JP4075485B2 - Semiconductor device and method for depositing amorphous high dielectric film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device having a high dielectric film that retains an amorphous state even after high-temperature heat treatment, and more particularly to a high dielectric constant gate insulating film used for a MOS transistor (MOS type field effect transistor).
[0002]
[Prior art]
In order to ensure high-speed operation and low-voltage operation of a minute MOS transistor, an attempt has been made to use a high dielectric constant material having a dielectric constant higher than that of SiO ₂ as a gate insulating film. For example, a MOS transistor has been proposed in which an amorphous thin film made of a high dielectric constant metal oxide such as HfO _x or ZrO _x is used as a gate insulating film.
[0003]
However, these metal oxides are easily crystallized at a temperature of 800 ° C. or higher. For this reason, when an amorphous metal oxide is used as the gate insulating film, the amorphous gate insulating film is crystallized by the activation heat treatment of the source / drain regions performed after the gate insulating film is deposited. Such crystallization of the gate insulating film generates a low dielectric constant SiO ₂ film on the surface of the silicon substrate that is the base of the gate insulating film, thereby increasing the effective thickness of the gate insulating film. In addition, since crystallization occurs in a cluster shape, a local fluctuation of the electrical characteristics and physical characteristics of the gate insulating film is generated. For this reason, the characteristics of the transistor are not stable.
[0004]
Methods for suppressing crystallization of such high dielectric constant metal oxides are disclosed in Japanese Patent Application Laid-Open Nos. 2000-12840 and 2001-77111. In the former, an amorphous thin film made of TaO _Y —AlO _X , TaO _Y —SiO _X , or a mixed oxide thereof is used as a gate insulating film. In the latter, an amorphous thin film made of a mixed oxide of HfO _Y or ZrO _Y and a trivalent metal oxide such as an oxide of Al, La or Sc is used as the gate insulating film. An amorphous thin film made of these mixed oxides has a high dielectric constant generated from an oxide of Ta, Hf, or Zr, and does not cause crystallization even by heat treatment at 800 ° C. or higher. For this reason, a uniform gate insulating film having a high dielectric constant can be stably manufactured.
[0005]
However, in these amorphous thin films in which crystallization is suppressed, an oxide of Ta, Hf or Zr having a high dielectric constant is oxidized to an oxide of a lower dielectric constant, such as SiO _x or a trivalent metal. Mixing things. For this reason, these amorphous thin films cannot have a high dielectric constant such as Ta, Hf or Zr oxides.
[0006]
[Problems to be solved by the invention]
As described above, the conventional amorphous high dielectric film made of a metal oxide having a high dielectric constant is easily crystallized at a low crystallization temperature. Therefore, when used as a gate insulating film, the transistor characteristics vary. There was a problem that it is easy to generate.
In addition, an amorphous thin film obtained by mixing a metal oxide with a low dielectric constant oxide in order to suppress crystallization has a problem that it is difficult to obtain a high dielectric constant.
[0007]
An object of the present invention is to provide an amorphous high-dielectric film that is suppressed from crystallization by heat treatment and has a high dielectric constant.
[0008]
[Means for Solving the Problems]
In the first configuration of the present invention for solving the above-mentioned problems, the material of the amorphous high dielectric film formed on the substrate is composed of a metal oxide having a high dielectric constant and an insulating oxide as components. Including mixed oxide. This mixed oxide is preferably composed of a metal oxide and an insulating oxide as components. However, the metal oxide and the insulating oxide can be the main components and other oxides can be included as long as the dielectric properties and the insulating properties are satisfied.
[0009]
As this metal oxide, an oxide of a transition metal to be a high dielectric, for example, HfO _x having a relative dielectric constant of about 30, ZrO _{x of} 12 to 25, Ta ₂ O _{x of} 25 to 65, TiO _{x of about} 55 Alternatively, 100 or more BST (BiSrTi oxide) or a mixed oxide containing these as components can be used. In particular, HfO _x and ZrO _x are preferable because they have excellent characteristics as a gate insulating film. Also, other transition metal oxides such as Y ₂ O _x , LaO _x , PrO _x , GdO _x , V ₂ O _x , Nb ₂ O _x , Cr ₂ O _x , Mo ₂ O _x or WO _x , or These mixed oxides may be used. Note that the above-described amorphous mixed oxide may have an oxygen concentration shifted by about 30% from the stoichiometric composition, and the oxygen concentration in this range is expressed as O _{x in} this specification.
[0010]
The insulating oxide is an oxide having an insulating property that does not deteriorate the insulating properties of the amorphous high-dielectric film. For example, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), or acid Silicon nitride (SiON) can be used. Further, as the insulating oxide, an oxide having an amorphous phase having a crystallization temperature higher than that of the above-described amorphous metal oxide may be used. As is well known, these insulating oxides are amorphous high dielectric films made of mixed oxides with metal oxides. Control.
[0011]
Furthermore, in the first configuration of the present invention, the composition in the amorphous high dielectric film has a composition distribution that changes in the film thickness direction. That is, there are many metal oxides and few insulating oxides in the vicinity of the substrate. On the other hand, as the distance from the substrate increases, the proportion of the metal oxide decreases and the proportion of the insulating oxide increases.
The above-described configuration of the present invention was invented based on the following knowledge regarding crystallization of an amorphous metal thin film, which was clarified by the inventors of the present invention.
[0012]
The inventors of the present invention have clarified through simulation that the crystallization of the amorphous metal oxide film starts from a position away from the substrate interface and propagates throughout the amorphous metal oxide film. Hereinafter, this simulation will be described.
FIGS. 2 and 3 are cross-sectional views (No. 1) and (No. 2), respectively, of the simulation results, and represent metal atom positions in the amorphous metal oxide layer deposited on the substrate.
[0013]
First, referring to FIG. 2A, a molecular arrangement in which an amorphous phase metal oxide layer 20 is laminated on an amorphous SiO ₂ substrate 1 is given as an initial condition. Here, for simplicity of explanation, a simulation using HfO ₂ as a metal oxide will be described. Next, a part of the portion where the metal oxide layer 20 is in contact with the substrate 1 (between the CDs in FIG. 2A) is replaced with a crystal nucleus 21 of the metal oxide. The crystal nucleus 21 was a cube having a side of 1.5 nm. Next, the temperature was raised to 1227 ° C., and the rearrangement position of the metal atom (here, Hf) in the metal oxide layer 20 was calculated. The calculation was done by simulation based on molecular dynamics. FIG. 2B shows a simulation result after 320 p seconds have elapsed from the temperature rise. Referring to FIG. 2B, the arrangement of the metal atoms in the metal oxide layer 20 after the heat treatment is such that the regular arrangement given as the crystal nuclei 21 disappears, and an amorphous phase similar to the initial condition is obtained. The arrangement has changed. This result reveals that even if crystal nuclei are generated near the interface with the substrate 1, the crystal nuclei do not grow and disappear. This indicates that the growth of crystal nuclei that leads to crystallization of the entire amorphous metal oxide layer 20 hardly occurs from the vicinity of the substrate.
[0014]
Next, referring to FIG. 3A, the crystal nucleus 21 is arranged at a position 1.5 nm away from the substrate 1 (between EF in FIG. 3), and the rearrangement position of the metal atoms after the heat treatment is calculated. did. Except for the position of the crystal nucleus 21, other conditions are the same as the above-described simulation conditions described with reference to FIG.
Referring to FIG. 3B, when 320 p seconds have elapsed after the temperature is raised to 1227 ° C., the entire metal oxide layer 20 is crystallized. This result reveals that crystal nuclei generated at a position away from the interface with the substrate 1 crystallize the entire metal oxide layer 20.
[0015]
The two simulation results described above with reference to FIGS. 2 and 3 show that the crystallization of the metal oxide layer 20 is triggered by a crystal nucleus generated at a position away from the interface with the substrate 1. The propagation to the entire layer 20 is shown. At this time, the metal oxide layer 20 in the vicinity of the substrate 1 is crystallized by propagation of crystallization that started at a position away from the interface, although spontaneous crystallization does not occur originally. That is, in the crystallization of the amorphous metal oxide layer 20, crystallization first occurs at a position away from the substrate, which propagates and crystallizes as a whole.
[0016]
The inventor of the present invention believes that the progress of the crystallization varies depending on the generation position of the crystal nucleus in this way, which is related to the potential of the metal oxide in contact with the crystal nucleus.
The average period of the crystal nucleus and the amorphous metal oxide in an unstrained state has a period close to the crystal lattice of the metal oxide on average. Therefore, at a position where the influence of the lattice mismatch with the substrate is small because it is far from the substrate, the potential period of the metal oxide substantially coincides with the potential period of the crystal nucleus. For this reason, crystal nuclei are easy to grow and the generation energy of crystal nuclei is small.
[0017]
On the other hand, the metal oxide in the vicinity of the substrate is greatly distorted due to lattice mismatch between the substrate and the metal oxide (in the case of amorphous, this means mismatch in average interatomic distance). Accordingly, in the vicinity of the substrate, the difference between the potential period of the crystal nucleus and the potential period of the surrounding metal oxide is large. For this reason, the growth of crystal nuclei is inhibited, and the generation energy of crystal nuclei is large.
[0018]
In this way, crystal nuclei are hardly generated near the substrate, and the growth of crystal nuclei is suppressed. On the other hand, at a position away from the substrate, crystal nuclei are easily generated and crystal nuclei grow easily. This simulation result fully explains the experimental facts conducted by the inventors of the present invention that when HfO _x is deposited to a thickness of 5 nm, it becomes an amorphous film, but when deposited at 25 nm under the same deposition conditions, it becomes a crystalline film. ing.
[0019]
The present invention was invented based on this finding. FIG. 1 is a sectional view for explaining the principle of the present invention. FIG. 1 (a) shows an amorphous high dielectric film according to the present invention formed on a substrate, and FIG. 1 (b) shows its composition distribution. Represents.
As shown in FIG. 1, the amorphous high dielectric film of the first configuration of the present invention has a large amount of metal oxide (see curve A in FIG. 1B) in the vicinity of the substrate 1 and is an insulating oxide. (See curve B in FIG. 1 (b)). Therefore, the amorphous high dielectric film 2 in the vicinity of the substrate 1 has a high composition ratio of a metal oxide having a high dielectric constant and a high dielectric constant. On the other hand, as the distance from the substrate 1 increases, the ratio of the metal oxide decreases and the ratio of the insulating oxide that suppresses crystallization increases. Therefore, crystallization of the amorphous high dielectric film 2 located at a position away from the substrate 1 is suppressed. In other words, the amorphous high dielectric film of this structure has a composition that allows a decrease in dielectric constant and suppresses crystallization at a position away from a substrate where crystallization is likely to occur, and dielectric near the substrate where crystallization is difficult to occur. The composition having a high dielectric constant is reduced by reducing the composition that lowers the rate.
[0020]
In such a configuration, since the occurrence of crystallization at a position away from the substrate is suppressed, it is possible to avoid crystallization of the entire amorphous high dielectric film caused by propagation from here. On the other hand, since the composition has a high dielectric constant in the vicinity of the substrate, the effective dielectric constant of the amorphous high dielectric film becomes high. An amorphous high dielectric film having such a high dielectric constant composition is generally easy to crystallize, but in this configuration, since it is disposed in the vicinity of the substrate, crystallization is sufficiently suppressed. Accordingly, an amorphous high dielectric film having suppressed crystallization and a high effective dielectric constant is provided.
[0021]
Compared with the conventional one, the conventional amorphous high dielectric film made of mixed oxide has a uniform composition as a whole. Therefore, conventionally, the entire amorphous high-dielectric film has to be formed with a composition that does not cause crystallization even in a portion that is farthest from the substrate and is most likely to be crystallized. Such a composition corresponds to the composition at the position farthest from the substrate in this configuration, that is, the composition of the portion having the highest insulating oxide and hence the lowest dielectric constant. For this reason, the effective dielectric constant of the conventional amorphous high dielectric film is lower than that of the present invention.
[0022]
In the first configuration, the composition ratio distribution of the metal oxide must have a high dielectric constant and a composition distribution that is difficult to crystallize. According to experiments, an amorphous high dielectric film having a metal oxide composition ratio of 50% and a thickness of 65 nm is crystallized by heat treatment at 1000 ° C. for several seconds. Therefore, the composition ratio of the metal oxide is desirably 50 mol% or less at a position away from the substrate. For example, the composition ratio of the metal oxide is 40 to 100 mol% in the vicinity of the substrate, more preferably 60 to 100 mol%, and 0 to 40 mol% at the farthest position from the substrate, more preferably 0 to 20 mol%. It is preferable that Here, 0 mol% and 100 mol% mean a composition that does not intentionally contain a metal oxide and a composition that does not intentionally contain a component other than a metal oxide.
[0023]
The simulation described above uses amorphous SiO ₂ as a substrate. Similar results were obtained when the substrate was replaced with crystalline SiO ₂ or with crystalline Si. This suggests that the tendency of crystallization depends on the average interatomic distance of the substrate underlying the amorphous high dielectric film, and that the difference between the crystalline and amorphous of the substrate does not have a significant effect. is doing.
[0024]
Note that the amorphous high dielectric film according to the present invention can be applied to general semiconductor devices using an amorphous high dielectric film. In particular, it is excellent as a gate insulating film of a field effect transistor. Further, it can be used as a dielectric of a capacitor to reduce leakage current.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with reference to a manufacturing process of an embodiment applied to a gate insulating film.
FIG. 4 is a cross-sectional process diagram of the first embodiment of the present invention, showing a process for manufacturing a MOS transistor. Referring to FIG. 4A, a transistor formation region defined by field oxide film 6 is formed on the surface of silicon substrate 1a, and the surface of silicon substrate 1a exposed in the transistor formation region is oxidized to have a thickness of 0. A 5 to 1 nm SiO ₂ thin film 1b is formed. The SiO ₂ thin film 1b prevents the formation of a SiO ₂ layer having a non-uniform thickness at the interface due to the reaction between the amorphous high dielectric film 2 deposited thereon and the silicon substrate 1a. If it is not necessary, it may not be formed.
[0026]
Next, referring to FIG. 4B, an amorphous high dielectric film 2 having a thickness of 4 nm is deposited on the entire surface of the silicon substrate 1a by using a CVD method (chemical vapor deposition method). In the CVD method, the substrate temperature was set to 500 ° C., Hf or Zr source gas and SiO ₂ or Al ₂ O ₃ source gas were mixed and supplied so that the total pressure became 65 Pa. Here, the mixing ratio of the Hf or Zr source gas to the SiO ₂ or Al ₂ O ₃ source gas is increased so that the composition ratio of Hf or Zr decreases by 5% every time the deposition proceeds by 0.5 nm. It decreased with the staircase. Of course, other methods of changing the composition ratio in addition to the mixing ratio of the source gases may be used.
[0027]
FIG. 5 is a composition distribution diagram of the first embodiment of the present invention, showing the composition distribution of the amorphous high dielectric film. As a result of the deposition of the amorphous high dielectric film 2 by the above CVD method, referring to FIG. 5, HfO _x or ZrO _x and SiO ₂ or SiO ₂ are formed on the SiO ₂ thin film 1b formed on the surface of the silicon substrate 1a. An amorphous high dielectric film 2 made of a mixed oxide with Al ₂ O ₃ was formed. FIG. 5 shows only a mixed oxide of HfO _x and SiO ₂ for the sake of simplicity.
[0028]
The component of the metal oxide having a high dielectric constant, for example, HfO _x , is 60 mol% at the interface with the substrate 1 with reference to the solid line (A) in FIG. 5 and linearly as the distance from the substrate 1 interface increases. It decreased to 20 mol% on the surface of the amorphous high dielectric film. On the other hand, the oxide that suppresses crystallization, such as SiO ₂ , increases from 40 mol% to 80 mol% as the distance from the substrate interface increases, contrary to the metal oxide distribution.
[0029]
Next, referring to FIG. 4C, a gate electrode 3 is formed on the amorphous high dielectric film 2, and the amorphous high dielectric film 2 and the SiO ₂ thin film extending outside the gate electrode 3 are formed. 1b is removed by etching. Next, after the low concentration region 4a is formed by ion implantation using the gate electrode 3 as a mask, the sidewall 3a is formed on the sidewall of the gate electrode 3, and the high concentration region 4b is formed by ion implantation.
[0030]
Next, referring to FIG. 4D, an activation heat treatment is performed at 1000 ° C. for 10 seconds by lamp annealing, and the low concentration region 4a and the high concentration region 4b that are ion-implanted are activated and activated. Source / drain regions comprising the region 5a and the high concentration region 5b are formed.
The gate insulating film of the MOS transistor manufactured by this process (a laminated film composed of the SiO ₂ thin film 1b having a thickness of 0.5 nm and the amorphous high dielectric film 2 having a thickness of 4 nm) has a high effective dielectric constant. The state of the completely amorphous phase was maintained.
[0031]
In the second embodiment of the present invention, the manufacturing process of the amorphous high dielectric film 2 of the first embodiment is changed to a sputtering method. Other manufacturing processes are the same as those in the first embodiment.
Referring to FIG. 1A, an SiO ₂ thin film 1b is formed on the surface of a silicon substrate 1a in the same manner as in the first embodiment. Next, referring to FIG. 4B, an amorphous high dielectric film 2 having a thickness of 5 nm was deposited on the entire surface of the silicon substrate 1a by sputtering. The sputtering conditions were a substrate temperature of 300 ° C., an Ar gas pressure of 1.0 Pa, and an initial sputtering power of 300 W. Note that it is preferable to mix an oxidizing gas with Ar gas in order to increase the amount of oxygen in the deposited film.
[0032]
As the target, a metal oxide, for example, a sintered plate of HfO ₂ or ZrO _{2 and} a sintered plate of Al ₂ O ₃ or a plate of SiO ₂ were used. Sputtering, and the first HfO ₂ or ZrO ₂ sintered plate deposited HfO ₂ or ZrO ₂ as a target. Next, amorphous high dielectric comprising a mixed oxide of metal oxide and Al ₂ O ₃ or SiO ₂ by sputtering HfO ₂ or ZrO ₂ and Al ₂ O ₃ or SiO ₂ simultaneously or alternately. Body film 2 was deposited.
[0033]
During sputtering, the sputter power of HfO ₂ or ZrO ₂ or the sputter power of Al ₂ O ₃ or SiO ₂ is adjusted so that the composition ratio of Hf or Zr decreases by 20% each time the deposition proceeds by 1.0 nm. did.
As a result of deposition of the amorphous high dielectric film by this sputtering method, a mixed oxide of HfO _x or ZrO _x and SiO ₂ or Al ₂ O ₃ is formed on the SiO ₂ thin film 1b formed on the surface of the silicon substrate 1a. An amorphous high dielectric film 2 made of was formed.
[0034]
The component of the metal oxide having a high dielectric constant, for example, HfO _x , is 100 mol% at the interface with the substrate 1, and decreases linearly with distance from the substrate 1 interface, and on the surface of the amorphous high dielectric film. It became 0 mol%. On the other hand, the oxide that suppresses crystallization, such as SiO ₂ , increases from 0 mol% to 100 mol% as it moves away from the substrate interface, contrary to the metal oxide distribution.
[0035]
Next, a MOS transistor was produced in the same process as in the first embodiment. The gate insulating film of this MOS transistor completely maintained the amorphous phase.
The present specification described above includes the inventions described in the following supplementary notes.
(Appendix 1) In a semiconductor device having an amorphous high dielectric film formed on a substrate,
The amorphous high dielectric film is composed of a mixed oxide containing a metal oxide having a high dielectric constant and an insulating oxide whose crystallization temperature of the amorphous phase is higher than that of the metal oxide.
2. A semiconductor device according to claim 1, wherein the composition distribution in the film thickness direction in the amorphous high dielectric film becomes smaller as the composition ratio of the metal oxide to the insulating oxide becomes farther from the substrate.
[0036]
(Appendix 2) In a semiconductor device having an amorphous high dielectric film formed on a substrate,
The amorphous high dielectric film is composed of a mixed oxide containing a metal oxide having a high dielectric constant and silicon oxide or aluminum oxide,
2. A semiconductor device according to claim 1, wherein the composition distribution in the film thickness direction of the amorphous high-dielectric film becomes smaller as the composition ratio of the metal oxide to the silicon oxide or the aluminum oxide is separated from the substrate.
[0037]
(Supplementary note 3) The semiconductor device according to Supplementary note 1 or 2, wherein the composition ratio of the metal oxide is 60 mol% or more near the substrate and 20% or less farthest from the substrate.
(Supplementary note 4) Supplementary note 1, wherein the metal oxide comprises HfO _x , ZrO _x , Ta ₂ O _x , TiO _x , Y ₂ O _x , La ₂ O _x or Pr ₂ O _x , or a mixed oxide thereof, 2. The semiconductor device according to 2 or 3.
[0038]
(Supplementary Note 5) The semiconductor device according to Supplementary Note 1, 2, or 3, wherein the metal oxide is HfO _x , ZrO _x, TiO _x , or a mixed oxide thereof.
(Additional remark 6) The semiconductor device of Additional remark 1, 2, 3, 4 or 5 provided with the field effect transistor which uses this amorphous | non-crystalline high dielectric film as a gate insulating film.
(Supplementary note 7) The semiconductor device according to supplementary notes 1, 2, 3, 4, 5, or 6, wherein the substrate includes a silicon substrate and a SiO ₂ thin film formed on the surface of the silicon substrate.
[0039]
(Supplementary note 8) The semiconductor device according to supplementary notes 1, 2, 3, 4, 5, 6 or 7, wherein the substrate is a silicon substrate.
(Appendix 9) An amorphous material comprising a mixed oxide containing a metal oxide having a high dielectric constant and an insulating oxide whose crystallization temperature is higher than that of the metal oxide on the substrate. In the method of depositing the high dielectric film,
The deposition condition of the amorphous high dielectric film is changed so that the composition ratio of the metal oxide to the insulating oxide in the amorphous high dielectric film becomes smaller as the deposition proceeds. A method for depositing a crystalline high dielectric film.
[0040]
(Supplementary note 10) The amorphous high dielectric film deposition method according to supplementary note 9, wherein the amorphous high dielectric film is deposited by a CVD method (chemical vapor deposition method).
[0041]
【The invention's effect】
As described above, according to the present invention, it is possible to form a dielectric film that is difficult to crystallize and has a high effective dielectric constant, which greatly contributes to improving the performance of a MOS transistor or a capacitor.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating the principle of the present invention. FIG. 2 is a cross-sectional view of a simulation result (part 1).
FIG. 3 is a cross-sectional view of a simulation result (part 2).
FIG. 4 is a cross-sectional process diagram of the first embodiment of the present invention. FIG. 5 is a composition distribution diagram of the first embodiment of the present invention.
1 substrate 1a silicon substrate 1b SiO ₂ film 2 amorphous high dielectric film 3 gate electrode 3a side wall 4 ion implantation regions 4a, 5a low density regions 4b, 5b high concentration region 5 the source-drain region 6 the field oxide film 20 metal Oxide layer 21 Crystal nucleus

Claims (5)

In a semiconductor device having an amorphous high dielectric film formed on a substrate , a silicon oxide thin film having a thickness between 0.5 nm and 1 nm is interposed between the substrate and the amorphous high dielectric film. Have
The amorphous high dielectric film is made of a mixed oxide containing a metal oxide having a relative dielectric constant of 12 or more and an insulating oxide whose crystallization temperature of the amorphous phase is higher than that of the metal oxide. Become
2. A semiconductor device according to claim 1, wherein the composition distribution in the film thickness direction in the amorphous high dielectric film becomes smaller as the composition ratio of the metal oxide to the insulating oxide becomes farther from the substrate. In a semiconductor device having an amorphous high dielectric film formed on a substrate,
A silicon oxide thin film having a thickness of 0.5 nm or more and 1 nm or less interposed between the substrate and the amorphous high dielectric film;
The amorphous high dielectric film is composed of a mixed oxide containing a metal oxide having a relative dielectric constant of 12 or more and silicon oxide or aluminum oxide,
2. A semiconductor device according to claim 1, wherein the composition distribution in the film thickness direction of the amorphous high-dielectric film becomes smaller as the composition ratio of the metal oxide to the silicon oxide or the aluminum oxide is separated from the substrate.   3. The semiconductor device according to claim 1, wherein the composition ratio of the metal oxide is 60 mol% or more near the substrate and 20% or less at the farthest distance from the substrate. On a substrate, an amorphous high oxide comprising a mixed oxide containing a metal oxide having a relative dielectric constant of 12 or more and an insulating oxide having a higher crystallization temperature of the amorphous phase than the metal oxide. In the dielectric film deposition method,
Forming a silicon oxide thin film having a thickness of 0.5 nm or more and 1 nm or less on the substrate surface;
The amorphous high dielectric film is formed on the silicon oxide thin film so that a composition ratio of the metal oxide to the insulating oxide in the amorphous high dielectric film decreases as the deposition proceeds. the method of depositing amorphous high dielectric film, which is deposited by changing the deposition conditions of the high dielectric film.   5. The amorphous high dielectric film deposition method according to claim 4, wherein the amorphous high dielectric film is deposited by a CVD method (chemical vapor deposition method).

Images