 5
As a sputtering target, a sputtering target made of an oxide sintered body of InGaO (In: Ga = 1: 9 (atomic ratio)) with a bulk resistance of 9 × 10 ⁶ Ωm was used, and the atmosphere during sputtering was changed to Ar, O ₂ and A device (Si / InGaON / Mo) was manufactured by forming a film in the same manner as in Example 1 except that the mixed gas atmosphere of N ₂ was used and sputtering was performed at a pulse DC of 100 kHz.
The flow rate of N ₂ in the mixed gas flow rate introduced during sputtering was 10% by volume, and the flow rate of O ₂ in the mixed gas flow rate was 1% by volume.
When the film obtained by sputtering was subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI), the In element, Ga element, O element and N element were found to be Confirmed that it exists.

The element (Si / InGaON / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C. and the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 1 × 10 ¹² Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 4.2 MV / cm, and the relative dielectric constant was 10.3.

Comparative Example 4
A film was formed in the same manner as in Example 5 except that the atmosphere during sputtering was a mixed gas atmosphere of Ar and O ₂ , and an element (Si / InGaO / Mo) was manufactured.
The flow rate of O ₂ in the mixed gas flow rate introduced at the time of sputtering was 1% by volume.
When a film obtained by sputtering is subjected to X-ray photoelectron spectroscopy measurement using an X-ray photoelectron spectrometer (Versa Probe, manufactured by ULVAC-PHI), In element, Ga element and O element are present. It was confirmed.

The element (Si / InGaO / Mo) thus obtained was measured for electrical resistivity using a semiconductor parameter analyzer (manufactured by Agilent: B1500). The temperature was 25 ° C., the electric field was 0.1 MV / cm. The electrical resistivity at the time of application was 9 × 10 ⁶ Ωm. Furthermore, the dielectric breakdown electric field (Ec) was 3.9 MV / cm, and the dielectric constant was 10.5.

Example 6
The composition of the sputtering target used in Example 1-5 and Comparative Example 1-4 and the insulating film formed using the sputtering target was analyzed by high frequency inductively coupled plasma emission spectroscopy (manufactured by Agilent: ICP5100). As a result, it was confirmed that the target and the insulating film had the same composition.

（表中、ＩＧＺＯ−１は、実施例１で使用した原子比Ｉｎ：Ｇａ：Ｚｎ＝１：１：１であるＩｎＧａＺｎＯの酸化物焼結体からなるスパッタリングターゲットを指す。
ＩＧＺＯ−２は、実施例３で使用した原子比Ｉｎ：Ｇａ：Ｚｎ＝１：３：１であるＩｎＧａＺｎＯの酸化物焼結体からなるスパッタリングターゲットを指す。）

(In the table, IGZO-1 refers to a sputtering target made of an oxide sintered body of InGaZnO having an atomic ratio of In: Ga: Zn = 1: 1: 1 used in Example 1.)
IGZO-2 refers to a sputtering target made of an oxide sintered body of InGaZnO having an atomic ratio of In: Ga: Zn = 1: 3: 1 used in Example 3. )

The film of the present invention is useful as an insulating film or protective film for semiconductor devices.
Since the film of the present invention can be formed by a method with excellent productivity, particularly DC sputtering, the industrial productivity of semiconductor devices can be improved.

1, 2, 3 Thin film transistor 10 Substrate 20 Gate electrode 30 Gate insulating film 40 Semiconductor film 50 Source electrode 52 Drain electrode 60 Channel part 70, 72 Protective layer (protective film)

Claims (17)

It contains at least one metal element selected from In, Ga, Zn, Al, and Sn, an oxygen element, and a nitrogen element, and has an electric resistivity of 1 × 10 at a temperature of 25 ° C. and an electric field of 0.1 MV / cm. ^{7 A} membrane that is at least Ωm.   The film | membrane of Claim 1 containing Ga element.   Furthermore, the film | membrane of Claim 2 containing In element.   Furthermore, the film | membrane of Claim 2 or 3 containing Zn element.   The laminated body containing the film | membrane in any one of Claims 1-4.   A semiconductor device comprising the film according to claim 1 as an insulating layer or a protective layer.   The semiconductor device according to claim 6, wherein the insulating layer is provided on at least one side of the gate electrode. Including a source electrode, a drain electrode, a semiconductor layer and a substrate,
The semiconductor device according to claim 6, wherein the semiconductor device includes the protective layer on at least the semiconductor layer among the source electrode, the drain electrode, and the semiconductor layer, and includes the protective layer, the semiconductor layer, and the substrate in this order. . A method for producing a film in which a sputtering target comprising an oxide sintered body containing at least one metal element selected from In, Ga, Zn, Al and Sn is sputtered by introducing a gas containing a nitrogen element,
The method for producing a film according to any one of claims 1 to 4, wherein a flow rate of the gas containing the nitrogen element is 1% by volume or more and 100% by volume or less in a total flow rate of the introduced gas.   The film manufacturing method according to claim 9, wherein a flow rate of the gas containing the nitrogen element in the total flow rate of the introduced gas is 2% by volume or more and 50% by volume or less.   The method for producing a film according to claim 9 or 10, wherein the gas to be introduced contains water, and a water flow rate in a total flow rate of the gas to be introduced is 0.1 vol% or more and 50 vol% or less.   The manufacturing method of the film | membrane in any one of Claims 9-11 in which the said oxide sintered compact contains Ga element.   The manufacturing method of the film | membrane in any one of Claims 9-12 whose ratio of Ga element to all the metal elements in the said oxide sintered compact is 50-100 atomic%.   The method for producing a film according to claim 12 or 13, wherein the oxide sintered body contains an In element.   The manufacturing method of the film | membrane in any one of Claims 12-14 in which the said oxide sintered compact contains Zn element. The manufacturing method of the film | membrane in any one of Claims 9-15 in which the said oxide sintered compact contains In element, Ga element, and Zn element in the following atomic ratio range.
In / (In + Ga + Zn) = 0.001 to 0.998 Ga / (In + Ga + Zn) = 0.001 to 0.998 Zn / (In + Ga + Zn) = 0.001 to 0.998   The method for producing a film according to claim 9, wherein the sputtering is DC sputtering.

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