JP2004311868A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which has a ferroelectric capacitor having excellent electrical properties, and also a method for manufacturing the semiconductor device having excellent electrical properties, in a high yield. <P>SOLUTION: In the semiconductor device having the ferroelectric capacitor; an amorphous metallic film, a conductive crystalline film, and a lower electrode of the ferroelectric capacitor are laminated in this order on an upper surface of a region which spreads across an amorphous interlayer insulating film and a conductive plug provided in the amorphous interlayer insulating film. After the conductive crystalline film is provided, the amorphous metallic film is preferably crystallized. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device having a ferroelectric capacitor such as a ferroelectric memory and a method for manufacturing the same.
[0002]
[Prior art]
Flash memories and ferroelectric memories are known as nonvolatile memories that can store information even when the power is turned off. A flash memory has a floating gate embedded in a gate insulating film of an insulated gate field effect transistor (IGFET), and stores information by accumulating charges representing stored information in the floating gate. For writing and erasing information, it is necessary to flow a tunnel current passing through an insulating film, which requires a relatively high voltage.
[0003]
A ferroelectric memory stores information using the hysteresis characteristics of a ferroelectric. A ferroelectric capacitor having a ferroelectric film as a dielectric between a pair of electrodes generates polarization according to the applied voltage between the electrodes, and has spontaneous polarization even when the applied voltage is removed. If the polarity of the applied voltage is reversed, the polarity of the spontaneous polarization is also reversed. In the ferroelectric memory, information can be read by detecting the spontaneous polarization. A ferroelectric memory operates at a lower voltage than a flash memory, and has a feature that high-speed writing can be performed with low power consumption.
[0004]
To describe a method of manufacturing a capacitor portion of a general ferroelectric memory, a lower electrode is formed by a sputtering method or the like, and then a ferroelectric film is formed. As the ferroelectric film, lead zirconate titanate (PZT: PbZr) _x Ti _1-x O ₃ ) Or PZT-based material in which PZT is doped with La or the like (PLZT: Pb _1-y La _y Zr _x Ti _1-x O ₃ ) Is often used. In the following, PZT, PZT-based material, SrBi ₂ Ta ₂ O ₉ (SBT, Y1) or a Bi layer structure compound in which SBT is doped with Nb or the like will be described. As a method for forming the ferroelectric film, a sputtering method, a sol-gel method, a metal / organic chemical vapor deposition (MOCVD) method, or the like is used. After crystallization of the ferroelectric film, an upper electrode is formed.
[0005]
In order to manufacture a ferroelectric memory having good electric characteristics and a high product yield, it is important to control the orientation of the ferroelectric film to be uniform. The orientation of the ferroelectric film is greatly affected by the orientation of the lower electrode. That is, by controlling the orientation of the lower electrode to be uniform, the orientation of the ferroelectric film can be made uniform. Therefore, in order to manufacture a ferroelectric memory having good electric characteristics and a high product yield, it is important to control the orientation of the lower electrode to be uniform.
[0006]
For example, SiO which is an interlayer insulating film on a substrate ₂ In a planar type ferroelectric memory in which a ferroelectric capacitor is provided on the entire surface of the film, the ferroelectric capacitor is made of SiO 2 as schematically shown in FIG. ₂ A lower electrode 2, a ferroelectric film 3, and an upper electrode 4 are formed on the film 1 in this order. SiO ₂ Since the film 1 is amorphous, the orientation of the lower electrode 2 thereon is also uniform. Therefore, the orientation of the ferroelectric film 3 thereon can be easily made uniform.
[0007]
On the other hand, for example, SiO ₂ Film 1 and SiO ₂ In a stack type ferroelectric memory in which a ferroelectric capacitor is provided above a region straddling the conductive plug 5 disposed in the film 1, as schematically shown in FIG. The lower electrode 2 is made of SiO ₂ The film is formed not only on the film 1 but also on the conductive plug 5. However, SiO ₂ While the film 1 is amorphous, a crystalline metal such as W (tungsten) is generally used for the conductive plug 5. Therefore, when the lower electrode 2 is formed thereon, SiO 2 ₂ The orientation is different between the portion 2a on the film 1 and the portion 2b on the plug. Such non-uniform orientation is not preferable because the orientation of the ferroelectric film is also non-uniform as schematically shown by 3a and 3b.
[0008]
As a technique for controlling the orientation of the lower electrode, a combination of a diffusion preventing conductive film provided on an oriented semiconductor film or an amorphous semiconductor and a lower electrode provided thereon is known (for example, see Patent Reference 1). However, at this level, it is considered insufficient to manufacture a ferroelectric capacitor having good electric characteristics and uniform performance without variation.
[0009]
[Patent Document 1]
WO 97/33316 pamphlet (p.5)
[0010]
[Problems to be solved by the invention]
An object of the present invention is to solve the above problems and provide a semiconductor device having a ferroelectric capacitor having a ferroelectric film having a uniform orientation, having excellent electric characteristics, and having uniform performance. I have.
[0011]
[Means for Solving the Problems]
According to one embodiment of the present invention, in a semiconductor device having a ferroelectric capacitor, an amorphous metal film and a conductive metal A semiconductor device is provided in which a crystal film and a lower electrode of a ferroelectric capacitor are stacked in this order. It is preferable that the amorphous metal film is crystallized after disposing the conductive crystal film. As a result, variation in the performance of the capacitor can be suppressed, and the defect rate of the semiconductor device using the capacitor can be reduced and the yield can be improved.
[0012]
According to another aspect of the present invention, in a method of manufacturing a semiconductor device having a ferroelectric capacitor, an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film have an amorphous There is provided a method of manufacturing a semiconductor device, comprising laminating a metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor in this order, arranging the conductive crystal film, and crystallizing the amorphous metal film. A semiconductor device having a ferroelectric capacitor having excellent electric characteristics can be manufactured with high yield.
[0013]
The conductive plug is made of at least one material selected from the group consisting of a metal, an alloy, a metal chloride, a metal silicide, a conductive oxide and silicon, and the amorphous metal film is made of Cr, Co, Ta, Nb, It is made of an alloy containing at least one metal selected from the group consisting of Al, Ti, Zr, W and Mo; the thickness of the amorphous metal film is 2 to 30 nm; and the conductive crystal film is Ta, Al, Ti, Cu, Ir, Pt, Re, Ru, alloys containing these metals, Al ₂ O ₃ , TiO ₂ , IrO ₂ , TiN and TaN, at least one material selected from the group consisting of: a conductive crystal film having a thickness of 2 to 30 nm; a lower electrode made of Ir or Pt; and a ferroelectric film. Is preferably a lead zirconate titanate film or a film obtained by doping lead zirconate titanate with at least one element selected from the group consisting of La, Ca, Sr, Ir, and Ru.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings, examples, and the like. It should be noted that these drawings, examples, and the like, and the description are merely examples of the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments can also belong to the category of the present invention as long as they conform to the gist of the present invention.
[0015]
According to the present invention, a semiconductor device having a ferroelectric capacitor includes an amorphous metal film, a conductive crystal film, and The lower electrode of the ferroelectric capacitor is laminated in this order. The amorphous metal film is often disposed in contact with the amorphous interlayer insulating film and the conductive plug disposed in the amorphous interlayer insulating film. This is because the orientation may affect the upper part of the amorphous interlayer insulating film or the conductive plug. Each of the amorphous metal film and the conductive crystal film may be composed of a plurality of layers.
[0016]
By forming the amorphous metal film 6 and the conductive crystal film 7 on a region extending over the amorphous interlayer insulating film and the conductive plug, the amorphous interlayer insulating film and the conductive plug can form a conductive crystal film. In addition, the influence on the orientation can be cut off, and a uniform orientation can be realized between the lower electrode 2 and the ferroelectric film 3 as shown in FIG. As a result, a ferroelectric film having a uniform orientation can be obtained. As a result, a semiconductor device having a ferroelectric capacitor having excellent electric characteristics can be obtained. This semiconductor device is particularly useful as a ferroelectric memory.
[0017]
In the present invention, the amorphous metal film means a film made of a metal material having an amorphous structure. The conductive crystal film means a film of a conductive material in a crystallized state. The amorphous state can be determined by showing a diffuse pattern by X-ray diffraction. Further, a crystallized material can be determined by showing a regular diffraction pattern by X-ray diffraction. Depending on the level of orientation required in the crystallized material, how much the diffused pattern that shows the diffuse pattern is made amorphous or how much the regular diffraction pattern is made the crystallized material depends on the level of orientation required in the crystallized material. It can be selected as appropriate. The level of this orientation can be determined from the half width of a rocking curve indicating the (111) orientation of the conductive crystal film. In order to have a ferroelectric film having a sufficiently uniform orientation and a semiconductor device having a ferroelectric capacitor having excellent electric characteristics, the half width of the rocking curve of this conductive crystal film is 4.2 ° or less. It is preferable that
[0018]
The semiconductor device having a ferroelectric capacitor according to the present invention has a ferroelectric film having a uniform orientation and a semiconductor device having a ferroelectric capacitor having excellent electric characteristics in the above-described configuration. After disposing the conductive crystal film, it is more preferable to perform a crystallization treatment to reduce the electric resistance of the amorphous metal film.
[0019]
The conductive plug according to the present invention is not particularly limited, and a known material can be used. It is preferable to use at least one material selected from the group consisting of metals, alloys, metal chlorides, metal silicides, conductive oxides and silicon. Tungsten (W) and polysilicon can be exemplified. The present invention is highly effective when the conductive plug shows a crystalline state unlike an amorphous interlayer insulating film. In this regard, it is difficult to avoid the crystalline state of W unless special conditions such as extremely rapid cooling are applied. The case where W is used for the conductive plug is particularly preferable as an application target of the present invention.
[0020]
The amorphous metal film according to the present invention is not particularly limited, and a known material can be used. However, a material that requires a high degree of rapid cooling to freeze the amorphous state is often not preferable. In this sense, an alloy is preferable because the crystallization rate can be easily controlled. Specifically, it is preferable that the amorphous metal film is made of an alloy containing at least one metal selected from the group consisting of Cr, Co, Ta, Nb, Al, Ti, Zr, W and Mo. For example, CrTa, a CrTa alloy containing CrTa containing other elements, a CrSi alloy containing CrSi, CrSi containing other elements, and a CoZr alloy containing CoZr or CoZr containing other elements. Can be. Examples of other elements include Co, Nb, Si, Al, Ti, Zr, W, and Mo. More specifically, it is a CoCrZr-based alloy, a CoTaZr-based alloy, a CoSiZr-based alloy, or the like. The ratio of each metal in the alloy can realize an amorphous state and can be arbitrarily determined as long as it does not contradict the purpose of the present invention.
The amorphous metal film preferably has a thickness of 2 to 30 nm. If it is too thin, it will be difficult to sufficiently block the influence of the orientation of the layer below it. If it is too thick, it will increase the cost.
[0021]
The conductive crystal film according to the present invention is not particularly limited, and a known material can be used. The conductive crystal film is made of Ta, Al, Ti, Cu, Ir, Pt, Re, Ru, an alloy containing these metals, Al ₂ O ₃ , TiO ₂ , IrO ₂ , TiN and TaN are preferably made of at least one material. This is because a uniform and stable alignment structure is easily obtained. Specifically, metals such as Pt, Ir, Ru, and Re, alloys containing at least such metals (eg, Pt-Ir), oxides such as Ir, Ru, and Re, or at least such metals are used. Containing metal oxides, such as SrRuO ₃ Can be mentioned. The degree of conductivity of the conductive crystal film is not particularly limited, and can be determined according to the actual situation.
[0022]
The thickness of the conductive crystal film is preferably in the range of 2 to 30 nm. If it is too thin, it is difficult to obtain a uniform orientation. If it is too thick, it will increase the cost.
[0023]
The lower electrode according to the present invention is not particularly limited, and a known material can be used. Ir or Pt can be exemplified.
[0024]
Further, the ferroelectric film according to the present invention is not particularly limited, and a known ferroelectric material can be used. However, a lead zirconate titanate (PZT) film or PZT may be formed of La, Ca, Sr, A material doped with at least one element of the group consisting of Ir and Ru (for example, PLZT (Pb _1-y La _y Zr _x Ti _1-x O ₃ )) And SrBi ₂ Ta ₂ O ₉ (SBT, Y1), or a Bi layer structure compound in which SBT is doped with Nb or the like.
[0025]
The method for manufacturing a semiconductor device having a ferroelectric capacitor according to the present invention includes the steps of: providing an amorphous metal film and a conductive A process of laminating the crystal film and the lower electrode of the ferroelectric capacitor in this order is included. Further, after the conductive crystal film is arranged, a process for crystallizing the amorphous metal film may be included. Through such film formation, a conductive crystal film having a uniform orientation can be formed, and therefore, it is easy to make the orientation of the lower electrode formed thereon and the ferroelectric film thereon further uniform. Becomes possible. Therefore, a semiconductor device having a ferroelectric capacitor having excellent electric characteristics can be manufactured with high yield.
[0026]
The treatment for crystallizing the amorphous metal film is not particularly limited, and a known heat treatment or the like can be employed. The processing time and conditions can be arbitrarily determined according to the required crystallization level. Generally speaking, the timing may be any time after the formation of the conductive crystal film. It is preferable that the conductive crystal film has already been crystallized at the time of film formation, but this is not an essential condition, and any conductive crystal film may be used as long as it can be crystallized prior to crystallization of the amorphous metal film.
[0027]
Regarding the material and thickness of the conductive plug, the amorphous metal film, the conductive crystal film, the lower electrode, and the ferroelectric film in this manufacturing method, the same embodiment as that of the semiconductor device according to the present invention is preferable. The method for forming the conductive plug, the amorphous metal film, the conductive crystal film, the lower electrode, and the ferroelectric film is not particularly limited, and a known method can be employed. For example, a method applicable from a sputtering method, a physical vapor method (PVD), a chemical vapor method (CVD), a sol-gel method, or the like can be appropriately selected.
[0028]
【Example】
Next, embodiments of the present invention will be described in detail.
[0029]
[Example 1]
The manufacturing process of the semiconductor device according to the present invention will be described with reference to the cross-sectional views of the silicon semiconductor device shown in FIGS. As shown in FIG. 3, first, a MOS transistor 20 was formed on a silicon substrate 10. After that, the SiO ₂ A plug contact hole 31 provided in the film was opened. In this contact hole, a 30-nm-thick adhesion layer 32 of TiN (50 nm-thickness) / Ti is formed by a sputtering method, and then W is deposited by a sputtering method. The plug 30 was formed. In this case, SiO ₂ The film corresponds to an amorphous interlayer insulating film, and the W plug corresponds to a conductive plug disposed in the amorphous interlayer insulating film.
[0030]
Next, as shown in FIG. 4, an amorphous metal film 40, a conductive crystal film (hereinafter, the conductive crystal film is also referred to as an orientation control layer) 50, a lower electrode 60, a ferroelectric film 70, and an upper electrode 80 in this order. Deposited to form a ferroelectric capacitor.
[0031]
As the amorphous metal film 40, amorphous Co ₉₄ Zr ₆ The layer was formed to a thickness of 20 nm by a sputtering method.
[0032]
Where Co ₉₄ Zr ₆ It is important to form a film in an amorphous state. For this reason, the conditions of an Ar gas pressure of 0.2 Pa, a DC power of 0.3 kW, and a temperature of 200 ° C. ₉₄ Zr ₆ Layers were made.
[0033]
Next, a Ti film 50 as an orientation control layer was formed to a thickness of 10 nm by a sputtering method. As a result of X-ray diffraction (XRD) measurement of the orientation of the Ti film, ₂ It had the same (001) orientation as on the film. On the other hand, when the Ti film was formed directly on the W plug, the orientation had various orientation components.
[0034]
Then, this sample was furnace ₂ Anneal in an atmosphere at 400 ° C. for 1 hour to obtain Co ₉₄ Zr ₆ The film 40 was crystallized. In this state, the orientation of the Ti film was confirmed again by XRD measurement, but no difference was found in the orientation of the Ti film before and after annealing. The half width of the rocking curve showing the (001) orientation of the Ti film was 4.2 °.
[0035]
In contrast, Co ₉₄ Zr ₆ When a Ti film is formed after the film is crystallized, SiO ₂ Co on the film and on the W plug ₉₄ Zr ₆ Since the orientation of the film is different, the orientation of the Ti film thereon is also different, and a film having a uniform orientation cannot be obtained.
[0036]
Further, an Ir film was formed as the lower electrode 60 to a thickness of 200 nm by a sputtering method under the conditions of an Ar gas pressure of 0.11 Pa, a DC power of 0.5 kW, and a temperature of 500 ° C.
[0037]
Thereafter, a PZT ferroelectric film 70 was formed with a thickness of 200 nm by a sputtering method under the conditions of an Ar gas pressure of 0.7 Pa, an RF power of 1.0 kW, and room temperature.
[0038]
Further, the formed PZT ferroelectric film 70 was mixed with Ar and O introduced at an oxygen gas flow rate of 50 mL / min and an argon gas flow rate of 1.95 L / min. ₂ Rapid heat treatment was performed at 600 ° C. for 90 seconds and at a rate of 125 ° C./second in a mixed atmosphere of
[0039]
At this stage, the XRD measurement was performed again to confirm the orientation of the Ir lower electrode 60 and the PZT ferroelectric film 70. As a result, no orientation other than (111) was confirmed, and a high (111) orientation was confirmed. Indicated. The half width of the rocking curve indicating the (111) orientation of the Ir lower electrode 60 is 2.0 °, and the half width of the rocking curve indicating the (111) orientation of the PZT ferroelectric film 70 is 3.0 °. there were.
[0040]
On the other hand, in the case where the Ti film was formed directly on the W plug without using the amorphous metal film, many orientations other than (111) were observed from the Ir lower electrode and the PZT ferroelectric film.
[0041]
After the PZT ferroelectric film 70 is subjected to the rapid heat treatment as described above, the IrO having a thickness of 20 nm serving as the upper electrode 80 of the ferroelectric capacitor is formed. ₂ The film was treated with an Ar gas pressure of 0.8 Pa, O ₂ Gas flow rate is 100cm in standard condition ³ / Min, DC power 1.0 kW, room temperature, and formed by a sputtering method.
[0042]
Here, the upper electrode 80 is not a Pt film but a conductive oxide, such as IrO. ₂ The reason for using the film is to improve the resistance to hydrogen degradation. In the case of a Pt film, since it has a catalytic action on hydrogen molecules, hydrogen radicals are generated, and the PZT ferroelectric film 70 is easily reduced and deteriorated. In contrast, IrO ₂ Since the electrode does not have a catalytic action, it does not easily generate hydrogen radicals, and the hydrogen deterioration resistance of the PZT film is significantly improved.
[0043]
Thereafter, recovery annealing was performed to recover damage (destruction of crystal) to the ferroelectric film due to sputtering or the like when forming the upper electrode. In this example, the furnace is 650 ° C. and O ₂ The conditions of the atmosphere and 60 minutes were adopted.
[0044]
Next, as shown in FIG. 5, a ferroelectric capacitor having a stack structure was formed by using patterning and etching techniques. In this example, the upper electrode 80, the ferroelectric film 70, the lower electrode 60, the orientation control layer 50, and the amorphous metal film 40 were collectively etched using plasma TEOS (tetraethoxysilane) / TiN as a hard mask.
[0045]
Next, as shown in FIG. 6, after forming a protective film 90 with a thickness of 10 nm, ₂ Furnace annealing was performed for 60 minutes under the following conditions. This protective film 90 protects the ferroelectric capacitor from process damage such as lead escape from the ferroelectric and hydrogen intrusion. In this example, alumina was formed to a thickness of 50 nm by a sputtering method.
[0046]
Next, as shown in FIG. 7, after the interlayer insulating film 100 was formed, planarization was performed by CMP. In this example, the interlayer insulating film is an oxide film using an HDP (High Density Plasma) device, and the remaining film thickness after the CMP is 300 nm on the upper electrode 80 of the ferroelectric capacitor.
[0047]
Next, as shown in FIG. 8, a contact hole connected to the W plug 30 was formed by using patterning and etching techniques. Thereafter, an adhesion layer and a W plug were further formed, and CMP was performed to form a W plug 110.
[0048]
In this example, an adhesion layer TiN (50 nm thick) is used, and 350 ° C. ₂ Plasma was applied for 120 seconds. Via-to-via contact can be realized by two of the W plug 110 and the W plug 30, and contact from the metal wiring formed later to the substrate is achieved.
[0049]
Thereafter, necessary wirings and the like were provided to manufacture a semiconductor device having a ferroelectric capacitor. The ferroelectric capacitor of this semiconductor device has uniform performance and little variation, and can realize a reduction in the defect rate of the semiconductor device and an improvement in the yield.
[0050]
From the contents disclosed above, the inventions shown in the following supplementary notes can be derived.
[0051]
(Supplementary Note 1) In a semiconductor device having a ferroelectric capacitor,
An amorphous metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor are laminated in this order on a region over a region between an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film.
Semiconductor device.
[0052]
(Supplementary Note 2) In a semiconductor device having a ferroelectric capacitor,
An amorphous metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor are laminated in this order on a region over a region between an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film. ,
After disposing the conductive crystal film, the amorphous metal film is crystallized.
Semiconductor device.
[0053]
(Supplementary Note 3) The semiconductor device according to Supplementary Note 1 or 2, wherein the conductive plug is made of at least one material selected from the group consisting of a metal, an alloy, a metal chloride, a metal silicide, a conductive oxide, and silicon. .
[0054]
(Supplementary Note 4) Any of the supplementary notes 1 to 3, wherein the amorphous metal film is made of an alloy containing at least one metal selected from the group consisting of Cr, Co, Ta, Nb, Al, Ti, Zr, W, and Mo. 13. A semiconductor device according to claim 1.
[0055]
(Supplementary Note 5) The semiconductor device according to any one of Supplementary Notes 1 to 4, wherein the amorphous metal film has a thickness of 2 to 30 nm.
[0056]
(Supplementary Note 6) The conductive crystal film is made of Ta, Al, Ti, Cu, Ir, Pt, Re, Ru, an alloy containing these metals, Al ₂ O ₃ , TiO ₂ , IrO ₂ 6. The semiconductor device according to any one of supplementary notes 1 to 5, comprising at least one material selected from the group consisting of TiN, TaN, and TaN.
[0057]
(Supplementary Note 7) The semiconductor device according to any one of Supplementary Notes 1 to 6, wherein the conductive crystal film has a thickness of 2 to 30 nm.
[0058]
(Supplementary Note 8) The semiconductor device according to any one of Supplementary Notes 1 to 7, wherein the lower electrode is made of Ir or Pt.
[0059]
(Supplementary Note 9) The ferroelectric film is a lead zirconate titanate film or a film obtained by doping lead zirconate titanate with at least one element selected from the group consisting of La, Ca, Sr, Ir, and Ru. 9. The semiconductor device according to any one of supplementary notes 1 to 8.
[0060]
(Supplementary Note 10) In the method of manufacturing a semiconductor device having a ferroelectric capacitor,
An amorphous metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor are laminated in this order on an upper portion of a region straddling an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film,
After arranging the conductive crystal film, including a process of crystallizing the amorphous metal film,
A method for manufacturing a semiconductor device.
[0061]
(Supplementary note 11) The supplementary note 10, including a process of manufacturing the conductive plug from at least one material selected from the group consisting of a metal, an alloy, a metal chloride, a metal silicide, a conductive oxide, and silicon. A method for manufacturing a semiconductor device.
[0062]
(Supplementary Note 12) Supplementary note 10 including a process of forming the amorphous metal film from an alloy containing at least one metal selected from the group consisting of Cr, Co, Ta, Nb, Al, Ti, Zr, W, and Mo. Or a method for manufacturing a semiconductor device according to item 11.
[0063]
(Supplementary Note 13) The method of manufacturing a semiconductor device according to any one of Supplementary Notes 10 to 12, including a process of forming the amorphous metal film so that the film thickness is 2 to 30 nm.
[0064]
(Supplementary Note 14) The conductive crystal film is formed of Ta, Al, Ti, Cu, Ir, Pt, Re, Ru, an alloy containing these metals, Al. ₂ O ₃ , TiO ₂ , IrO ₂ 14. The method for manufacturing a semiconductor device according to any one of supplementary notes 10 to 13, further comprising a process of manufacturing from any one material selected from the group consisting of TiN and TaN.
[0065]
(Supplementary Note 15) The method of manufacturing a semiconductor device according to any one of Supplementary Notes 10 to 14, further comprising a process of forming the conductive crystal film to have a thickness of 2 to 30 nm.
[0066]
(Supplementary Note 16) The method of manufacturing a semiconductor device according to any one of Supplementary Notes 10 to 15, including a process of configuring the lower electrode with Ir or Pt.
[0067]
(Supplementary Note 17) The ferroelectric film is formed as a lead zirconate titanate (PZT) film or a film in which PZT is doped with at least one element selected from the group consisting of La, Ca, Sr, Ir, and Ru. 17. The method for manufacturing a semiconductor device according to any one of supplementary notes 10 to 16, further comprising:
[0068]
【The invention's effect】
According to the features of the present invention, it is possible to manufacture a semiconductor device having a ferroelectric capacitor having excellent electric characteristics and uniform performance. Further, a semiconductor device having a ferroelectric capacitor having excellent electric characteristics can be manufactured with high yield.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a planar type ferroelectric memory and a stack type ferroelectric memory.
FIG. 2 is a schematic sectional view of a semiconductor device according to the present invention.
FIG. 3 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device having a ferroelectric capacitor according to an embodiment of the present invention.
FIG. 4 is another schematic cross-sectional view showing a step of manufacturing a semiconductor device having a ferroelectric capacitor according to the embodiment of the present invention.
FIG. 5 is another schematic cross-sectional view showing a step of manufacturing a semiconductor device having a ferroelectric capacitor according to the embodiment of the present invention.
FIG. 6 is another schematic cross-sectional view showing a step of manufacturing a semiconductor device having a ferroelectric capacitor according to the embodiment of the present invention.
FIG. 7 is another schematic cross-sectional view showing a step of manufacturing a semiconductor device having a ferroelectric capacitor according to the embodiment of the present invention.
FIG. 8 is another schematic cross-sectional view showing a step of manufacturing a semiconductor device having a ferroelectric capacitor according to the embodiment of the present invention.
[Explanation of symbols]
1 SiO ₂ film
2 Lower electrode
3 Ferroelectric film
4 Upper electrode
5 Conductive plug
6 Amorphous metal film
7 Conductive crystal film
10. Silicon substrate
20 MOS transistors
30 W plug
40 Amorphous metal film
50 Orientation control layer
60 lower electrode
70 Ferroelectric film
80 Upper electrode
90 Protective film
100 interlayer insulating film
110 W plug

Claims (5)

In a semiconductor device having a ferroelectric capacitor,
An amorphous metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor are laminated in this order on a region over a region between an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film. Semiconductor device. In a semiconductor device having a ferroelectric capacitor,
An amorphous metal film, a conductive crystal film, and a lower electrode of a ferroelectric capacitor are laminated in this order on a region over a region between an amorphous interlayer insulating film and a conductive plug disposed in the amorphous interlayer insulating film. ,
A semiconductor device comprising a step of crystallizing the amorphous metal film after disposing the conductive crystal film. 3. The semiconductor device according to claim 1, wherein said amorphous metal film is made of an alloy containing at least one metal selected from the group consisting of Cr, Co, Ta, Nb, Al, Ti, Zr, W and Mo. . Said conductive crystal film is selected Ta, Al, Ti, Cu, Ir, Pt, Re, Ru, alloys containing these _metals, from the group consisting of _{Al 2 O 3, TiO 2,} IrO 2, TiN and TaN The semiconductor device according to claim 1, wherein the semiconductor device is made of at least one material. The ferroelectric film is a lead zirconate titanate film or a film obtained by doping lead zirconate titanate with at least one element selected from the group consisting of La, Ca, Sr, Ir, and Ru. 5. The semiconductor device according to any one of items 1 to 4,

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