JP6503543B2 - Transition metal silicide film, method and apparatus for manufacturing the same, and semiconductor device - Google Patents

Description

  The present invention relates to a transition metal silicide film composed of transition metal atoms and silicon excellent in electrical characteristics, a semiconductor device using the transition metal silicide film, and a method and an apparatus for manufacturing the transition metal silicide film.

  Transition metal silicide films made of metal and silicon are also called transition metal silicon compounds or transition metal silicides, and research and development have been advanced in recent years. Transition metal silicide films that make use of metal characteristics are called metallic silicides or metallic silicides, and are excellent in heat resistance, oxidation resistance, corrosion resistance, electrical conductivity, etc., and they are electrodes, high temperature structures, environmental coatings, etc. It is expected as a material for A transition metal silicide film utilizing characteristics as a semiconductor is called a silicide semiconductor or a silicide semiconductor or a semiconducting silicide, and is expected as a material for a light emitting element, a solar cell, a thermoelectric conversion element or the like. In addition, in the technical field of semiconductor devices, transition metal silicide films are known as materials having a good matching with processes such as LSI using silicon.

The present inventors have previously, MSi _n (where, M: a transition metal, Si: silicon, n = 7-16) proposes a transition metal silicide film according to the semiconductor device using the transition metal silicide film It proposed (refer patent document 1 and patent document 2).

  In addition, the present inventors have previously reported research on the reaction process of transition metal-containing silicon clusters (see Non-Patent Documents 1 and 2).

  As a result of investigation of prior documents related to the present application, there have been patent documents in which a sputtering method and a chemical vapor deposition (CVD) method are exemplified as a method of producing a transition metal silicide film (Patent Document 3) See 4, 5).

International Publication WO2009 / 107669 JP, 2011-66401, A JP-A-8-306882 JP 10-303144 A Japanese Patent Laid-Open No. 2002-47569

PHYSICAL REVIEW LETTERS, 86, 1733 (2001). CHEMICAL PHYSICS LETTERS, 388, 463 (2004).

MSi _n has already been proposed by the present inventors (where, M: a transition metal, Si: silicon, n = 7-16) a transition metal silicide film according to the will be described (see Patent Document 1).
Transition metal silicide film described in Patent Document 1 (MSi _n film), by a transition metal-containing silicon cluster are bonded to each other Si-Si, first neighbor atoms and the second neighbor atoms of the transition metal atom is Si atoms It has a structure. By having this structure, a semiconductor thin film described later can be formed.
In transition metal silicides (for example, MSi ₂ ) exhibiting metal-like electrical characteristics, which have been known, up to the patent document 1, no silicon clusters containing transition metal atoms are present. For example, in the crystal structure (C11b type) of MSi ₂ , when M is tungsten (W), 10 Si atoms are coordinated around W atoms, but around 10 Si atoms. There are also other W atoms. That is, ten Si atoms are shared by a plurality of W atoms. The closest atom to the W atom is a Si atom, and the second adjacent atom is a W atom.
In Patent Document 1, focusing on the fact that the transition metal-encapsulated silicon cluster is an open semiconductor of the gap E _HL of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), and it is aggregated. Proposed that a semiconductor film having a finite band gap can be produced. In particular, when M is molybdenum (Mo) or W, and a transition metal-containing silicon cluster having a silicon composition ratio n = 10 and 12 is deposited, the band gap of the formed semiconductor film has a value of 0.S. More than 8 eV. When the valence electron number of the contained transition metal atom is an odd number, the total valence electron number of the transition metal-included silicon cluster becomes an odd number (odd electron system), so E _HL becomes 0 eV in a strict sense. However, by aggregating the transition metal-encapsulated silicon clusters, bonds are formed between the clusters, and charges are exchanged with relaxation of the structure, so that the transition metal-encapsulated silicon clusters in the even electron system are aggregated. As such, it becomes a semiconductor film. That is, instead of E _HL , a semiconductor film can be formed by aggregating a transition metal-encapsulated silicon cluster in which the half occupied orbital (SUMO) and the gap E _{SL of} LUMO are open.
As described above, the transition metal silicide film MSi _n (where M: transition metal, Si: silicon, n = 7-16) according to Patent Document 1 is a compound of transition metal and silicon, and is a transition metal atom. A transition metal-containing silicon cluster in which 7 or more and 16 or less Si atoms surround is used as a unit structure, and Si is disposed in the first and second adjacent atoms of the transition metal atom, and has the following features There is. The first is suppression of deterioration due to hydrogen desorption, and the second is electric conductivity controllability by the field effect and high carrier mobility.

  The present inventors have also proposed that a film having a transition metal-containing silicon cluster as a unit structure can be substituted for amorphous silicon and used in the channel region of a thin film transistor (see Patent Document 2).

Transition metal-containing silicon cluster, and the transition metal silicide film MSi _n film (where, M: a transition metal, Si: silicon, n = 7-16) were they as a unit structure as a manufacturing method of laser ablation or ion trap The method has been used (see Patent Documents 1 and 2). These methods are poor in film thickness controllability and composition controllability, are not suitable for increasing the area of the substrate, have limitations in improving the deposition rate, and have problems in that simultaneous processing of a plurality of substrates is difficult. is there. Furthermore, in the laser ablation method, the substrate is damaged by the influence of high-speed particles and plasma, and in the ion trap method, since ions are used, it can not be deposited on the insulator substrate, and the electric conductivity When a high substrate is used, the high kinetic energy of ions may damage the substrate. Therefore, the conventional method is difficult to cope with integration, miniaturization, and area increase, and there is a problem that it is not suitable for manufacturing an LSI or a display.

On the other hand, sputtering methods and chemical vapor deposition (CVD) methods are known as conventional methods for producing transition metal silicide films (see Patent Documents 3, 4, and 5). For example, as a method of manufacturing W silicide film and W film using the CVD method, there is known a method of supplying a source gas of WF ₆ and SiH ₄ and utilizing surface reaction on a heated substrate (patented) References 4 and 5). SiH ₄ is used as a reducing agent for F in WF ₆ and the reduced WF _x (x = <6) reacts on the heated silicon substrate surface to form a W silicide film (WSi on the silicon substrate). ₂ ) A W film is formed (see Patent Document 4). Further, by using iron pentacarbonyl and SiH ₄ , an iron silicide (FeSi ₂ ) film is formed by a surface reaction on a silicon substrate heated to 500 ° C. (see Patent Document 5). The transition metal silicide film produced by utilizing the substrate surface reaction shown in Patent Documents 4 and 5 is presumed to have a silicon / metal composition ratio of 3 or less. This is due to the solid solution limit of impurities in silicon and the stoichiometric composition ratio of the silicon compound. For example, if it is attempted to penetrate or replace metal atoms while maintaining the crystal structure of silicon, the composition ratio of silicon / metal is limited by the limit value (solid solution limit) of the amount of metal atoms dissolved in silicon. Ru. On the other hand, when using a reaction (eutectic reaction) in which a compound of silicon and metal is cooled and separated from the liquid phase to form a solid phase, the composition ratio of silicon / metal conforms to the stoichiometric composition ratio. In the transition metal silicide film produced by the conventional CVD method based on the substrate surface reaction, the composition ratio of silicon / metal is limited to 3 or less in order to follow the principle of the composition ratio limitation. For example, even if it is a film called a silicon-rich W silicide film, the composition ratio of Si / W is 2.2-3.0 because it is manufactured using the surface reaction of the substrate. It was the following (refer patent document 3).

  Conventionally, a transition metal silicide film in which the composition ratio of silicon / transition metal exceeds 3 has not been realized. In addition, transition metal silicide films having characteristics useful as semiconductor devices have not been realized.

  The present invention is intended to solve these problems, and it is an object of the present invention to provide a transition metal silicide film in which the composition ratio of silicon / transition metal is more than 3. Another object of the present invention is to provide a laminated structure, a transistor, and a semiconductor device provided with a transition metal silicide film in which the composition ratio of silicon / transition metal is more than 3. Another object of the present invention is to provide a method and an apparatus for producing a transition metal silicide film in which the composition ratio of silicon / transition metal exceeds 3.

  The present invention has the following features to achieve the above object.

The present invention relates to a transition metal silicide film, which is a transition metal silicide film having a silicon / transition metal composition ratio of more than 3 and 16 or less, and manufactured by a chemical reaction of a source gas of transition metal and a source gas of silicon. It is characterized by For example, the transition metal is at least one or more of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, tungsten, rhenium, osmium and iridium. is there. For example, the transition metal is tungsten, and the composition ratio of silicon / transition metal is more than 3 and 14 or less.
The present invention relates to a semiconductor device and is characterized by including the transition metal silicide film of the present invention.
The present invention relates to a method of manufacturing a transition metal silicide film, wherein a precursor gas of transition metal and a precursor gas of silicon are chemically reacted in a gas phase to form a precursor having a silicon / transition metal composition ratio of greater than 3 and 16 or less. After preparing the body in the gas phase, the precursor is deposited on the substrate to produce a transition metal silicide film having a silicon / transition metal composition ratio of greater than 3 and 16 or less on the substrate. I assume. For example, using at least one of a gas composed of fluorine and a transition metal, a gas composed of chlorine and a transition metal, and a gas composed of an organic substance and a transition metal as a source gas of a transition metal, a source material of silicon As the gas, at least one of a silane gas composed of hydrogen and silicon, a disilane gas, a trisilane gas, a higher order silane gas, a gas composed of chlorine and silicon, and a gas composed of an organic substance and silicon is used. For example, a chemical reaction is caused in the gas phase by maintaining the transition metal source gas and the silicon source gas at a temperature of 50 ° C. or more and 420 ° C. or less. For example, a chemical reaction is caused in the gas phase by using light in a wavelength range that absorbs only the transition metal source gas and does not absorb the silicon source gas.
The present invention relates to an apparatus for producing a transition metal silicide film, which is a production apparatus for producing a transition metal silicide film by chemical vapor deposition by supplying a source gas of transition metal and a source gas of silicon, wherein A heating mechanism is provided to maintain the temperatures of the source gas and the source gas of silicon at 50 ° C. or more and 420 ° C. or less. The present invention also relates to a manufacturing apparatus for a transition metal silicide film, which is a manufacturing apparatus for manufacturing a transition metal silicide film by chemical vapor deposition by supplying a raw material gas of a transition metal and a raw material gas of silicon. It is characterized by comprising an irradiation mechanism of light in a wavelength range in which only the metal source gas absorbs and the silicon source gas does not absorb.

  In the present invention, the source gas is chemically reacted in the gas phase to produce a precursor, and the precursor is deposited on the substrate. Thus, for example, the temperature, pressure and flow rate of the source gas are adjusted. The film thickness can be controlled by the thickness of several atomic layers by decreasing the deposition rate to about 0.1 nm / min, and the composition ratio of silicon / transition metal can be controlled with a resolution of about 0.1 step. it can.

  The manufacturing method of the present invention reduces damage to the substrate and is suitable for increasing the area of the substrate and simultaneous processing of a plurality of substrates, as compared with the conventional laser ablation method or ion trap method. Controllability and uniformity, and coverage with a step structure, etc., it is advantageous for industrial manufacture of LSIs and displays in which miniaturization, integration and enlargement are important.

  According to the present invention, since the composition ratio of silicon / transition metal is a transition metal silicide film having a ratio of more than 3 and 16 or less, the optical gap is 0.1 eV or more and 1.5 eV or less, and the carrier mobility is 10, for example. The above characteristics are possible, and electrical characteristics are improved in a transistor using a transition metal silicide film, an electrode stack structure, and the like. In addition, since the composition ratio and the optical gap and the carrier mobility show a correlation, it is easy to realize a film having desired characteristics according to the application.

It is a schematic diagram showing a reaction process of SiH ₄ and WF ₆ in the first embodiment. It is a schematic diagram showing a reaction process of the 1 n in the embodiment of (Si / W composition ratio) = 12 precursor WSi _n and SiH ₄ in. FIG. 13 is a schematic view showing a process of producing a tungsten silicide film (WSi _n film, Si / W composition ratio n = 12) on the substrate by aggregating the precursor WSi ₁₂ in the first embodiment. It is a figure explaining the relationship between a substrate and the film deposited in a 1st embodiment. (A) shows the case where the precursor WSi _n is deposited on the quartz glass substrate 13, and (b) shows the case where the precursor WSi _n is deposited on the Si substrate. It is a schematic diagram of the manufacturing apparatus for producing a transition metal silicide film | membrane in 1st Embodiment. It is a cross-sectional schematic diagram of the film-forming chamber seen from the gas introduction port side in the manufacturing apparatus of FIG. FIG. 16 is a schematic view showing another example of a manufacturing apparatus for manufacturing a transition metal silicide film in the first embodiment. FIG. 16 is a schematic view showing another example of a manufacturing apparatus for manufacturing a transition metal silicide film in the first embodiment. FIG. 16 is a schematic view showing another example of a manufacturing apparatus for manufacturing a transition metal silicide film in the first embodiment. FIG. 16 is a schematic view showing another example of a manufacturing apparatus for manufacturing a transition metal silicide film in the first embodiment. Is a diagram showing the relationship between the composition ratio n and SiH ₄ gas pressure Si / W of WSi _n film in the first embodiment. It is a diagram showing the relationship between Si / W composition ratio n and heater temperature of WSi _n film in the first embodiment. Is a graph showing the relationship between the composition ratio n and the optical gap of the Si / W of WSi _n film in the first embodiment. Of WSi _n film in the first embodiment, a view showing the optical gap and the electron mobility. It is a cross-sectional schematic diagram of the N-MOS transistor in 2nd Embodiment. It is a cross-sectional schematic diagram explaining the case where the WSi _n film | membrane of composition inclination is used for an electrode structure in 2nd Embodiment. It is a cross-sectional schematic diagram of the non-junction type transistor which has a source / drain structure in 2nd Embodiment. It is a bird's-eye view of the principal part which shows a source / drain field of a solid type transistor in a 2nd embodiment. It is a bird's-eye view of the principal part which shows the source / drain region of a nanowire type transistor in a 2nd embodiment. In the third embodiment, a cross-sectional schematic view of a thin film transistor composed of the channel layer of WSi _n film. In the third embodiment, a cross-sectional schematic view of a thin film transistor composed of the channel layer of WSi _n film.

  Embodiments of the present invention will be described below.

  The present inventors chemically react the source gas in the gas phase rather than chemically react the source gas on the substrate surface, more specifically, the composition ratio of silicon / transition metal exceeds 3 By realizing the precursor in the vapor phase and depositing the precursor on the substrate, it is realized that a transition metal silicide film in which the composition ratio of silicon / transition metal exceeds 3 can be produced.

The embodiment of the present invention relates to a transition metal silicide film having a silicon / transition metal composition ratio of more than 3 and 16 or less, wherein a precursor gas of a transition metal and a precursor gas of silicon are chemically reacted in the gas phase. And a transition metal silicide film produced by depositing the precursor on a substrate. The transition metal silicide film of the present invention, MSi _n film (where, M: a transition metal, Si: silicon, 3 <n ≦ 16) referred to.

MSi _n film of the embodiment of the present invention is to prepare a precursor by a chemical reaction in the gas phase of the raw material gas of the material gas and the silicon of the transition metal, since the precursor is prepared by depositing on the substrate At least one of fluorine, chlorine, an organic substance, and hydrogen, which constitutes a raw material gas of transition metal and a raw material gas of silicon, is unavoidably contained in the film as an unreacted component. These unreacted components can be detected by temperature programmed desorption analysis, photoelectron spectroscopy analysis or the like.

The MSi _n film embodiment of the present invention, the optical gap is 1.5eV or less than 0.1 eV. For use as a semiconductor device, the optical gap is preferably larger than 0 eV and the energy gap is open.
As described below, M is a case of tungsten (W) n is 3 than the large 14 following MSi _n film (WSi _n film) was 1.5eV or less larger than 0.1 eV. The value of the optical gap is due to the fact that the precursor which is a component of WSi _n film holds the energy gap. For example, when the precursor is a Si ₁₂ cluster containing W atoms, the precursor holds an energy gap of 1.3 eV or more and 1.7 eV or less. WSi _n film, by reflecting the energy gap of the precursor, to form an energy gap. Also, by randomly bonding the precursors, an amorphous network structure of silicon is formed, and a state is formed at the bottom of the energy gap of the WSi _n film. Also, the optical gap has a positive correlation with the composition ratio n of Si / W. As the composition ratio n of Si / W increases, the optical gap (approximately 1.5 eV or more and approximately 2.0 eV or less) of the hydrogenated amorphous silicon film approaches.
Also, the present invention is implemented using titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, rhenium, osmium, iridium as the transition metal M other than W. also in the embodiment MSi _n film is a optical gap is 1.5eV or less than 0.1 eV, can be inferred that there is a positive correlation with Si / M composition ratio n. This is due to the fact that each of the precursors composed of M and Si has an inherent energy gap, similar to the precursor composed of W and Si.

In the WSi _n film according to the embodiment of the present invention, the carrier mobility is 0 cm ² / Vs or more and 17 cm ² / Vs or less. MSi of the embodiment of the present invention using titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, rhenium, osmium, iridium as M other than W Similarly to the WSi _n film, it is possible to analogize that the _n film also has a carrier mobility of about 17 cm ² / Vs or more, which is greater than 0 cm ² / Vs. This is due to the fact that the components of the MSi _n film is composed of the precursor. When the precursor maintains the Si cluster structure in the film, the electronic structure is locally aligned, carrier scattering is suppressed, and carrier mobility is improved. The carrier mobility is also correlated with the composition ratio n of Si / M. This is because the electronic structure of the Si cluster structure in the film is locally aligned and carrier scattering is suppressed by the increase of the composition ratio n of Si / M.

Transition metal M constituting the MSi _n film of the embodiment of the present invention, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, tungsten, rhenium, Osmium, iridium, or a combination of two or more.
The raw material gas of M and Si by chemical reaction in the gas phase to prepare a precursor, to deposit the precursor to the substrate to produce a MSi _n film. When the precursor is a Si _n cluster containing M atoms, when the sum (Z + n) of the atomic number Z of M and the Si / M composition ratio n becomes 86, the electrons of the Si _n cluster containing M atoms The state is a closed shell structure and has a stable composition. For example, in the case of iridium of Z = 77, the maximum value n of the composition ratio of Si / iridium is 9 (= 86−77), and in the case of hafnium of Z = 72, the maximum value n of composition ratio of Si / hafnium is 14 In the case of W of Z = 74, the maximum value n of the composition ratio of Si / W is 12 (86-74). Therefore, the Si / W composition ratio n of the WSi _n film produced from the precursor of the Si _n cluster containing W atoms is preferably 12 or less. However, as can be seen from the following embodiments, during production of WSi _n film, that silicon source gas such as SiH ₄ is taken into the film, Si / W composition ratio of WSi _n film plus 2 There may be a degree of deviation. It is also effective to use this to make a precursor smaller than the target composition ratio in the gas phase, deposit it, and then increase the composition ratio by reaction with SiH ₄ gas. Incidentally, M and Si constituting the MSi _n film is not required to maintain a Si _n cluster structure containing therein the M atoms in the film, n is a film which is a numerical range of 16 or less larger than 3 there Would be useful.

MSi _n film embodiment of the present invention is applicable to various layers of a semiconductor device according to the electric characteristics of the thin film.
For example, the MSi _n film embodiment of the present invention, by inserting the contact interface between the semiconductor substrate and the metal electrode, a semiconductor substrate, MSi _n film, by forming a laminated structure are laminated in this order of the metal electrode, a semiconductor The contact resistance at the laminated interface can be reduced and the conductivity of electricity flowing between the metal electrode and the semiconductor substrate can be improved as compared with the laminated structure in which the substrate and the metal electrode are laminated in this order. The stacked structure may be provided in at least one of the source and the drain of the transistor.
For example, _assuming that the MSin film is arranged and configured as a channel region, the drive current is improved more than a transistor arranged and configured as a conventional hydrogenated amorphous silicon film as a channel region.

To produce the MSi _n film embodiment of the present invention, by supplying the source gas and silicon source gas transition metals, the raw material gas by a chemical reaction in the gas phase precursor of a transition metal and silicon prepared, by depositing the precursor under the substrate and a metal electrode, to produce a MSi _n film. The manufacturing method and the manufacturing apparatus for carrying out the manufacturing method have, for example, the following configurations.

In the embodiment of the present invention, a precursor of a transition metal source gas and a source gas of silicon are supplied to cause a chemical reaction in a gas phase to produce a precursor, and the precursor is deposited on a substrate to form Si. / composition ratio of M to produce the 16 following MSi _n film greater than 3. At this time, Si composition ratio of the MSi _n film, need not be identical to the Si composition ratio of the precursors. For example, the composition ratio of the film can be increased more than that of the precursor by a reaction in which Si is added to the film surface from the Si source gas after deposition of the precursor. However, the controllability of the film composition ratio is higher when the deposition is performed under conditions where no surface reaction occurs.

  Using at least one of a gas composed of fluorine and a transition metal, a gas composed of chlorine and a transition metal, and a gas composed of an organic substance and a transition metal as a source gas of the transition metal preferable. In addition, as source gases for silicon, at least one of a silane gas composed of hydrogen and silicon, a disilane gas, a trisilane gas, a higher order silane gas, a gas composed of chlorine and silicon, and a gas composed of an organic substance and silicon It is preferable to use any gas.

In order to control the Si / M composition ratio n of MSi _n film, the pressure of the silicon source gas, in the deposition chamber is preferably controlled within a range of 2000Pa at least 0.1. The silicon source gas and a transition metal source gas undergoes a chemical reaction by colliding with the gas phase to form a precursor of a MSi _n film, that the precursor and the silicon source gas repeatedly collide, precursor The Si / M composition ratio is increased. When the pressure of the silicon source gas is increased, the number of collisions between the silicon source gas and the precursor is increased, and the chance of the chemical reaction between the silicon source gas and the precursor is increased, so the Si / M composition ratio of the precursor is Increase. Therefore, the Si / M composition ratio n of the pressure and the MSi _n film of a silicon material gas have a positive correlation. On the other hand, to the extent that the pressure of the silicon source gas exceeds a certain value, also increases the pressure of the silicon source gas, Si / M composition ratio n of MSi _n film becomes a constant value. There are two reasons for this: first, the reaction energy is insufficient, and second, the precursor reaches a stable composition in the gas phase.
The first reason is as follows. In order to cause a chemical reaction between the precursor and the silicon source gas, reaction energy is required. When the gas temperature is lower than the reaction energy, no chemical reaction occurs even if the silicon source gas and the precursor repeatedly collide. That is, even if the gas pressure is increased under a low gas temperature, the Si / M composition ratio of the precursor does not increase.
The second reason is as follows. When the atomic number of M is Z, when the Si / M composition ratio of the precursor reaches the value of 86-Z, the gas phase stability becomes high, and even if the precursor and silicon source gas repeatedly collide, the reaction I can not proceed. Therefore, in the precursor in which the Si / M composition ratio reaches the value of 86-Z, the Si / M composition ratio of the precursor exceeds the value of 86-Z even if the pressure and temperature of the silicon source gas are increased. Not increase.
As can be seen from the first and second reasons, in order to control the composition of MSi _n film with high accuracy, it is preferable to control the gas pressure and gas temperature.

The Si / M composition ratio n of MSi _n film to control with high precision, after introducing the silicon source gas, a method of introducing a transition metal raw material gas is preferred. For example, in order to produce a WSi ₁₂ film, it is necessary to set the Si / W composition ratio of the precursor produced in the gas phase to 12. After the film forming chamber is sufficiently filled with the Si source gas, the W source gas is introduced to efficiently collide the W source gas with the Si source gas and the precursor with the Si source gas in the gas phase, It can cause a reaction. On the other hand, when the Si source gas and the W source gas are simultaneously introduced, the film forming chamber is not sufficiently filled with the Si source gas, and the collision or chemistry of the W source gas and the Si source gas, and the precursor and the Si source gas The chance of reaction is reduced and the precursor reaches the substrate before the Si / W composition ratio reaches 12. Alternatively, precursors having a Si / W composition ratio of less than 12 are bonded in the gas phase, and a precursor satisfying the Si / W composition ratio of 12 in the gas phase can not be produced.

The MSi _n film of Si / M composition ratio n to control with high accuracy, the mass flow ratio of the source gas of the silicon / transition metal, is preferably in the range of 10,000 or less 0.1 or more. For example, after the Si source gas is introduced and the desired gas pressure is reached, the source gas of the transition metal is introduced under the condition that the mass flow ratio of the source gas of silicon / transition metal is low. The partial pressure of the raw material gas of silicon and transition metal in the film chamber changes, which makes it difficult to control the composition of the precursor. By increasing the mass flow ratio of the silicon / transition metal source gas, the partial pressure of the silicon and transition metal source gas can be stabilized.

  In the embodiments of the present invention, precursors generated by chemical reaction in the gas phase are deposited on a substrate.

  In an embodiment of the present invention, the manufacturing apparatus controls a flow rate of at least one of a pipe for introducing a source gas of transition metal and a source gas of silicon, and a source gas of the transition metal and a source gas of silicon. Mechanism, a deposition chamber where the source gas of the transition metal and the source gas of the silicon react, a gas pressure control mechanism for controlling the pressure of the source gas of the transition metal and the source gas of the silicon, and unreacted Preferably, the transition metal source gas and the exhaust mechanism for exhausting the silicon source gas are provided, and the transition metal source gas and the silicon source gas are supplied, and a precursor generated by a chemical reaction in a gas phase The body is deposited on a substrate to make a transition metal silicide film with a silicon / transition metal composition ratio greater than 3 and less than or equal to 16.

  In the embodiment of the present invention, it is preferable to provide energy to react the source gas of transition metal and the source gas of silicon. A method of raising the temperature of the gas, or a method of irradiating the gas with light, or both can be used. The reason is that selective energy can be used by using heat or light.

  For example, when the gas temperature is set to 420 ° C. or more, the source gases of silicon react with each other to form an amorphous silicon film. On the other hand, when the gas temperature is 50 ° C. or lower, the transition metal source gas and the silicon source gas do not react with each other, and a precursor is not formed. In order to prevent the reaction between the silicon source gases and to react only the transition metal source gas and the silicon source gas or the precursor and the silicon source gas, the transition metal source gas and the silicon source gas are reacted. The gas temperature may be set in a selective temperature range which is higher than the temperature at which the source gases of silicon react with each other.

  For example, in the case of using light, it is preferable to use light in a wavelength range where only the source gas of the transition metal absorbs, without absorbing the source gas of silicon. When the source gas of silicon absorbs light, the source gases of silicon cause a chemical reaction to form an amorphous silicon film.

As an embodiment of the present invention, the manufacturing apparatus preferably includes a heating mechanism or a light irradiation mechanism as an energy source for reacting the source gas of transition metal and the source gas of silicon in the gas phase. When SiH ₄ is used as the source gas of silicon, it is preferable to set the source gas of the transition metal and the SiH ₄ gas to a temperature of 50 ° C. or more and 420 ° C. or less. When the temperature is 50 ° C. or less, the source gas of the transition metal and the SiH ₄ gas do not react, and when the temperature exceeds 420 ° C., the SiH ₄ gases react with each other.
Preferably, the heating mechanism is provided on at least one of the outer wall and the inner wall of the deposition chamber, the deposition substrate in the deposition chamber, and the support mechanism for the deposition substrate. In order to heat the source gas, in particular, a structure in which a heating mechanism is attached to the inner wall or the outer wall of the film forming chamber is preferable. In order to heat source gas, it is preferable to set it as the structure which attached the heating mechanism to the inner wall or outer wall of gas introduction piping. In order to heat the source gas, it is preferable to have a structure in which a heating mechanism is attached to the deposition substrate, and the reaction promotion in the gas phase near the substrate is more effective than reaction promotion on the substrate surface.
It is preferable to utilize a wavelength range of 100 nm to 300 nm in which only the transition metal source gas absorbs light and the silicon source gas does not absorb light. A semiconductor laser, an excimer laser, an excimer lamp, and a deuterium lamp may be installed in the manufacturing apparatus as a light source in this wavelength range.
In order to prevent light excitation of the silicon source gas, a short wavelength cut filter may be provided between the light source and the film forming chamber. Alternatively, a light introducing transparent window having a role of a short wavelength cut filter may be provided.
For example, the manufacturing apparatus is configured such that light strikes the source gases of transition metals and silicon, and the place where the light strikes the source gases is directly above the deposition substrate, between the gas inlet and the deposition substrate, gas inlet, gas introduction It can be any one or more in the path.

First Embodiment
The transition metal silicide film of the first embodiment of the present invention will be described below with reference to the drawings. The case where the transition metal of the transition metal silicide film is tungsten W will be described as a representative example.

FIG. 1 is a schematic view showing a reaction process of SiH ₄ and WF ₆ . As shown in the upper left, first, when SiH ₄ and WF ₆ collide in the gas phase (upper left arrow), SiH ₄ and WF ₆ react to form n = 1 precursor WSi _n . Next, as indicated by the arrows in sequence, the precursor WSi _n repeatedly collides with SiH ₄ to promote Si enrichment, that is, increase in n value. Here, SiH ₄ and WF ₆ have high stability at room temperature, and the reactivity is poor, so that the reaction does not proceed with mere collision of molecules alone. Therefore, in the event of a collision, the reaction can be promoted by providing energy assistance such as heat and light. Alternatively, the reaction can be promoted by applying energy to SiH ₄ or WF ₆ before collision. However, if energy is applied nonselectively here, SiH ₄ reacts with each other when it collides, and an amorphous Si film is formed. By selectively applying energy to prevent this, it is possible to cause a reaction of only SiH ₄ and WF ₆ or only of a precursor WSi _n and SiH ₄ .

FIG. 2 is a schematic view showing the reaction process of n = 12 precursors WSi _n and SiH ₄ . The precursor WSi _n has high gas phase stability when n = 12, and the reaction does not proceed further even if it repeatedly collides with SiH ₄ . In the figure, the precursor WSi ₁₂ 1, Si is shown in a state invisible one. For details of these reaction processes, Non-Patent Documents 1 and 2 can be cited as references.

The stable composition of the precursor MSi _n when the transition metal M is other than W, precursors HfSi _n at n = 14, the precursor TaSi _n at n = 13, n = 12 in the precursor MoSi _n, the precursor Resi _n n = 11 and n = 9 for the precursor IrSi _n . When these precursors are produced in the gas phase, a gas source serving as a transition metal source is used as in the precursor WSi _n . For example, a chlorine-based gas of MoCl ₆ as a Mo source gas, TaCl ₅ as a Ta source gas, and HfCl ₄ as a Hf source gas is used. Since fluorine and chlorine have close electronegativity, the reaction process between these transition metal gas sources and SiH ₄ is similar to the reaction process of WF ₆ and SiH ₄ .

Figure 3 is permitted to aggregate precursor WSi _12, a schematic diagram silicon-rich tungsten silicide film (WSi _n film, n = 12) are shown the process of manufacturing the substrate. After the precursor WSi ₁₂ was synthesized in the gas phase, it is deposited on the substrate to produce a WSi ₁₂ film precursor WSi ₁₂ with each other to form a bond. By performing Raman scattering measurement or photoelectron spectroscopy (XPS) of the WSi _n film, the bonding state of Si-Si in the film can be observed. Further, residual fluorine and residual hydrogen in the film can be observed by thermal desorption analysis (TDS), XPS or Raman scattering measurement.

FIG. 4 is a diagram for explaining the relationship between a substrate and a film to be deposited. For the deposition substrate, a semiconductor such as Si or Ge, an insulator such as quartz or sapphire or a resin, or a metal can be used. As shown in FIG. 4A, in the case where the precursor WSi _n 4 is deposited on the quartz glass substrate 13, “a WSi _n film in an amorphous state in which the precursors WSi _n 4 randomly form a bonding network. 12 can be made. Further, as shown in FIG. 4B, when the precursor WSi _n 4 is deposited on the Si substrate 23 having a clean surface, the “WSi _n film in the epitaxial crystal state” can be produced. . In the case of producing a WSi _n film 22 in an epitaxial crystal state, it is necessary to select a deposition substrate. This is because the growth film thickness and defect density of the epitaxial film change depending largely on the lattice constant of the deposition substrate and the cleanliness of the surface.

FIG. 5 is a schematic view of a manufacturing apparatus for manufacturing a transition metal silicide film. The manufacturing apparatus includes a film forming chamber 27 in which a transition metal source gas reacts with a silicon source gas, a gas pipe 26 introducing a transition metal source gas and a silicon source gas, a transition metal source gas and a silicon source A gas flow rate control mechanism such as a gas flow rate controller 25 that controls the flow rate of at least one of the gases, and a gas pressure control mechanism (pressure gauge 32, which controls the pressure of the transition metal source gas and the silicon source gas Valve 30), an exhaust mechanism (exhaust port 29) for exhausting the raw material gas of unreacted transition metal and the raw material gas of silicon, the substrate 3 for depositing the precursor in the film forming chamber 27, and And a substrate stage 31 for supporting and moving.
In FIG. 5, the heater 28 is installed on the outer wall of the film forming chamber 27. The heater 28 has a function of warming the gas in the film forming chamber 27. By providing a heating mechanism also on the substrate stage 31, it is possible to assist the increase of the gas temperature and to promote the Si enrichment of the film.
The manufacturing apparatus includes a plurality of gas cylinders 24 each storing a source gas and an atmosphere gas (dilution gas), and the source gas and the atmosphere gas are introduced into the film forming chamber 27 via the respective gas pipes 26.
For example, in the case of manufacturing the WSi _n film, using SiH ₄ and WF ₆ as a source gas. A higher order silane gas such as Si ₂ H ₆ or Si ₃ H ₈ can be used as the Si raw material, and a chloride gas such as WCl ₆ can also be used as the W raw material. It is characterized that the higher order silane gas is more reactive than SiH ₄ . Alternatively, Ar or H ₂ gas may be used as the dilution gas. As shown, gas is supplied from a plurality of gas cylinders (from the left in the figure, WF ₆ , SiH ₄ , Ar, H ₂ ).
By installing the gas flow rate controller 25 in the middle of the gas pipe 26, the flow rate of the gas introduced into the film forming chamber 27 is controlled. The pressure in the film forming chamber 27 is confirmed by the pressure gauge 32 installed in the film forming chamber 27 and the throttle of the valve 30 installed at the exhaust port 29 for gas exhaust (arrows in the drawing) is adjusted. Thus, the pressure in the deposition chamber is controlled. In order to cause a gas phase reaction between SiH ₄ and WF _{6 in} the film forming chamber, it is necessary to secure a sufficient reaction space, and the distance between the gas exhaust port 29 and the gas inlet is sufficiently separated, and It is desirable that the capacity of the deposition chamber be sufficiently large. By enlarging the reaction space, it is possible to cause a sufficient gas phase reaction in the film formation chamber. For example, a WSi _n film can be manufactured by using a single tube with a diameter of 203 mm and a length of 1 m as the size of the deposition chamber.

6 is a schematic cross-sectional view of a film forming chamber as viewed from the gas inlet side in the manufacturing apparatus of FIG. In the drawing, the heater 28 is provided on the outer wall of the film forming chamber 27 and can heat gas phases such as SiH ₄ , WF ₆ , Ar, and H ₂ introduced into the film forming chamber. In order to make the vapor phase temperature in the film forming chamber uniform, it is preferable to use a cylindrical chamber in the film forming chamber so that the substrate 3 is positioned at the center of the cylinder. Further, the shape of the film formation chamber, the installation place of the heater, and the installation place of the substrate are not limited to the above, and can be appropriately designed.

FIG. 7 is a schematic view of an example in which the heater 28 is disposed at a location away from the substrate 3 and in the vicinity of the gas inlet. The WSi _n film can be produced even if the heater is not located near the substrate but located away from the substrate.

FIG. 8 is a schematic view of another example of a manufacturing apparatus for manufacturing a transition metal silicide film. In FIG. 8, unlike the manufacturing apparatus of FIGS. 5 to 7, the heater 28 is installed on the outer wall of the gas pipe 26 for WF ₆ gas. By previously heating the WF ₆ gas introduced into the film forming chamber 27, a WSi _n film can be produced. The heater 28, by installing to the tip of the WF ₆ gas in the gas pipe 26, it is possible to introduce a WF ₆ gas while maintaining a high temperature in a deposition chamber, it is effective in Si enrichment WSi _n film .

FIG. 9 is a schematic view of another example of a manufacturing apparatus for manufacturing a transition metal silicide film. As shown in FIG. 9, extend the gas piping 26 of WF ₆ gas close to the substrate 3 was placed in the film forming chamber 27, by the distance between the gas pipe outlet and the substrate 3 to the variable, SiH ₄ and WF ₆ It is possible to control the Si composition ratio of the WSi _n film by controlling the distance until W reaches the substrate.

Also, the WSi _n film can be produced by installing a heater not only on the WF ₆ gas piping but also on one or more of the SiH ₄ gas piping, Ar gas piping, and H ₂ gas piping.

FIG. 10 is a schematic view of another example of a manufacturing apparatus for manufacturing a transition metal silicide film. The lamp 34 as a light source by placing the film forming chamber 27, the raw material gas is excited by light, it can be manufactured WSi _n film.
When a WSi _n film is produced using SiH ₄ and WF ₆ , SiH ₄ is excited by light of a wavelength range of about 150 nm or less, and WF ₆ is excited by light of a wavelength range of about 200 nm or less. Therefore, when light of a wavelength range of about 150 nm or less is used, both SiH ₄ and WF ₆ are photoexcited, reaction between SiH ₄ progresses, and an amorphous Si film is formed. In order to prevent this, it is necessary to use light in a wavelength range in which only WF ₆ is selectively photoexcited without SiH ₄ being photoexcited, so a wavelength within the range of about 200 nm or less and more than about 150 nm selectively photoexcited a raw material gas by using the light, i.e., it is possible to photoexcitation only WF _6, to produce the WSi _n film. For example, an Xe excimer lamp with a center wavelength of 172 nm can be applied. Also, by using a material that blocks light in the wavelength range of about 150 nm or less for the light transmission window 33, or inserting a filter that blocks light in the wavelength range of about 150 nm or less between the light transmission window and the lamp Similar effects can be obtained.
When Si ₂ H ₆ is used instead of SiH ₄ as the Si source, the reaction between Si source gases can be prevented by using light in the wavelength range of about 190 nm to 200 nm to produce a WSi _n film. it can. When Si ₃ H ₈ is used as the Si source, selective photoexcitation of WF ₆ is impossible because Si ₃ H ₈ absorbs light of a wavelength range of about 210 nm or less.
The installation position of the light source is effective at any position of the position immediately above the substrate, the position parallel to the substrate, any position in the film forming chamber apart from the substrate, the introduction port of gas piping, and the like.
Light, the light irradiation range is wide, as the light intensity is strong, it is possible to increase the deposition rate of the WSi _n film. Although a WSi _n film can be produced also by laser light, a lamp light with a wide light irradiation range is preferable from the viewpoint of the film forming speed.

FIG. 11 is a view showing the relationship between the Si / W composition ratio n of the WSi _n film manufactured using the manufacturing apparatus of FIG. 5 and the SiH ₄ gas pressure. As production conditions, WF ₆ gas flow rate was 0.2 sccm, SiH ₄ gas flow rate was 10 sccm, heater temperature was 50-300 ° C., substrate temperature was 350-420 ° C., and gas pressure was 10-1350 Pa. Here, since the SiH ₄ / WF ₆ gas flow ratio is as large as 50, the gas pressure is almost determined by SiH ₄ , and the gas pressure is adjusted by adjusting the throttling of the valve 30 located at the exhaust port of FIG. It controlled. A quartz glass substrate was used as the deposition substrate. Focusing on the WSi _n film fabricated under the conditions of a heater temperature of 300 ° C., a substrate temperature of 420 ° C., and a heater temperature of 300 ° C. and a substrate temperature of 350 ° C., the Si / W composition ratio n increases as the SiH ₄ gas pressure increases. The Si / W composition ratio n became constant at 12 above a specific gas pressure. This is because when the number of collisions of SiH ₄ and WF ₆ increases with the increase of the SiH ₄ gas pressure, the precursor WSi _n is enriched with Si, and then the precursor WSi _n becomes n = 12 It is a stable composition and shows that the reaction is self-terminating. By setting the manufacturing conditions under which the gas temperature is lower than these manufacturing conditions, the Si / W composition ratio n at the time of self-stop can be reduced. For example, the heater temperature 50 ° C., WSi _n film produced under the conditions of a substrate temperature of 350 ° C. has Si / W composition ratio n reaction at less than approximately 5 to self-limiting. This is because, with the Si / W composition ratio n of the precursor WSi _n is increased, because the energy required for the reaction of the precursor WSi _n and SiH ₄ is increased. It has been shown that under the conditions of a heater temperature of 50 ° C. and a substrate temperature of 350 ° C., the energy for causing the reaction of the precursor WSi _n and SiH _{4 to be} less than about 5 can not be satisfied. Since the gas temperature at this time is radiant heat from the substrate and heat conducted from the substrate to the gas, the temperature is slightly lower than 350 ° C. of the substrate temperature. Further, the temperature of the gas is determined not only by the temperatures of the substrate and the heater but also by the positional relationship between the substrate and the heater, the convection of the gas, the gas flow rate, and the gas pressure.

FIG. 12 is a view showing the relationship between the Si composition ratio n of the WSi _n film manufactured using the manufacturing apparatus of FIG. 5 and the heater temperature. As the manufacturing conditions, the WF ₆ gas flow rate was 0.2 sccm, the SiH ₄ gas flow rate was 10 sccm, the heater temperature was 50 to 400 ° C., the substrate temperature was 390 ° C., and the gas pressure was 1300 Pa. With the increase of the heater temperature, that is, the increase of the gas temperature in the film formation chamber, the composition ratio n of Si increases and becomes constant at n = 12. According to FIG. 12, it can be seen that the WSi ₁₂ film was formed based on the precursor WSi ₁₂ having high gas phase stability.

Heater temperature (50-300 ° C.), substrate temperature (350-420 ° C.), SiH ₄ gas pressure (10-1350 Pa) of WSi _n film manufactured under the manufacturing conditions shown in FIG. 11 using the manufacturing apparatus of FIG. The composition ratio n of Si, the optical gap (eV), and the electron mobility (cm ² / Vs) are shown in Table 1. The electron mobility was calculated by Hall effect measurement. Note that part of the optical gap with a heater temperature of 300 ° C. and a substrate temperature of 350 ° C. and electron mobility data are omitted because they can not be measured because the sheet resistance is too high because the film thickness is thin.

Similarly, the manufacturing conditions of WSi _n film shown in FIG. 12, heater temperature (45-380 ℃), the substrate temperature (390 ℃), SiH ₄ gas pressure (1300 Pa), and the composition ratio of Si of WSi _n film n, optical gap (eV), and electron mobility (cm ² / Vs) are shown in Table 2.

FIG. 13 is a diagram showing the relationship between the optical gap and the composition ratio n of Si in the WSi _n films shown in FIG. 10 and FIG. According to the figure, it can be seen that the optical gap can be controlled in the range of 0.1 eV to 1.5 eV. When the Si composition ratio n is about 2 or less, the optical gap is closed. When a WSi _n film is used for a semiconductor device, it is preferable that n is larger than 3 and the energy gap is open. Also, according to the figure, there is a fixed relationship between the optical gap and the Si / W composition ratio n regardless of the manufacturing conditions. This indicates that main factors for determining the optical gap of WSi _n film is Si / W composition ratio n. For example, when the Si / W composition ratio n is in the range of more than 3 and 14 or less, the optical gap can be controlled in the range of about 0.1 eV to 1.5 eV.

FIG. 14 is a view showing the optical gap and the electron mobility of the WSi _n films shown in FIG. 10 and FIG. According to the figure, the electron mobility tends to increase as the optical gap increases. From FIG. 14, it is understood that the electron mobility is in the range of 0.1-17 cm ² / Vs when the optical gap is in the range of 0.1 eV to 1.5 eV. When the optical gap is small, the Fermi level exists near the center of the optical gap, and the electron concentration and the hole concentration are balanced to reduce the apparent electron mobility. On the other hand, when the optical gap is large, the Fermi level is relatively present at the conduction band end side, the balance between the electron concentration and the hole concentration is broken, and the apparent electron mobility is increased.

The Si-rich W and Si compound film (Si / W composition ratio = 8) formed by sputtering maintains the same Si / W composition ratio as the WSi _n film, but W atoms and Si atoms Have a network structure randomly coupled, and the optical gap and carrier mobility show almost zero. In _{order to} distinguish a WSi _n film from a film formed by sputtering, in addition to the evaluation of the optical gap and carrier mobility, evaluation of the bonding state of atoms in the film by photoelectron spectroscopy (XPS) or Raman scattering measurement, transmission electron It is effective to observe a cross-sectional image by a microscope and evaluate the electrical bonding characteristics with a semiconductor substrate.

Second Embodiment
The present embodiment is an example in which a transition metal silicide film is applied to an electrode stack structure in a semiconductor device. The structure is a laminated structure in which a transition metal silicide film is inserted at the contact interface between a semiconductor substrate and a metal electrode, and is formed by laminating a semiconductor substrate, a transition metal silicide film, and a metal electrode in this order.

Figure 15 is a schematic cross-sectional view of the N-MOS transistor of Si with source / drain structure of inserting the WSi _n film 42 in the contact interface between the metal film (metal electrode 44) and the semiconductor substrate (N-type Si substrate 41) . In the center of the figure, the gate insulating film 43 and the gate electrode (metal electrode 44) are stacked on the P-type Si substrate 40. By using a WSi _n film (for example, n = 8-12) having a high Si composition ratio n, it is possible to reduce the defect level generated at the contact interface between the Si substrate and the WSi _n film, and between the metal and the Si substrate It is possible to control the height of the energy barrier generated by reducing the contact resistance of the metal / Si substrate. The electrode structure provided with the WSi _n film is effective not only for the N-MOS transistor but also for the P-MOS transistor, and also effective for not only the Si transistor but also the Ge transistor.

In the WSi _n film inserted between the semiconductor substrate and the metal film, the composition ratio is inclined so that the Si / W composition ratio n decreases stepwise or continuously from the Si substrate to the metal film. can do. In FIG. 16, the Si composition on the Si substrate 50, Si substrate to metal W film 56, WSi ₁₂ film 51, WSi ₁₀ film 52, WSi ₆ film 53, WSi ₄ film 54, WSi ₂ film 55, and so on. The configuration in which the ratio n decreases is schematically illustrated. For W film of a metal film can be manufactured by the same manufacturing apparatus as WSi _n film, it is possible to continuously produce in the same deposition chamber from WSi _n film to the W film. In junctions of semiconductors, semiconductors and insulators, or dissimilar materials of semiconductors and metals, an energy barrier such as a band offset or a Schottky barrier is formed at the junction interface, which causes electric conduction to be inhibited. By inserting a WSi _n film between the semiconductor substrate and the metal film, the band offset can be changed stepwise or continuously from the semiconductor substrate to the metal, so that the parasitic resistance due to the energy barrier can be reduced. There is.

FIG. 17 is a schematic sectional view of a non-junction transistor having a source / drain structure in which a WSi _n film 42 is inserted at the contact interface of a metal electrode 44 and a silicon on insulator (SOI) substrate 50 composed of Si and SiO _2. FIG. Unlike the transistor of FIG. 15, no PN junction is formed in the source / drain region by doping. Since the dopant concentrations in the channel and the source / drain regions are the same, it is effective in suppressing the variation in transistor characteristics. In particular, lowering the dopant concentration is effective in suppressing one of the short channel effects, that is, the Drain-Induced Barrier Lowering (DIBL). However, if the dopant concentration is low, the contact resistance between the metal and the SOI substrate will be high. By inserting a WSi _n film at the contact interface between the metal and the SOI substrate, the height of the energy barrier generated between the metal and the SOI substrate can be controlled to reduce the contact resistance between the metal and the SOI substrate. . A WSi _n film in which the Si composition ratio n changes from the Si substrate to the metal film as shown in FIG. 16 may be used.

FIG. 18 is a bird's-eye view of an essential part showing source / drain regions of a three-dimensional transistor. In FIG. 18, a three-dimensional Si structure is formed on a part of a Si substrate 50 having an SiO ₂ film 57 on the surface, and a WSi _n film 42 is formed between the side surface of the Si structure and the three-dimensional metal electrode 44. Is provided. WSi _n film, to form a gas phase reaction, is excellent in coating properties can be uniformly deposited on the three-dimensional structure.

FIG. 19 is a bird's-eye view of an essential part showing source / drain regions of the nanowire type transistor. In FIG. 19, an intervening layer made of a WSi _n film 42 is provided between the Si nanowire 58 and the cylindrical metal electrode 44 surrounding the periphery thereof. WSi _n film 42 is to be formed in a gas phase reaction, is excellent in coating properties can be uniformly deposited on the three-dimensional structure.

Third Embodiment
The present embodiment is an example in which a transition metal silicide film is applied as a semiconductor layer.
Figure 20 is a cross-sectional schematic view of a thin film transistor composed of the channel layer of WSi _n film. By using the high carrier mobility of the WSi _n film, the driving power of the thin film transistor can be improved. In the figure, the WSi _n film 42 is formed on the glass substrate 60, the gate insulating film 43 and the metal electrode 44 are stacked on the W Si _n film 42 in the gate structure portion, and the metal electrode 44 is in the source / drain structure portion. It is provided.
Figure 21 is a cross-sectional schematic view of a thin film transistor composed of the channel layer of WSi _n film. The WSi _n film 42 is configured to decrease the Si composition ratio n stepwise or continuously from the glass substrate 60 to the metal electrode 44. In the gate structure portion, high carrier mobility can be obtained by forming the channel layer below the gate insulating film 43 with a high Si composition ratio n, and in the source / drain structure portion, the metal electrode 44 and A low electrical resistivity can be obtained by configuring the contact point with a low Si composition ratio n. As a result, the driving power of the thin film transistor can be improved as a whole.

  Note that the examples shown in the above-described embodiment and the like are described to facilitate understanding of the invention, and the present invention is not limited to this embodiment.

  Since the transition metal silicide film of the present invention can realize a film having desired optical gap and electron mobility characteristics, it can be widely used for an electrode structure of a semiconductor device, a semiconductor channel layer, a display, and the like. Further, according to the manufacturing method and the manufacturing apparatus of the present invention, it is suitable for increasing the area and uniformity of the transition metal silicide film, and further integration and miniaturization of LSI can be expected, which is industrially useful.

Reference Signs List 1 WSi ₁₂ precursor 2 WSi ₁₂ film 3 substrate 4 WSi _n precursor 12 amorphous WSi _n film 13 quartz glass substrate 22 epitaxial crystalline WSi _n film 23 Si substrate having a clean surface 24 gas cylinder 25 gas flow controller 26 Gas piping 27 deposition chamber 28 heater 29 exhaust port 30 valve 31 substrate stage 32 pressure gauge 33 light transmission window 34 lamp 40 P type Si substrate 41 N type Si substrate 42 WSi _n film 43 gate insulating film 44 metal electrode 50 Si substrate or SOI substrate 51 WSi ₁₂ film 52 WSi ₁₀ film 53 WSi ₆ film 54 WSi ₄ film 55 WSi ₂ film 56 W film 57 SiO ₂ film 58 Si nanowire 60 glass substrate

Claims (9)

Silicon / transition metal (wherein the transition metal is at least one of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, tungsten, rhenium, osmium, iridium) A transition metal silicide film having a composition ratio of 1 or more and 3 or more and 16 or less (in the case of tungsten, except the composition ratio is less than 5) , and it is a fluorine, chlorine, organic substance and hydrogen A transition metal silicide film characterized in that at least one is contained in the film. The transition metal silicide film according to claim 1, wherein the transition metal is tungsten, and the composition ratio of silicon / transition metal is greater than 3 and less than or equal to 14 (except for less than 5) .   A semiconductor device comprising the transition metal silicide film according to claim 1. The chemical reaction between the source gas of transition metal and the source gas of silicon in the gas phase produces a precursor having a silicon / transition metal composition ratio of greater than 3 and 16 or less in the gas phase, and then the precursor 2. The transition metal silicide according to claim 1, wherein a transition metal silicide film having a silicon / transition metal composition ratio of more than 3 and 16 or less is formed on the substrate by depositing Method of producing a membrane At least one of a gas composed of fluorine and a transition metal, a gas composed of chlorine and a transition metal, and a gas composed of an organic substance and a transition metal as a source gas of a transition metal, and a source gas of a silicon And at least one of a silane gas composed of hydrogen and silicon, a disilane gas, a trisilane gas, a higher order silane gas, a gas composed of chlorine and silicon, and a gas composed of an organic substance and silicon A method of manufacturing a transition metal silicide film according to claim 4 . 5. The transition metal silicide film according to claim 4 , wherein a chemical reaction is caused in a gas phase by maintaining the transition metal source gas and the silicon source gas at a temperature of 50 ° C. or more and 420 ° C. or less. Production method. The transition metal silicide according to claim 4 , wherein a chemical reaction is caused in a gas phase by using light in a wavelength range that absorbs only the source gas of the transition metal and does not absorb the source gas of the silicon. Method of producing a membrane A manufacturing apparatus for producing a transition metal silicide film by chemical vapor deposition by supplying a source gas of transition metal and a source gas of silicon, wherein the temperature of the source gas of the transition metal and the source gas of silicon is 50 ° C. 2. The apparatus for manufacturing a transition metal silicide film according to claim 1, further comprising a heating mechanism for maintaining the temperature at 420 ° C. or less. A manufacturing apparatus for producing a transition metal silicide film by chemical vapor deposition by supplying a raw material gas of transition metal and a raw material gas of silicon, wherein only the raw material gas of the transition metal is absorbed, and the raw material gas of silicon is The apparatus for producing a transition metal silicide film according to claim 1, further comprising an irradiation mechanism of light in a wavelength range that does not absorb light.

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