JP4852744B2 - Dielectric film capacitor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a dielectric film capacitor and a manufacturing method thereof.

  For example, devices in the information industry field, such as mobile communication terminals represented by mobile phones, will be required to increase in speed, capacity, and size in the future. It is advanced extensively and vigorously. Among them, dielectric materials having an ABOx type (perovskite type) crystal structure typified by barium titanate, barium strontium titanate, and lead zirconate titanate are widely used in the field of electronic devices such as capacitors and memory materials. Yes.

  However, in order to further reduce the size and performance of these electronic devices, it is indispensable to reduce the thickness of the element. To that end, the establishment of manufacturing technology for high-performance and high-quality dielectric film capacitors is the key. It has become.

  A dielectric film capacitor generally has a structure in which a substrate, an insulating layer, a lower electrode, a dielectric film, and an upper electrode are sequentially laminated. The dielectric film capacitor can be formed by sputtering, CVD method (chemical vapor deposition method), MBE method (molecular beam epitaxy method), sol-gel method, MOD method (organometallic decomposition method) or the like. Among these, the liquid phase method is expected in view of low production cost, easy composition control and shape application, and no need for expensive equipment.

  When forming a dielectric film by a vapor phase method, it is generally necessary to improve the dielectric characteristics of the dielectric film by heat-treating the formed dielectric film in an oxidizing atmosphere. In addition, when forming a dielectric film by a liquid phase method, generally, a sol-gel solution in which an organic compound as a raw material of the dielectric film is dissolved in an organic solvent or a solution in which dielectric material particles are dispersed is applied. It is necessary to heat-treat the coating film obtained in an oxidizing atmosphere. For this reason, a noble metal that is difficult to oxidize is used for the lower electrode. Specifically, platinum (Pt) -based material is often used as the material for the lower electrode.

  When forming a dielectric film capacitor on a silicon wafer, for example, a lower electrode (eg, a Pt film) is formed on a silicon-based insulating layer (eg, a silicon oxide layer) formed on the silicon wafer. However, since the adhesion between the silicon-based insulating layer and the lower electrode (particularly the Pt film) is poor, the lower electrode is easily peeled off from the silicon-based insulating layer. The peeling of the lower electrode makes it very difficult to manufacture a dielectric film capacitor using a technique such as patterning or dicing cut. In order to solve this problem, as an attempt to improve the adhesion between the silicon-based insulating layer and the lower electrode, a method for forming an adhesion layer between the silicon-based insulating layer and the lower electrode has been reported.

  For example, in Patent Document 1, an attempt is made to improve the adhesion between the silicon oxide layer and the noble metal electrode film by forming a titanium (Ti) film as an adhesion layer between the silicon oxide layer and the noble metal electrode film. However, the oxidation of the Ti film may cause the substrate to warp, or the oxide generated by the oxidation of the Ti film may diffuse to the interface between the noble metal electrode film and the dielectric film.

  For example, in Patent Document 2, a gold (Au) film is created as an adhesion layer between a silicon oxide layer and a platinum electrode film, and the stress of the platinum electrode film is relaxed, whereby the silicon oxide layer and the platinum electrode film are I am trying to improve the adhesion. However, the production of a multilayer noble metal thin film is disadvantageous in terms of cost when manufacturing an actual device. In addition, the adhesion between the Au film and the silicon oxide layer is not good, and it is difficult to say that the adhesion is improved.

For example, in Patent Documents 3 and 4, an adhesion layer using the same material as the dielectric film is formed as an adhesion layer between the silicon oxide layer and the platinum electrode film, thereby reducing the stress of the film, thereby An attempt is made to improve the adhesion between the layer and the platinum electrode film. According to this method, since the adhesion layer and the dielectric layer are made of the same material, even if the adhesion layer diffuses to the interface between the lower electrode and the dielectric film, the characteristics are not deteriorated. However, since it is necessary to select a dielectric material that can function as an adhesion layer, the material composition that can be used as the dielectric film is limited, which is not preferable in terms of the characteristics of the dielectric film capacitor.
JP-A-8-78636 JP 2004-349394 A JP 2005-85812 A Japanese Patent Laid-Open No. 2005-101431

  The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the adhesion between the lower electrode and a layer provided under the lower electrode, and is hardly oxidized and thermally stable. It is an object to provide a dielectric film capacitor that can provide a simple electrode structure, has a good yield, and has excellent characteristics, and a method for manufacturing the same.

  Another object of the present invention is to provide an electronic circuit component including the dielectric film capacitor of the present invention.

1. The dielectric film capacitor of the present invention is
A lower electrode made of a material containing platinum and having a thickness of 10 to 100 nm;
A dielectric film including an oxide having an ABOx type crystal structure provided above the lower electrode;
An upper electrode provided above the dielectric film;
including.

  Here, in the dielectric film capacitor according to the present invention, the lower electrode may have a sheet resistance of 0.1 to 3.0Ω / □.

  Here, in the dielectric film capacitor of the present invention, in the oxide having the ABOx type crystal structure, the metal species A is one or more metals selected from Li, Na, Ca, Sr, Ba, and La. The metal species B can be one or more metals selected from Ti, Zr, Ta, and Nb.

  Here, in the dielectric film capacitor of the present invention, the lower electrode may be provided on a silicon-based insulating layer.

  In this case, the silicon insulating layer may have a thickness of 100 to 2000 nm.

In this case, the silicon-based insulating layer may have a volume resistivity of 10 ¹⁰ Ωcm or more.

  Further, in this case, an intermediate layer in which metal and silicon are mixed can be formed between the silicon-based insulating layer and the upper electrode.

  In addition, in this case, the silicon-based insulating layer may be silicon oxide.

2. The manufacturing method of the dielectric film capacitor of the present invention includes:
(A) forming a lower electrode made of a material containing platinum and having a thickness of 10 to 100 nm;
(B) directly forming a dielectric film containing an oxide having an ABOx type crystal structure on the lower electrode;
(C) forming an upper electrode above the dielectric film;
including.

  Here, in the method for manufacturing a dielectric film capacitor of the present invention, the step (b) may include a step of forming the dielectric film by applying a dielectric film forming composition.

  In this case, the composition for forming a dielectric film comprises (i) particles having an ABOx type crystal structure, (ii) a metal alkoxide containing a metal species A and a metal species B, a metal carboxylate, a metal complex, and a metal hydroxide. (I) and / or (ii) or at least one of the components selected from the group of compounds and (iii) an organic solvent, wherein the metal species A is Li, Na, Ca, Sr, Ba , And La, and the metal species B may be one or more metals selected from Ti, Zr, Ta, and Nb.

  3. The electronic circuit component of the present invention includes the dielectric film capacitor of the present invention.

  According to the dielectric film capacitor of the present invention, by including the lower electrode having a thickness of 10 to 100 nm made of a material containing platinum, adhesion between the lower electrode and a layer provided under the lower electrode is achieved. In addition, the surface roughness of the lower electrode is good, an electrode structure that is hardly oxidized and is thermally stable can be provided, the yield is good, and the characteristics are excellent.

  According to the dielectric film capacitor manufacturing method of the present invention, the dielectric film capacitor of the present invention can be obtained efficiently.

  Hereinafter, the dielectric film capacitor of the present embodiment, the manufacturing method thereof, and the electronic circuit component will be described in detail.

1. Dielectric Film Capacitor FIG. 1F is a cross-sectional view schematically showing a dielectric film capacitor 20 according to one embodiment of the present invention.

  The dielectric film capacitor 20 according to the present embodiment includes a lower electrode 22, a dielectric film 24 provided above the lower electrode 22, and an upper electrode 26 provided above the dielectric film 24. The dielectric film 24 includes an oxide having an ABOx type crystal structure.

  The dielectric film capacitor 20 of the present embodiment can be used as, for example, a thin film capacitor built in an interposer.

  The dielectric film capacitor 20 of the present embodiment can be used as a ferroelectric film capacitor of a ferroelectric memory device (not shown), for example. In this case, a charge as information is stored in the dielectric film 24 of the dielectric film capacitor 20. Further, in this case, the ferroelectric memory device includes a transistor (not shown) such as a thin film transistor (TFT) and a MOSFET together with the dielectric film capacitor 20.

  The lower electrode 22 is made of a material containing platinum, and preferably made of platinum or an alloy of platinum and a metal other than platinum (for example, at least one metal selected from ruthenium, rhodium, palladium, osmium, and iridium). Become. The film thickness d (see FIG. 1 (F)) of the lower electrode 22 is 10 to 100 nm, more preferably 10 to 70 nm, and still more preferably 10 to 50 nm. If the thickness of the lower electrode 22 is smaller than 10 nm, the electric resistance may be too high. On the other hand, if the thickness is larger than 100 nm, the adhesion between the lower electrode 22 and the layer below it is reduced, and the lower electrode 22 Since surface roughness becomes large, it is not preferable. The lower electrode 22 may be a single layer film or a laminated multilayer film.

  Further, the lower electrode 22 preferably has a sheet resistance of 0.1 to 3.0Ω / □, and more preferably has a sheet resistance of 0.1 to 1.0Ω / □. When the surface resistance of the lower electrode 22 exceeds 3.0Ω / □, the capacitor has a large resistance loss.

In the oxide having an ABOx type crystal structure constituting the dielectric film 24, the metal species A can be one or more metals selected from Li, Na, Ca, Sr, Ba, and La. B can be one or more metals selected from Ti, Zr, Ta, and Nb. For example, the dielectric film 24 can be made of (Pb (Zr, Ti) O ₃ ) (PZT), SrBi ₂ Ta ₂ O ₉ (SBT), (Bi, La) ₄ Ti ₃ O ₁₂ (BLT). .

  The upper electrode 26 may be formed of the above-described materials exemplified as materials that can be used for the lower electrode 22, or may be formed of aluminum, silver, nickel, or the like. The upper electrode 26 may be a single layer film or a laminated multilayer film.

  In the present embodiment, the lower electrode 22 is provided on the insulating layer 12. This insulating layer 12 can be, for example, a silicon-based insulating layer. The silicon-based insulating layer is an insulating layer containing silicon, and the film thickness is preferably 100 to 2000 nm, and more preferably 100 to 500 nm. Here, when the film thickness of the silicon-based insulating layer is less than 100 nm, the leakage current is large. On the other hand, when the film thickness of the silicon-based insulating layer exceeds 2000 nm, the stress applied to the substrate becomes strong.

In addition, the silicon-based insulating layer preferably has a volume resistivity of 10 ¹⁰ Ωcm or more, and more preferably has a volume resistivity of 10 ¹² Ωcm or more. When the volume resistivity of the silicon-based insulating layer is less than 10 ¹⁰ Ωcm, the leakage current increases.

  Examples of the silicon-based insulating layer include a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and a silicon-based low-k film. Although not shown, a contact layer may be provided below the lower electrode 22.

  When the insulating layer 12 is a silicon-based insulating layer, an intermediate layer (not shown) in which metal and silicon are mixed may be formed between the silicon-based insulating layer and the lower electrode 22. The intermediate layer in which the metal and silicon are mixed is formed by a reaction between the metal constituting the lower electrode 22 and the silicon atoms constituting the silicon-based insulating layer. By forming an intermediate layer in which metal and silicon are mixed between the silicon-based insulating layer and the lower electrode 22, adhesion between the lower electrode 22 and the silicon-based insulating layer can be improved.

  For example, when the lower electrode 22 is made of a material containing platinum, an intermediate layer in which platinum and silicon are mixed is formed between the silicon-based insulating layer and the lower electrode 22. In particular, when the lower electrode 22 is made of a material containing platinum, the adhesion between the lower electrode 22 and the silicon-based insulating layer is poor, and the lower electrode 22 may peel off from the silicon-based insulating layer. In this case, according to the dielectric film capacitor 20 of the present embodiment, the silicon-based insulating layer (insulating layer 12) and the electrode made of a material containing platinum (lower electrode 22) are intermediate layers in which platinum and silicon are mixed. By disposing via, the adhesion between the silicon-based insulating layer (insulating layer 12) and the lower electrode 22 can be improved.

  According to the dielectric film capacitor of the present invention, the lower electrode 22 and the layer provided under the lower electrode 22 (FIG. 1 ( In F), the adhesion with the insulating layer 12) is improved, the surface roughness of the lower electrode 22 is good, it is possible to provide a thermally stable electrode structure that is hardly oxidized, the yield is good, and the characteristics are excellent. ing. Accordingly, for example, when the dielectric film 24 and the upper electrode 26 formed on the lower electrode 22 are patterned, the lower electrode 22 can be prevented from being peeled off.

  In particular, when the lower electrode 22 is made of a material containing platinum and the layer provided under the lower electrode 22 is a silicon-based insulating layer, the adhesion between the lower electrode 22 and the silicon-based insulating layer is improved satisfactorily. The lower electrode 22 can be prevented from peeling off.

  Further, since the surface roughness of the lower electrode 22 is good, the leakage current flowing through the dielectric thin film is reduced, and the reliability of the dielectric thin film with respect to the withstand voltage is improved.

2. Method for Manufacturing Dielectric Film Capacitor Next, a method for manufacturing the dielectric film capacitor 20 of the present embodiment will be described with reference to FIGS. 1 (A) to 1 (F). 1A to 1F are cross-sectional views schematically showing one manufacturing process of the dielectric film capacitor 20 according to one embodiment of the present invention.

  The manufacturing method of the dielectric film capacitor 20 of the present embodiment includes (a) a step of forming a lower electrode made of platinum and having a thickness of 10 to 100 nm, and (b) an ABOx on the lower electrode 22. A step of directly forming a dielectric film 24 containing an oxide having a type crystal structure; and (c) a step of forming an upper electrode 26 above the dielectric film 24.

  Hereinafter, each manufacturing process of the dielectric film capacitor 20 of this Embodiment is demonstrated.

2.1. Formation of Lower Electrode 22 First, as shown in FIG. 1A, a substrate 10 is prepared. The substrate 10 can be, for example, a semiconductor substrate such as a silicon substrate, an SOI substrate, a sapphire substrate, or a compound semiconductor substrate.

  Next, as illustrated in FIG. 1B, the insulating layer 12 is formed over the substrate 10. As the material of the insulating layer 12, those exemplified in the column of “dielectric film capacitor” can be used. The insulating layer 12 can be formed using a known method (for example, a CVD method, a thermal oxidation method, a spin coating method).

  Next, as illustrated in FIG. 1C, a lower electrode 22 made of a material containing platinum and having a thickness of 10 to 100 nm is formed over the insulating layer 12. The film formation method of the lower electrode 22 is not particularly limited, but can be formed using, for example, a sputtering method.

2.2. Formation of Dielectric Film 24a Next, as shown in FIG. 1D, the dielectric film 24a is formed directly on the lower electrode 22. The dielectric film 24a is patterned in a process described later to form a dielectric film 24 having a predetermined pattern (see FIG. 1F). The dielectric film 24a can be formed by, for example, sputtering, CVD method (chemical vapor deposition method), MBE method (molecular beam epitaxy method), sol-gel method, MOD method (organometallic decomposition method) or the like. In addition, the dielectric film 24a is preferably formed by a liquid phase method that does not require an expensive apparatus from the viewpoint of manufacturing cost, composition control, and ease of shape assignment. When the dielectric film 24a is formed by the liquid phase method, the dielectric film 24a can be formed by applying a dielectric film forming composition.

  The composition for forming a dielectric film of the present embodiment includes (i) particles having an ABOx type crystal structure, (ii) metal alkoxide containing metal species A and B, metal carboxylate, metal complex, and metal water. It can be a composition comprising (i) and (ii) or any one of at least one component selected from the group of oxides and (iii) an organic solvent.

  The concentration of the oxide particles having the (BO) ABOx type crystal structure contained in the dielectric film forming composition of the present embodiment is 20 to 3 wt%, preferably 15 to 5 wt%.

  Here, specific examples of the metal species A and the metal species B are as described above in the section of “Dielectric film capacitor”.

  Examples of the organic solvent (iii) included in the dielectric assembly forming composition of the present embodiment include alcohol solvents, polyhydric alcohol solvents, ether solvents, ketone solvents, ester solvents, and the like. be able to.

  The dielectric film-forming composition of the present embodiment is applied onto the lower electrode 22 to form a coating film, and this coating film is dried as necessary, preferably further heated and fired, so that the dielectric The film 24a can be obtained.

  Examples of the coating method of the dielectric film forming composition of the present embodiment include an open spin coating method, a sealed spin coating method, a mist-coating LSM-CVD method (solution vaporization chemical vapor deposition method), and a dipping method. A known coating method such as a spray method, a roll coating method, a printing method, an ink jet method, or an electrophoretic electrodeposition method can be used.

  The coating film is usually dried at a temperature of 50 to 300 ° C, preferably 100 to 250 ° C. In addition, the dielectric film 24a finally obtained is set to a desired film thickness by repeatedly applying a dielectric film forming composition and, if necessary, repeating a series of operations until drying. Can do. Then, the dielectric film 24a can be obtained by heating and baking this coating film at a temperature of usually 300 to 900 ° C., preferably 400 to 750 ° C.

2.3. Formation of Upper Electrode 26a and Formation of Dielectric Film 24 and Upper Electrode 26 Next, as shown in FIG. 1E, the upper electrode 26a is formed on the dielectric film 24a. The method for forming the upper electrode 26a is not particularly limited as long as it does not cause non-negligible damage to the dielectric film 24a. For example, a vapor deposition method or a sputtering method can be used.

  Next, as shown in FIG. 1E, a resist layer R is formed on the upper electrode 26a by, for example, photolithography. In the present embodiment, the resist R has a planar shape and size corresponding to the planar pattern of the desired dielectric film 24 and upper electrode 26. Using this resist R as a mask, the dielectric film 24a and the upper electrode 26a are patterned. Thereby, the dielectric film 24 and the upper electrode 26 are formed (see FIG. 1F). As shown in FIG. 1F, the end faces of the dielectric film 24 and the upper electrode 26 are coincident.

  Here, for the patterning of the dielectric film 24a and the upper electrode 26a, a known method such as wet etching or dry etching can be used.

  Through the above steps, the dielectric film capacitor 20 of the present embodiment can be obtained (see FIG. 1F).

3. Electronic Circuit Component The electronic circuit component of the present embodiment includes the dielectric film capacitor 20 of the present embodiment. Although the use of the electronic circuit component of this embodiment is not particularly limited, it can be used for electronic devices such as mobile communication terminals (for example, mobile phones), information processing devices, and amusement devices.

4). Examples Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

4.1. Example 1
4.1.1. Preparation of Dielectric Film Forming Composition First, a dielectric film forming composition used for forming the dielectric film capacitor of this example was prepared.

113.71 g of Ti (OCH (CH ₃ ) ₂ ) ₄ was added to 609.04 g of ethylene glycol monomethyl ether, and the mixture was stirred at 25 ° C. for 30 minutes. Thereafter, 77.33 g of Ba (OH) ₂ .H ₂ O was added and dissolved, followed by heating at 80 ° C. for 2 hours. Thereafter, the insoluble matter was removed by filtration through a Teflon (registered trademark) filter having a pore diameter of 0.2 μm.

  620.00 g of the reaction solution was cooled to 0 ° C., and 167.40 g of water corresponding to 30-fold mol of Ba was added and stirred vigorously to obtain a hydrolysis / condensation product. Then, the produced hydrolyzate / condensate was allowed to stand at 60 ° C. for 3 hours for crystallization.

  After crystallization, the crystal particles and the supernatant solution were separated by decantation, 600 g of ethylene glycol monomethyl ether was added, and the mixture was allowed to stand again at 60 ° C. and left for 3 hours. This operation was repeated 4 times.

After separating the crystal particles and the supernatant solution, ethylene glycol monomethyl ether is added so that the solid content concentration in terms of BaTiO ₃ is 10% by weight, and further polyoxypropylene-polyoxyethylene condensation of ethylenediamine as a dispersant. The product was added in an amount of 0.1 weight per 100 weight of the particles, and the crystal particles were dispersed with an ultrasonic disperser. Thus, a dielectric film forming composition (1) according to this example containing the ABOx type crystal structure as component (i) was obtained.

  The particle size distribution of the particles having an ABOx type crystal structure contained in the obtained dielectric film forming composition (1) is measured by a dynamic light scattering type particle size distribution measuring device (model name “LB-500”, Horiba, Ltd.). FIG. 3 shows the results of measurement by a dynamic scattering method using Seisakusho Co., Ltd. According to FIG. 3, it can be seen that the particles contained in the dielectric film forming composition (1) have a particle distribution (average particle diameter of about 40 nm) mainly composed of 40 nm. The particle dispersion was easily filtered with a filter having a pore diameter of 200 nm to remove coarse particles.

Further, the crystal structure of the particles having the ABOx type crystal structure (component (i)) of this example was confirmed by X-ray analysis. X-ray diffraction measured by an X-ray diffractometer (model name “MXP18A”, manufactured by MacScience Co., Ltd.) obtained by dripping the obtained particle dispersion having an ABOx type crystal structure onto a glass plate and drying it at room temperature The chart is shown in FIG. According to FIG. 4, it can be determined that the particles in the dielectric film forming composition (1) having an ABOx type crystal structure have an ABOx type crystal structure of a BaTiO ₃ composite oxide.

4.1.2. Formation of Dielectric Film Capacitor 20 4.1.2a. Formation of Lower Electrode 22 First, as shown in FIG. 1A, a substrate 10 made of single crystal silicon is prepared. Next, as shown in FIG. 1B, an insulating layer (silicon oxide layer) 12 having a thickness of 0.1 μm is formed on the substrate 10 by thermal oxidation.

  Next, as shown in FIG. 1C, a resist pattern is formed on the insulating layer 12, a Pt film having a thickness of 30 nm is formed thereon by sputtering, and then the resist pattern is dissolved and removed. Thus, the lower electrode 22 made of Pt was formed.

4.1.2b. Formation of Dielectric Film 24a Next, as shown in FIG. 1D, a dielectric film 24a was formed on the lower electrode 22. In this embodiment, an example in which the dielectric film 24a is formed by a liquid phase method is shown.

  A dielectric film forming composition (1) is applied on a lower electrode 22 made of Pt having a film thickness of 30 nm with good adhesion and good surface roughness using a spin coater at 300 rpm for 5 seconds, and subsequently at 3000 rpm. After forming a coating film by spin coating for 15 seconds, the coating film was dried at 250 ° C. for 1 minute, and then the coating film was heated and baked at 750 ° C. for 60 minutes. This operation was performed twice to produce a dielectric film 24a having a thickness of 195 nm.

4.1.3. Formation of Upper Electrode 26a and Formation of Dielectric Film 24 and Upper Electrode 26 Next, as shown in FIG. 1E, an upper electrode (Al film having a thickness of 200 nm is formed on the dielectric film 24a by sputtering. ) 26a was formed. Next, a resist layer R was formed on the upper electrode 26a by photolithography. Using this resist R as a mask, both the dielectric film 24a and the upper electrode 26a are wet-etched to form the dielectric film 24 and the upper electrode 26 having a plane area of 0.5 mm in diameter (see FIG. 1F). . Through the above steps, the dielectric film capacitor 20 of this example was obtained.

4.1.4. Evaluation of Electrical Characteristics of Dielectric Film Capacitor 20 The dielectric constant, dielectric loss, and leakage current of the dielectric film capacitor 20 obtained in this example were measured. The relative dielectric constant and dielectric loss were measured using a Precision LCR meter HP4284A (manufactured by Yokogawa Hewlett-Packard Co., Ltd.), and the leakage current was measured using an electrometer 6517A (manufactured by Keithley Instruments Co., Ltd.). As a result, the dielectric constant was 195 and the dielectric loss was 0.04 at a measurement frequency of 100 kHz, and the leakage current was 2.70 × 10 ⁻⁷ (A / cm ² ) at 0.2 MV / cm.

  As is clear from the measurement results, a dielectric film 24a is formed on the lower electrode 22 made of Pt by applying a dielectric film forming composition, and then the upper electrode is formed on the dielectric film 24a. After forming 26a, the dielectric film 24a and the upper electrode 26a are patterned by wet etching to form the dielectric film 24 and the upper electrode 26, thereby producing the dielectric film capacitor 20 showing good electrical characteristics. We were able to.

4.2. Comparative Example 1
In the manufacturing process of the dielectric capacitor of the present example, the manufacturing process of the dielectric capacitor of Comparative Example 1 is the same as the manufacturing process of the dielectric capacitor of the present example except that the film thickness of the lower electrode 22 is set to 300 nm. Tried to create. However, as shown in Table 1 and FIG. 2, in Comparative Example 1, when the lower electrode 22 was baked at 750 ° C. for 60 minutes, the lower electrode 22 was peeled off and the dielectric capacitor was not completed. As the cause, in the lower electrode 22 having a film thickness of 300 nm in Comparative Example 1, it is surmised that the lower electrode 22 was peeled off due to poor adhesion between the lower electrode 22 and the layer below it. Further, the lower electrode 22 having a film thickness of 300 nm of Comparative Example 1 has a large surface roughness at any of annealing temperatures of 600 ° C., 750 ° C., and 900 ° C., and is not suitable as a lower electrode of a dielectric capacitor. Met.

4.3. Example 2
A lower electrode 22 (platinum film) having a different film thickness was formed by the same method as in Example 1. These lower electrodes 22 were annealed, and it was investigated whether or not the adhesiveness changed due to the difference in annealing temperature (annealing temperature). The results are shown in Table 1. The adhesion of the lower electrode 22 was evaluated by a cross cut tape peeling test.

  Here, the annealing temperature corresponds to the firing temperature when the dielectric film 24 a formed on the lower electrode 22 is formed. That is, in Example 2, the influence (here, surface roughness) of the firing temperature of the dielectric film 24a on the lower electrode 22 was investigated.

In Table 1, the evaluation results “A” and “B” are as follows.
A: No peeling of the lower electrode 22 B: Peeling of the lower electrode 22

  Moreover, the surface roughness of the lower electrode 22 was investigated using Alpha-Step IQ SURFACE PROFILER (made by KLA TENCOR). The result is shown in FIG. In FIG. 2, plots of 300 nm, 70 nm, 50 nm, and 30 nm correspond to Comparative Example 1 and Test Examples 1 to 3 in Table 1, respectively. In Table 1, Comparative Example 2 is a case where a Ti film 100 nm is formed as an adhesion layer between the lower electrode 22 and the insulating layer 12, and a lower electrode 22 having a thickness of 200 nm is formed on the adhesion layer. The evaluation results of the adhesion are shown.

  From the results of Table 1 and FIG. 2, the lower electrode 22 having a film thickness of 100 nm or less (particularly, film thickness of 70 nm or less) has excellent adhesion and good surface roughness. It is clear that it is suitable.

  Further, from the result of Comparative Example 2, when an adhesion layer (Ti film) was formed between the lower electrode 22 and the insulating layer 12, the lower electrode 22 was peeled off when the annealing temperature was 900 ° C. That is, it was found that when the adhesion layer was formed, the adhesion decreased as the annealing temperature increased. On the other hand, in Test Examples 1 to 3, since the adhesion layer is not formed between the lower electrode 22 and the insulating layer 12 and the film thickness of the lower electrode 22 is 10 to 100 nm, the annealing temperature is high. Even in this case, it is clear that the adhesion between the lower electrode 22 and the insulating layer 12 can be maintained.

1A to 1F are cross-sectional views schematically showing one manufacturing process of the dielectric film capacitor 20 according to one embodiment of the present invention. FIG. 2 is a graph showing the measurement results of the surface roughness of the lower electrode 22 obtained in Example 1. 3 is a graph showing the particle size distribution of particles (component (i)) in a dispersion of oxide particles having an ABOx type crystal structure obtained in Example 1. FIG. FIG. 4 is a diagram showing the results of X-ray diffraction of a dried product of the dielectric film forming composition (1) obtained in Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Substrate 12 ... Insulating layer 20 ... Dielectric film capacitor 22 ... Lower electrode 24, 24a ... Dielectric film 26, 26a ... Upper electrode R ... Resist layer

Claims (10)

A silicon-based insulating layer;
A lower electrode having a thickness of 10 to 100 nm made of a material containing platinum , provided on the silicon-based insulating layer ;
A dielectric film including an oxide having an ABOx type crystal structure provided above the lower electrode;
An upper electrode provided above the dielectric film;
Only including,
A dielectric film capacitor in which an intermediate layer in which platinum and silicon are mixed is formed between the silicon-based insulating layer and the lower electrode . In claim 1,
The lower electrode is a dielectric film capacitor having a sheet resistance of 0.1 to 3.0Ω / □. In claim 1 or 2,
In the oxide having the ABOx type crystal structure, the metal species A is one or more metals selected from Li, Na, Ca, Sr, Ba, and La, and the metal species B is Ti, Zr, Ta, And a dielectric film capacitor which is at least one metal selected from Nb. In any of claims 1 to 3 ,
A dielectric film capacitor having a thickness of the silicon-based insulating layer of 100 to 2000 nm. In any of claims 1 to 4 ,
The silicon-based insulating layer is a dielectric film capacitor having a volume resistivity of 10 ¹⁰ Ωcm or more. In any of claims 1 to 5 ,
A dielectric film capacitor, wherein the silicon-based insulating layer is a silicon oxide layer. Forming a silicon-based insulating layer;
(A) forming a lower electrode having a thickness of 10 to 100 nm made of a material containing platinum on the silicon-based insulating layer ;
(B) directly forming a dielectric film containing an oxide having an ABOx type crystal structure on the lower electrode;
(C) forming an upper electrode above the dielectric film;
Only including,
The dielectric film capacitor manufacturing method, wherein an intermediate layer in which platinum and silicon are mixed is formed between the silicon-based insulating layer and the lower electrode by the step (a) . In claim 7 ,
The step (b) includes a step of forming the dielectric film by applying a dielectric film forming composition. In claim 8 ,
The dielectric film-forming composition comprises (i) particles having an ABOx type crystal structure, (ii) a metal alkoxide containing metal species A and B, a metal carboxylate, a metal complex, and a metal hydroxide. Including (i) and (ii) or any one of at least one component selected from (iii) an organic solvent,
The metal species A is one or more metals selected from Li, Na, Ca, Sr, Ba, and La,
The method for producing a dielectric film capacitor, wherein the metal species B is one or more metals selected from Ti, Zr, Ta, and Nb. It claims 1 comprises a dielectric film capacitor according to any one of 6, the electronic circuit component.

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