JP2005072475A - Method for manufacturing capacitor, capacitor, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a capacitor to manufacture a capacitor at low costs, a capacitor to be acquired by this manufacturing method, and a semiconductor device equipped with such capacitor. <P>SOLUTION: This method for manufacturing the capacitor 1 having a structure where a dielectric film 3 is inserted between a first electrode 2 and a second electrode 4 comprises a step to form a first electrode 2 on a base 53, a step to arrange a liquid-shaped body including the forming materials of the dielectric film 3 on the first electrode 2 by a drop discharging method, a step to form the dielectric film 3 by carrying out the heat treatment of the liquid-shaped body, and a step to form the second electrode 4 on the dielectric film 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a capacitor, a capacitor obtained thereby, and a semiconductor device including the capacitor.

In a semiconductor device, various capacitors are used as its constituent elements (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4). For example, capacitors are used in an oscillation circuit, a power supply circuit, and the like in a semiconductor device for the purpose of preventing operational amplifier oscillation, stabilizing, smoothing, and boosting circuits.
As such a capacitor, in the case where the capacitor is built in a circuit, a dielectric film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is formed by using silicon, metal, titanium nitride, aluminum nitride, etc. A structure sandwiched between upper and lower electrode films is often used. In addition, capacitors that are externally attached to a circuit or the like are known, such as a multilayer capacitor provided with a ceramic dielectric film such as barium titanate.
In manufacturing such a capacitor, in particular, a sputtering method, a CVD method, a laser ablation method, or the like is used to form the dielectric film.
JP-A-7-226485 JP-A-9-139480 JP-A-5-82801 Japanese Patent Laid-Open No. 5-47587

  However, in such a capacitor manufacturing method, the dielectric film is formed by a sputtering method, a CVD method, a laser ablation method, etc., and therefore a large-scale film forming apparatus is required and the initial cost is high. In addition, since a great amount of energy is required for film formation, there is a problem that the running cost increases. In addition, when patterning is performed by etching after film formation, the use efficiency of the material is poor, and further, a photolitho mask and a chemical for etching are required, resulting in an increase in cost and productivity due to an increase in the number of processes. There is also a problem that decreases.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to provide a capacitor manufacturing method capable of manufacturing a capacitor, in particular, a capacitor, a capacitor obtained thereby, and such a capacitor. An object of the present invention is to provide a provided semiconductor device.

In order to achieve the above object, a method for manufacturing a capacitor according to the present invention is a method for manufacturing a capacitor having a structure in which a dielectric film is sandwiched between a first electrode and a second electrode, and the first electrode is formed on a substrate. A step of disposing a liquid material containing the dielectric film forming material on the first electrode by a droplet discharge method, and a step of forming the dielectric film by heat-treating the liquid material And a step of forming a second electrode on the dielectric film.
According to this capacitor manufacturing method, a liquid material is arranged by a droplet discharge method, and a dielectric film is formed by heat-treating the liquid material. Costs can be reduced because it is advantageous in terms of efficiency and energy consumption. Further, by disposing the liquid material at a desired position, patterning by etching becomes unnecessary, so that damage to the dielectric film due to etching is eliminated.

Further, in the method for manufacturing a capacitor, before the step of disposing the liquid material on the first electrode by a droplet discharge method, self-using fluoroalkylsilane on the surface of the substrate and the first electrode. Forming an organized film. In this case, after the step of forming a self-assembled film using fluoroalkylsilane on the surface of the substrate and the first electrode dielectric film, the fluoroalkylsilane formed on the surface of the first electrode is irradiated with light. It is preferable to include the process of irradiating.
According to this configuration, when the liquid material is disposed on the first electrode, the liquid repellent portion made of fluoroalkylsilane is formed on the surface of the substrate around the first electrode. To prevent it from spreading wet around it. Therefore, it is possible to easily form a dielectric film having a desired shape on the first electrode.

In the method of manufacturing a capacitor, the step of forming the first electrode includes a step of disposing a first liquid material in which first metal fine particles are dispersed in a first dispersion medium on the substrate by a droplet discharge method. And a step of removing the first dispersion medium by heat-treating the first liquid, and a step of forming the first electrode by sintering the first metal fine particles.
In this way, the first electrode is also formed by disposing the liquid material by the droplet discharge method and heat-treating it, so that a large-scale film forming apparatus is not required and the use efficiency of the material is reduced. Costs can be reduced because it is advantageous in terms of energy consumption.

In the method for manufacturing a capacitor, in the step of forming the second electrode, a second liquid material in which second metal fine particles are dispersed in a second dispersion medium is disposed on the dielectric film by a droplet discharge method. A step of heat-treating the second liquid on the dielectric film to remove the second dispersion medium, a step of forming the second electrode by sintering the second metal fine particles, Is preferably included.
In this way, the second electrode is also formed by disposing the liquid material by the droplet discharge method and heat-treating it, so that a large-scale film forming apparatus is not required and the use efficiency of the material is increased. Costs can be reduced because it is advantageous in terms of energy consumption.

In the method for manufacturing a capacitor, the first metal fine particles are fine particles composed of at least one of platinum, iridium, ruthenium, gold, or silver, and a heat treatment temperature for sintering the first metal fine particles is: The second metal fine particles are preferably fine particles composed of at least one of platinum, iridium, ruthenium, gold, or silver, and the heat treatment temperature for sintering the second metal fine particles is preferably 400 ° C. or less. The temperature is preferably 400 ° C. or lower.
In this way, it is possible to form an electrode made of a stable metal film which is low in resistance and difficult to oxidize. In addition, since the heat treatment temperature is set to 400 ° C. or lower, for example, when other semiconductor elements or wirings are formed on the substrate, it is possible to reduce the thermal influence on them.

The capacitor of the present invention is obtained by the method for manufacturing a capacitor.
According to this capacitor, the cost is reduced and the dielectric film is not damaged due to etching.

The semiconductor device of the present invention includes the capacitor.
According to this semiconductor device, the cost is reduced by including the capacitor.

The present invention will be described in detail below.
First, the structure of a capacitor to which the manufacturing method of the present invention is applied will be described with reference to FIG. Reference numeral 1 in FIG. 1 denotes a capacitor. The capacitor 1 is a circuit as a capacitor 1a that is replaced with, for example, a conventional circuit internal capacitor in the semiconductor device 50 according to an embodiment of the semiconductor device of the present invention shown in FIG. In contrast, the capacitor 1b is replaced with an external capacitor.

  Here, in the semiconductor device 50, various transistors such as CMOS transistors and memory elements are formed on the substrate 51, and various wirings that electrically connect between these and the capacitors 1a and 1b. A plug or the like is formed on or in the interlayer insulating film. Note that the layers up to the interlayer insulating film 52 on which the capacitors 1a and 1b are formed are referred to as a base 53 in the present invention. Although not shown, a protective layer, wiring, and the like are formed on the capacitors 1a and 1b, and an insulating layer is formed to cover them.

  As shown in FIG. 1, the capacitor 1 used as the capacitors 1 a and 1 b is formed on the interlayer insulating film 52 (on the base 53) made of, for example, polyimide, and is formed on the interlayer insulating film 52. The first electrode 2, the dielectric film 3 formed on the first electrode 2, and the second electrode 4 formed on the dielectric film 3. That is, the capacitor 1 has a structure in which the dielectric film 3 is sandwiched between the first electrode 2 and the second electrode 4, and the embedded wiring 5 formed in the interlayer insulating film 52 is formed on the first electrode 2. Are connected, and another wiring (not shown) is connected to the second electrode 4.

As will be described later, the first electrode 2 and the second electrode 4 are both formed of a metal sintered body formed by sintering metal fine particles. Specifically, it is formed by sintering fine particles of at least one of platinum, iridium, ruthenium, gold, or silver.
Although the dielectric film 3 is not particularly limited, for example, lead zirconate titanate (Pb (Zr, Ti) O ₃ ), barium strontium titanate ((Ba _1-x Sr _x ) TiO ₃ ), or zircon titanate. lead _{(Pb (Zr, Ti) O} 3) formed by addition of another metal to _{Pb (Zr x Ti y M z} ) O 3 ( however, M is at least one member selected Nb, Ta, from V, x + y + z = 1) is formed as a main component.

Next, an embodiment of a method for manufacturing a capacitor according to the present invention will be described based on the method for manufacturing the capacitor 1 having such a configuration. In this embodiment, the capacitor manufacturing method of the present invention is shown as an example in the case of being applied to the manufacturing of the capacitor 1 (1a, 1b) in the semiconductor device 50 shown in FIG.
In the present invention, the droplet discharge method is a method for forming a desired pattern on a substrate by discharging droplets made of a liquid material into a desired pattern, and is a generic term for an ink jet method. However, the liquid material (droplet) to be ejected is not a so-called ink used for printed matter, but a liquid material containing various material substances constituting the device. Specifically, the material substance is a conductive substance or an insulating substance. The substance etc. which can function as are mentioned.

  First, an example of an ejection head used for a droplet ejection method will be described prior to a description of a specific method for manufacturing the capacitor 1. As shown in FIGS. 3A and 3B, the discharge head 34 includes, for example, a stainless steel nozzle plate 12 and a diaphragm 13, and both are joined via a partition member (reservoir plate) 14. . A plurality of cavities 15 and reservoirs 16 are formed between the nozzle plate 12 and the diaphragm 13 by the partition member 14, and the cavities 15 and the reservoirs 16 communicate with each other via a flow path 17. Yes.

  Each cavity 15 and the inside of the reservoir 16 are filled with a liquid material, and a flow path 17 between them functions as a supply port for supplying the liquid material from the reservoir 16 to the cavity 15. . In addition, a plurality of hole-shaped nozzles 18 for injecting a liquid material from the cavity 15 are formed in the nozzle plate 12 in a state of being aligned vertically and horizontally. On the other hand, a hole 19 that opens into the reservoir 16 is formed in the diaphragm 13, and a liquid tank (not shown) is connected to the hole 19 via a tube (not shown).

  Also, a piezoelectric element (piezo element) 20 is joined to the surface of the diaphragm 13 opposite to the surface facing the cavity 15 as shown in FIG. The piezoelectric element 20 is sandwiched between a pair of electrodes 21 and 21 and is configured to bend so as to protrude outward when energized.

The diaphragm 13 to which the piezoelectric element 20 is bonded in such a configuration is bent together with the piezoelectric element 20 at the same time, thereby increasing the volume of the cavity 15. Then, the cavity 15 and the reservoir 16 communicate with each other, and when the reservoir 16 is filled with the liquid material, the liquid material corresponding to the increased volume in the cavity 15 flows from the reservoir 16. It flows in through the path 17.
When the energization to the piezoelectric element 20 is released from such a state, both the piezoelectric element 20 and the diaphragm 13 return to their original shapes. Accordingly, since the cavity 15 also returns to its original volume, the pressure of the liquid material inside the cavity 15 rises, and the liquid droplet 22 is discharged from the nozzle 18.

  The ejection means of the ejection head may be other than the electromechanical transducer using the piezoelectric element (piezo element) 20, for example, a method using an electrothermal transducer as an energy generating element, a charge control type, It is also possible to employ a continuous method such as a pressure vibration type, an electrostatic suction method, or a method in which an electromagnetic wave such as a laser is irradiated to generate heat and a liquid material is discharged by the action of this heat generation.

(First electrode forming step)
First, as shown in FIG. 4A, a liquid material containing metal fine particles is transferred to a desired position on the interlayer insulating film 52 of the substrate 53 by a droplet discharge method (inkjet method) using the discharge head 34, that is, Arranged on the embedded wiring 5. The metal fine particles contained in the liquid, that is, the metal fine particles used as the material for forming the first electrode 2 are one or more selected from platinum, iridium, ruthenium, gold, silver, etc., and these metal fine particles are dispersed. It is dispersed in a medium and adjusted to a liquid material. The particle diameter of the metal fine particles is preferably 50 nm or more and 0.1 μm or less. By setting the particle size within such a range, it is easy to disperse in the dispersion medium, and the ejection property from the ejection head 34 is improved. In addition, about the metal fine particle, the dispersibility in a dispersion medium may be improved by coating the surface with organic substance etc.

  As the dispersion medium for dispersing the metal fine particles, those having a vapor pressure at room temperature of 0.001 mmHg to 200 mmHg are preferable. This is because if the vapor pressure exceeds 200 mmHg, the dispersion medium evaporates first when a coating film is formed by discharge, and it becomes difficult to form a good coating film. On the other hand, if the vapor pressure at room temperature is less than 0.001 mmHg, the drying rate becomes slow and the dispersion medium tends to remain in the coating film, and it becomes difficult to obtain a good conductive film after the heat treatment in the subsequent step. is there. In particular, when the vapor pressure of the dispersion medium is 50 mmHg or less, nozzle clogging due to drying hardly occurs when droplets are ejected from the ejection head 34 and stable ejection is more preferable.

  The solvent to be used is not particularly limited as long as the metal fine particles can be dispersed well without causing aggregation. Specifically, in addition to water, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydronaphthalene , Hydrocarbon solvents such as cyclohexylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis (2-methoxy Ethyl) ether, ether solvents such as p-dioxane, propylene carbonate, γ-butyrolactone, N-methyl 2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, can be mentioned polar solvents such as cyclohexanone. Of these, water, alcohols, hydrocarbon solvents, ether solvents are preferred, and more preferred solvents are the dispersibility of the metal fine particles, the stability of the dispersion, and the ease of application to the ink jet method. Can include water and hydrocarbon-based dispersion media. These dispersion media can be used alone or as a mixture of two or more.

  When forming the dispersion by dispersing the metal fine particles in a dispersion medium, the concentration of the metal fine particles in the dispersion is preferably 1 wt% or more and 80 wt% or less, particularly in this range. It is desirable to adjust according to the film thickness of the metal film (first electrode 2). If it exceeds 80% by weight, aggregation of metal fine particles tends to occur and it becomes difficult to obtain a uniform coating film. If it is less than 1% by weight, it takes a long time for drying to evaporate the dispersion medium. This is because productivity decreases.

In this metal fine particle dispersion, a trace amount of a surface tension adjusting material such as a fluorine-based material, a silicon-based material, or a nonionic material may be added as necessary within a range not impairing the intended function.
Nonionic surface tension modifiers improve the wettability of the dispersion to the object to be applied, improve the leveling of the applied film, and help prevent the occurrence of coating crushing and distortion skin. Become. The metal fine particle dispersion prepared by adding this nonionic surface tension adjusting agent preferably has a viscosity of 1 mPa · s to 50 mPa · s. When the viscosity is less than 1 mPa · s, the peripheral portion of the nozzle of the droplet discharge head 34 is likely to become dirty due to the outflow of the liquid material, and when the viscosity exceeds 50 mPa · s, the clogging frequency in the nozzle holes is increased. It will be expensive.

  Furthermore, it is desirable that the metal fine particle dispersion thus prepared has a surface tension in the range of 20 dyn / cm to 70 dyn / cm. When the surface tension is less than 20 dyn / cm, the wettability of the ink composition with respect to the nozzle surface increases, and thus flight bending easily occurs. When the surface tension exceeds 70 dyn / cm, the shape of the meniscus at the nozzle tip is not stable. This is because it becomes difficult to control the discharge amount and discharge timing of the composition.

When such a metal fine particle dispersion is disposed at a desired position on the interlayer insulating film 52 by the ejection head 34 and applied in a predetermined pattern with the metal fine particle dispersion, the substrate 53 is heated to form the metal fine particle dispersion. Apply heat treatment. Then, the dispersion medium is removed from the metal fine particle dispersion, and further, the metal fine particles are sintered, so that the electrical contact between the fine particles is sufficiently good as shown in FIG. 4B. Is formed.
The conditions for the heat treatment are not particularly limited, and general conditions can be adopted. For example, the heat treatment atmosphere may be performed in the air, or may be performed in an inert gas atmosphere such as nitrogen, argon, or helium as necessary. The heat treatment temperature is appropriately determined in consideration of the boiling point (vapor pressure) of the dispersion medium, the pressure, and the thermal behavior of the metal fine particles, but is preferably 400 ° C. or less. By setting the temperature to 400 ° C. or lower, for example, when another semiconductor element, Al wiring, a protective layer made of resin, an insulating layer, or the like is formed on the base 53, the thermal influence on these may be sufficiently reduced. Because it can.

As a heating method in the heat treatment, lamp annealing can be performed in addition to the treatment by a normal hot plate, electric furnace or the like. When heat treatment is performed with a hot plate or an electric furnace, the conditions are, for example, a heat treatment temperature of 300 ° C. and a treatment time of 30 minutes. By forming the first electrode 2 under such conditions, the thickness of the obtained first electrode 2 is, for example, about 0.1 μm.
The light source used for lamp annealing is not particularly limited, but excimers such as infrared lamps, xenon lamps, YAG lasers, argon lasers, carbon dioxide lasers, XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl, etc. A laser or the like can be used as a light source. In general, these light sources have an output in the range of 10 W to 5000 W, but in the present embodiment, a range of 100 W to 1000 W is sufficient.

(Dielectric film formation process)
Next, when forming a dielectric film forming material, for example, Pb (Zr, Ti) O ₃ , each of the constituent metals of the oxide, that is, Pb, Zr, Ti is contained as a precursor material. A metal salt such as metal alkoxide or acetate is prepared for each metal element. These metal compounds are mixed so that the composition ratio of Pb, Zr, and Ti is a predetermined ratio set in advance in the Pb (Zr, Ti) O ₃ . In order to give the precursor compound thus mixed with physical properties suitable for ejection by the droplet ejection method, for example, by adding an appropriate solvent or dispersion medium such as alcohols, the sol It is preferable to prepare it in the form of a liquid.

Subsequently, the sol-like liquid material thus prepared is arranged (applied) on the first electrode 2 by the discharge head 34 so as to have a uniform thickness.
Next, drying is performed at a predetermined temperature (for example, 200 ° C.) for a predetermined time (for example, 10 minutes), and the liquid component in the liquid is removed. Furthermore, after this drying, degreasing (pre-baking) for a predetermined time (for example, 10 minutes) at a predetermined high temperature (for example, 400 ° C.) in an air atmosphere, thereby thermally decomposing the organic component coordinated to the metal, Is oxidized to a metal oxide. And each process of such application | coating → drying → degreasing is repeated predetermined times, and a metal oxide is made into desired thickness.

Thereafter, heat treatment is performed at a predetermined temperature, for example, 350 to 450 ° C. for 10 minutes while flowing oxygen in an RTA (Rapid Thermal Annealing) furnace, for example, and the metal oxide is baked to form the first electrode as shown in FIG. A dielectric film 3 is formed on the substrate 2 to a thickness of about 0.2 μm. It is desirable to perform heat treatment at a low temperature so that the entire dielectric film is not crystallized so that the dielectric film does not have electrical hysteresis. In order to prevent thermal influence on the base 53, the heat treatment temperature is preferably 450 ° C. or lower.
Here, when the dielectric film 3 is formed of the sol-like liquid material as described above, when the liquid material is discharged, the liquid material 3 wets and spreads, so that the desired shape, that is, the entire surface of the first electrode 2 is substantially covered. It becomes difficult to become a simple shape.
Therefore, prior to the formation of the dielectric film 3, a self-assembled film using, for example, fluoroalkylsilane is formed on the surface of the base 53 (interlayer insulating film 52) on which the first electrode 2 is formed, and the sol-like film is formed. A liquid repellent portion having a low affinity for the liquid may be formed.

(Liquid repellent part forming step)
For example, as shown in FIG. 5, the liquid-repellent portion is formed on the surface of the base 53, that is, on the surface of the first electrode 2 and the exposed surface of the interlayer insulating film 52 with respect to the sol-like liquid material. A self-assembled film 1001 made of fluoroalkylsilane or the like is formed so as to have a predetermined contact angle. The contact angle is preferably 20 [deg] or more and 60 [deg] or less.
The organic molecular film for treating the surfaces of the first electrode 2 and the interlayer insulating film 52 has a first functional group capable of binding to them and a surface property of a substrate such as a lyophilic group or a liquid repellent group on the opposite side. Each of the surfaces is provided with a second functional group that controls surface energy, and a linear or partially branched carbon chain that connects the first and second functional groups to each other. To form a molecular film, for example, a monomolecular film.

  The self-assembled film 1001 is composed of a binding functional group capable of reacting with constituent atoms of the first electrode 2 and the interlayer insulating film 52 serving as an underlayer and other linear molecules, and the mutual relationship between the linear molecules. It is a film formed by orienting a compound having extremely high orientation by action. Therefore, the self-assembled film 1001 is formed by aligning single molecules, so that the film thickness becomes extremely thin, and it becomes a uniform film at the molecular level. Further, since the same molecule is located on the surface of the film, the film surface is imparted with uniform and excellent liquid repellency and lyophilicity.

As the compound having high orientation, that is, the compound forming the self-assembled film 1001, fluoroalkylsilane (FAS) is used for the reason of providing adhesion to the base 53 side and good liquid repellency. Preferably used. When fluoroalkylsilane is used, each compound is oriented so that the fluoroalkyl group is located on the surface of the film and the self-assembled film 1001 is formed, so that uniform liquid repellency is imparted to the surface of the film.
Examples of such fluoroalkylsilanes include heptadecafluoro-1,1,2,2 tetrahydrodecyltriethoxysilane, heptadecafluoro-1,1,2,2 tetrahydrodecyltrimethoxysilane, heptadecafluoro-1, 1,2,2 tetrahydrodecyltrichlorosilane, tridecafluoro-1,1,2,2 tetrahydrooctyltriethoxysilane, tridecafluoro-1,1,2,2 tetrahydrooctyltrimethoxysilane, tridecafluoro-1, 1,2,2 tetrahydrooctyltrichlorosilane, trifluoropropyltrimethoxysilane and the like are preferably used. In use, one compound (FAS) may be used alone, or two or more compounds (FAS) may be used in combination.

In order to form such a self-assembled film 1001, the raw material compound (FAS) and the base 53 are placed in the same sealed container. Then, in the case of room temperature, the self-assembled film 1001 is formed on the substrate 53 by leaving it for about 2 to 3 days. Further, if the entire sealed container is kept at 100 ° C., the self-assembled film 1001 is formed on the substrate 53 in about 3 hours.
Further, instead of the formation method from the gas phase, the self-assembled film 1001 can be formed from the liquid phase. For example, the self-assembled film 1001 can be formed on the substrate by immersing the substrate in a solution containing the raw material compound, washing, and drying.
Note that before the self-assembled film 1000 is formed, it is desirable to perform pretreatment by irradiating the substrate surface with ultraviolet light or washing with a solvent.

In this way, the surface of the first electrode 2 and the surface of the interlayer insulating film 52 are made liquid repellent, and in particular, the sol-like liquid disposed on the surface of the first electrode 2 is made difficult to wet and spread. It is possible to prevent the dielectric film 3 obtained from spreading out to the surface of the insulating film 52 and greatly different from the desired shape.
In order to make the dielectric film 3 have a desired shape, that is, a shape that covers almost the entire surface of the first electrode 2, at least the surface of the interlayer insulating film 52 (base 53) around the first electrode 2 is liquid repellent. A part may be formed. The surface of the first electrode 2 may not necessarily be a liquid repellent part, but may be a lyophilic part (a part having a high affinity for the sol-like liquid material), for example.

  In order to make the surface of the first electrode 2 a lyophilic part, for example, the self-assembled film is passed through a mask (not shown) in which an opening pattern corresponding to a desired pattern, that is, the surface shape of the first electrode 2 is formed. 1001 is irradiated with ultraviolet light or the like. Then, in the region irradiated with ultraviolet light, the self-assembled film 1001 is removed, and, for example, a hydroxyl group is exposed on the surface. Thereby, it becomes a lyophilic part which shows the property which becomes very wet easily compared with the area | region of FAS.

  Further, the second self-assembled film may be formed in the region where the FAS is removed as described above. The compound that forms this second self-assembled film also has a binding functional group and a functional group that modifies the surface in the same manner as FAS, and the binding functional group binds to a hydroxyl group or the like on the substrate surface. It is supposed to form a self-assembled film. However, the functional group that modifies the surface of the second self-assembled film is different from FAS in that it exhibits lyophilicity or has a strong binding force with metal fine particles. Or thiol group. By forming such a second self-assembled film, it is possible to more reliably distribute the sol-like liquid material on the first electrode 2 and form the dielectric film 3 having a desired shape. Become. In addition, the adhesion of the obtained dielectric film 3 to the first electrode 2 is also increased. Examples of the compound forming the second self-assembled film include 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxysilane. Can be mentioned.

(Second electrode forming step)
When the dielectric film 3 is formed in this way, the second electrode 4 is subsequently formed on the dielectric film 3 as shown in FIG. The formation of the second electrode 4 can be performed by substantially the same formation method as the formation method of the first electrode 2 described above. That is, a liquid material containing metal fine particles is disposed on the dielectric film 3 by a droplet discharge method (inkjet method) using the discharge head 34, and then heat treatment is performed to sinter the metal fine particles. The second electrode 4 is formed. As a result, the capacitor 1 (1a, 1b) is obtained.
As the metal fine particles contained in the liquid, that is, the metal fine particles used as the material for forming the second electrode 4, as in the case of the first electrode 2, one kind selected from platinum, iridium, ruthenium, gold, silver, etc. Multiple species are used. Further, the heat treatment is preferably performed at 400 ° C. or lower.

Prior to the formation of the second electrode 4, a liquid repellent part forming step performed as a pretreatment for forming the dielectric film 3 may be performed. That is, the above-described liquid repellent portion made of fluoroalkylsilane (FAS) or the like is formed on the surface of the dielectric film 3 and the surface of the interlayer insulating film 52 to prevent the liquid from spreading and preventing the second electrode 4 from becoming dielectric. It may be selectively formed on the body film 3. Also, when forming the first electrode 2 described above, a liquid repellent portion may be formed on the surface of the base 53 (interlayer insulating film 52) prior to the formation. Further, when the liquid repellent part is formed as a pretreatment for the formation of the electrodes 2 and 4 as described above, the part where the liquid material is directly arranged is made a lyophilic part by ultraviolet light irradiation or the like as described above. Also good.
Moreover, about the 1st electrode 2 and the 2nd electrode 4, you may make it employ | adopt a vapor deposition method, a sputtering method, etc., without employ | adopting the droplet discharge method as the formation method.
When the second electrode 4 is formed in this way, the semiconductor device 50 is obtained by forming the wiring connected to the second electrode 4, the protective layer covering them, and the insulating layer.

  In such a manufacturing method of the capacitor 1, since the dielectric film 3 is formed by arranging a sol-like liquid material by a droplet discharge method and heat-treating it, a large-scale film forming apparatus is provided. This is not necessary, and is advantageous in terms of material use efficiency and energy consumption, and therefore, cost reduction can be achieved. Furthermore, by disposing the liquid material at a desired position, patterning by etching becomes unnecessary, so that it is possible to improve the characteristics without damaging the dielectric film due to etching.

  In addition, the semiconductor device 50 including the capacitor 1 obtained in this way is reduced in cost because the dielectric film 3 is formed by using the droplet discharge method. Also, by forming the capacitor 1 by the droplet discharge method, different types can be made separately on the same plane. Therefore, for example, as a conventional internal capacitor or external capacitor, the manufacturing method of the present invention can be applied to easily and inexpensively manufacture them. In particular, there are cases where the required capacitances are different depending on what is used inside the circuit and what is externally attached. However, for example, by using materials having different dielectric constants as the material for forming the dielectric film, It can be done easily.

It is a sectional side view showing an example of a capacitor concerning the present invention. It is a sectional side view which shows one Embodiment of the semiconductor device of this invention. (A) is a principal part perspective view of a discharge head, (b) is a principal part side sectional view similarly. (A)-(d) is a sectional side view for demonstrating the manufacturing method of a capacitor. It is a sectional side view for demonstrating the example at the time of forming a liquid repellent part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Capacitor, 2 ... 1st electrode, 3 ... Dielectric film, 4 ... 2nd electrode,
DESCRIPTION OF SYMBOLS 50 ... Semiconductor device, 51 ... Board | substrate, 52 ... Interlayer insulation film, 53 ... Base | substrate

Claims (9)

In a method of manufacturing a capacitor having a structure in which a dielectric film is sandwiched between a first electrode and a second electrode,
Forming the first electrode on a substrate;
Disposing a liquid containing the dielectric film forming material on the first electrode by a droplet discharge method;
Forming the dielectric film by heat-treating the liquid;
Forming a second electrode on the dielectric film;
A method for manufacturing a capacitor, comprising: Forming a self-assembled film using fluoroalkylsilane on the surface of the substrate and the first electrode before the step of disposing the liquid on the first electrode by a droplet discharge method;
The method of manufacturing a capacitor according to claim 1, comprising: Irradiating the fluoroalkylsilane formed on the first electrode surface with light after the step of forming a self-assembled film using fluoroalkylsilane on the surface of the substrate and the first electrode dielectric film;
The method of manufacturing a capacitor according to claim 1, comprising: The step of forming the first electrode includes:
Disposing a first liquid in which first metal fine particles are dispersed in a first dispersion medium on the substrate by a droplet discharge method;
Removing the first dispersion medium by heat-treating the first liquid;
Forming the first electrode by sintering the first metal fine particles;
The method for manufacturing a capacitor according to claim 1, comprising: The step of forming the second electrode includes:
Disposing a second liquid material in which second metal fine particles are dispersed in a second dispersion medium on the dielectric film by a droplet discharge method;
Removing the second dispersion medium by heat-treating the second liquid on the dielectric film;
Forming a second electrode by sintering the second metal fine particles;
The method for manufacturing a capacitor according to claim 1, wherein The first metal fine particles are fine particles composed of at least one of platinum, iridium, ruthenium, gold, or silver.
The method of manufacturing a capacitor according to claim 4, wherein a heat treatment temperature for sintering the first metal fine particles is 400 ° C. or less. The first metal fine particles are fine particles composed of at least one of platinum, iridium, ruthenium, gold, or silver.
The method of manufacturing a capacitor according to claim 5, wherein a heat treatment temperature for sintering the second metal fine particles is 400 ° C. or less.   A capacitor obtained by the method for producing a capacitor according to claim 1. A semiconductor device comprising the capacitor according to claim 8.

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