JP2003282829A - Ferroelectric memory element and method and device for manufacturing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing ferroelectric memory element by which a capacitor portion can be formed on the surface of a substrate with high shape accuracy and which can cope with an increase in area of the substrate. <P>SOLUTION: The ferroelectric memory element manufactured by this method is provided with a capacitor portion having a laminated structure of a first electrode 32, a ferroelectric film 34, and a second electrode 36 on a substrate 25. The first electrode 32, the ferroelectric film 34, and the second electrode 36 are formed one after another after the pattern of a surface modifying film 30 having such a surface characteristic that hardly causes the material constituting the capacitor portion to deposit on the surface of the film 30 is formed in an area except the forming area of the first electrode 32. The surface modifying film 30 formed on one substrate 25 is divided into a plurality of partial patterns and each partial pattern is formed by micro-contact printing. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferroelectric memory element, a method of manufacturing a ferroelectric memory element, and a manufacturing apparatus of a ferroelectric memory element.

[0002]

2. Description of the Related Art Ferroelectric memory devices (FeRAM) are
A ferroelectric film is used for the capacitor part, and data is retained by its spontaneous polarization. The capacitor portion of the ferroelectric memory device has a first electrode, a ferroelectric film, and
And a laminated structure of the second electrode, which has been conventionally formed by dry etching using a reactive gas with a resist pattern as an etching mask. However, in the conventional technique, the material forming the capacitor portion, in particular, platinum (Pt) or iridium (Ir), which is preferably used as an electrode material, has a low reactivity with the gas used for etching, and thus is usually used. Etching is performed by etching (sputter etching) with an enhanced physical action. In this case, the secondary products generated by etching are not removed in the gas phase,
It is reattached to the sidewall of the resist pattern. It is very difficult to remove this reattachment, and it remains as a structure, resulting in a problem that the shape accuracy is deteriorated. As one of the methods for avoiding this, when the etching is advanced while the resist is receding, the re-adhesion of secondary products to the sidewall of the resist pattern does not occur. However, such an etching method makes it difficult to achieve high integration because the side wall becomes a capacitor portion having an inclined side wall.

Further, usually, a method is used in which the above-mentioned laminated structure corresponding to a capacitor portion for a plurality of chips is formed on the surface of one substrate, and finally cut into individual chips. In order to increase the manufacturing efficiency, it is required to increase the area of the base material and increase the number of chips formed on the surface of one base material.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to form a capacitor portion on a base material with a high shape accuracy, and it is possible to cope with an increase in the area of the base material. An object of the present invention is to provide a method and an apparatus for manufacturing a body memory element, and a ferroelectric element obtained by the method.

[0005]

According to a first method of manufacturing a ferroelectric element of the present invention, a first electrode, a ferroelectric film, and
And a method of manufacturing a ferroelectric memory device having a capacitor portion having a laminated structure of a second electrode, wherein a thin film pattern forming either the first electrode, the ferroelectric film or the second electrode is formed. A step of forming a pattern of the surface modification film in a region excluding the formation region of the thin film pattern,
The method has a step of forming the thin film pattern in a formation region of the thin film pattern, and in the step of forming the pattern of the surface modification film, a plurality of patterns of the surface modification film formed on one substrate are formed. It is characterized in that it is divided into partial patterns and each partial pattern is formed by microcontact printing. Alternatively, when forming the thin film pattern, the pattern of the surface modification film may be formed in the formation region of the thin film pattern, and then the thin film pattern may be formed on the surface modification film.

According to this manufacturing method, the surface of the surface modification film has surface characteristics such that the material for forming the thin film pattern is less likely to be deposited than the surface of the thin film pattern forming region. Thus, the thin film pattern can be accurately formed on the surface of the region where the pattern of the surface modification film is not formed, that is, the region where the thin film pattern is formed, without etching. Alternatively, the surface of the surface modification film is configured to have a surface property that a material for forming the thin film pattern is more likely to be deposited than the surface of a region where the thin film pattern is not formed, A thin film pattern can be accurately formed on the pattern without etching. Also,
By dividing the pattern of the surface modification film formed on one substrate into a plurality of partial patterns and forming each partial pattern by microcontact printing, the substrate is slightly warped. Also, it is possible to form the pattern of the surface modification film having excellent shape accuracy with good reproducibility. Therefore, the thin film pattern can be accurately manufactured even in a region having a large area, so that a ferroelectric memory device having excellent reliability can be obtained.
In addition, it is possible to achieve miniaturization of the manufacturing apparatus and reduce the waste of materials compared to the case where the surface modification film is formed on the entire surface of the base material collectively by microcontact printing. It is possible to improve the use efficiency of the, and reduce the cost.

According to a second method of manufacturing a ferroelectric memory device of the present invention, a ferroelectric having a capacitor portion having a laminated structure of a first electrode, a ferroelectric film and a second electrode on a base material. In the method of manufacturing a memory element, the step of forming a thin film pattern forming any one of the first electrode, the ferroelectric film, and the second electrode includes the step of forming a thin film by irradiating the entire surface of the base material with radiation. A step of forming a surface modification film having a property of breaking the bond with the lower layer of the pattern, and a state in which a mask and a weight layer having radiation transparency are sequentially laminated on the surface modification film, with respect to the surface modification film. Forming a pattern of the surface modification film in an area other than the area where the thin film pattern is formed by irradiating radiation to pattern the surface modification film, and the thin film pattern is formed in the area where the thin film pattern is formed. The step of forming the pattern of the surface modification film, the weight layer laminated on one base material is provided by being divided into a plurality of partial weight layers. The method is characterized by including the step of irradiating the region where the weight layer is provided with the radiation. Alternatively, when the surface modification film is irradiated with radiation to pattern the surface modification film, a pattern of the surface modification film is formed in a region where the thin film pattern is formed, and then the thin film pattern is formed on the surface modification film. May be formed.

According to this manufacturing method, the surface of the surface modification film has surface characteristics in which the material for forming the thin film pattern is less likely to be deposited than the surface of the region where the thin film pattern is formed. Thus, the thin film pattern can be accurately formed on the surface of the region where the pattern of the surface modification film is not formed, that is, the region where the thin film pattern is formed, without etching. Alternatively, the surface of the surface modification film is configured to have a surface property that a material for forming the thin film pattern is more likely to be deposited than the surface of a region where the thin film pattern is not formed, A thin film pattern can be accurately formed on the pattern without etching. Also,
When the surface modification film is patterned, a mask is laminated on the surface modification film, and a partial weight layer having a smaller area than the surface of the base material is provided on the mask to perform radiation irradiation, thereby The adhesion between the mask and the surface modification film is improved, and the accuracy of the pattern shape can be further improved, as compared with the case where a weight layer having substantially the same size as the entire surface of the material is used.

According to another aspect of the present invention, there is provided a manufacturing apparatus of a ferroelectric memory device, a holding means for holding a base material, and a surface of the base material provided facing the surface of the base material held by the holding means. A stamp having a pattern shape having a smaller area than that, means for wetting the stamp with a solution capable of forming a surface modification film, and moving the relative position of the stamp and the base material in a direction parallel to the surface of the base material. And a means for bringing the stamp into contact with the surface of the base material.

According to this manufacturing apparatus, the step of dividing the pattern of the surface modification film formed on one substrate into a plurality of partial patterns and forming each partial pattern by microcontact printing is carried out. Therefore, it is possible to form a pattern of the surface modification film having excellent shape accuracy with good reproducibility in a region having a large area. Further, since the size of the stamp is smaller than that of the surface of the base material, it is possible to reduce the size of the apparatus, improve the efficiency of using the material, and reduce the cost.

The present invention also provides a ferroelectric memory device obtained by the manufacturing method of the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) A method of manufacturing a ferroelectric memory device according to a first embodiment of the present invention will be described with reference to FIGS. The ferroelectric memory element is a non-volatile semiconductor memory device. The minimum unit for storing information is a memory cell, and for example, a memory cell is configured by combining one transistor and one capacitor portion.
Then, such a plurality of memory cells are arranged to form a memory array. In this case, the plurality of memory cells can be regularly arranged and arranged in a plurality of rows and a plurality of columns.

Reference numeral 10 in the figure denotes a substrate made of a semiconductor wafer or the like. The substrate 10 is one in which one surface 10a is divided into a large number of regions, a chip structure is formed in each region, and then cut into individual chips. For example, the substrate 10 has a substantially circular shape with a diameter of 100 mm to 300 mm, and one substrate 1
For example, about 10 to 1000 rectangular chips are cut out from 0.

(Transistor Forming Step) First, as shown in FIG. 1, a transistor 12 for controlling a ferroelectric memory element is formed on a substrate 10. A structure in which a functional device such as a transistor is provided on the substrate 10 as necessary corresponds to the base material 25 in the present invention. The transistor 12 may have a known structure and may be a thin film transistor (TFT). If it is a MOSFET, the transistor 12 has a drain and a source 14, 1
6 and a gate electrode 18. The gate electrode 18 is connected to the word line 44 (see FIG. 7). The electrode 20 connected to one of the drain and source 14 is connected to the bit line 42 (see FIG. 7). The electrode (plug) 22 connected to the other one of the drain and source 16 is the first electrode 32 (see FIG. 5) of the capacitor portion of the ferroelectric memory element.
(See (C)). Each memory cell has an L
OCOS (Loca 1 Oxidation of Sil
icon) 17 and S on the transistor 12.
An interlayer insulating film 19 made of iO ₂ or the like is formed.

(Capacitor Portion Forming Step) Next, the capacitor portion is formed. First, as shown in FIG. 2, by forming a pattern of the surface modification film 30 on the surface of the base material 25, selectivity is given to the surface characteristics of the base material 25. Here, imparting selectivity to the surface characteristics of the base material 25 means forming areas on the surface of the base material 25 having different surface characteristics such as wettability with a material to be deposited on the surface. In the present embodiment, specifically, the interlayer insulating film 19 and the electrode (plug) 2 formed on the substrate 10
2 is an exposed surface and is a material for forming a member forming the capacitor portion (a material for a first electrode 32 and a material for a ferroelectric film 34, which will be described later) in a region other than a region where the capacitor portion is formed. , And the material of the second electrode 36) is formed, the surface modification film 30 is formed. After that, FIG.
As shown in (A) to (C), the first electrode 32, the ferroelectric film 34, and the second electrode 36 of the capacitor portion are sequentially formed in a region where the surface modification film 30 is not formed, for example, by chemical vapor deposition. It is formed by a phase growth method (CVD), a physical vapor deposition method, or a liquid phase method.

(Surface Modification Film Forming Step) In the present embodiment, the surface modification film 30 is formed by microcontact printing. To form the surface modification film 30 by using microcontact printing, as shown in FIG. 2, a solution obtained by dissolving a substance forming the surface modification film 30 in a solvent on a stamp 61 formed of polydimethylsiloxane or the like. After soaking, the stamp 61 is brought into contact with the surface of the base material 25 to transfer the substance forming the surface modification film 30. As the substance forming the surface modification film 30, for example, a silane coupling agent (organosilicon compound) or a thiol compound can be used. Here, the thiol compound is a general term for organic compounds having a mercapto group (—SH) (R ¹ —SH; R ¹ is a substitutable hydrocarbon group such as an alkyl group). These compounds are dissolved in an organic solvent such as dichloromethane or trichloromethane to give a solution of about 0.1 to 10 mM. Also,
The silane coupling agent is R ² _n SiX _4-n (n is a natural number, R ² is H, a substitutable hydrocarbon group such as an alkyl group)
X is -OR ³ , -COOH,
-OOCR ^3, an ^{_{-NH 3-n R 3 n,}} -OCN, halogen, etc. (R ³ are replaceable hydrocarbon group such as an alkyl group). Among these silane coupling agents and thiol compounds, compounds having a fluorine atom such that R ¹ and R ³ are C _n F _{2n + 1} C _m H _2m (n and m are natural numbers) are particularly preferable for the surface free energy. Is small and its affinity with other materials is small, so that it is preferably used. Alternatively, a mercapto group or -C
A film made of a compound having an OOH group can also be used. The surface modification film 30 made of the above materials may be a monomolecular film or may be used in the form of a cumulative film thereof.

When forming the surface modification film 30,
As shown in FIG. 3, the surface modification film 30 to be formed on one substrate 25 is divided into a plurality of partial patterns 30a, and one stamp 61 has a convex shape corresponding to one partial pattern 30a. Part is provided and the stamp 61 is brought into contact with different regions of the base material 25 a plurality of times.
The surface modification film 30 is formed on top. A plurality of stamps 61 may be used for one substrate 25. One partial pattern 30a is preferably a pattern corresponding to one to a plurality of chips because it is possible to avoid the boundary between the partial patterns from existing on the chip. If the size (area) of one partial pattern 30a formed by one stamp 61 is too large, the partial pattern 30a may be warped when the base material 25 is warped.
There is a possibility that the shape accuracy of is poor. On the other hand, since the size (area) is too and production efficiency small one partial pattern 30a is deteriorated, preferably in the 0.5 cm ² to 20 cm ² approximately area.

FIG. 4 shows an example of an apparatus preferably used for forming the surface modification film 30. In the figure, reference numeral 61 indicates a stamp, and 25 indicates a base material. The base material 25 is held by the holding means 220. The stamp 61 is provided so as to face one surface 25a of the base material 25, and the stamp position control mechanism 230 allows the stamp 61 to be perpendicular to the one surface 25a of the light transmissive substrate 25 and to be perpendicular to the Z direction. It is configured to be movable in various X and Y directions. Further, although not shown, means for wetting the stamp 61 with a solution containing a substance forming the surface modification film 30 is provided by an appropriate coating method such as a dipping method or a spin coating method.

In order to form the surface modification film 30 by microcontact printing using the apparatus having such a structure, first, the stamp 61 is wetted with a solution containing the substance forming the surface modification film 30 and then the stamp position control mechanism. Two
The base material 25 is moved in the X direction and / or the Y direction by 30 to be positioned above the stamp position, and then moved in the Z direction to bring the stamp 61 into contact with the base material 25.
Further, after moving the stamp 61 in the X direction and / or the Y direction to position it above the other stamp positions, Z
The operation of moving in the direction and contacting the base material 25 is repeated. Further, in this example, two stamps 61 are provided, and the movements of the two stamps 61 are independently controlled.

(Step of Forming First Electrode) After the pattern of the surface modification film 30 is formed on the base material 25 in this manner, as shown in FIG. In the region where the film 30 is not formed, a first electrode which becomes a lower electrode of the capacitor portion of the ferroelectric memory device is formed.
The electrode 32 is formed. Here, the planar shape of the first electrode 32 and the planar shape of the plug 22 do not have to be completely the same. In the present embodiment, the region where the surface modification film 30 is formed is called the second region 26, and the other region is called the first region 24.

Specifically, the transistor 12 is formed on the substrate 10.
A film forming process by, for example, a vapor phase method is performed on the entire surface of the base material 25 on which the above are formed. At this time, the second area 2
Since it is difficult to form a film in No. 6, the film is selectively formed in the first region 24, and the first electrode 32 is formed only in the first region 24. As the vapor phase method, CVD, especially MOCVD (M
etal Organic Chemical Vapo
It is preferable to apply r Deposition).
It is preferable that no film is formed in the second region 26, but the film forming speed may be two or more orders of magnitude slower than the film forming in the first region 24. Further, in forming the first electrode 32, a method of selectively supplying a solution of the material in a liquid phase state to the first region 24, or a method of forming a mist of the solution of the material by ultrasonic waves or the like It is also preferable to employ the mist deposition method of selectively supplying to the region 24. First
As a material forming the electrode 32, for example, Pt, Ir or the like can be used. First region 24 on substrate 25
And the surface modification film 30 (second region 26) containing the material as described above is formed to form the selectivity of the surface characteristics, for Pt, for example, (C ₅ H
₇ O ₂ ) ₂ Pt, (C ₅ HFO ₂ ) ₂ Pt, (C ₃ H ₅ ) (C ₅
H ₅ ) Pt may be used as a material for forming an electrode, and Ir may be selectively deposited by using, for example, (C ₃ H ₅ ) ₃ Ir as a material for forming an electrode.

(Ferroelectric Film Forming Step) After forming the first electrode 32, a ferroelectric film 34 is formed on the first electrode 32, as shown in FIG. 5B. Specifically, the film is formed on the first electrode 32 and the film is formed on the second region 26 by performing a film forming process by, for example, a vapor phase method on the entire surface of the substrate 25. Since it is difficult, the ferroelectric layer 34 is formed only on the first electrode 32. CV as a vapor phase method
D, especially MOCVD can be preferably used. Further, in forming the ferroelectric film 34, a method of selectively supplying a solution of the material in a liquid state onto a region excluding the second region 26, that is, the first electrode 32 by an inkjet method or the like,
Or the solution of the material is made into mist by ultrasonic waves, etc.
It is also preferable to employ a mist deposition method in which the electrode 32 is selectively supplied. The composition of the ferroelectric film 34 can be any composition as long as it exhibits ferroelectricity and can be used as a capacitor insulating film and can be formed by CVD. For example, in addition to the PZT-based piezoelectric material, a material to which a metal oxide such as niobium, nickel oxide or magnesium oxide is added can be applied. Specifically, lead titanate (P
bTiO ₃ ), lead zirconate titanate (Pb (Zr, T
i) O ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La), (TiO ₃ ), lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O)
₃ ) or lead zirconium titanate magnesium niobate (Pb (Zr, Ti) (Mg, Nb) O ₃ ) or the like can be used. Alternatively, SBT having Sr, Bi, or Ta as a constituent element can be used.

The material of the ferroelectric film 34 is the base material 2
When the first region 24 and the surface modification film 30 (second region 26) containing the material as described above are formed on the surface 5 to form the selectivity of the surface characteristics, for example, in the case of PZT, for Pb, Pb (C ₂ H ₅ ) ₄ , (C ₂ H ₅ ) ₃ PbOCH ₂ C (C
H ₃ ) ₃ , Pb (C ₁₁ H ₁₉ O ₂ ) _2, etc., and for Zr,
_{Zr (n-OC 4 H 9} ) 4, Zr (t-OC 4 H 9) 4, Zr
_{(C 11 H 19 O 2)} 4, Zr (C 11 H 19 O 2) ₄ or the like, materials for forming the respective ferroelectric film _{34 Ti (i-C 3 H} 7) 4 or the like for Ti And in the case of SBT,
Sr (C ₁₁ H ₁₉ O ₂ ) ₂ etc. for Sr, Bi (C ₆ H ₅ ) ₃ etc. for Bi, Ta (OC ₂
It is preferable to use H ₅ ) ₅ or the like as a material for forming the ferroelectric film 34, respectively.

(Second Electrode Forming Step) After forming the ferroelectric film 34, a second electrode 36 is formed on the ferroelectric film 34, as shown in FIG. Specifically, a film forming process is performed on the entire surface of the base material 25 by, for example, a vapor phase method to form a film on the ferroelectric film 34 and a film on the second region 26. The second electrode 36 is formed only on the ferroelectric film 34 because it is difficult to be formed. CV as a vapor phase method
D, especially MOCVD can be preferably used.
To form the second electrode 36, the ferroelectric film 3 formed in a region other than the second region 26 in a liquid state of a solution of the material.
It is also possible to adopt a method of selectively supplying the liquid onto the surface 4 by an inkjet method or the like, or a mist deposition method of forming a solution of the material into mist by ultrasonic waves and selectively supplying it to a portion other than the second region 26. preferable. The second electrode 36
The same material as that of the above-mentioned first electrode 32 can be used as the constituent material of the above.

(Step of Removing Surface Modification Film, etc.) In this way, the first electrode 32, the ferroelectric film 34, and the second electrode 36 are formed.
After forming the capacitor portion by stacking the above, the surface modification film 30 in the second region 26 may be removed as shown in FIG. When the surface modification film 30 is formed of, for example, a silane coupling agent, the surface modification film 30 can be removed by exposing the surface modification film 30 to light because the bonding of molecules is broken at the interface with the interlayer insulating film 19. 30 can be removed. Alternatively, it can be removed by irradiating a laser, an electron beam or an ion beam. When removing the surface modification film 30, it is preferable to also remove the substance adhering to it. For example, when the material of the first electrode 32, the ferroelectric film 34, or the second electrode 36 adheres to the surface modification film 30, they may be removed. The step of removing the surface modification film 30 is not an essential requirement of the present invention, and the surface modification film 30 may be left. Further, when the ferroelectric film 34 is formed on the side surface of the first electrode 32 or the second electrode 36 is formed on at least one side surface of the first electrode 32 and the ferroelectric film 34,
It is preferable to remove these. In the removing step, for example, dry etching can be applied.

(Structure of Ferroelectric Memory Element) A ferroelectric memory element can be manufactured by the above steps.
According to this embodiment, the first electrode 32 and the ferroelectric film 3 are not etched through the etching mask.
4 and the second electrode 36 can be formed. The obtained ferroelectric memory device includes a lower electrode composed of the first electrode 32 formed in the first region 24, a ferroelectric film 34 formed on the first electrode 32, and a ferroelectric film 34. A capacitor portion including an upper electrode formed of the second electrode 36 formed above is provided. Further, in the second region 26 excluding the first region 24, the surface modification film 30 in which the material for forming the capacitor portion is less likely to be deposited in the vapor phase or the liquid phase than the surface of the base material 25 is formed. May be.

FIG. 7 is a plan view illustrating a ferroelectric memory device according to this embodiment. The cell structure of the ferroelectric memory device shown in this figure is a 2T · 2C (2 transistors, 2 capacitors) type. The transistor 12 is
It is formed in the region 40. The electrode 20 connected to one of the drain and source 14 (see FIG. 6) is connected to the pit line 42 shown in FIG. 7. Gate electrode 18 (FIG. 6)
(Refer to FIG. 7) is connected to the word line 44 shown in FIG.
The electrode 22 connected to the other one of the drain and source 16 (see FIG. 6) is connected to the drive line 46 shown in FIG. 7. A ferroelectric film 34 is formed on the electrode 22 via the first electrode 32.

According to the present embodiment, by providing the surface modification film 30 in the second region 26, the material forming the capacitor portion is deposited in the second region 26 more than in the first region 24. Since the surface characteristics of the first electrode 3 are difficult
2. The three thin film patterns of the ferroelectric film 34 and the second electrode 36 can all be formed by the selective deposition process as described above. Therefore, the capacitor portion can be accurately formed without performing the conventional etching process using the etching mask. Further, since the surface modification film 30 to be formed on one substrate 25 is divided into a plurality of partial patterns 30a and each partial pattern 30a is formed by microcontact printing,
The surface modification film 30 can be formed with good reproducibility and reliability. Therefore, the shape accuracy of the first electrode 32, the ferroelectric film 34, and the second electrode 36 formed on the first region 24 becomes high. Further, since the stamp 61 having the partial pattern 30a having a relatively small area is used, the base material 2 is temporarily used.
Even if there is some warpage in 5, the in-plane uniformity in the contact state between the stamp 61 and the base material 25 is good, and the shape accuracy of the surface modification film 30 is excellent. Further, the smaller the area of the stamp 61 is, the less the amount of the solution containing the material forming the surface modification film 30 is wasted is used.
The material usage efficiency can be improved, and the cost can be reduced. Further, according to the manufacturing apparatus of the present embodiment, the area of the stamp 61 can be reduced, so that the means for applying the solution containing the substance forming the surface modification film 30 to the stamp 61 can also be configured small. Therefore, the manufacturing apparatus can be downsized.

(Second Embodiment) Next, a second embodiment of the manufacturing method of the present invention will be described. FIG. 8 (A)-
FIG. 6C is a diagram illustrating a method of manufacturing the ferroelectric memory element according to the second embodiment of the present invention in the order of steps. The major difference of this embodiment from the first embodiment is that
The point is that the surface modification film 30 is formed not by microcontact printing but by first forming the surface modification film 30b on the entire surface of the base material 25 and then patterning this. 8, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

First, as in the first embodiment, a base material 25 having the transistors 12 and the like formed on the substrate 10 is formed, and then the base material 25 is formed as shown in FIG. 8 (A).
A surface modification film 30b is formed on the entire surface of the. The material forming the surface modification film 30b is capable of exhibiting surface characteristics in which the material forming the capacitor portion is less likely to be deposited than the surface of the base material 25, and the surface modification film 30b is irradiated with radiation such as ultraviolet rays. A material having a property of breaking the bond with the lower layer, in this embodiment, the bond with the base material 25 is used. As a substance forming such a surface modification film 22b, tridecafluorotetrahydrooctyltriethoxysilane (fluoroalkylsilane), octadecyltrimethoxysilane, octadecyltrichlorosilane, or the like can be used.

Next, as shown in FIG. 8B, the surface modification film 30b is irradiated with radiation while a photomask 71 and a weight layer 72 are sequentially stacked on the surface modification film 30b. The surface modification film 30b is patterned by. In this case, since the resist is not used, the resist removal is unnecessary. Note that the present invention does not exclude patterning the surface modification film 30b by applying a photoresist process. The photomask 71 is configured to transmit radiation in the formation region of the capacitor portion, and as shown in FIG. 8C, the surface modification film 30 patterned by irradiation of radiation is a region other than the formation region of the capacitor portion. It is left in the (second region 26).

The weight layer 72 is made of a material that transmits the above-mentioned radiation, and for example, a glass plate or quartz is used. Further, when the weight layer 72 is provided on the photomask 71 and the radiation is applied, as shown in FIG. 9, one base material 25 is divided into a plurality of regions, and a portion corresponding to one region is divided. With one or more weight layers 72a provided on the photomask 71, the region where the partial weight layers 72a are provided is irradiated with radiation. Then, by repeating the operation of moving the position where the partial weight layer 72a is provided and irradiating with radiation, patterning is performed on the entire region of the surface modification film 30b. If the region where one partial weight layer 72a is provided is a region where one to a plurality of chips are formed,
It is more preferable that the boundary between the partial weight layer 72a and the partial weight layer 72a can be prevented from existing on the chip. If the size (area) of one partial weight layer 72a is too large, the patterning accuracy of the surface modification film 30b may be deteriorated when the substrate 25 is warped, etc. 0.5c because the efficiency becomes poor
It is preferably m ^{2 to 20} cm ² .

In this way, after the surface modification film 30 is formed on the second region 26 on the base material 25, the first electrode 32 and the ferroelectric film 34 are formed in the same manner as in the first embodiment. , And the second electrode 36 are stacked to form a capacitor portion. Furthermore, the surface modification film 30 in the second region 26 may be removed after forming the capacitor portion. The ferroelectric memory element obtained in this embodiment has the same structure as the ferroelectric memory element obtained in the first embodiment.

According to the present embodiment, the three thin film patterns of the first electrode 32, the ferroelectric film 34, and the second electrode 36 can all be formed by the selective deposition process. Therefore, the capacitor portion can be accurately formed without performing the conventional etching process using the etching mask. When patterning the surface modification film 30b, the partial weight layer 7 having a smaller area than the base material 25 is formed.
By using 2a, it is possible to improve the adhesion between the mask 71 and the surface modification film 30b, as compared with the case of using a large-area weight layer. Thereby, the surface modification film 30
Can be patterned with high accuracy, so that the shape accuracy of the capacitor portion formed on the surface modification film 30 becomes good.

In the first embodiment, the thin film pattern forming the first electrode 32, the thin film pattern forming the ferroelectric film 34, and the thin film pattern forming the second electrode 36 are all as described above. Although it is formed by the selective deposition process, at least one of these three thin film patterns may be formed by the selective deposition process, and etching need not be performed in the steps using the selective deposition process. The shape accuracy can be improved as compared with the method in which the pattern is formed by etching. For example, if the surface modification layer 30 is provided in the second region after the first electrode 32 is formed by a method such as film formation and then patterning, the ferroelectric film 34 and the second electrode 36 are formed by a selective deposition process. Can be formed. In addition, if the surface modification layer 30 is provided in the second region after the first electrode 32 and the ferroelectric film 34 are formed by a method such as patterning after film formation, the second electrode 36 is formed by the selective deposition process. Can be formed. The patterning of the ferroelectric film 34 may be performed after forming the second electrode 36.
In particular, if the selective deposition process is applied when forming the second electrode 36, etching is not performed, so the ferroelectric film 3
It is preferable because the characteristic deterioration of No. 4 does not occur.

Further, in the first embodiment, the surface modification film 30 is formed in the region (second region 26) other than the region where the capacitor portion is formed, and the capacitor portion is formed in the first region 24. As a modification thereof, the surface modification film 30 may be formed in the first region 24, that is, the formation region of the capacitor portion. In this case, the surface characteristics of the surface modification film 30 are such that the material of the first electrode 32, the material of the ferroelectric film 34,
And / or the material of the second electrode 36 is preferentially deposited, and the first electrode 32, the ferroelectric film 34, or the second electrode 36 is selectively formed on the surface modification film 30. Suitable materials for forming a surface modified film in which the material of such a capacitor portion is likely to be volume are, for example, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyldimethylethoxysilane, aminopropylmethyldiethoxysilane. , Aminophenyltrimethoxysilane, mercaptopropyltriethoxysilane, phenyltrichlorosilane and the like.

[0037]

According to the present invention, as compared with the conventional method of forming the thin film pattern forming the first electrode, the ferroelectric film and the second electrode of the capacitor portion by using the etching mask having the resist pattern, The capacitor portion can be formed with high precision. Moreover, even if the base material is warped to some extent, the capacitor portion can be formed with good shape accuracy, so that it is possible to cope with an increase in the area of the base material and a highly reliable ferroelectric material. A memory device is obtained.

[Brief description of drawings]

FIG. 1 shows a first embodiment of a manufacturing method of the present invention and is a cross-sectional view showing a step of manufacturing a base material.

FIG. 2 shows a first embodiment according to the manufacturing method of the present invention and is a cross-sectional view showing a step of forming a surface modification film.

FIG. 3 shows a first embodiment according to the manufacturing method of the present invention, and is a schematic plan view for explaining a step of forming a surface modification film.

FIG. 4 is a schematic configuration diagram showing an embodiment of a manufacturing apparatus of the present invention.

FIG. 5 shows a first embodiment according to the manufacturing method of the present invention, and is a cross-sectional view showing a step of forming a capacitor portion.

FIG. 6 is a cross-sectional view showing the first embodiment according to the manufacturing method of the present invention, showing the step of removing the surface modification film.

FIG. 7 is a plan view showing an embodiment of a ferroelectric memory element according to the present invention.

FIG. 8 shows a second embodiment of the manufacturing method of the present invention, and is a cross-sectional view showing a step of forming a surface modification film.

FIG. 9 shows a second embodiment according to the manufacturing method of the present invention, and is a schematic plan view for explaining a step of forming a capacitor portion.

[Explanation of symbols]

10 substrates 25 base material 30 Surface modified film 30a partial pattern 32 first electrode (thin film pattern) 34 Ferroelectric film (thin film pattern) 36 Second electrode (thin film pattern) 61 stamps 71 mask 72 layers 72a Partial weight layer

Claims (6)

[Claims] 1. A method of manufacturing a ferroelectric memory device comprising a capacitor portion having a laminated structure of a first electrode, a ferroelectric film, and a second electrode on a substrate, the first electrode comprising: The step of forming a thin film pattern forming either the ferroelectric film or the second electrode includes the step of forming a pattern of the surface modification film in a region excluding the formation region of the thin film pattern, and the formation region of the thin film pattern. The method includes the step of forming the thin film pattern, and in the step of forming the pattern of the surface modification film, 1
A method of manufacturing a ferroelectric memory device, characterized in that the pattern of the surface modification film formed on a single substrate is divided into a plurality of partial patterns, and each partial pattern is formed by microcontact printing. 2. A method of manufacturing a ferroelectric memory device comprising a capacitor portion having a laminated structure of a first electrode, a ferroelectric film, and a second electrode on a substrate, the first electrode comprising: A step of forming a thin film pattern forming either the ferroelectric film or the second electrode, a step of forming a pattern of the surface modification film in a formation region of the thin film pattern,
The method has a step of forming the thin film pattern on the surface modification film, and in the step of forming the pattern of the surface modification film, 1
A method of manufacturing a ferroelectric memory device, characterized in that the pattern of the surface modification film formed on a single substrate is divided into a plurality of partial patterns, and each partial pattern is formed by microcontact printing. 3. A method of manufacturing a ferroelectric memory device comprising a capacitor portion having a laminated structure of a first electrode, a ferroelectric film, and a second electrode on a substrate, the first electrode comprising: The surface modification film having a property that the step of forming a thin film pattern forming either the ferroelectric film or the second electrode has the property of breaking the bond with the lower layer of the thin film pattern by irradiation of radiation on the entire surface of the substrate. And a step of forming a mask and a radiation-transmitting weight layer on the surface modification film in this order, and irradiating the surface modification film with radiation to pattern the surface modification film. The step of forming a pattern of the surface modification film in a region excluding the formation region of the thin film pattern, and the step of forming the thin film pattern in the formation region of the thin film pattern, In the step of forming the turn, 1
The method further comprises a step of dividing the weight layer to be laminated on a base material into a plurality of partial weight layers, and irradiating the region where the partial weight layers are provided with the radiation. And method for manufacturing a ferroelectric memory device. 4. A method of manufacturing a ferroelectric memory device, comprising: a substrate, and a capacitor portion having a laminated structure of a first electrode, a ferroelectric film, and a second electrode, the first electrode comprising: The surface modification film having a property that the step of forming a thin film pattern forming either the ferroelectric film or the second electrode has the property of breaking the bond with the lower layer of the thin film pattern by irradiation of radiation on the entire surface of the substrate. And a step of forming a mask and a radiation-transmitting weight layer on the surface modification film in this order, and irradiating the surface modification film with radiation to pattern the surface modification film. The step of forming a pattern of the surface modification film on the formation region of the thin film pattern, and the step of forming the thin film pattern on the surface modification film, thereby forming the pattern of the surface modification film. In extent, 1
The method further comprises a step of dividing the weight layer to be laminated on a base material into a plurality of partial weight layers, and irradiating the region where the partial weight layers are provided with the radiation. And method for manufacturing a ferroelectric memory device. 5. A holding means for holding a base material, and a stamp having a pattern shape having an area smaller than the surface of the base material, the stamp being provided so as to face the surface of the base material held by the holding means. A means for wetting the stamp with a solution capable of forming a surface modification film, a means for moving the relative position of the stamp and the base material in a direction parallel to the surface of the base material, and a means for moving the stamp to the base material. An apparatus for manufacturing a ferroelectric memory device, comprising means for contacting a surface. 6. A ferroelectric memory device obtained by the manufacturing method according to claim 1.