JP2007273548A - Electric resistance changing element, semiconductor device equipped with electric resistance changing element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistance changing element capable of reducing the variation of operating voltage upon forming. <P>SOLUTION: A resistance changing film 4, in which a metal oxide or a metallic oxynitride containing at least either one of Zr and Hf as a principal constituent is provided with fluorite structure, and a pair of first and second electrodes 2, 6 provided so as to pinch the resistance changing film are provided. The crystal structure of the resistance changing film is provided with Bevan cluster in a part or the whole of it and when V shows a vacancy, in which negative ion is not existing in a negative ion site in the fluorite type crystal structure, M shows the metallic element of the metal oxide or the metallic oxynitride and S shows the maximum octahedron type cavity site in the fluorite type crystal structure, the direction of array of a straight chain type continuous chain of (-S-V-M-V-S-) in the unit cell of the Bevan cluster is provided with the direction of crystal substantially orthogonal to the principal surface of the film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric resistance change element, a semiconductor device including the electric resistance change element, and a manufacturing method thereof.

With the widespread use of mobile phones and the like, a large amount of flash memory has been used. However, the flash memory has a problem that the writing speed is slow. Various non-volatile memories have been proposed in the past, but MRAM (Magnetic Random Access Memory), which has been considered to be capable of diverting the technology of hard disks that have been rapidly increased in capacity in recent years, and large-capacity DVD (Digital Versatile Disk) in recent years. In addition to PRAM (Phase change Random Access Memory), the technology of which is considered to be divertable, the operating principle is unknown, but RRAM (Resistive Random Access Memory) has been studied rapidly since the resistance change phenomenon was reported in recent years. ) The study of replacing the flash memory with a non-volatile memory based on a novel operating principle has progressed. In particular, the RRAM includes an electrical resistance change element having a simple element structure (see, for example, Patent Document 1), and according to the operation principle considered to be most prominent at present, the element size dependency (scaling problem) is almost the same. Because it is not, it is attracting attention.
JP 2005-317976 A

  However, in the RRAM, after the resistance change film of the electric resistance change element is formed, it is necessary to change the resistance change so that it can be programmed by a high voltage process called forming that breaks the insulation of the resistance change film. Since conventional forming is spontaneous breakdown, it is considered that the irregular forming path is such that defects randomly generated in the film due to high voltage stress are connected. In fact, as shown in FIG. 4A of Patent Document 1, it is considered that the voltage causing the resistance change varies in the range of 0.7 V to 1.2 V, and reflects an irregular dielectric breakdown path.

  The present invention has been made in consideration of the above circumstances, and provides an electric resistance change element capable of reducing variations in operating voltage during forming, a semiconductor device including the electric resistance change element, and a method for manufacturing the same. The purpose is to provide.

  The electrical resistance change element according to the first embodiment of the present invention includes a metal oxide or metal oxynitride containing at least one element of Zr and Hf as a main component, and the metal oxide or metal oxynitride is fluorescent. Stone-type structure, structure lacking anion sites in fluorite-type structure, structure distorted in a state where cubic fluorite-type crystal system becomes hexagonal crystal system, cubic fluorite-type crystal system is rhombohedral A resistance change film having a crystal structure which is one of the structures distorted into a crystal system, and a pair of first and second electrodes provided so as to sandwich the resistance change film, A crystal structure of the resistance change film has a Bevan cluster partly or entirely, V is a vacancy in which an anion does not exist at an anion site in a fluorite crystal structure, and M is the metal oxide or metal oxynitride Metal element, S, fluorite type When the largest octahedral-type void site in the crystal structure is used, the direction of the linear chain arrangement as “... -SVMVVS” in the unit cell of the Bevan cluster is the film. And having a crystal orientation that is substantially perpendicular to the principal plane of the substrate.

The resistance change film is formed by contacting at least two or more Bevan clusters in the “−VMVV−” direction, so that “−S− (VMVSV−) _n ” (n May have a chain in which the chain direction is substantially perpendicular to the main surface of the resistance change film.

In addition, between at least one of the first and second electrodes and the resistance change film,
A film having a metal oxide or metal oxynitride containing at least one of amorphous Zr and Hf as a main component may be provided.

  The electrical resistance change film may include oxynitride, and a nitrogen content ratio may be 10.0 atomic% or more and 57.1 atomic% or less.

  The chain direction of the resistance change film may be an angle of 10 degrees or less with respect to the normal line of the main surface of the resistance change film.

The crystals in the resistance change film are:
The composition formula is described by M ₂ ON ₂ (where M is one or more of Zr and Hf), and the space group to which the crystal belongs is Ia / 3 (international notation 206),
The composition formula is described by M ₇ O ₈ N ₄ (where M is one or more of Zr and Hf), and the space group to which the crystal belongs is R / 3 (International No. 146),
The composition formula is M ₇ O _{2 (4p + 3) / p} N _{4 (p−1) / p} (where M is one or more of Zr and Hf, p is an integer of 1 or more, and p is an odd number) Or p is a multiple of 6) and the space group to which the crystal belongs is P / 3 (International notation 143)
And the composition formula is M ₇ O _{2 (4p + 3) / p} N _{4 (p−1) / p} (where M is one or more of Zr and Hf, p is an integer of 1 or more, and p is 6) The space group to which the crystal belongs is R / 3 (international notation 146).
Any of these may be sufficient.

  The oxide or oxynitride includes Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Mg, Ca, Sr. , Ba contains one or more elements Me, and the total number of all kinds of the elements Me included in the oxide or oxynitride is [Me], and the oxide or oxynitride If the total number of elements Zr and Hf contained in [M] is [M], the ratio [Me] / ([Me] + [M]) may be 0.07 or more and 0.22 or less.

  A semiconductor device according to a second aspect of the present invention includes any one of the above-described electrical resistance change elements as a nonvolatile memory element of a memory device.

  A transistor having one end connected to the electrical resistance change element may be provided.

  A semiconductor device according to a third aspect of the present invention includes a nonvolatile logic element including the electrical resistance change element according to any one of the above and a transistor having one end connected to the electrical resistance change element. May be.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising: forming a first film made of a metal oxynitride containing at least one of Zr and Hf as a main component on a substrate;
Forming a second film containing a substance that crystallizes at a temperature of 800 ° C. or lower on the first film, and annealing the first film and the first film by performing annealing at a temperature higher than 800 ° C. And orienting so that the direction in which the energy at the interface with the second film is lowest is substantially perpendicular to the main surface of the first film.

  Note that the substance that crystallizes at a temperature of 800 ° C. or lower may contain silicon as a main component.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical resistance change element which can reduce the dispersion | variation in the operating voltage at the time of forming, a semiconductor device provided with this electrical resistance change element, and its manufacturing method can be obtained.

  Before describing embodiments of the present invention, the concept of the present invention will be described.

The structure in which the concept of the present invention is simplified is directed to a state in which the orientation of the crystal that facilitates dielectric breakdown in the resistance change film can be regarded as being perpendicular to the main surface of the film. In metal oxynitrides mainly containing zirconium or hafnium, Zr ₇ O ₈ N ₄ ([N] = 21.1 atomic%), Zr ₂ ON ₂ ([N] = 40.0 atomic%), Hf ₇ Compositions such as O ₈ N ₄ ([N] = 21.1 atomic%) and Hf ₂ ON ₂ ([N] = 40.0 atomic%) are known to be single phase, and the crystal structure is also known. . The metal oxynitride crystal includes “...- S- (VMV-S-) _n ...” (Where n is an integer of 1 or more, V is an anion at an anion site in a fluorite-type crystal structure) There is a chain such as vacancies such that M does not exist, M is a metal element constituting the metal oxynitride, and S is the largest octahedral void site in the fluorite crystal structure. When the chain as described above exists, the electron orbit of the metal element M extends to the vacancy site V of the anion, so that the band gap from the metal element M adjacent to the metal element M via the vacancy V on the chain. Becomes narrower and dielectric breakdown tends to occur.

  Such vacancies are not limited to zirconium or hafnium oxynitride, but also occur when a trivalent element or a divalent element is added to an oxide or nitride or oxynitride of zirconium or hafnium. It has been known. Further, in the oxide or nitride or oxynitride of zirconium or hafnium, “...- SV-Mm-VS -...” (Mm is Zr, Hf, Y, Sc, lanthanoid element, Al, Mg, Ca , Sr, Ba or more, V is a vacancy where no anion exists in the anion site in the fluorite crystal structure, S is the largest octahedral void site in the fluorite crystal structure) Since it is also known that the cohesive energy of crystals decreases when a chain is formed, it is possible to produce a direction in which dielectric breakdown is likely to occur even if such a substance is used.

  If the direction in which breakdown is likely to occur is oriented so that it can be regarded as being substantially perpendicular to the main surface of the film, the breakdown path is considered to be linear. Therefore, the present inventors have considered that it is possible to suppress variation in resistance change characteristics if a linear dielectric breakdown path can be formed by forming.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
A semiconductor device according to a first embodiment of the present invention is shown in FIG. The semiconductor device of this embodiment includes an electrical resistance change element (nonvolatile memory element) 1. The electrical resistance change element 1 is provided on a substrate 11 and includes a resistance change film 4 and two electrodes 2 and 6 formed so as to sandwich the resistance change film 4. As shown in FIG. 1, the resistance change film 4 has an orientation in which the 111 direction is perpendicular to the substrate 11.

  Next, a method for manufacturing the electrical resistance change element 1 according to this embodiment will be described.

First, an electrically conductive film is formed as an electrode 2 on the substrate 11. Various deposition methods are available, such as sputtering, CVD (Chemical Vapor Deposition) (including similar deposition methods such as ALD: Atomic Layer Deposition), MBE (Molecular Beam Epitaxy), solution coating, and hydrothermal synthesis. is there. Of these, sputtering and CVD are easy to balance film quality and industrial profitability. Examples of the electrically conductive film include various electrically conductive oxides such as SrRuO ₃ , metal compounds such as ZrN or HfN, and simple metals such as Ir and Pt. Although a substance having a small chemical reaction with the substance is preferable, it is not an essential condition.

  In addition, it is also possible to provide one or more barrier films between the substrate 11 and the electrically conductive film 2 so that the substrate 11 and the electrically conductive film 2 do not react. It is. In addition, the conductive film can be formed epitaxially on the substrate. It is also possible to sandwich one or more lattice relaxation films between the substrate and the electrically conductive film so that the electrically conductive film is epitaxial with respect to the substrate. In order to adjust the lattice constant of the substrate and the electrically conductive film, it is possible to apply stress or tension to the substrate or the electrically conductive film.

Next, a film 4 that can be regarded as having a composition of Hf ₂ ON _{2 is formed} on the electrically conductive film 2. The film forming method may be any of the methods described above, or a method of performing nitriding treatment after forming HfO ₂ is also possible. The Hf ₂ ON ₂ film 4 may be amorphous, or may be formed so as to have an orientation in which the 111 direction is perpendicular to the substrate 11 from the beginning. In the present embodiment, an orientation in which the 111 direction is perpendicular to the substrate 11 is obtained by a heat treatment described later. In general, those skilled in the art know that the crystallinity and orientation of a film can be changed by changing the film formation conditions. In this embodiment, an amorphous Hf ₂ ON ₂ film is formed by chemical sputtering.

In the present embodiment, an Hf ₂ ON ₂ film that is hafnium oxynitride is used as the resistance change film 4, but a Zr ₂ ON ₂ film can also be used. Zr and Hf are known to have very similar chemical properties and are known to be oxynitrides having a similar crystal structure. Because of their very similar chemical properties, it is difficult to completely separate them even with current technology. Usually available hafnium or zirconium contains about 1 atom% of each other as impurities. From this, the chemical similarity is clear. Those skilled in the art usually know that a structure having the same effect can be easily obtained by using either element of hafnium or zirconium. Since hafnium has a higher melting point than zirconium, it is preferable to use hafnium when heat resistance is required. Zirconium is more resource-intensive than hafnium and is inexpensive, so if zirconium has sufficient heat resistance, zirconium is sufficient. It is industrially preferable to use. The ionic radii of each other are almost the same and are dissolved in each other in an arbitrary composition. For example, it can be easily inferred that the same effect can be expected even with an oxynitride such as HfZrON ₂ in which both are equally mixed. The

Next, an electrically conductive film is formed as an electrode 6 on the Hf ₂ ON ₂ film 4. The same material as the electrode 2 below the Hf ₂ ON ₂ film 4 or a different material may be used. Subsequently, a spike annealing process at 1050 ° C. is performed on the laminated film including the electrode 2, the Hf ₂ ON ₂ film 4, and the electrode 6. As a result, the Hf ₂ ON ₂ film is oriented so that the 111 direction in which the energy at the interface is lowest is perpendicular to the substrate due to the influence of the interface. The X-ray diffraction profile of the Hf ₂ ON ₂ film 4 crystallized by such a method and the half-value width of the rocking curve are shown in FIGS.

  The peak appearing in the graph shown in FIG. 2 measured by the 2θ / θ method and the graph shown in FIG. 3 measured by the thin film method is different from the fact that the crystal showing the peak is oriented with respect to the substrate surface. Means. When actually examining the rocking curve, the rocking curve at 2θ = 31.04 ° shown in FIG. 4 and the rocking curve at 2θ = 64.36 ° shown in FIG. I understood. Therefore, it was found that the 111 direction of the crystal in the film forms an angle of 10 degrees or less with respect to the normal direction to the substrate surface.

The X-ray diffraction peak position from the hafnium oxynitride crystal is calculated to confirm that the X-ray diffraction peak position in the graph shown in FIG. 3 is from the Hf ₂ ON ₂ crystal. This is shown in 6 (a) and 6 (b). FIG. 6A shows the calculation results in the range of 2θ from 10 degrees to 70 degrees, and FIG. 6B shows the strength of FIG. 6A in the range of 2θ from 10 degrees to 28 degrees. It is the figure expanded twice. As can be seen from FIGS. 6A and 6B, since the X-ray diffraction peaks of hafnium oxynitride are similar to each other, it is difficult to identify which crystal is based only on the peak profile. .

Therefore, the results of fitting the measured peak positions to the calculated peak positions by the least square method are shown in FIGS. 7 (a) and 7 (b). FIG. 7A is a diagram showing a result of fitting so that the surface separation (dobs.) Corresponding to the observed peak position and the surface separation (dcalc.) Corresponding to the calculated peak position are minimized. FIG. 7B shows the calculated lattice constant. In FIG. 7A, h, k, and l indicate the crystal plane indices, do-dc indicates the difference between the interplanar spacing (dobs.) And the interplanar spacing (dcalc.), And Qo. Indicates the interplanar spacing (dobs. ) Represents the wave number of the X-ray, and Qc. Represents the wave number of the X-ray corresponding to the surface interval (dcalc.). In FIG. 7B, a represents a calculated lattice constant, and Δa represents a standard deviation. 7 (a) and 7 (b), when it is assumed that the crystal is a cubic (space group Ia / 3 (international notation 206)) Hf ₂ ON ₂ crystal, the measured value of the peak position is good as the calculated value. It turns out that they match. When other crystal structures were assumed, the measured values and the calculated values did not match, so it was found that the assumption of the crystal structure could be denied. The symbol “/ 3” means that the symbol “−” is added on the numeral 3.

In this process, it is necessary to pay sufficient attention to the interface layer. For example, if there is an interface reaction layer having a composition that suppresses the formation of crystal nuclei or crystal growth at the interface, more severe heat treatment conditions are required to form the oriented Hf ₂ ON ₂ film 4. As a specific example, when a silicide electrode film is used as the electrodes 2 and 6, a silicon atom constituting silicide is mixed in the Hf ₂ ON ₂ film, and an interface reaction phase made of HfSiON is formed to about 1 nm. Since crystal growth of HfSiON is suppressed more than that of Hf ₂ ON ₂ , processing at a higher temperature or longer time is required to achieve the present embodiment, and it is difficult to use in an actual LSI process. is required. As another example of not paying sufficient attention to the interface, for example, when the morphology is poor at the interface, crystal growth is particularly induced at the tip, and the crystal orientation after annealing is disturbed or the morphology is poor. It will come to enlarge.

The Hf ₂ ON ₂ crystal is a cubic crystal and can be regarded as a structure in which anions having a fluorite-type crystal structure are deficient (vacancies are generated at the anion sites). As shown in FIG. 8, the Hf ₂ ON ₂ film 4 oriented so that the film thickness direction is the 111 direction is “...− S− (V−Hf−V−S−) _n . There is a chain that tends to cause dielectric breakdown. However, n is a sufficiently large value, and is an integer value that can be practically regarded as a value obtained by dividing the crystal grain size in the film by the basic period of the chain. In addition to the 111 direction, there are chains in the directions 11-1, 1-11, and -111. The angle formed by the film thickness direction of the Hf ₂ ON ₂ film 4 is 70.5 as shown in FIG. It is unlikely that dielectric breakdown will occur in that direction.

  From the above, the electrical resistance change element 1 of the present embodiment has a dielectric breakdown because the direction of the chain of holes is substantially perpendicular to the film surface as shown in FIG. The path is in a direction substantially perpendicular to the membrane surface. In this specification, the fact that the dielectric breakdown path (chain direction) is substantially perpendicular to the film surface means that the dielectric breakdown path is within 10 degrees with respect to the normal of the film surface. To do.

  On the other hand, in the conventional electric resistance change element, as shown in FIG. 19B, the holes formed in the resistance change film 40 are not formed in a direction substantially perpendicular to the film surface, but are bent. Therefore, the dielectric breakdown path is not in a direction substantially perpendicular to the film surface.

  As described above, according to this embodiment, the resistance change film 4 has a chain in which dielectric breakdown is likely to occur in the 111 direction, that is, the direction perpendicular to the film surface. For this reason, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

(Second Embodiment)
Next, a semiconductor device according to a second embodiment of the invention will be described.

In the semiconductor device of the first embodiment, the resistance change film 4 is an Hf ₂ ON ₂ film (or Zr ₂ H ₂ , Zr _x Hf _1-x ON ₂ ) having a nitrogen composition ratio [N] of 40.0 atomic%. Hf ₇ O ₈ N ₄ film (or Zr ₇ O ₈ N ₄ film, Zr _x Hf _1-x O ₈ N ₄ film) having a nitrogen composition [N] of 21.1 atomic% is used. It is also possible to use it. The semiconductor device according to the second embodiment has a configuration in which an Hf ₇ O ₈ N ₄ film is used as the resistance change film 4 in the semiconductor device according to the first embodiment.

The Hf ₇ O ₈ N ₄ crystal is rhombohedral (space group R / 3 (international notation No. 146)) and can be regarded as a structure in which a cubic fluorite crystal is deformed in the 111 direction. The symbol “/ 3” means that the symbol “−” is provided on the number 3. There are some defects in the anion site when it is regarded as a fluorite structure, and FIG. As shown in FIG. 1, a chain that easily causes dielectric breakdown such as “... -S- (V-Hf-V-S-) _n ...” Is generated in the 111 direction, where n is a sufficiently large value. It is an integer value that can be virtually regarded as the value obtained by dividing the crystal grain size by the basic period of the chain.The unit cell of this crystal structure is a Bevan cluster, and the Bevan cluster is equal to the crystal grain size in the chain direction. It is a structure that is laminated to the length of. The van cluster has a form as shown in FIG. 10B and is basically a fluorite-type structure, but a cluster such as M ₇ A _14-2 is formed by the absence of two anion sites. Here, M represents Hf or Zr, and A represents an anion.

It is also possible to take the rhombohedral crystal as a coordinate axis. In this case, the rhombohedral crystal is a hexagonal crystal and the chain is in the 0001 direction. In the case of Hf ₇ O ₈ N ₄ , the chain is limited to the 111 direction when the rhombohedral coordinate axis is adopted, that is, the 0001 direction when the hexagonal coordinate axis is adopted.

  As described above, according to the present embodiment, the resistance change film 4 has a chain in which dielectric breakdown is likely to occur in the 111 direction when the rhombohedral coordinate axis is adopted, that is, in a direction substantially perpendicular to the film surface. ing. For this reason, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

(Third embodiment)
Next, a semiconductor device according to a third embodiment of the present invention will be described.

The semiconductor device of this embodiment is the same as the resistance change film 4 of the semiconductor device of the first embodiment, but is an Hf ₇ O _9.2 N _3.2 film having a nitrogen composition ratio [N] of 16.5 atomic% (or Zr ₇ O _9.2 N _3.2 film, Zr _x Hf _1-x O _9.2 N _3.2 film). Note that a Zr ₇ O _9.2 N _3.2 film or a Zr _x Hf _1-x O _9.2 N _3.2 film may be used instead of the Hf ₇ O _9.2 N _3.2 film.

The Hf ₇ O _9.2 N _3.2 crystal is rhombohedral (space group P / 3 (international notation No. 143)), and five Bevan clusters are represented by “-S- (V-Hf-VS— ) It is a structure in which one layer of M ₇ O ₁₄ cluster is laminated so as to form a ₅ ”chain, and then has the same shape as one layer of Bevan cluster, but has no defect at the anion site. Here, M represents Hf or Zr.

Therefore, in the case of a crystal structure having such a composition, the chain is interrupted in five periods, and a structure in which a layer having no defect for one period is sandwiched, that is, “...- S-{(V-Hf-VS— ) ₅ (O—Hf—O—S—)} _m ... Here, m represents an integer of 1 or more.

  In this case as well, by forming the crystal so that the 111 direction is the normal direction of the substrate, a chain in which 5 cycles of dielectric breakdown is likely to occur is substantially oriented in the film thickness direction. It can be seen that there is an effect of inducing the linearity to align the characteristics after dielectric breakdown.

  As described above, this embodiment can also reduce variations in the operating voltage during forming, as in the first or second embodiment. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

(Fourth embodiment)
Next, a semiconductor device according to a fourth embodiment of the present invention is described.

In the third embodiment, the resistance change film 4 is an Hf ₇ O _9.2 N _3.2 film (or Zr ₇ O _9.2 N _3.2 ) having a nitrogen composition ratio [N] of 16.5 atomic%. Film, Zr _x Hf _1-x O _9.2 N _3.2 film, etc.), but more generally the composition ratio [N] of nitrogen is 100 × (4p−4) / (19p + 2) atomic% _{Hf 7 O 2 (4p + 3} ) / p N 4 (p-1) / p film _{(Zr 7 O 2 (4p +} 3) / p N 4 (p-1) / p _{layer, Zr 7x Hf 7 (1-} x) O _{2 (4p + 3) / pN4 (p-1) / p} film) can be used. Here, p is an integer of 1 or more. The semiconductor device of the fourth embodiment has a configuration in which the Hf ₇ O _{2 (4p + 3) / p} N _{4 (p−1) / p} film is used as the resistance change film in the semiconductor device of the third embodiment.

  In this case, if p is an odd number, or if p is a multiple of 6, the space group of the crystal is P / 3, and p is a multiple of 6 plus 2 or p is a multiple of 6 The space group of the crystal is R / 3 in the case of an integer obtained by adding 4 to.

In this case, (V-1) Bevan clusters (p-1) are stacked so as to form a "-S- (V-Hf-VS-) _(p-1) " chain, and then the same shape as a single layer of Bevan cluster. However, it is a structure in which one layer of M ₇ O ₁₄ clusters having no defect at the anion site is laminated. Here, M represents Hf or Zr.

Therefore, in the case of a crystal structure having such a composition, the chain is interrupted at a (p-1) period, and a structure in which a layer having no defect for one period is sandwiched, that is, "... -S-{(V-Hf- V-S-) _(p-1) (O-Hf-O-S-)} _m . Here, m is an integer of 1 or more.

  In this case as well, by forming the crystal so that the 111 direction is substantially the normal direction of the substrate, a structure in which the dielectric breakdown for (p-1) periods tends to occur is oriented in the film thickness direction. . Thereby, it can be seen that there is an effect that the dielectric breakdown path is guided linearly and the characteristics after dielectric breakdown are made uniform.

In particular, when p = 2, [N] = 10.0 atomic% Hf ₇ O ₁₁ N ₂ film (or Zr ₇ O ₁₁ N ₂ film, Zr _7x Hf _{7 (1-x)} O ₁₁ N ₂ film The structure is such that one layer of a Bevan cluster and an M ₇ O ₁₄ cluster having the same shape as the one layer of the Bevan cluster but having no defects at the anion site are laminated. However, M is Hf or Zr.

In such a case, the situation is "...- S- (V-Hf-V-S-O-Hf-OS-) _m ..." where "...- S- (V-Hf-V-S-"). ) ... "is the shortest chain, but there is no change in the situation in which dielectric breakdown in the 111 direction is most likely to occur because the arrangement such as V-Hf-V faces the 111 direction.

  As described above, according to the present embodiment, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

(Fifth embodiment)
Next, a semiconductor device according to a fifth embodiment of the present invention will be described with reference to FIG. The semiconductor device of this embodiment has a configuration in which the electrical resistance change element 1 in the semiconductor device of the first embodiment shown in FIG. 1 is replaced with the electrical resistance change element 1A shown in FIG. The electrical resistance change element 1A according to the present embodiment is the electrical resistance change element shown in FIG. 1, in which the resistance change film 4 has an amorphous film 7 and a dielectric breakdown induction path in the film thickness direction (direction perpendicular to the film surface). The film 8 is replaced with a laminated film with the film 8 having.

  Next, a method for manufacturing the electrical resistance change element according to this embodiment will be described.

  First, a conductive film to be the electrode 2 is formed on the silicon substrate 11. Subsequently, an amorphous HfON film 7 having a nitrogen composition ratio [N] of 40 atomic% was formed on the conductive film 2. A polycrystalline silicon film serving as the electrode 6 was formed on the HfON film 7, and spike annealing (about several milliseconds) was performed at 1065 ° C. FIG. 12 shows a cross-sectional photograph of the electrical resistance change element configured as described above.

As can be seen from FIG. 12, the columnar crystal 8 of Hf ₂ ON ₂ is formed on the side of the HfON film 7 in contact with the polycrystalline silicon film 6. FIG. 13 shows the orientation of the Hf ₂ ON ₂ columnar crystal 8 examined with respect to each crystal. From FIG. 13, it can be seen that most crystals are oriented so that the 111 direction is the film thickness direction. The fact that the crystal orientation reflects the information of the film deposition direction means that the crystal nucleus is generated in the portion having the information of the film deposition direction, that is, the interface portion of the HfON film 7. It is none other than. 12 and 13, crystal nuclei are generated at the interface with the polycrystalline silicon film 6 on the side where silicon is not contained up to the interface of the HfON film 7, and the crystal nuclei have low energy at the interface. 12 and FIG. 13 can be understood by assuming that the columnar Hf ₂ ON ₂ crystal 8 is grown in the 111 direction as described above and the columnar Hf ₂ ON ₂ crystal 8 is grown from the above crystal nucleus.

  On the other hand, on the substrate side where silicon is considered to be mixed at the interface, it is considered that crystal nucleation or crystal growth was suppressed due to silicon, and as a result, it remained amorphous even after annealing. Therefore, FIG. 12 and FIG. 13 are photographs simply showing that controlling the interface layer is important for producing the structure of this embodiment.

  Even a film in which annealing for crystallization is insufficient and an amorphous portion remains as shown in FIG. 12 is sufficiently effective for suppressing, for example, variations in driving voltage of the RRAM. This is because the thickness of the amorphous part, that is, the part where the irregular dielectric breakdown occurs is reduced, so that the variation is reduced.

  It is desirable that the amorphous portion be suppressed to the size of a stress-induced defect site (relatively large for HfSiON, about 2 nm to 4 nm). This is because, since dielectric breakdown occurs at most one defect, the dielectric breakdown path can be maintained in a straight line. Thus, if the film thickness of the amorphous part is about the size of the stress-induced defect site, the same effect of suppressing characteristic variation as the structure without the amorphous part already described can be expected.

  If a structure in which an amorphous part remains as described above is adopted, it can be applied in a relatively wide range of heat treatment conditions. For example, depending on spike annealing, the distribution of the heat treatment temperature in the substrate surface may be a problem. There is a great advantage that even if there is a temperature distribution in the substrate surface, there is no effect on variation in characteristics.

  In this embodiment, the spike annealing is performed at 1065 ° C. However, since the polycrystalline silicon film formed on the HfON film 7 is crystallized at a temperature of 800 ° C. or lower, the spike annealing is performed at a temperature exceeding 800 ° C. You may go.

  As described above, according to the present embodiment, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

  In the present embodiment, it goes without saying that the same effect can be obtained even if Zr or an alloy of Hf and Zr is used instead of Hf.

(Sixth embodiment)
Next, a semiconductor device according to a sixth embodiment of the present invention will be described.

  In the fifth embodiment, an amorphous HfON film having a nitrogen composition ratio (that is, nitrogen concentration) of 40 atomic% is formed. However, in the semiconductor device of the sixth embodiment, amorphous HfON having a nitrogen concentration of 40 atomic% is formed. Instead of the film, an amorphous HfON film having a nitrogen concentration of 50 atomic% is formed.

When such a HfON film having a nitrogen concentration of 50 atomic% is annealed and grown to crystal, the Hf ₂ ON ₂ crystal part having a nitrogen concentration of 40 atomic% is left amorphous without being crystallized. In addition, excess nitrogen is concentrated and separated into an amorphous HfON film portion having a nitrogen concentration higher than 50 atomic% before annealing.

Note that the upper limit of the nitrogen concentration of the amorphous HfON film is 57.1 atomic%. This is because the amorphous HfON film at this time becomes Hf ₃ N ₄ having a nitrogen concentration of 57.1 atomic%. This is because Hf ₃ N ₄ is known as a metastable insulator and is known to exist stably even after heat treatment at about 1000 ° C. If there is even a small amount of oxygen during the annealing, it is estimated that Hf ₂ ON ₂ is deposited by the amount of oxygen, and after the oxygen is exhausted, it is in an Hf ₃ N ₄ amorphous state.

On the other hand, an HfON film having a nitrogen concentration exceeding 57.1 atomic% deviates from the range of (HfO ₂ ) _1-x (Hf ₃ N ₄ ) _x , which is a quasi-alloyed composition formula, and nitrogen is single in the film. There is a high possibility that the separated gas is contained in the form of bubbles, and there is a concern about the adverse effect on device characteristics.

Further, the lower limit of the nitrogen concentration is considered to be 10.0 atomic%. This is because when the nitrogen concentration is 10.0 atomic% or less, not only the above-mentioned chain does not occur, but also HfO ₂ crystals are precipitated, which may make it difficult to produce an oriented state.

  As described above, according to the present embodiment, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

  In the present embodiment, it goes without saying that the same effect can be obtained even if Zr or an alloy of Hf and Zr is used instead of Hf.

(Seventh embodiment)
Next, a semiconductor device according to a seventh embodiment of the invention will be described.

  The resistance change film 4 in the first to fourth embodiments or the film 8 having the dielectric breakdown induction path in the fifth to sixth embodiments is an oxide or oxynitride of Hf or Zr, or an oxide of an alloy of Hf and Zr. Or oxynitride. In the semiconductor device of this embodiment, as the resistance change film 4 or the film 8 having a dielectric breakdown induction path, an oxide or oxynitride of Hf or Zr, an oxide or oxynitride of an alloy of Hf and Zr, and a rare earth element are used. (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) or alkaline earth elements (Mg, Ca, Sr, Ba) or Al 7 to 22 atomic% is included. That is, the oxide or oxynitride includes any one or more elements Me of rare earth elements, alkaline earth elements, and Al, and all of the elements Me included in the oxide or oxynitride. [Me] / ([Me] + [M] where [Me] is the total number of elements of the above type and [M] is the total number of elements of Zr and Hf contained in the oxide or oxynitride. ]) Is 0.07 or more and 0.22 or less.

  Such a crystal has a fluorite structure, or a structure that can be regarded as a displacement structure at the atomic position (displacement without atomic diffusion, a martensitic displacement), or a derivative structure caused by an atomic defect at the atomic position. Thus, an orientation is produced such that the 111 direction when regarded as a fluorite-type crystal structure is substantially parallel to the film thickness direction.

  Rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) or alkaline earth elements (Mg, Ca, Sr, Ba) to be added ) Or that Al is preferably contained in an amount of 7 atomic% or more and 22 atomic% or less corresponds to the fact that ion conductivity is known to increase in this composition range (see, for example, FIG. 14). 14 is quoted from A. Kvist, Physics of electrolyte (ed. J Hladic) vol. 1 Academic Press ('72).

  High ion conductivity means that the anion site is deficient. As shown in Fig. 15 (Diffuse scattering and disorder in zirconia, Friedrich Frey, Hans Boysen and Ines Kaiser-Bischoff, quoted from Z. Kristallogr. 220 (2005) 1017-1026) It is known that the pair tends to be paired, and a shape like a Bevan cluster appears locally.

  However, in this structure, an arrangement such as “—S (—V—Mm—V—S) —” (where Mm is one or more of Hf, Zr, rare earth element, alkaline earth element, and Al) has 111 directions, This is a situation that occurs randomly in the 11-1 direction, the 1-11 direction, and the -111 direction.

  When the additive element is less than 7 atomic%, the arrangement is far away from each other, so that dielectric breakdown hardly occurs. When the added element exceeds 22 atomic%, the arrangement becomes easy to chain, but the ionic radius of the element added to the cation site is different from the ionic radius of Hf or Zr. The conductivity of is reduced. That is, dielectric breakdown is less likely to occur.

  Even if there is a defect in the anion site near the rare earth element, alkaline earth element, or Al, the d-orbital of the rare earth element, alkaline earth element, or Al is empty, so dielectric breakdown is likely to occur in the band. is not.

Therefore, the dielectric breakdown induction mechanism of this embodiment is based on a principle different from that of the first to sixth embodiments. That is, an anion flows by applying an electric field, and as a result, a chain such as “−S (−V−Mm−V−S) _p −” is aligned in the film thickness direction, and is not on the chain but in the vicinity of the chain. This is due to a mechanism in which dielectric breakdown occurs due to deficiency of the anion. However, p represents an integer of 2 or more, and Mm represents one or more of Hf, Zr, rare earth elements, alkaline earth elements, and Al.

  Considering the mechanism according to the present embodiment, it is expected that the dielectric breakdown path is more complicated as compared with the configuration shown in the first to sixth embodiments. However, this may be sufficient in practice.

  As described above, according to the present embodiment, it is possible to reduce variations in operating voltage during forming. Thereby, an electrical resistance change element with uniform operating characteristics can be obtained.

In the first to seventh embodiments, as the material of the electrodes 2 and 6 for the resistance change film (hereinafter simply referred to as electrode material), for example, an electrically conductive oxide such as SrRuO ₃ , ZrN or HfN is used. Such metal compounds and simple metals such as Ir and Pt can be used.

  It is also possible to use TiN or TiAlN as the electrode material. TiN and TiAlN can be epitaxially grown on 100 surfaces of a silicon substrate, and are chemically stable and have a melting point of about 3290 ° C., so there is no diffusion to the resistance change film even when heat treatment is performed. There are advantages such as. Although TiAlN has an advantage of better oxidation resistance than TiN, there is a problem that manufacturing conditions become slightly severe.

  Further, ZrN, ZrAlN, HfN, HfAlN, or the like can be used as the electrode material. These also have high melting points. ZrN has a melting point of 2960 ° C. and HfN has a melting point of 3305 ° C. Although there is no accurate data on the melting points of ZrAlN and HfAlN, they are expected to be slightly higher than the melting points of ZrN and HfN, respectively. In addition to being chemically stable, there are advantages such as no diffusion to the resistance change film even when heat treatment is performed. Other metal nitrides generally have a high melting point, are chemically stable, and exhibit metallic electrical conductivity. For example, TaN has a high melting point of 3090 ° C, NbN has a high melting point of 2300 ° C, VN has a high melting point of 2050 ° C, and the like, and is a chemically stable metal.

In addition, an oxide of a platinum group element such as RuO _X , OsO _X , RhO _X , IrO _X , PdO _X , or PtO _X can be used as the electrode material. Although these melting points exceed 1000 ° C. at the maximum and are not necessarily high, since they are oxides that exhibit metallic electrical conduction, they are chemically different from resistance change films such as oxides or oxynitrides. There is an advantage such as excellent stability. In addition to these, SrRuO ₃ , Sr ₂ RuO ₄ , BaRuO _{3 and the} like are also known as oxides exhibiting metallic electrical conduction. The melting point of the platinum group oxide to which these alkaline earth metals are added exceeds 1000 ° C. and is considered to be more preferable. In particular, SrRuO ₃ is one of the most preferred electrode materials. These addition, for example a single metal oxide NbO, etc. and MoO _2, LaTiO ₃ perovskite similar composite metal _{oxide, LaVO 3, SrFeO 3, CaVO} 3, SrMoO 3, SrIrO 3, BaMoO 3, BaIrO 3, _{CaMoO 3, CaNbO 3, SrNbO 3} , BaNbO 3, KMoO 3, LaMnO 3, LaNiO 3, SrCrO 3, Pb 2 M 2 O 7, LiTi 2 O 4, YCoO 3, ErCoO 3, LaCoO 3, Ln 2 NiO 4 ( Ln is a lanthanoid element), La ₄ BaCu ₅ O ₁₃ , La ₅ SrCu ₆ O ₁₅ , Bi ₄ Se ₄ Cu ₅ O _{19 + y} and the like, and pyrochlore complex oxide A ₂ B ₂ O _7-x (A is Y, Ln) (Ln is a lanthanoid element), Tl, In, Pb, Bi B, Cd, etc. B is Ti, V, Cr, Mn, Nb, Mo, Zr, Tc, Hf, Re, Ru, Rh, Pd, Os, Ir, Pt, Si, Ge, Sn, Ga, Sb, etc.) Or La _(2-x) Ba _x CuO ₄ (x is a value that becomes a superconducting composition or an overdoped composition region), La _(2-x) Sr _x CuO ₄ (x is a value of a copper oxide high-temperature superconductor ₎ Superconducting expression composition or value that becomes an excessively doped composition region), YBa ₂ Cu ₃ O ₇ , YmBa ₂ Cu ₃ O ₇ (Ym is Yt, Lu, Tm, Ho, etc.), Bi ₂ Sr ₂ Ca _{(n-1) Cu n O (2n + 4)} (n = 1,2,3), TlM 2 Ca (n-1) Cu n O (2n + 2.5) ( n is an integer from 1 to 5, M is Ba or Sr), Tl _{2 M 2 Ca (n-1} ) Cu n O (2n + 4) (n is From up to 3 integers, M is Ba or _{Sr), HgBa 2 Ca (n} -1) Cu n O (2n + 2) ( n is an integer from 1 to _{3), Nd (2-x} ) Ce x CuO 4, Sr _(1-x) Nd _x CuO ₂ , Sr _(1-x) Ba _x CuO ₂ (where x is a superconducting expression composition or an overdoped composition region), La _1.6 Sr _0.4 CaCu ₂ O ₆ , La _1.7 Ca _1.3 Cu ₂ O ₆ or the like, Ba _(1-x) K _x BiO ₃ (x is a value that becomes a superconducting expression composition or an excessively doped composition region _{) of} an oxide superconductor, Sr ₂ RuO ₄ , BaPb _(1-x) Bi _x O ₃ , Bi _(2-x) Gd _x Ru ₂ O ₇ , La _(1-x) Sr _x MnO ₃ , Zn _(1-x) Li _x V ₂ O ₄ etc. and, compositional deviation oxide semiconductor _SnO 2, TiO _{, Cu 2 O, Ag 2 O} , In 2 O 3, Tl 2 O 3, ZnO, BaTi (Nb) O 3, SrTi (Nb) O 3, LaCrO 3, WO 3, TlOF like or by being doped Mott insulators NiO, CoO, CuO, Cr ₂ O ₃ , MnO, (V _(1-x) Cr _x ) ₂ O ₃ , Fe ₃ O ₄ , VO ₂ , which have come to exhibit metallic electrical conduction, Ti ₂ O ₃ , Ti _n O _(2n−1) (n is an integer from 3 to 6), etc., and EuO _x (Gd) of the f-electron electric conductor (x is a value of 1.5 or more and 2 or less) Etc. are also possible. Although a substance having a small chemical reaction with a surrounding substance after heat treatment at about 1050 ° C. is preferable, it is not an essential condition.

Further, as electrode materials, HfB, HfB ₂ , HfC, TaB, TaC, TaC ₂ , Ta ₂ C, TaN, WB, WC, W ₂ C, WC ₂ , WN, which are compound-based electrical conductors not containing oxygen, ReB, ReC, ReN, OsB, OsC, OsN, IrB, IrC, IrN, PtB, PtC, PtN, RuB, RuC, RuN, RhB, RhC, RhN, PdB, PdC, PdN, LnB ₆ (Ln is a lanthanoid element) , LnC (Ln is a lanthanoid element), LnN (Ln is a lanthanoid element), ZrB, ZrB ₂ , ZrC, NbB, NbC, NbC ₂ , Nb ₂ C, NbN, MoB, MoC, Mo ₂ C, MoN, TiB, TiB _{2, TiC, VB, VC,} VN, CrB, CrC, Cr 3 C 2, CrN, MnB, MnC, MnN, Fe FeC, FeN, CoB, CoC, CoN, NiB, NiC, NiN, HfSi, ZrSi, TiSi, TaSi, WSi, ReSi, OsSi, IrSi, PtSi, NbSi, MoSi, RuSi, RhSi, PdSi, VSi, CrSi, MnSi FeSi, CoSi, CoSi ₂ , NiSi, NiSi ₂ , LnSi (Ln is a lanthanoid element), or the like can also be used. Since these have a high melting point, there is an advantage that there is little contamination with the resistance change film.

  Also, as the electrode material, refractory metals such as Hf, Zr, Ti, Ta, W, Re, Os, Ir, Pt, Nb, Mo, Ru, Rh, Pd, V, Cr, Mn, Fe, Co, Ni It is also possible to use simple substances, alloys thereof, and elements obtained by adding elements to these refractory metals. The advantages due to the high melting point are the same as above.

(Eighth embodiment)
Next, a method for fabricating a semiconductor device according to the eighth embodiment of the present invention will be described with reference to FIGS. The semiconductor device manufactured by the manufacturing method of the present embodiment is a storage device having at least one memory cell, and the memory cell is the electrical resistance change element according to any one of the first to seventh embodiments, for example, The electrical resistance change element 1 according to the first embodiment and a selection transistor are provided.

  First, an amorphous HfON gate insulating film 24 is formed on the silicon substrate 11. The composition is such that the nitrogen composition ratio [N] is 21.1 atomic%. At both interfaces of the HfON gate insulating film 24, SiON films 24a and 24b containing silicon as a main component are formed. A polycrystalline silicon film 26 is formed on the HfON gate insulating film 24 via the interface film 24b. Thereafter, the polycrystalline silicon film 26, the interface film 24b, and the HfON gate insulating film 24 are patterned into a gate electrode shape. Subsequently, ions are implanted to form source / drain regions 22a and 22b in the silicon substrate 11 (see FIG. 16).

Next, as shown in FIG. 17, an amorphous Hf ₇ O ₈ N ₄ film 4 is formed in a region including the source / drain regions 22a and 22b of the transistor, but SiON is not formed at least on the upper interface, and Hf _{The 7} O ₈ N ₄ film 4 is exposed.

Next, a polycrystalline silicon film to be the electrode 6 is formed on the Hf ₇ O ₈ N ₄ film 4 directly above the region 22b and patterned, whereby the transistor 20 and the electric resistance change element (nonvolatile memory element) 2 And the source / drain regions 22a and 22b of the transistor 20 are exposed. Thereafter, spike annealing at 1100 ° C. is performed. As a result, the polycrystalline silicon and the source / drain regions 22a and 22b of the transistor are activated so as to be conductive, and the HfON of the gate insulating film 24 of the transistor 20 is amorphous. Then, the Hf ₇ O ₈ N ₄ film 4 is formed so that the film thickness direction is the 111 direction. With such a manufacturing method, a memory cell having one select transistor 20 is manufactured for one nonvolatile memory element 1 (see FIG. 18).

In this embodiment, even if Zr or an alloy of Hf and Zr is used instead of Hf, the same effect can be obtained as in the case described in the first embodiment. Further, in the present embodiment, in place of the _Hf 7 _O 8 _{N 4} as the resistance change layer 4, it may be used _Hf 2 ON ₂ and _Zr 7 _O 8 _{N 4} and _Zr 2 ON _2.

(Ninth embodiment)
Next, a method for fabricating a semiconductor device according to the ninth embodiment of the present invention will be described with reference to FIGS. The semiconductor device manufactured by the manufacturing method of the present embodiment is a memory device, and has a configuration in which the nitrogen composition of the resistance change film manufactured by the manufacturing method of the eighth embodiment is changed.

  First, an amorphous HfON gate insulating film 24 is formed on the silicon substrate 11. The composition of the amorphous HfON gate insulating film 24 is such that the nitrogen composition ratio [N] is 15.4 atomic%. Both interfaces of the HfON gate insulating film 24 are provided with interface films 24a and 24b made of HfSiON having Hf / (Hf + Si) of 15 atomic%, and the nitrogen concentration [N] of these interface films 24a and 24b is 17 atomic%. And Subsequently, after forming an electrode film 26 made of TiN, gate processing is performed. Subsequently, source / drain regions 22a and 22b are formed by ion implantation.

Next, as shown in FIG. 17, an amorphous Hf ₇ O _9.5 N ₃ film 4 is formed in a region including the source / drain regions 22a and 22b, but SiON is not formed at least on the upper interface, and Hf _{The 7} O _9.5 N ₃ film 4 is exposed.

  An electrode 6 made of Pt is formed on these, and a structure made of a gate and a nonvolatile memory element is formed by etching to expose the source / drain regions 22a and 22b of the transistor (FIG. 18).

Thereafter, spike annealing at 1100 ° C. is performed. As a result, the source / drain regions 22a and 22b of the transistor 20 are activated so as to be conductive, and the HfON of the gate insulating film 24 of the transistor 20 is amorphous, but the film thickness is in the nonvolatile memory element 1 portion. The Hf ₇ O _9.5 N ₃ film 4 is formed so that the direction is the 111 direction. With such a manufacturing method, an element structure having one read transistor is manufactured for one nonvolatile memory element.

  Since Pt is easily crystallized by heat treatment at 800 ° C. or lower, it can be expected to promote the generation of crystal nuclei in the electrical resistance change film. In addition to Pt, a similar manufacturing method is possible as long as it is a material that is easily crystallized at 800 ° C. or lower.

  In the present embodiment, it goes without saying that the same effect can be obtained even if Zr or an alloy of Hf and Zr is used instead of Hf.

(10th Embodiment)
Next, the semiconductor device of this embodiment will be described with reference to FIG. The semiconductor device of this embodiment is an integrated memory device having a select transistor type (1T1R type) arrangement, and its schematic configuration is shown in FIG. The integrated memory device of this embodiment has a configuration in which the electrical resistance change element described in the first to seventh embodiments is used as the nonvolatile memory element 183 of the memory cell. In this case, the memory cell includes a nonvolatile memory element 183 and a selection transistor 182. Such a configuration of the memory cell has an advantage that high-speed operation is possible, but has a disadvantage that the memory cell becomes large. Note that the memory cell is provided in an intersection region between the bit line 185 and the word line 184. One end of the nonvolatile memory element 183 is connected to the bit line 185, and the other end is connected to one of the source and the drain of the selection transistor 182. The other of the source and the drain of the selection transistor 182 is connected to the read word line 186 and the gate is connected to the word line 184.

  Further, the electrical resistance change element described in the first to seventh embodiments can be used as the memory cell 183 of the integrated memory device having the cross-point type (1R type) arrangement shown in FIG. In this case, no selection transistor is required, and the electric resistance change element is depicted as an electric resistance change element 183 shown in FIG. Such a structure is advantageous for high integration by minimizing the area of the memory cell. However, if the resistance change amount of the resistance change film is not sufficiently large, the same word line 184 or the same bit shown in FIG. There is a drawback that even the resistance value of another resistance change portion connected to the line 185 is read. Nevertheless, when a cross-point structure is used, there is an advantage that multilayering is easy.

  As programmable logic circuits or reconfigurable logic circuits, FPGA (Field Programmable Gate Alley), CPLD (Complex Programmable Logic Device) and the like are known. SRAM (Static Random Access Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), antifuse, and flash memory are used as logic elements that hold information that determines the operation of the logic circuit. It has been broken.

  The electrical resistance change element according to the first to seventh embodiments can be used as a non-volatile logic element that holds the above information because it can use substantially the same process as the gate insulating film manufacturing process of a transistor.

Sectional drawing which shows the semiconductor device by 1st Embodiment of this invention. The figure which shows the experimental result which measured the X-ray diffraction from the crystal | crystallization in the resistance change film which concerns on 1st Embodiment by 2 (theta) / (theta) method. The figure which shows the experimental result which measured the X-ray diffraction from the crystal | crystallization in the resistance change film which concerns on the semiconductor device of 1st Embodiment by the thin film method. The figure which shows the rocking curve in 2 (theta) = 31.04 degrees. The figure which shows the rocking curve in 2 (theta) = 64.36 degrees. The figure which calculated the X-ray-diffraction peak position from the crystal | crystallization of hafnium oxynitride. With respect to the X-ray diffraction peak position of the crystal in the resistance change film according to the semiconductor device of the first embodiment, the least square method is performed so as to minimize the difference between the experimental value and the calculated value, thereby identifying the crystal and the crystal lattice constant. Figure obtained. The figure which shows the atomic arrangement | sequence in the resistance change film which concerns on the semiconductor device of 1st Embodiment. The figure explaining the direction of the chain | strand which made the anion missing. The figure which shows the arrangement | sequence of the atom in the resistance change film which concerns on the semiconductor device of 2nd Embodiment of this invention. Sectional drawing which shows the semiconductor device by 5th Embodiment of this invention. The microscope picture which shows the cross section of the electrical resistance change element of the semiconductor device by 5th Embodiment. The microscope picture which shows the orientation of the crystal | crystallization of the resistance change film which concerns on the semiconductor device by 5th Embodiment. The figure which shows the change of oxygen transfer when changing the addition amount of rare earths to zirconia. The figure which shows that when the anion site defect | deletion generate | occur | produced when rare earth was added to zirconia increased, both ends of a metal atom became a pair and became a Bevan cluster structure. Sectional drawing which shows the manufacturing method of the semiconductor device by 8th Embodiment of this invention. Sectional drawing which shows the manufacturing method of 8th Embodiment. Sectional drawing which shows the manufacturing method of 8th Embodiment. The figure which shows the generation | occurrence | production form of the void | hole in the resistance change film which concerns on 1st Embodiment. A circuit diagram showing a semiconductor device by a 10th embodiment of the present invention. A circuit diagram showing a semiconductor device by a modification of a 10th embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric resistance change element 2 Electrode 4 Resistance change film 6 Electrode 7 Amorphous film 8 Film | membrane which has a dielectric breakdown induction path 11 Substrate 20 Select transistor 22a, 22b Source / drain region 24 Gate insulating film 24a Interface layer 24b Interface layer 26 Electrode

Claims (12)

It has a metal oxide or metal oxynitride containing at least one element of Zr and Hf as a main component, and the metal oxide or metal oxynitride has a fluorite structure, and an anion site is deficient in the fluorite structure Or a structure distorted into a state where the cubic fluorite-type crystal system becomes a hexagonal crystal system, or a structure distorted into a state where the cubic fluorite-type crystal system becomes a rhombohedral crystal system A resistance change film having a crystal structure of
A pair of first and second electrodes provided so as to sandwich the variable resistance film;
With
A crystal structure of the resistance change film has a Bevan cluster partly or entirely, V is a vacancy in which an anion does not exist at an anion site in a fluorite crystal structure, and M is the metal oxide or metal oxynitride When the metal element of the product, S, is the largest octahedral void site in the fluorite-type crystal structure, it is a straight chain that becomes “-SVMVSV-” in the unit cell of the Bevan cluster. An electric resistance change element, characterized in that a chain arrangement direction has a crystal orientation that is substantially perpendicular to a main surface of the film. The resistance change film is formed by contacting at least two Bevan clusters in the “-VMVV-” direction, so that “-S- (VMVSV-) _n ” (where n is 2). 2. The electricity according to claim 1, further comprising: a chain that is an integer equal to or greater than an integer), wherein the chain direction is substantially perpendicular to a main surface of the resistance change film. Variable resistance element. Between at least one of the first and second electrodes and the resistance change film,
3. The electric resistance change element according to claim 1, wherein a film having a metal oxide or metal oxynitride containing at least one of amorphous Zr and Hf as a main component is provided.   4. The electricity according to claim 1, wherein the electrical resistance change film includes an oxynitride, and a nitrogen content ratio is 10.0 atomic% or more and 57.1 atomic% or less. Variable resistance element.   5. The electrical resistance change element according to claim 1, wherein a direction of the chain of the resistance change film is an angle of 10 degrees or less with respect to a normal line of the main surface of the resistance change film. . The crystals in the resistance change film are:
The composition formula is described by M ₂ ON ₂ (where M is one or more of Zr and Hf), and the space group to which the crystal belongs is Ia / 3 (international notation 206),
The composition formula is described by M ₇ O ₈ N ₄ (where M is one or more of Zr and Hf), and the space group to which the crystal belongs is R / 3 (International No. 146),
The composition formula is M ₇ O _{2 (4p + 3) / p} N _{4 (p−1) / p} (where M is one or more of Zr and Hf, p is an integer of 1 or more, and p is an odd number) Or p is a multiple of 6) and the space group to which the crystal belongs is P / 3 (International notation 143)
And the composition formula is M ₇ O _{2 (4p + 3) / p} N _{4 (p−1) / p} (where M is one or more of Zr and Hf, p is an integer of 1 or more, and p is 6) The space group to which the crystal belongs is R / 3 (international notation No. 146) () (in the case where p is an integer obtained by adding 2 to the multiple or p is an integer obtained by adding 4 to the multiple of 6))
The electrical resistance change element according to claim 1, wherein the electrical resistance change element is any one of the above.   The oxide or oxynitride includes Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Mg, Ca, Sr, Ba And the total number of all types of the element Me contained in the oxide or oxynitride is [Me] and is contained in the oxide or oxynitride The ratio [Me] / ([Me] + [M]) is 0.07 or more and 0.22 or less, where [M] is the total number of elements of Zr and Hf that are generated. The electrical resistance change element in any one of thru | or 6.   8. A semiconductor device comprising the electrical resistance change element according to claim 1 as a nonvolatile memory element of a memory device.   9. The semiconductor device according to claim 8, further comprising a transistor having one end connected to the electric resistance change element.   A semiconductor device comprising: a nonvolatile logic element including the electrical resistance change element according to claim 1 and a transistor having one end connected to the electrical resistance change element. Forming a first film made of a metal oxynitride containing at least one of Zr and Hf as a main component on a substrate;
Forming a second film containing a substance that crystallizes at a temperature of 800 ° C. or lower on the first film;
Oriented so that the direction in which the energy at the interface between the first film and the second film is lowest is substantially perpendicular to the main surface of the first film by annealing at a temperature exceeding 800 ° C. Step to
A method for manufacturing a semiconductor device, comprising:   12. The method of manufacturing a semiconductor device according to claim 11, wherein the substance that crystallizes at a temperature of 800 [deg.] C. or lower contains silicon as a main component.