TWI464779B - Methods for forming a ruthenium-based film on a substrate - Google Patents

Description

Method for forming a ruthenium base film on a substrate [Reciprocal Reference of Related Applications]

The benefit of the U.S. Provisional Application Serial No. 60/890,916, filed on Feb. 21, 2007, which is incorporated herein by reference in its entirety, is incorporated by reference.

background

The present invention is generally related to the field of semiconductor fabrication. More specifically, the present invention relates to a method of forming a ruthenium-containing film on a substrate.

Antimony and antimony compounds such as antimony oxide are considered to be promising materials for capacitor electrode materials in next generation DRAMs. High dielectric constant materials (also known as high k materials) such as alumina, tantalum pentoxide, yttria and barium strontium titanate (BST) are currently used for such capacitor electrodes. However, such high k materials are produced by using temperatures up to 600 ° C, which causes oxidation of polycrystalline germanium, antimony and aluminum and causes loss of capacitance. On the other hand, niobium and tantalum oxide exhibit high oxidation resistance and high conductivity, and are suitable for use as capacitor electrode materials. It also effectively acts as an oxygen diffusion barrier. It has also been proposed to use ruthenium as a gate metal for lanthanide oxides. In addition, it is easier to etch ruthenium by ozone and by using a plasma of oxygen than platinum and other precious metal compounds. The use of ruthenium as a barrier layer for separating low-k materials from copper plating and its use as a seed layer has recently attracted attention.

A high quality film of ruthenium and ruthenium oxide (RuO ₂ ) can be deposited from high purity ruthenium tetroxide (RuO ₄ ) before appropriate conditions. The precursor can also be used for deposition (film formation) of a perovskite-type material such as cerium oxide which exhibits excellent conductivity and is very similar to the three-dimensional structure of the barium titanate and barium titanate.

However, high purity osmium tetroxide is a strong oxidant and is considered to be highly toxic. In addition, high purity osmium tetroxide has a boiling point of about 130 ° C and thus carries the risk of explosion at high temperatures (above about 108 ° C). It is therefore recommended to store pure osmium tetroxide at low temperatures to avoid the possibility of decomposition (explosion).

In view of the nature of ruthenium tetroxide (RuO ₄ ) (especially the risk of explosion during storage), it is often necessary to dilute it in a suitable solvent when acting as a reactant. It is known to use, for example, water, carbon tetrachloride, and an alkane as the solvent.

In the case of water as a solvent, it is additionally necessary to add a stabilizer such as NalO ₄ to prevent RuO ₄ from reacting and decomposing during storage. Additionally, the use of the RuO ₄ aqueous solution as a sulfhydryl precursor may result in the introduction of impurities into the membrane and tool (eg, the reaction chamber).

The electronics industry is abandoning carbon tetrachloride (due to its high toxicity), so carbon tetrachloride is not an ideal solvent choice for osmium tetroxide precursor solutions.

Alkanes such as pentane and octane can be used as a solvent for RuO ₄ , but when an alkane containing dissolved RuO ₄ is used as a sulfhydryl precursor in film production, an alkane (for example, pentane) and RuO ₄ are used. The reaction causes the incorporation of carbon. Carbon causes an increase in the electrical resistance of the ruthenium type film, and therefore, carbon which occurs during film production can be regarded as undesirable.

This article describes a novel method of providing a film on a substrate in a semiconductor process And preparations. The disclosed methods and formulations utilize a mixture of osmium tetroxide dissolved in a mixture of at least two non-flammable fluorinated solvents.

In one embodiment, a method of providing a film on a substrate in a semiconductor process includes providing a reaction chamber and a substrate contained within the chamber. A sulfhydryl precursor is provided wherein the precursor comprises a mixture of at least two non-flammable fluorinated solvents, osmium tetroxide dissolved in a solvent mixture, and less than about 100 ppm moisture. A ruthenium containing film is then deposited on the substrate.

Other embodiments of the invention may include, but are not limited to, one or more of the following features: each of the non-flammable fluorinated solvents having the general formula C _x H _y F _z O _t N _u ; 3; y+z 2x+2; z 1; t 0; u 0; and t+u 0 where x, y, z, t, and u are integers.

The solvent mixture is a mixture of methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether; the solvent mixture comprises between about 10% and about 90% by volume, preferably about 30%, of methyl nonafluorobutyl ether; solvent The mixture comprises between about 10% and about 90% by volume, preferably about 70%, of ethyl nonafluorobutyl ether; the precursor contains less than about 1 ppm moisture; and the precursor contains less than about 1 ppm unassociated Or free oxygen (O ₂ ); the pressure in the reaction chamber is maintained between about 0.01 torr to about 1000 torr; the film is deposited to a temperature maintained between about 50 ° C and about 800 ° C, preferably about 100 ° C. On a substrate between about 600 ° C; introducing a gas reducing agent into the reaction chamber, and depositing the ruthenium containing film on the substrate via a reaction between the reducing agent and the precursor; the reducing agent is hydrogen, air or oxygen One of the same; introducing a reducing agent and a precursor into the chamber; introducing the precursor into the evaporator in a liquid state; at least partially evaporating the precursor to form a gaseous precursor; introducing the liquid precursor into the evaporator via pressurization with an inert gas; Evaporating at least about 99% of the liquid precursor in the evaporator; evaporating substantially in the evaporator All liquid precursors; evaporating the liquid precursor at a temperature between about 10 ° C and about 80 ° C; the substrate is a ruthenium-type substrate suitable for semiconductor fabrication; and the substrate is a ceramic-based substrate.

The features and technical advantages of the present invention are set forth in the <RTIgt; Additional features and advantages of the invention will be described hereinafter, which form the subject matter of the invention. Those skilled in the art will appreciate that the concept and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for the same purpose. Those skilled in the art should also recognize that The equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

For a better understanding of the nature and objects of the present invention, reference should be made to the accompanying drawings. A specific example of the device; and Figure 2 illustrates another specific example of a device for depositing a ruthenium containing film.

In general, the present invention relates to a method for providing a film on a substrate in a semiconductor process that provides a reaction chamber and a substrate contained within the chamber. A sulfhydryl precursor mixture is provided wherein the precursor comprises a mixture of at least two non-flammable fluorinated solvents, osmium tetroxide dissolved in a solvent mixture, and less than about 100 ppm moisture. A ruthenium containing film is then deposited on the substrate.

Non-flammable solvents are preferably used in the precursor mixture because non-flammable solvents are preferred when the mixture is used in an environment above room temperature. Non-flammable solvents are also preferred because, in general, they minimize the risk of carbon being introduced into the film deposited on the substrate. In general, fluorinated solvents are preferred because the presence of fluorine in the solvent molecules renders them non-flammable without introducing significant negative effects into the composition of the film.

In some embodiments of the invention, the solvent mixture is comprised of at least two solvents, each of which can be described according to the following general formula; C _x H _y F _z O _t N _u wherein: x 3; y+z 2x+2; z 1; t 0; u 0; and t+u 0, and wherein x, y, z, t, and u are integers.

Several solvents satisfy this formula and are suitable for use in solvent mixtures. Such solvents include: methyl perfluoropropyl ether; methyl nonafluorobutyl ether; ethyl nonafluorobutyl ether; 1,1,1,2,2,3,4,5,5,5-decafluoro- 3-methoxy-4-(trifluoromethyl)-pentane; 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-12 Fluor-2-trifluoromethyl-hexane; C ₉ F ₁₂ N; C ₁₂ F ₂₇ N; C ₁₂ F ₃₃ N; C ₆ F ₁₄ ; C ₈ F ₁₆ ; C ₇ F ₁₆ ; C ₅ F ₁₀ H ₂ ; C ₄ F ₅ H ₅ ; 1,1,2,3,3 pentafluoropropane; CF3CFHCF2CH2OCF2CFHOC3F7 and C3F7OCFHCF2CH(CH3)OCF2CFHOC4F9.

In one embodiment, the solvent mixture is a mixture of methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether. Both of these are available from 3M Company and are sold under the trade names Novec HFE 7100 and Novec HFE 7200. C ₅ F ₁₀ H _{2 is} also available from DuPont under the trade name Vertrel.

In some embodiments, the substrate comprising the deposited ruthenium film can vary. The substrate can be a semiconductor substrate that may already have other layers of material deposited thereon by other semiconductor fabrication steps. The substrate can also be a ceramic substrate (eg, ceria, etc.), a metal substrate, or a polymeric substrate.

In some embodiments, the substrate has a different shape. The substrate can be flat, such as a typical semiconductor wafer or a ceramic substrate for a parallel circuit. The substrate can also be a raised or spherical surface. The substrate may also be a nanoparticle or another material characterized by a large specific surface area.

The concentration of ruthenium tetroxide (RuO ₄ ) of the precursor mixture according to the present invention is appropriately selected depending on the film formation conditions and the material of the substrate on which the film is to be formed.

Specific examples of sulfhydryl precursors in accordance with the present invention provide at least the following advantages.

Since the pure form of RuO ₄ poses a risk of explosion, the dissolution of RuO ₄ in the fluorinated solvent mixture allows for the treatment of RuO ₄ in a stable form during storage or storage without the risk of explosion.

The non-flammable solvent mixture does not react with RuO ₄ , so that decomposition of RuO ₄ occurs in the case of using water. This stabilizes the long-term storage (storage) of the sulfhydryl precursor.

In fact, the desired ruthenium film can be produced because the non-flammable solvent fluorinated solvent in the ruthenium-based precursor does not react with RuO ₄ when the precursor is used in the form of a gas and the film is produced by thermal CVD.

In the case of the current ruthenium-based precursor, the non-flammable solvent mixture does not react with the active Ru compound produced when RuO ₄ is decomposed in the reaction chamber, and the solvent mixture is discharged from the reaction chamber together with any unreacted gas. This makes it possible to obtain a desired ruthenium film which does not contain an undesirable compound such as an oxide.

On the contrary, if the sulfhydryl precursor is formed by dissolving RnO ₄ in water and then the film formation by thermal CVD is performed by transferring the precursor to the reaction chamber in a gaseous form, RuO ₄ will undergo decomposition and Produces active Ru. This active Ru will then react with water to produce an undesirable oxide. This makes it difficult to produce the desired ruthenium film. In some embodiments, the sulfhydryl precursor is substantially free of moisture and contains less than 100 ppm, preferably less than 1 ppm moisture.

The non-flammable solvent mixture in the sulfhydryl precursor is preferably non-toxic. This makes it possible to carry out film production in a safe environment when a gas-containing ruthenium precursor is used to produce a ruthenium-containing film by thermal CVD.

The fluorinated solvent mixture in the ruthenium-based precursor is preferably non-flammable and exhibits high thermal stability, which makes it possible to avoid the use of the ruthenium-based precursor in the form of a gas for the production of a ruthenium-containing film by thermal CVD. Incorporating carbon into the membrane and decomposition, combustion or explosion caused by the solvent mixture.

According to various embodiments, a ruthenium-containing film is formed by depositing at least a ruthenium-based precursor of the present invention into a reaction chamber containing a substrate in a gaseous form to deposit a ruthenium-containing film on the substrate.

According to such methods, it is possible that the ruthenium-containing film deposition includes, but is not limited to, a ruthenium film, a ruthenium oxide film (RuO ₂ film), and a ruthenate film.

Method for forming a ruthenium film

According to a specific example, a ruthenium film is formed by introducing a sulfhydryl precursor in a gaseous form and a gas reducing agent into a reaction chamber containing a substrate and depositing ruthenium on the substrate by reacting the precursor with a reducing agent. .

In some embodiments, the sulfhydryl precursor can be introduced into the reaction chamber by using a bubbler system. That is, a sulfhydryl precursor as a liquid as mentioned above may be placed in a container and an inert gas (eg, nitrogen, argon, helium, etc.) may be bubbled into this by using an inert gas bubbler. (may The temperature is controlled by the vessel, which results in the transfer of the precursor of the invention entrained in the inert gas into the reaction chamber.

In some embodiments, the sulfhydryl precursor can be introduced into the reaction chamber via a direct evaporation system. Such systems are well known in the art and can include liquid mass flow controllers and evaporators such as glass or metal tubing. An inert gas (eg, nitrogen, argon, helium, etc.) can be used to pressurize the liquid phase ruthenium based precursor and flow it from the storage vessel through the liquid flow controller and into the evaporator. If an inert gas is not used to flow the liquid, a vacuum (or lower pressure environment) can be created downstream of the precursor storage vessel (eg, at the evaporator outlet). In some embodiments, the evaporator is heated to a temperature between about 10 ° C and about 80 ° C. The temperature of the evaporator causes the liquid phase precursor to evaporate into a gas phase precursor. In some embodiments, about 99%, and preferably all, of the liquid precursor is vaporized into a gas phase precursor. This vapor phase precursor is then passed to the reaction chamber.

In some embodiments, the reducing agent under consideration reduces osmium tetroxide to a ruthenium metal. This reducing agent may be specifically exemplified by hydrogen (H ₂ ), but is not limited thereto. Other possible reducing agents include hydrazine and its derivatives and hydrocarbons (eg, olefins, alkynes, aromatic rings, etc.). A single reducing agent or a combination of two or more reducing agents may be used. Hydrogen is especially preferred for reducing agents.

In some embodiments, chemical vapor deposition (CVD) or atomic layer deposition (ALD) can be used to form a tantalum film.

In the specific example of the deposition method used for CVD, the gas reducing agent and the gas sulfhydryl precursor according to the present invention are simultaneously introduced into the reaction chamber. The reducing agent reacts with the RuO ₄ in the precursor in a gas phase, resulting in the reduction of RuO ₄ to ruthenium, which is deposited on the substrate. The non-flammable fluorinated solvent mixture accompanying RuO ₄ in the gas precursor does not decompose during this deposition, and thus also avoids its incorporation into the resulting ruthenium film.

During this film generation, the total pressure in the reaction chamber is preferably maintained between about 0.01 torr and 1000 torr, and more preferably between about 0.1 torr and 10 torr. The substrate is preferably heated to between about 50 ° C and 800 ° C, and more preferably between about 100 ° C and 400 ° C. The reducing agent is allowed to enter the reaction chamber in a sufficient amount to reduce RuO ₄ in the precursor to the base metal. When, for example, hydrogen is used as the reducing agent, at least 4 moles of hydrogen is used per 1 mole of RuO ₄ in the precursor. The by-product in this case is H ₂ O.

In some embodiments of the deposition method for use with ALD, a gas sulfhydryl precursor is initially introduced into the reaction chamber and a very thin layer of ruthenium oxide is formed on the substrate by absorption and decomposition of the precursor (eg, Monoatomic layer). The interior of the reaction chamber is then rinsed with an inert gas (eg, nitrogen, helium, argon) to remove unreacted or unabsorbed sulfhydryl precursors (including the particular non-flammable fluorinated solvent mixture above). This rinse is followed by introduction of a gaseous reducing agent into the reaction chamber. The incoming reducing agent reacts with the monoatomic layer of cerium oxide formed on the substrate and reduces cerium oxide to the cerium metal. This results in the formation of a monoatomic layer of tantalum on the substrate. When it is desired to grow a thicker ruthenium film, the following procedure can be repeated after flushing the unreacted reducing agent and the gaseous reaction product produced by the reducing agent from the reaction chamber: introducing a gas sulfhydryl precursor, rinsing/removing the residual sulfhydryl precursor Body, introducing a reducing agent, flushing/removing the reducing agent and the gaseous reaction product.

In some specific examples, the pulse can be pulsed using ALD. The introduction of the gas sulfhydryl precursor and the reducing agent is carried out. The gas sulfhydryl precursor can be introduced, for example, at a flow rate of from about 0.1 sccm to 10 sccm for between about 0.01 seconds and 10 seconds, and the reducing agent can be introduced, for example, at a flow rate of from about 0.5 sccm to 100 sccm. 0.01 seconds. The flushing gas can also be introduced, for example, at a flow rate of from about 100 sccm to 5000 sccm for between about 0.01 seconds and 10 seconds.

During ALD, the total pressure in the reaction chamber is preferably maintained between about 0.1 torr and 10 torr, while the substrate temperature is preferably maintained between about 100 and 600 °C.

Used to form ruthenium oxide film (RuO) ₂ Membrane method

According to some embodiments, the sulfhydryl precursor is introduced into the reaction chamber containing the substrate in the form of a gas. The ruthenium-based precursor can be introduced into the reaction chamber in gaseous form by a bubbler system or via a direct evaporation system. In this case, the substrate is heated to a temperature at which RuO _{4 in} the precursor is decomposed and solid cerium oxide (cerium oxide) is produced. The solid cerium oxide produced by the decomposition of RuO _{4 is} deposited on the substrate. The non-flammable fluorinated solvent mixture accompanying RuO ₄ in the gas precursor does not decompose during the deposition of cerium oxide, and thus also avoids its incorporation into the cerium oxide film. Solid ruthenium oxide (RuO ₂ ) acts as a decomposition catalyst for the gas RuO ₄ . Therefore, once the solid RuO _{4 which} is decomposed by heating and thus decomposed is deposited on the substrate, the gas RuO ₄ can be satisfactorily decomposed (even when the heating temperature is lowered).

During this yttrium oxide deposition, the total pressure within the reaction chamber is preferably between about 0.01 torr and 1000 torr, and more preferably between about 0.1 torr and 5 torr. Preferably, the substrate is heated to about 150 ° C, and more preferably heated to A temperature between about 350 ° C and 400 ° C.

The substrate fed to the film formation method as described above can be exemplified by a semiconductor substrate such as a tantalum substrate. For example, the following can be used to form the semiconductor substrate: low-k film, high-k film, C-doped yttria film, titanium nitride film, copper film, tantalum nitride film, molybdenum Film, tungsten film and ferroelectric film. The tantalum film and the tantalum oxide film provided by the present invention exhibit excellent adhesion to these films and will not crack even when subjected to chemical mechanical polishing (CMP). Further, the incorporation of impurities such as carbon and a halogen such as fluorine does not occur at all in the ruthenium film, ruthenium oxide or ruthenium containing film. In addition, the gestational phase is not necessary or very short in the present invention, which causes the ruthenium film and the ruthenium oxide film to be deposited in a correspondingly shorter period of time (in the case of ALD, from the initial early stage, for CVD for several minutes).

Turning now to Figure 1, an illustrative example of a device that can be used to perform a film deposition process by CVD is described.

The apparatus illustrated in Figure 1 is provided with a reaction chamber 11, a feed source 12 for the ruthenium based precursor, a feed source 13 for the reductant gas, and a feed source 14 for the inert gas typically used as a carrier gas and/or diluent gas. . In the case of a single wafer tool, a susceptor (not shown) is provided in the reaction chamber 11, and a single semiconductor substrate (not shown) such as a ruthenium substrate is mounted on the susceptor. The interior of the susceptor is equipped with a heater for heating the semiconductor substrate to a specified reaction temperature. In the case of a batch tool, 5 to 200 semiconductor substrates are housed in the reaction chamber 11. The heater in the batch tool can have a different structure than the heater in the single wafer tool.

The ruthenium-based precursor feed source 12 introduces the ruthenium-based precursor into the reaction chamber 11 by using a bubbler system or a direct evaporation system as described above, and is connected to the inert gas feed source via line L1. 14. The line L1 is provided with a shut-off valve V1 and has a flow rate controller downstream of the shut-off valve V1, for example, a mass flow controller MFC1. The sulfhydryl precursor is introduced into the reaction chamber 11 from the feed source 12 via line L2. From the upstream side, the following items are provided in the considered line L2: UV spectrometer UVS, pressure gauge PG1, shut-off valve V2 and shut-off valve V3. The UV spectrometer UVS acts to confirm the presence of the precursor (specifically RuO ₄ ) in line L2 and to detect its concentration.

The feed source 13 of reducing agent gas comprises a vessel holding a reducing agent in the form of a gas. The reducing agent gas is allowed to enter the reaction chamber 11 from the feed source 13 via line L3. A shut-off valve V4 is provided in line L3. Line L3 is connected to line L2.

The inert gas feed source 14 contains a vessel that holds an inert gas in the form of a gas. Inert gas can be introduced into the reaction chamber 11 from this feed source via line L4. From the upstream side, the following items are provided in the considered line L4: shut-off valve V6, mass flow controller MFC3 and pressure gauge PG2. Line L4 is engaged with line L3 upstream of shut-off valve V4. Line L1 branches off from line L4 upstream of shut-off valve V6.

The line L5 upstream of the shut-off valve V1 branches off the branch line L1. This line L5 is engaged with the line L2 between the shut-off valves V2 and V3. The shut-off valve V7 and the mass flow controller MFC4 are disposed in the line L5 in a given sequence from the upstream side.

The line L6 reaching the reaction chamber 11 branches between the shut-off valves V3 and V4. A shut-off valve V8 is provided in this line L6.

A line L7 reaching the pump PMP is provided at the bottom of the reaction chamber 11, and from the upstream side, the following items are provided in the line L7 under consideration: a pressure gauge PG3, a butterfly valve BV for regulating back pressure, and heat Well 15. The heat sink 15 includes a tube having a heater on the circumference. Since ₄ by thermal decomposition of the precursor gas RuO converted to solid ruthenium oxide, and thus may be converted to a solid by ruthenium oxide (which is deposited on the inner wall of the pipe) from the gas stream and introduced to eliminate this heat sink 15 of RuO ₄ .

In order to generate the diaphragm by using the apparatus illustrated in Fig. 1, first, the shutoff valves V1, V2, and V5 are closed and the switches V6, V7, V3, V4, and V8 are opened. When the pump PMP is operated, the inert gas from the inert gas feed source 14 is introduced into the reaction chamber 11 via line L4 and through L5 of line L6.

The switch valve V5 is then switched and the reductant gas is introduced into the reaction chamber 11 from the reductant gas feed source 13, then the switch valves V1 and V2 are switched and the inert gas from the inert gas feed source 14 is introduced via line L1. The sulfhydryl precursor is fed into the source 12. This results in the introduction of a gaseous precursor (RuO ₄ and the non-flammable solvent specified above, preferably a fluorinated solvent) into the reaction chamber 11 via line L2 and line L6. The reducing agent gas and RuO ₄ are reacted in the reaction chamber 11 to cause the base metal to deposit on the semiconductor substrate.

In order to produce a solid yttria film by using the apparatus illustrated in Figure 1, the apparatus is prepared by closing the shut-off valves V5 and V4 and V6 and keeping the valves closed (since no reducing agent will be used). The pump PMP is activated to create a vacuum environment, and the switches are closed to valves V3, V7 and V8 to allow inert gas to flow into the reaction chamber. In this state, the switch opens the valves V1, V2 and introduces the inert gas from the inert gas feed source 14 into the feed source 12 of the ruthenium-based precursor via line L4 and line L1, resulting in the gas precursor (RuO ₄ and The non-flammable solvent specified above, preferably a fluorinated solvent, is introduced into the reaction chamber 11 via line L2 and line L6. Since the reaction chamber 11 is being heated, RuO ₄ introduced into the reaction chamber 11 undergoes thermal decomposition to solid cerium oxide deposited on the substrate.

Turning now to Figure 2, an illustrative example of a device that can be used to implement a film deposition process by ALD is described.

The apparatus illustrated in FIG. 2 has a structure in which a line L8 is provided in the apparatus illustrated in FIG. 1; this line L8 itself has a shut-off valve V2', and has the same heat sink 15 downstream of the shut-off valve V2'. Heat sink 15'. Therefore, the same reference numerals are assigned to the same elements as those in FIG. 1, and such elements will not be described in detail. One end of the installed line L8 is connected to the line L2 between the ultraviolet spectrometer UVS and the pressure gauge PG1, and the other end is connected to the line L7 between the heat trap 15 and the pump PMP.

In order to generate the diaphragm by ALD using the apparatus illustrated in Fig. 2, the shutoff valves V2 and V5 are first closed and the switches V6, V7, V3, V4, V8 and V9 are opened, as are the valves V1 and V2'. When the pump PMP is operating, a vacuum condition is created in the different lines, wherein the inert gas from the inert gas feed source 14 is introduced via L4 and L5 and passed into the reaction chamber 11 via line L6. The inert gas is passed through line L1 through feed source 12 of the ruthenium-based precursor to cause a gas precursor (RuO ₄ and a non-flammable fluorinated solvent mixture) to accompany the flow of the inert gas in L2 and L8.

After performing this initial preparation, close the shut-off valve V2' and switch off Valve V2, and a pulse of the gas precursor is delivered to the reaction chamber 11. After this, the shut-off valve V2 is simultaneously closed and the switch is closed by the valve V2', which causes the gas precursor (which will decompose in the heat trap 15') to accompany the passage of the inert gas via the line L8. The flushing of the inside of the reaction chamber by introducing an inert gas from the L4 and the L5 via L6 causes the unreacted precursor (including the solvent mixture) and the resulting pair to be removed from the inside of the reaction chamber 11. product. Switching valve V5 is then switched off and a pulse of reductant gas is passed from reductant gas feed source 13 along with inert gas from inert gas feed source 14 to reaction chamber 11. After this, the shut-off valve V5 is closed, causing a pulse of inert gas to be transferred into the reaction chamber 11 and removal of reaction by-products, unreacted reducing agents, and the like from the reaction chamber 11. This processing cycle can be repeated until a ruthenium film having the desired thickness is obtained.

Method for forming a niobate film

In some embodiments, by introducing a sulfhydryl precursor and a gaseous organometallic compound as defined above in a gaseous form into a reaction chamber holding the substrate and reacting the precursor with the organometallic compound in the presence of an oxidizing gas and Thereby, the niobate is deposited on the surface of the substrate to form a niobate film.

As described above, the sulfhydryl precursor can be introduced into the reaction chamber by a bubbler system or a direct evaporation system.

When, for example, a ferroelectric film of BaRuO _x is to be produced, Ba(DPM) ₂ which is a β-diketone/yttrium complex can be used as the organometallic compound. When a ferroelectric film of SrRuO _x is to be produced, Sr(DPM) ₂ which is a β-diketone/ruthenium complex can be used as the organometallic compound. Here, DPM is an abbreviation for dipivaloylmethanate or 2,2,6,6-tetramethyl-3,5-pimelate (TMHD).

The oxygen containing gas can be, for example, oxygen, ozone or N ₂ O.

In some embodiments, CVD can be used to form the ferroelectric film mentioned above, in which case a sulfhydryl precursor in gaseous form and an organometallic metal in gaseous form are introduced into the reaction chamber. Next, RuO ₄ in the precursor reacts with the organometallic compound in the vapor phase in the presence of oxygen, which results in, for example, the formation of BaRuO _x (or SrRuO _x ) and its deposition on the substrate. At the same time, however, the non-flammable fluorinated solvent mixture accompanying RuO ₄ in the gas precursor does not decompose during deposition of the ferroelectric film, thereby also avoiding incorporation into the film.

The temperature in the reaction chamber is preferably between about 450 ° C and 800 ° C, which is the reaction temperature of the gas.

The ruthenate film produced by this method (e.g., BaRuO _x and SrRuO _x) exhibit ferroelectric properties and may be used (for example) capacitor. Further, since a thin ferroelectric film can be produced by this method, these films can be used as an electrode material, just like a Ru film and a RuO ₂ film. Specifically, such ferroelectric films (specifically, SrRuO _x ) can be used as the upper and lower electrode materials of the separate ferroelectric (or as a buffer layer between the ferroelectric and electrode materials). These ferroelectric films (which are oxides) prevent the diffusion of oxygen and PbO relative to ferroelectric materials such as lead lanthanum titanate (PLT) and lead zirconate titanate (PZT), and at the same time, by using the same calcium titanium As such ferroelectric materials, the mineral structure can increase the adhesion at the interface between the electrode material and the ferroelectric substances, and can particularly prevent or reduce the occurrence of a low dielectric constant layer which may occur at the interface and can prevent Or reduce degradation.

Example

The following non-limiting examples are provided to further illustrate specific examples of the invention. However, the embodiments are not intended to be exhaustive or to limit the scope of the invention described herein.

Example 1:

The ruthenium precursor prepared from osmium tetroxide dissolved in a solvent mixture of 48% HFE-7100 and 52% HFE-7200 is directly evaporated at various evaporator temperatures to determine the corresponding direct evaporation (defined as Precursor liquid flow rate without liquid residue in the evaporator. High purity argon is used as a carrier gas to pressurize the liquid precursor and flow it into the evaporator. The substrate vacuum pressure at the outlet of the evaporator was 67 torr, and a glass U-tube filled with glass beads was used as the evaporator.

While the invention has been shown and described with respect to the specific embodiments of the present invention, it may be modified by those skilled in the art without departing from the scope of the invention. The specific examples described herein are illustrative only and not limiting. Many variations and modifications of the compositions and methods are possible and are within the scope of the invention. Therefore, the scope of the invention is not limited to the specific examples described herein, but is only limited by the scope of the appended claims. Domains will include all equivalents of the subject matter of the patent application.

11‧‧‧Reaction chamber

12‧‧‧ Feed source

13‧‧‧ Feed source

14‧‧‧ Feed source

15‧‧‧Hot trap

15'‧‧‧Hot trap

BV‧‧‧Butterfly Valve

L1‧‧‧ pipeline

L2‧‧‧ pipeline

L3‧‧‧ pipeline

L4‧‧‧ pipeline

L5‧‧‧ pipeline

L6‧‧‧ pipeline

L7‧‧‧ pipeline

L8‧‧‧ pipeline

MFC1‧‧‧ Mass Flow Controller

MFC3‧‧‧ Mass Flow Controller

MFC4‧‧‧ Mass Flow Controller

PG1‧‧‧ pressure gauge

PG2‧‧‧ pressure gauge

PG3‧‧‧ pressure gauge

PMP‧‧‧ pump

UVS‧‧‧UV spectrometer

V1‧‧‧Shutdown valve

V2‧‧‧Shutdown valve

V2'‧‧‧Shutdown valve

V3‧‧‧Shutdown valve

V4‧‧‧Shutdown valve

V5‧‧‧Shutdown valve

V6‧‧‧Shutdown valve

V7‧‧‧Shutdown valve

V8‧‧‧Shutdown valve

V9‧‧‧Shutdown valve

Figure 1 illustrates a specific example of a device for depositing a ruthenium-containing film; and Figure 2 illustrates another specific example of a device for depositing a ruthenium-containing film.

11‧‧‧Reaction chamber

12‧‧‧ Feed source

13‧‧‧ Feed source

14‧‧‧ Feed source

15‧‧‧Hot trap

BV‧‧‧Butterfly Valve

L1‧‧‧ pipeline

L2‧‧‧ pipeline

L3‧‧‧ pipeline

L4‧‧‧ pipeline

L5‧‧‧ pipeline

L6‧‧‧ pipeline

L7‧‧‧ pipeline

MFC1‧‧‧ Mass Flow Controller

MFC3‧‧‧ Mass Flow Controller

MFC4‧‧‧ Mass Flow Controller

PG1‧‧‧ pressure gauge

PG2‧‧‧ pressure gauge

PG3‧‧‧ pressure gauge

PMP‧‧‧ pump

UVS: UV‧‧‧ Spectrometer

V1‧‧‧Shutdown valve

V2‧‧‧Shutdown valve

V3‧‧‧Shutdown valve

V4‧‧‧Shutdown valve

V5‧‧‧Shutdown valve

V6‧‧‧Shutdown valve

V7‧‧‧Shutdown valve

V8‧‧‧Shutdown valve

Claims (19)

A method of forming a film on a substrate in a semiconductor process, comprising: a) providing a reaction chamber and a substrate contained within the chamber; b) providing a sulfhydryl precursor, wherein the precursor comprises: 1) methyl a solvent mixture of nonafluorobutyl ether and ethyl nonafluorobutyl ether; 2) ruthenium tetroxide dissolved in a solvent mixture; and 3) moisture of less than about 100 ppm; and c) deposition of a ruthenium-containing film on the substrate. The method of claim 1, wherein the solvent mixture comprises: a) from about 10% to about 90% by volume of methyl nonafluorobutyl ether; and b) from about 10% to about 90% by volume Ethyl nonafluorobutyl ether. The method of claim 2, wherein the solvent mixture comprises: a) about 30% by volume of methyl nonafluorobutyl ether; and b) about 70% by volume of ethyl nonafluorobutyl ether. The method of claim 1, wherein the precursor comprises less than about 1 ppm moisture. The method of claim 1, wherein the precursor further comprises less than about 1 ppm of unassociated oxygen. The method of claim 1, wherein the pressure in the reaction chamber is maintained between 0.01 torr and 1000 torr. The method of claim 1, wherein the film deposition step is The substrate temperature between 50 ° C and 800 ° C is carried out. The method of claim 7, wherein the film deposition step is carried out at a substrate temperature between about 100 ° C and about 600 ° C. The method of claim 1, further comprising introducing a gas reducing agent into the reaction chamber and depositing a ruthenium containing film on the substrate at least in part by reacting the precursor with a gaseous reducing agent. The method of claim 9, wherein the reducing agent is hydrogen. The method of claim 9, wherein the reducing agent is air or oxygen. The method of claim 9, further comprising simultaneously introducing a reducing agent and a precursor into the chamber. The method of claim 1, further comprising a) introducing a precursor into the evaporator, wherein the precursor is initially in a liquid state; b) evaporating the precursor to form a precursor that is at least partially in a gaseous state; and c) The precursor is introduced into the reaction chamber. The method of claim 13, further comprising introducing the liquid precursor into the evaporator by pressurizing the liquid precursor with an inert gas. The method of claim 13, further comprising evaporating at least about 99% of the liquid precursor. The method of claim 13, wherein the entire liquid precursor is evaporated to form a gaseous precursor. The method of claim 13, further comprising evaporating the precursor at a temperature between about 10 ° C and about 80 ° C. The method of claim 1, wherein the substrate is a tantalum substrate suitable for semiconductor fabrication. The method of claim 1, wherein the substrate is a ceramic-based material.