Patent Application
20130295768
The present invention relates to a substrate processing apparatus that processes a substrate using plasma, and a method of manufacturing a semiconductor device.
In a semiconductor logic device, a DRAM device and the like, in order to suppress an increase in an electric resistance accompanying down-scaling, a metal nitride film for example containing titanium nitrides (hereafter simply referred to as titanium nitride (TiN) film) is employed as a material of electrodes, wirings and the like. The metal nitride film can be formed for example by a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method. In order to form the titanium nitride film by such methods, a titanium tetrachloride (TiCl4) gas containing chlorines is used as a precursor gas. A method of forming the titanium nitride film is described for example in Patent Document 1.
Patent Document 1: WO2007/020874
However, it has been found by a research of the inventors that impurities such as chlorine atoms, carbon atoms and the like remain in a film when a titanium nitride film is formed by the aforementioned methods. Especially, in a case of using a titanium tetrachloride gas as a precursor gas, chlorine atom residues in the titanium nitride film become prominent. Residual substances such as the chlorine atoms, the carbon atoms and the like increase an electric resistance of the titanium nitride film, and it becomes difficult to form a film that satisfies properties required in down-scaling of integrated circuits and in improving device properties in the recent years.
The chlorine atoms can be removed by forming the titanium nitride film under a high temperature, or by performing a high temperature treatment on the titanium nitride film after having formed the same. However, if the high temperature treatment is performed on titanium nitride films formed for example for an upper electrode and a lower electrode of a DRAM capacitor, properties of a capacitance insulating film and the like sandwiched by the titanium nitride films are deteriorated, whereby in some cases a leak current is increased. Further, in some cases, a circuit property may be deteriorated due to an occurrence of diffusion in a source region and a drain region formed on a substrate in advance, whereby a performance of a semiconductor device may be reduced. Nonetheless, if a process of removing the chlorine atoms is performed in a temperature range by which the aforementioned property deterioration and diffusion would not occur, it then becomes difficult to sufficiently remove the residual chlorines.
Further, a surface of the titanium nitride film is naturally oxidized, and is of a layer containing a large content of oxygen atoms. The oxygen atoms remaining in the titanium nitride film increase the electric resistance of the titanium nitride film. Further, the oxygen atoms change an interfacial property of the titanium nitride film and the capacitance insulating film and the like formed on top thereof, and deteriorate device properties.
Further, in a case of forming the upper electrode and the lower electrode of the DRAM by the titanium nitride films, although a metal oxide film and the like that is the capacitance insulating film is formed after having formed the titanium nitride film as the lower electrode, in some cases the titanium nitride film as the lower electrode is oxidized upon forming the metal oxide film, and the device properties may thereby be deteriorated.
An object of the present invention is to provide a metal processing apparatus, and a method of manufacturing a semiconductor device that can achieve one or both of reducing a chlorine atom residual amount and an oxygen atom residual amount in a metal nitride film and improving an oxidation resistance property of the metal nitride film in a temperature range by which properties of other films adjacent to the metal nitride film are not deteriorated.
According to one embodiment, there is provided a substrate processing apparatus including: a process chamber into which a substrate is carried, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate; a substrate support unit configured to support and heat the substrate within the process chamber; a gas supply unit configured to supply either or both of nitrogen atom-containing gas and hydrogen atom-containing gas to an inside of the process chamber; a gas exhaust unit configured to exhaust the gas from the inside of the process chamber; a plasma generation unit configured to excite the gas supplied to the inside of the process chamber; and a control unit configured to control the substrate support unit, the gas supply unit, and the plasma generation unit.
According to another embodiment, there is provided a method of manufacturing a semiconductor device, the method including: carrying a substrate into a process chamber and supporting the substrate by a substrate support unit, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate; heating the substrate by the substrate support unit; supplying, by a gas supply unit, either or both of nitrogen atom-containing gas and hydrogen atom-containing gas to an inside of the process chamber; and exciting, by a plasma generation unit, the gas supplied to the inside of the process chamber.
According to the substrate processing apparatus and the method of manufacturing a semiconductor device according to the invention, residual amounts of chlorine atoms and oxygen atoms in the metal nitride film can be reduced in a temperature range in which properties of other films adjacent to the metal nitride film are not deteriorated, and an oxidation resistance can be improved while improving properties of the metal nitride film.
As described above, when high temperature processing for example at 750° C. or more is performed on a titanium nitride film, properties of other films adjacent to the titanium nitride film are deteriorated, and in some cases a leaking current of a capacitor of a DRAM for example may be increased. Further, there may be cases where a circuit property is deteriorated by diffusions occurring in a source region and a drain region formed in advance on a substrate, and a performance of a semiconductor device is decreased. On the other hand, if a process of removing chlorine atoms is performed in a temperature range in which the properties of the films adjacent to the titanium nitride film are not deteriorated, it becomes difficult to sufficiently remove residual chlorine.
In regards to this, the inventors have conducted intensive studies on a method of improving an oxidation resistance of a titanium nitride film while reducing the residual amounts of chlorine and oxygen within the titanium nitride film in the temperature range in which the properties of the other films adjacent to the titanium nitride film are not deteriorated. As a result, the inventors have found that the above problem can be solved by activating a gas, in which a hydrogen atom-containing gas is mixed with a nitrogen atom-containing gas, by using plasma, and supplying the activated gas to the titanium nitride film formed on the substrate. The invention has been made based on the above discovery achieved by the inventors. An embodiment will be described below.
First, an exemplary configuration of a substrate processing apparatus that performs a method of manufacturing a semiconductor device of the embodiment will be described with reference to
The MMT apparatus includes a processing furnace 202 that performs plasma processing on the silicon substrate 100. The processing furnace 202 includes a processing container 203 that configures a process chamber 201, a susceptor 217, a gate valve 244, a shower head 236, a gas exhaust opening 235, a cylindrical electrode 215, an upper magnet 216a, a lower magnet 216b, and a controller 121.
The processing container 203 configuring the process chamber 201 includes a dome-shaped upper container 210 that is a first container, and a bowl-shaped lower portion container 211 that is a second container. Further, the process chamber 201 is formed by the lower container 211 being covered with the upper container 210. The upper container 210 is formed of a nonmetallic material such as aluminum oxide (Al2O3) or quartz (SiO2), and the lower container 211 is formed of, for example, aluminum (Al).
A susceptor 217 supporting the silicon substrate 100 is disposed at the center on a bottom side in the process chamber 201. The susceptor 217 is formed of a nonmetallic material such as aluminum nitride (AlN), ceramics, or quartz so as to reduce metallic contamination of a film formed on the silicon substrate 100.
A heater 217b as a heating mechanism is integrally embedded inside the susceptor 217, and is configured to heat the silicon substrate 100. When power is supplied to the heater 217b, it is capable of heating a surface of the silicon substrate 100 to, for example, about 200 to 750° C.
A substrate support unit of the embodiment mainly includes the susceptor 217, the heater 217b, and a second electrode 217c.
The susceptor 217 is electrically insulated from the lower container 211. A second electrode (not shown) as an electrode for changing an impedance is installed inside the susceptor 217. The second electrode is arranged via an impedance changing mechanism 274. The impedance changing mechanism 274 includes coils and variable capacitors, and is configured to control a potential of the silicon substrate 100 via the second electrode 217c and the susceptor 217 by controlling a pattern number of coils and capacity values of the variable capacitors.
A susceptor lifting mechanism 268 for lifting and lowering the susceptor 217 is provided in the susceptor 217. The susceptor 217 has through holes 217a provided therein. At least three wafer push-up pins 266 for pushing the silicon substrate 100 upward are provided on a bottom surface of the aforementioned lower container 211. Further, the through holes 217a and the wafer push-up pins 266 are arranged relative to one another so that the wafer push-up pins 266 penetrate the through holes 217a without coming into contact with the susceptor 217 when the susceptor 217 is lowered by the susceptor lifting mechanism 268.
A gate valve 244 as a gate valve is provided on a side wall of the lower container 211. When the gate valve 244 is open, the silicon substrate 100 can be introduced into the process chamber 201 by using a transfer mechanism (not shown), or the silicon substrate 100 can be taken out of the process chamber 201. By closing the gate valve 244, the process chamber 201 can be airtightly closed.
The shower head 236 for supplying a gas into the process chamber 201 is provided at an upper portion of the process chamber 201. The shower head 236 includes a cover body 233 on a cap, a gas inlet 234, a buffer chamber 237, an opening 238, a blocking plate 240, and a gas outlet 239.
A downstream end of a gas supplying pipe 232 for supplying a gas into the buffer chamber 237 is connected to the gas inlet 234 via an O-ring 203b as a sealing member. The buffer chamber 237 functions as a dispersing space for dispersing the gas introduced through the gas inlet 234.
A downstream end of a nitrogen gas supplying pipe 232a for supplying an N2 gas as a nitrogen atom-containing gas, a downstream end of a hydrogen gas supplying pipe 232b for supplying an H2 gas as a hydrogen atom-containing gas, and a downstream end of a noble gas supplying pipe 232c for supplying a noble gas such as helium (He) and argon (Ar) as a dilution gas are connected to, and joined at, an upstream side of the gas supplying pipe 234.
A nitrogen gas cylinder 250a, a mass flow controller 251a as a flow rate controlling apparatus, and a valve 252a as an on-off valve are connected to the nitrogen gas supplying pipe 232a in order from an upstream side. A hydrogen gas cylinder 250b, a mass flow controller 251b as a flow rate controlling apparatus, and a valve 252b as an on-off valve are connected to the hydrogen gas supplying pipe 232b in order from an upstream side. A noble gas cylinder 250c, a mass flow controller 251c as a flow rate controlling apparatus, and a valve 252c as an on-off valve are connected to the noble gas supplying pipe 232c in order from an upstream side.
A gas supply unit of the embodiment mainly includes the gas supplying pipe 234, the nitrogen gas supplying pipe 232a, the hydrogen gas supplying pipe 232b, the noble gas supplying pipe 232c, the nitrogen gas cylinder 250a, the hydrogen gas cylinder 250b, the noble gas cylinder 250c, the mass flow controllers 251a to 252c, and the valves 252a to 252c. The gas supplying pipe 234, the nitrogen gas supplying pipe 232a, the hydrogen gas supplying pipe 232b, and the noble gas supplying pipe 232c are formed of a nonmetallic material such as quartz or aluminum oxide, and a metallic material such as SUS. The gas supplying pipes are configured to arbitrarily supply the N2 gas, the H2 gas, and the noble gas into the process chamber 201 via the buffer chamber 237 by opening and closing of these valves 252a to 252c and flow rate control by the mass flow controllers 251a to 252c.
Although a case of providing the gas cylinder for each of the N2 gas, the H2 gas, and the noble gas has been described here, the invention is not limited to such an embodiment, and an ammonia (NH3) gas cylinder may be provided instead of the nitrogen gas cylinder 250a and the hydrogen gas cylinder 250b. Further, to increase a ratio of nitrogen in a reactant gas supplied into the process chamber 201, an N2 gas cylinder may further be provided to add the N2 gas to the NH3 gas.
A gas exhaust opening 235 for exhausting the reactant gas and the like from the process chamber 201 is provided on a lower portion of the side wall of the lower container 211. An upstream end of a gas exhaust pipe 231 for exhausting a gas is connected to the gas exhaust opening 235. An APC 242 that is a pressure regulator, a valve 243b that is an on-off valve, and a vacuum pump 246 that is an exhaust apparatus are provided on the gas exhaust pipe 231 in order from an upstream side. A gas exhaust unit of the embodiment mainly includes the gas exhaust opening 235, the gas exhaust pipe 231, the APC 242, the valve 243b, and the vacuum pump 246. The gas exhaust unit is configured to exhaust the interior of the process chamber 201 by activating the vacuum pump 246 and opening the valve 243b. Further, the gas exhaust unit is configured to adjust a pressure value inside the process chamber 201 by adjusting a divergence of the APC 242.
A cylindrical electrode 215 as a first electrode is provided on an outer periphery of the processing container 203 (upper container 210) so as to surround a plasma generating region 224 within the process chamber 201. The cylindrical electrode 215 is formed cylindrically, for example, in the form of a round cylinder. The cylindrical electrode 215 is connected, via an impedance matching box 272 that performs matching of impedances, to a high frequency power source 273 that generates high frequency power. The cylindrical electrode 215 functions as a discharge mechanism that excites the gas to be supplied into the process chamber 201 to thereby generate plasma.
An upper magnet 216a and a lower magnet 216b are respectively attached to upper and lower end portions on an outer surface of the cylindrical electrode 215. The upper magnet 216a and the lower magnet 216b are each configured as a permanent magnet formed cylindrically, for example, in the form of a ring.
The upper magnet 216a and the lower magnet 216b each include magnetic poles on both ends along a radial direction of the process chamber 201 (that is, on an inner circumferential end and an outer circumferential end of each magnet). Orientations of the magnetic poles of the upper magnet 216a and the lower magnet 216b are disposed so as to be opposite to one another. That is, the magnetic poles on inner circumferential portions of the upper magnet 216a and the lower magnet 216b are of different poles. Due to this, a line of magnetic force in a cylindrical axis direction is formed along an inner surface of the cylindrical electrode 215.
A plasma generation unit of the embodiment mainly includes the cylindrical electrode 215, the impedance matching box 272, the high frequency power source 273, the upper magnet 216a, and the lower magnet 216b. By forming an electric field by supplying the high frequency power to the cylindrical electrode 215, and forming a magnetic field by using the upper magnet 216a and the lower magnet 216b after having introduced a mixed gas of the N2 gas and the H2 gas into the process chamber 201, magnetron discharge plasma is generated in the process chamber 201. At this occasion, an ionization rate of the plasma is increased by the aforementioned electromagnetic field causing discharged electrons to move orbitally, and the plasma with long life and high density can be generated.
Note that a metallic blocking plate 223 for effectively blocking the electromagnetic field is provided around the cylindrical electrode 215, the upper magnet 216a, and the lower magnet 216b so that the electromagnetic field formed thereby does not adversely affect an external environment or an apparatus such as another processing furnace.
Further, the controller 121 as a control unit is configured to control the APC 242, the valve 243b, and the vacuum pump 246 through a signal line A, to control the susceptor lifting mechanism 268 through a signal line B, to control the gate valve 244 through a signal line C, to control the impedance matching box 272 and the high frequency power source 273 through a signal line D, to control the mass flow controllers 251a to 252c and the valves 252a to 252c through a signal line E, and further to control a heater embedded in the susceptor and the impedance changing mechanism 274 through a signal line not shown.
Next, a substrate processing step that is performed as one of the steps in a semiconductor manufacturing step of the embodiment will be described. This step is performed by the aforementioned MMT apparatus as the substrate processing apparatus. Note that in the following description, operations of respective units configuring the MMT apparatus are controlled by the controller 121. Here, an example in which a metal nitride film (titanium nitride film) formed as a lower electrode of a capacitor is subjected to nitriding by using plasma will be described.
First, the susceptor 217 is lowered to a transporting position of the silicon substrate 100, and the wafer push-up pins 266 are inserted into the through holes 217a of the susceptor 217. As a result, the push-up pins 266 protrude from a surface of the susceptor 217 by a predetermined height.
Then, the gate valve 244 is opened, and the silicon substrate 100 is introduced into the process chamber 201 by using a transporting mechanism that is not shown. As a result, the silicon substrate 100 is horizontally supported on the wafer push-up pins 266 protruding from the surface of the susceptor 217. On the silicon substrate 100, the titanium nitride film as the lower electrode of the capacitor is formed in advance by a CVD method or an ALD method. The titanium nitride film is formed by another CVD apparatus or ALD apparatus (not shown) using a titanium tetrachloride (TiCl4) gas containing chlorines as a precursor gas. Note that since the titanium tetrachloride gas is used as the precursor gas, chlorine atoms are remaining in the titanium nitride film. Further, a natural oxide film is formed on a surface of the titanium nitride film. The natural oxide film is formed when the silicon substrate 100 is introduced into the process chamber 201 from the aforementioned CVD apparatus or ALD apparatus.
Upon introducing the silicon substrate 100 into the process chamber 201, the transporting mechanism is evacuated to the outside of the process chamber 201, and the process chamber 201 is sealed by closing the gate valve 244. Then, by using the susceptor lifting mechanism 268, the susceptor 217 is lifted. As a result, the silicon substrate 100 is disposed on an upper surface of the susceptor 217. Thereafter, the susceptor 217 is lifted to a predetermined position, and the silicon substrate 100 is lifted to a predetermined processing position.
Note that, to introduce the silicon substrate 100 into the process chamber 201, it is preferable to supply the N2 gas and the noble gas as inactive gases from a gas supplying line to fill the process chamber 201 with the inactive gases, and reduce an oxygen concentration while the process chamber 201 is exhausted by a gas exhaust line. That is, it is preferable to supply the inactive gas into the process chamber 201 via the buffer chamber 237 by opening the valve 243a or the valve 243c while the process chamber 201 is exhausted by activating the vacuum pump 246 and opening the valve 243b.
Next, power is supplied to a heater 217h embedded inside the susceptor 217, and the surface of the silicon substrate 100 is heated. A surface temperature of the silicon substrate 100 is preferably a temperature that is 200° C. or more and less than 750° C., more preferably 200° C. or more and 700° C. or less.
Note that, in a heating process of the silicon substrate 100, when the surface temperature is heated to 750° C. or more, diffusion occurs in a source region and a drain region formed in the silicon substrate 100, which may deteriorate a circuit property and decrease a performance of a semiconductor device. By limiting the temperature of the silicon substrate 100 as above, the diffusion of impurities in the source region and the drain region formed in the silicon substrate 100, the deterioration of the circuit property, and the decrease in the performance of the semiconductor device can be suppressed. In the following description, the surface temperature of the silicon substrate 100 is set at, for example, 450° C.
Here, an example of using a mixed gas of the N2 gas and the H2 gas as the reactant gas will be described.
First, the valves 252a and 252b are opened to introduce (supply) the reactant gas that is the mixed gas of the N2 gas and the H2 gas into the process chamber 201 via the buffer chamber 237. At this occasion, divergences of the mass flow controllers 251a and 251b are respectively controlled so as to cause a flow rate of the N2 gas included in the reactant gas and a flow rate of the H2 gas included in the reactant gas become predetermined flow rates. The flow rate of the H2 gas to be supplied into the process chamber 201 is in a range of 0 sccm or more and 600 sccm or less. Further, the flow rate of the N2 gas to be supplied into the process chamber 201 is in a range of 0 sccm or more and 600 sccm or less. Note that, in this occasion, the valve 252c may be opened to supply the noble gas as the dilution gas into the process chamber 201, and a concentration of the mixed gas of the N2 gas and the H2 gas to be supplied into the process chamber 201 may be adjusted. A ratio of nitrogen atoms to hydrogen atoms contained in the gases supplied into the process chamber 201 is in a range of 0 or more and 100 or less.
Further, after having started the introduction of the reactant gas into the process chamber 201, the vacuum pump 246 and the APC 242 are used to adjust a pressure within the process chamber 201 to be in a range of 0.1 to 300 Pa, more preferably 0.1 to 100 Pa, for example 30 Pa.
After having started the introduction of the reactant gas, magnetron discharge is generated in the process chamber 201 by applying high frequency power to the cylindrical electrode 215 from the high frequency power source 273 via the impedance matching box 272, and applying a magnetic force by the upper magnet 216a and the lower magnet 216b into the process chamber 201. As a result, highly concentrated plasma is generated in the plasma generating region 224 above the silicon substrate 100. Note that the power to be applied to the cylindrical electrode 215 is in a range of, for example, 100 to 3000 W, for example, 800 W. At this occasion, a voltage Vpp can be applied to the silicon substrate 100 via the second electrode 217c provided on the susceptor 217. The voltage Vpp is controlled by the impedance changing mechanism 274 connected to the second electrode 217c. An impedance value (voltage Vpp) is controlled beforehand to a desired value after having introduced the substrate.
By forming a plasma state as aforementioned, the N2 gas and the H2 gas supplied into the process chamber 201 are excited and activated. Further, nitrogen radicals (N*) and hydrogen radicals (H*) generated thereby react with the surface of the silicon substrate 100. In this reaction, reduction by the hydrogen, and collision and replenishment of nitrogen atoms to the surface of the titanium nitride film are performed. As a result, a hydrogen chloride gas is generated by the reaction between chlorine components and the hydrogen, and an aqueous (H2O) gas is generated by the reaction between oxygen components and the hydrogen. Both of the generated gases are discharged to the outside of the titanium nitride film. Further, the nitrogen atoms are introduced into the titanium nitride film, and the titanium nitride film with a stronger bonding degree is formed. Chemical reaction formulas in the reaction are shown below.
TiCl+N*+H*→*TiN+HCl↑ (Formula 1)
TiO+N*+2H*→*TiN+H2O↑ (Formula 2)
When the nitriding of the titanium nitride film has ended, the power supply to the cylindrical electrode 215 is stopped, and the valves 252a and 252b are closed to stop the gas supply into the process chamber 201. Then, the residual gas within the process chamber 201 is exhausted using the gas exhaust pipe 231. Further, the susceptor 217 is lowered to the transporting position of the silicon substrate 100, and causes the silicon substrate 100 to be supported on the wafer push-up pins 266 protruding from the surface of the susceptor 217. Then, the gate valve 244 is opened, the silicon substrate 100 is taken out of the process chamber 201 by using the transporting mechanism that is not shown, and the substrate processing step of the embodiment ends.
According to the embodiment, one or more of the advantageous effects described below can be achieved.
(a) According to the embodiment, the residual amount of the chlorine atoms in the titanium nitride film can be reduced, a quality of the titanium nitride film can be improved, and an electric resistance of the titanium nitride film can be reduced.
(b) According to the embodiment, the residual amount of the oxygen atoms in the titanium nitride film can be reduced, and the electric resistance of the titanium nitride film can be reduced. Further, introduction of the nitrogen atoms into the titanium nitride film is enhanced, whereby the bonding degree of the titanium nitride film can be increased, and the electric resistance of the titanium nitride film can be reduced.
(c) According to the embodiment, the aforementioned substrate processing step is performed at a temperature of 200° C. or more and less than 750° C. (hereinafter referred to as a processing temperature region), or preferably at a temperature of 200° C. or more and 700° C. or less. As a result, the electric resistance of the titanium nitride film can be reduced, and a property thereof can be improved.
According to
Note that, as shown in
Further, as shown in
(d) According to the embodiment, an oxidation resistance of the titanium nitride film can be improved. As a result, natural oxidization of the titanium nitride film can be suppressed, and the electric resistance of the titanium nitride film can be reduced. Further, to form a metal oxide film and the like as a capacitance insulating film by using an oxidizing agent such as O2 or O3 on the titanium nitride film as the lower electrode of the DRAM, the oxidization of the titanium nitride film by the oxidizing agent can be suppressed, and an interfacial quality can be improved.
As shown in
(e) Further, according to the embodiment, the highly concentrated plasma is generated in the vicinity of the silicon substrate 100, that is, in the plasma generating region 224 above the silicon substrate 100, and the nitrogen radicals (N*) and the hydrogen radicals (H*) are generated inside the process chamber 201. Therefore, the generated radicals can effectively be supplied to the titanium nitride film before being deactivated. Further, a processing speed of the aforementioned substrate processing (nitriding using the plasma) can be improved. Note that in a remote plasma method of generating plasma outside the process chamber 201 to generate radicals thereat, the generated radicals tend to be deactivated before being supplied to the silicon substrate 100, and it is difficult to effectively supply the radicals to the silicon substrate 100.
(f) Further, as a result of intensive studies, it has been found that a property of a thin film to be formed can be changed by performing the processing by changing a ratio of the nitrogen gas to the hydrogen gas in the processing gas. Hereinbelow, a modification of the sheet resistance ratio in the case of changing the ratio of the nitrogen gas in the processing gas will be described.
As shown in
(g) Further, it has been found that, similarly by using the nitrogen gas (N2) and the ammonia gas (NH3) as the processing gas, the residual amount of the chlorine atoms and the residual amount of the oxygen atoms in the titanium nitride film can be reduced, the electric resistance of the titanium nitride film can be reduced, and the oxidation resistance can be improved.
As shown in
(h) Further, as a result of intensive studies, it has been found that a property of the film formed on the silicon substrate 100 can be improved by changing the voltage Vpp to be applied to the second electrode 217c. Hereinbelow, a modification of TiOx and TiNx concentrations in the TiN film in a case with the voltage Vpp of 50 V to 300 V, for example, when the change is caused to take place with the voltage Vpplow (50 V) and the voltage Vpphigh (300 V).
As shown in
As shown in
From
The aforementioned capacitor layer is a high-k film, and is for example ZrO. Such a ZrO film is formed by using tetrakis ethylmethylamino zirconium (TEMAZ) and ozone (O3) gas, in an atmosphere of about 250° C.
The embodiments have been described above specifically, but the present invention is not limited to the aforementioned embodiments and can be modified in various manners without departing from the spirit of the present invention.
For example, in the aforementioned embodiments, the case of processing the silicon substrate 100 on the surface of which the titanium nitride film is formed has been described. However, the invention is not limited to such a configuration, and may similarly process other substrates containing chlorine atoms and metallic atoms, such as a glass substrate on the surface of which the titanium nitride film is formed.
Further, for example, in the aforementioned embodiments, the case of using the mixed gas of the H2 gas and the N2 gas and the case of using the mixed gas of the NH3 gas and the N2 gas as the reactant gas have been described. However, the invention is not limited to such configurations. Depending on various conditions such as an amount of remaining chlorine in the titanium nitride film, processing temperature, processing pressure, and supply flow rate, the NH3 gas alone, the mixed gas of NH3 gas and the H2 gas, the mixed gas of NH3 gas and the N2 gas, the N2 gas alone, a monomethylhydrazine (CH6N2) gas, or a gas obtained by mixing these gases at arbitrary rates can be used as the reactant gas, for example. Further, the gas containing nitrogen and the gas containing hydrogen as aforementioned may alternately be supplied.
Further, in the aforementioned embodiments, although the natural oxide film has been described as an example of the oxide film formed on the substrate, the invention is not limited to this example. For example, the natural oxide film may be removed before moving the substrate into the present apparatus. In this case, since the natural oxide film is absent from the substrate surface, it becomes possible to surely remove the oxygen atoms mixed into the substrate.
Hereinbelow, the preferred embodiments will supplementarily be described.
According to one embodiment, there is provided a substrate processing apparatus including:
a process chamber into which a substrate is carried, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate;
a substrate support unit configured to support and heat the substrate within the process chamber;
a gas supply unit configured to supply either or both of nitrogen atom-containing gas and hydrogen atom-containing gas to an inside of the process chamber;
a gas exhaust unit configured to exhaust the gas from the inside of the process chamber;
a plasma generation unit configured to excite the nitrogen atom-containing gas and the hydrogen atom-containing gas supplied to the inside of the process chamber; and
a control unit configured to control the substrate support unit, the gas supply unit, and the plasma generation unit.
Preferably, the metal nitride film described in the Supplementary Note 1 is a titanium nitride film.
Preferably, the metal nitride film described in the Supplementary Note 1 is a lower electrode of a capacitor.
Preferably, the capacitor described in the Supplementary Note 3 is a high-k film.
Preferably, the plasma generation unit described in the Supplementary Note 1 is provided to generate plasma within the process chamber.
Preferably, the nitrogen atom-containing gas described in the Supplementary Note 1 is any of a nitrogen gas, an ammonia gas, and a monomethylhydrazine gas, and the hydrogen atom-containing gas is any of a hydrogen gas, an ammonia gas, and a monomethylhydrazine gas.
Preferably, a ratio of a nitrogen gas to a hydrogen gas supplied into the process chamber described in the Supplementary Note 1 is in a range of 0 or more and 0.75 or less.
More preferably, the ratio of the nitrogen gas to the hydrogen gas supplied into the process chamber described in the Supplementary Note 1 is in a range of larger than 0 and 0.75 or less.
Preferably, a ratio of the nitrogen gas to a gas containing nitrogen and hydrogen supplied into the process chamber described in the Supplementary Note 1 is in a range of 0 or more and 0.87 or less.
According to another embodiment, there is provided a method of manufacturing a semiconductor device, the method including:
carrying a substrate into a process chamber and supporting the substrate by a substrate support unit, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate;
heating the substrate by the substrate support unit;
supplying nitrogen atom-containing gas and hydrogen atom-containing gas by a gas supply unit to an inside of the process chamber and exhausting the process chamber by a gas exhaust unit; and
exciting the nitrogen atom-containing gas and the hydrogen atom-containing gas supplied into the process chamber by a plasma generation unit.
According to yet another embodiment, there is provided a method of manufacturing a semiconductor device, the method including:
carrying a substrate into a process chamber, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate;
processing the substrate within the process chamber with a reactant gas containing excited nitrogen atoms; and
taking out the substrate from the process chamber.
Preferably, the reactant gas described in the Supplementary Note 11 further contains hydrogen atoms.
Preferably, the metal nitride film described in the Supplementary Note 11 is a titanium-containing film.
Preferably, the reactant gas described in the Supplementary Note 11 is an ammonia gas, or a mixed gas of nitrogen components and ammonia components.
According to yet another embodiment, the reactant gas described in the Supplementary Notes 1 to 14 is diluted with a noble gas.
According to yet another embodiment, there is provided a substrate processing apparatus including:
a process chamber into which a substrate is carried, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate;
a gas supply unit configured to supply a reactant gas to an inside of the process chamber;
a plasma generation unit configured to excite the reactant gas within the process chamber; and
a control unit configured to control the gas supply unit and the plasma generation unit so that the substrate is processed within the process chamber with the reactant gas containing excited nitrogen atoms.
According to yet another embodiment, there is provided a substrate processing apparatus including:
a process chamber into which a substrate is carried, wherein a chlorine atom-containing metal nitride film, in which a natural oxide film is formed on a top side thereof, is formed on the substrate;
a substrate support unit configured to support and heat the substrate within the process chamber;
a gas supply unit configured to supply a nitrogen atom-containing first processing gas and a hydrogen atom-containing second processing gas alternately to an inside of the process chamber;
a gas exhaust unit configured to exhaust the process chamber;
a plasma generation unit configured to excite the first processing gas and the second processing gas supplied into the process chamber; and
a control unit configured to control the substrate support unit, the gas supply unit, the gas exhaust unit, and the plasma generation unit.
According to yet another embodiment, the substrate support unit described in the Supplementary Notes 1 to 17 has a second electrode provided thereon, and a voltage Vpp is applied to the substrate.
According to the substrate processing apparatus and the method of manufacturing a semiconductor device of the embodiment, the residual amounts of the chlorine atoms and the oxygen atoms in the metal nitride film can be reduced in the temperature range that does not deteriorate the property of other films adjacent to the metal nitride film, and the oxidation resistance can be improved while the property of the metal nitride film is improved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-285774 | Dec 2010 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/079908 | 12/22/2011 | WO | 00 | 6/21/2013 |
