JP2020191463A - MANUFACTURING METHOD OF HfN FILM AND HfN FILM - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an HfN film and an HfN film capable of stably supplying a raw material by reacting a raw material gas and a thin film-forming raw material in a reaction chamber and being able to be used for a long period of time. SOLUTION: The shower nozzle 15 is provided to supply vaporized raw material gas via a pipe 14 and inject it onto a film-deposited substrate P arranged to face the surface of the nozzle. The shower nozzle is an HfN film using a film forming apparatus composed of an outer wall 15a that expands around the pipe introduction port 14a, a peripheral wall 15c that rises from the expanded end of the outer wall, and a nozzle surface 15b that covers the end of the peripheral wall. The gas supply port 16 is provided so as to directly supply the reaction gas to the reaction chamber, and the wafer is mounted on the susceptor. The flow rate of the raw material gas TEMAH is 0.2 CCM, the pressure of the reaction chamber is 4 Torr, the temperature of the susceptor is in the range of 250 ° C. or higher and 270 ° C. or lower, and the flow rate of the reaction gas NH3 is 9.0 CCM or higher and 15.0 CCM or lower. The range of. [Selection diagram] FIG. 8

Description

The present invention relates to a method for producing an HfN film and an HfN film.

In recent years, in the field of electronic devices, it has been desired to further reduce the size and performance of electronic devices as well as to increase the density of circuits, and it is desired to reduce the thickness of dielectric materials used for electronic components. There is a CVD method as one method for thinning such a material.
This CVD method has features such as a higher film forming rate than the PVD method, the sol-gel method, and other film forming methods, and easy production of a multilayer thin film. Further, the MOCVD method is a CVD method using a compound containing an organic substance as a raw material, and has advantages such as high safety and no contamination of a halide in the film.

The raw materials used in the MOCVD method are generally solid powders or liquids, and these raw materials are generally placed in a container and heated under reduced pressure to vaporize the raw materials, which are then sent into the film forming chamber by a carrier gas. There is.

FIG. 12 is a schematic explanatory view of a thin film film forming apparatus used in such a MOCVD method.
In FIG. 12, 31 is a vaporizer, 32 is a combustion chamber, 33 is a reaction vessel, 34 is a pipe, and 35 is a substantially conical shower nozzle.

In the vaporizer 1, for example, a mixed raw material obtained by mixing a plurality of types (Ba, Sr, Ti) of liquid raw materials pressurized with He gas at a desired ratio is transported at a constant speed to vaporize the raw material whose flow rate is controlled. To do. The vaporization conditions were a set temperature of 250 ° C. and a vaporization pressure of 2 kPa. The raw material gas vaporized by the vaporizer 1 is mixed with the carrier gas Ar and introduced into the combustion chamber 32 via a pipe heated to 250 to 260 ° C.

The combustion chamber 32 has a structure in which oxygen and a raw material gas are mixed and heated while passing through a thin tube set to a desired temperature. The raw material gas leaving the combustion chamber 32 is introduced into the reaction vessel 33 through the pipe 34 and the shower nozzle 5 heated to 260 to 270 ° C. In the combustion chamber 32, the temperature is set so that at least a part of the organic solvent in the raw material gas burns.

The shower nozzle 35 can mix oxygen with the raw material gas inside the shower nozzle 35, if necessary. The substrate P to be filmed, which forms a dielectric film formed on the shower nozzle 35 so as to face each other at predetermined intervals, is placed on a susceptor 36 made of aluminum nitride and heated by a heater 37. A thermocouple is attached to the susceptor 36, and feedback control based on the thermocouple indicated value and temperature control based on the input power to the heater 37 are possible.

The raw material gas vaporized by the vaporizer 31 is mixed in the combustion chamber 32 and introduced into the reaction vessel 33 through the shower nozzle 35, and a dielectric film is formed on the substrate P to be formed.

In order to form a thin film such as a nitride film, for example, an HfN film, with the above MOCVD apparatus, a film forming method is adopted in which ammonia (NH3) or the like is added as a raw material gas from a vaporization tube upstream of the reaction chamber (reactor). However, there has been a problem that ammonia (NH3), which is a raw material gas, and a thin film-forming raw material do not react well in a reaction vessel serving as a reaction chamber, and a film cannot be formed.

JP 2000-216150 Japanese Patent Application Laid-Open No. 2005-072196

Under such circumstances, the technique for forming an HfN film or the like has not been established at present, and a manufacturing method capable of forming an HfN film or the like as a product and the emergence of an HfN film have been desired.

In the present invention, the raw material gas and the thin film-forming raw material react in a reaction vessel serving as a reaction chamber so that an HfN film can be formed, and a stable raw material can be supplied to the reaction part, and long-term use is possible. It is an object of the present invention to provide a method for producing an HfN film and an HfN film capable of providing an HfN film.

In the method for producing an HfN film according to claim 1 of the present invention, a raw material gas vaporized by a vaporizer is supplied via a pipe, and the raw material gas is supplied to a substrate to be deposited facing the nozzle surface. A shower nozzle for injecting gas is provided, and the shower nozzle is composed of an outer wall that expands around the introduction port of the pipe, a peripheral wall that rises from the expanded end of the outer wall, and a nozzle surface that covers the end of the peripheral wall. In a film forming apparatus, a gas supply port is provided so as to directly supply the reaction gas to the reaction chamber, a wafer is mounted on the susceptor, and the temperature of the susceptor ranges from 250 ° C. or higher to 270 ° C. or lower. The flow rate of the raw material gas TEMAH is 0.2 CCM,
A method for producing an HfN membrane, wherein the pressure of the reaction chamber is 4 Torr and the flow rate of the reaction gas NH ₃ is in the range of 9.0 CCM or more and 15.0 CCM or less.

If the temperature of the susceptor is less than 250 ° C, thermal decomposition does not occur at the time of film formation, which causes a problem that the film quality deteriorates. If the temperature of the susceptor exceeds 270 ° C, the film formation rate decreases. A problem occurs. Further, if the flow rate of the reaction gas NH ₃ is less than 9.0 CCM, the oxygen concentration in the HfN film increases, and the oxygen concentration increases depending on the number of days after the oxygen concentration in the HfN film has elapsed. If the flow rate of the reaction gas NH ₃ exceeds 15.0 CCM, a problem occurs in which the oxygen concentration increases depending on the number of days that the oxygen concentration in the HfN film has elapsed.

The HfN film according to claim 2 of the present invention is characterized in that the N / Hf is in the range of 0.734 or more and 0.757 or less, and the oxygen concentration is 2.5 atomic% or less. Is.

The HfN membrane according to claim 3 of the present invention is the HfN membrane according to claim 2, wherein the oxygen concentration in the membrane has a fluctuation range of 0.01 atomic% or less after 10 days have passed. It is an HfN film.

According to the method for producing an HfN film according to claim 1 of the present invention, it is possible to provide a method for producing an HfN film in which the oxygen concentration in the HfN film is reduced and the increase in the oxygen concentration due to the elapsed days is suppressed.

According to the HfN film according to claims 2 and 3 of the present invention, it is possible to provide an HfN film in which the oxygen concentration in the HfN film is reduced and the increase in the oxygen concentration due to the elapsed days is suppressed.

According to the present invention, the raw material gas and the thin film-forming raw material react in a reaction vessel serving as a reaction chamber so that an HfN film can be formed, and a stable raw material supply to the reaction part is possible. It is possible to provide a method for producing an HfN film and an HfN film that can be used for a long period of time.

In the manufacture of HfN film embodiment, a virtual film formation rate, a diagram of the relationship between the NH ₃ flow rate. The figure of the relationship between the amount of oxygen in the HfN film and the elapsed days in the production of the HfN film of an Example. FIG relationship in the manufacture of HfN film embodiment, the XRF analysis strength, the NH ₃ flow rate. In the manufacture of HfN film embodiment, a virtual film formation rate, a diagram of the relationship between the NH ₃ flow rate. FIG. 5 is a diagram of the relationship between the XRF analysis intensity and the NH ₃ flow rate at a susceptor temperature of 260 ° C. in the production of the HfN film of the example. FIG. 5 is a diagram of the relationship between the amount of oxygen in the HfN film and the number of elapsed days at a susceptor temperature of 260 ° C. in the production of the HfN film of the example. The figure of the relationship between the virtual film formation rate and the susceptor temperature in the production of the HfN film of an Example. The figure of the film forming apparatus of this invention. The figure of the vaporizer of this invention. The figure of the vaporizer of this invention. The figure of the shower head of this invention. Diagram of conventional film deposition equipment

In the method for producing an HfN film according to an embodiment of the present invention, a raw material gas vaporized by a vaporizer is supplied via a pipe and the raw material gas is injected onto a substrate to be deposited which is arranged to face the nozzle surface. The shower nozzle is composed of an outer wall that expands around the introduction port of the pipe, a peripheral wall that rises from the expanded end of the outer wall, and a nozzle surface that covers the end of the peripheral wall. A method for producing an HfN film using a film device, in which a gas supply port is provided so as to directly supply the reaction gas to the reaction chamber, a wafer is mounted on the susceptor, and the flow rate of the raw material gas TEMAH is 0. At 2 CCM, reaction chamber pressure 4 Torr,
A method for producing an HfN film, wherein the temperature of the susceptor is in the range of 250 ° C. or higher and 270 ° C. or lower, and the flow rate of the reaction gas NH ₃ is in the range of 9.0 CCM or higher and 15.0 CCM or lower. ..

The HfN film according to the embodiment of the present invention is an HfN film having an N / Hf in the range of 0.734 or more and 0.757 or less and an oxygen concentration of 2.5 atomic% or less. is there. The HfN membrane is characterized in that the oxygen concentration in the membrane has a fluctuation range of 0.01 atomic% or less after 10 days have passed.

(Example 1)
(Film formation equipment)
FIG. 8 shows a thin film film forming apparatus used in the MOCVD method of this embodiment.
In FIG. 8A, 11 is a vaporizer, 12 is a heater, 13 is a reaction vessel, 14 is a pipe, 15 is a substantially conical shower nozzle, and 16 is a reaction gas directly supplied to the reaction vessel (reaction chamber). The gas supply port 17 for this purpose is a heater.

The shower nozzle 15 can mix oxygen with the raw material gas inside the shower nozzle 15 if necessary. The substrate P to be filmed for forming the dielectric film arranged in the reaction vessel 13 is opposed to the shower nozzle 15 at a predetermined interval. Further, the shower nozzle 15 is integrally provided with a peripheral wall 15c between the outer wall 15a extending from the center thereof and the nozzle surface 15b.

The peripheral wall 15c is for securing the distance between the outer wall 15a and the nozzle surface 15b, and the difference in the flow velocity of the raw material gas between the vicinity of the center and the vicinity of the end of the nozzle surface 15b can be reduced. The height h of the peripheral wall 15c shall be the maximum height of the shower nozzle 15, that is, half or more (h> H / 2) of the height H from the introduction port 14a of the pipe 14 to the center of the nozzle surface 15b. Is preferable.

As a result, when the carrier gas vaporized by the vaporizer 11 is introduced into the reaction vessel 13 through the shower nozzle 15, the difference in flow velocity of the raw material gas between the vicinity of the center and the vicinity of the end of the nozzle surface 15b is alleviated, and the nozzle surface 15b is relaxed. The pressure difference when the gas is introduced into the reaction vessel 13 can be relaxed (indicated by the length of the arrow in the figure), and a substantially uniform dielectric film can be formed on the substrate P to be formed.

By the way, in the above embodiment, the shower nozzle 15 is integrally continuous with the pipe 14, but for example, as shown in FIG. 3B, the shower nozzle 15 is above the tip of the pipe 14. It may be connected.

(Raw material gas, reaction gas)
To prepare a hafnium nitride (HfN) thin film, TEMAH (Hf [NCH3C2H5] 4, tetrakismethylethylaminohafnium) and ECH (epichlorohydrin (C3H5ClO)) are used as raw material solutions.
For the thin film raw materials TEMHA, ECH and ECH, the carrier gas is Ar, N2 or the like.
The reaction gas is, for example, O3, H2 + N2, O2, H2S, CO, N2, etc., in addition to ammonia (NH3).
The reaction gas is diluted with the carrier gas Ar or N2 and supplied.
Adjust the reactive gas (ammonia gas, etc.) and the raw material solution at a ratio that satisfies the stoichiometric ratio of the membrane.
When forming a thin film of aluminum nitride (AlN), hafnium oxide (HfO), and niobium nitride (Nb3N5) in addition to hafnium nitride (HfN), the raw material solution is appropriately changed.

(shower head)
FIG. 11 shows a shower head used in the thin film film forming apparatus according to this example.
The shower head 41 provided in the reaction vessel 13 (reaction chamber) is composed of a shower nozzle 42 and a shower plate 43.
A gas supply port 16 for directly supplying the reaction gas to the reaction vessel 13 (reaction chamber) is provided in the shower head 41.
The shower plate 43 is formed with a flow path for the raw material gas and a flow path for the ammonia gas and the like separately.
This configuration is a means for preventing the raw material gas from mixing with ammonia gas, which is a reaction gas, and upstream of the shower plate before reaching the substrate.
Further, the shower head 41 has a means for cooling the supply passages of the raw material gas and the reaction gas.

(Vaporizer)
8 and 9 show the vaporizer according to this example.
In the vaporizer of this example, the gas passage 2 formed inside the dispersion portion main body 1 constituting the dispersion portion, the gas introduction port 4 for introducing the pressurized carrier gas 3 into the gas passage 2, and the gas. A means (raw material supply hole) 6 for supplying the raw material solution 5 to the carrier gas passing through the passage 2, a gas outlet 7 for sending the carrier gas containing the dispersed raw material solution 5 to the vaporization unit 22, and a gas passage. A dispersion unit 8 having a means (cooling water) 18 for cooling the carrier gas flowing in the 2 and one end connected to the reaction tube of the MOCVD apparatus and the other end connected to the gas outlet 7 of the dispersion unit 8. It has a vaporization tube 20 and a heating means (heater) 21 for heating the vaporization tube 20, and heats and vaporizes the carrier gas in which the raw material solution is dispersed, which is sent from the dispersion unit 8. It has a vaporization unit 22 for the purpose.

(Example 2)
1, in the manufacture of HfN film embodiment, a virtual film formation rate, a diagram of the relationship between the NH ₃ flow rate. The susceptor temperature 400 ℃, 300 ℃, 260 ℃ , 200 ℃, a virtual film formation rate at the conditions 100 ° C., a diagram of the relationship between the NH ₃ flow rate.

From FIG. 1, the following matters were found.
At 260 ° C. or lower, there is almost no thermal decomposition. This is because when the NH ₃ flow rate is 1 CCM or less, the virtual film formation rate is extremely low.
However, even under the condition of 260 ° C. or lower, the HfN film can be formed by the NH ₃ flow rate.
The susceptor temperature 400 ℃, 300 ℃, 260 ℃ , 200 ℃, in any of the conditions of 100 ° C., a large influence of the NH ₃ flow rate.

FIG. 2 is a diagram of the relationship between the amount of oxygen in the HfN film and the number of elapsed days in the production of the HfN film of the example.

From FIG. 2, the following matters were found.
HfN film formed by pyrolysis (400 ° C., at 300 ° C., NH ₃ flow rate of 0 and the conditions), the oxygen content, higher from 0.06 to 0.21 and the numerical at age, oxygen It was found that the amount tended to increase and the film quality was poor.
When the NH ₃ flow rate is 1 CCM, the oxygen content is as high as 0.05 to 0.14, and the film quality is still poor.
The HfN film under the condition that the NH ₃ flow rate is 5 CCM has an oxygen content of 0.04 or less, and the oxygen content does not change even after the number of days in the atmosphere.

3, in the manufacture of HfN film embodiment, the XRF analysis intensity diagrams of the relationship between the NH ₃ flow rate. The susceptor temperature is 300 ° C.
Under the condition that the NH ₃ flow rate is 3CC or less, the XRF analysis intensity (O / Hf, N / Hf, C / Hf)
The value of is changing and the film quality is poor.
On the other hand, under the condition that the NH ₃ flow rate is 5 CC or less, the numerical values of the XRF analysis intensity (O / Hf, N / Hf, C / Hf) are stable and the film quality is good.

4, in the manufacture of HfN film embodiment, in the conditions of susceptor temperature 260 ° C., a virtual film formation rate, a diagram of the relationship between the NH ₃ flow rate.
NH ₃ flow rate is at 9CCM, virtual film forming rate at 0.33, was found to be the maximum. When the NH ₃ flow rate is between 9 CCM and 15 CCM, the film formation rate is a stable condition.

5, in the manufacture of HfN film embodiment, a diagram of the relationship between the susceptor temperature 260 ° C., O / Hf of XRF analysis strength, N / Hf, and C / Hf, the NH ₃ flow rate.
From the characteristic diagrams of O / Hf, N / Hf, and C / Hf, when the NH ₃ flow rate is 5 CCM, the XRF analysis intensity O / Hf is not stable, while the NH ₃ flow rate is 9 CCM and tends to be stable. It is in.

FIG. 6 is a diagram of the relationship between the amount of oxygen (atomic%) in the HfN film at a susceptor temperature of 260 ° C. and the number of elapsed days in the production of the HfN film of the example.
The amount of oxygen in the HfN membrane (atomic%) under the condition that the NH ₃ flow rate is 9 CCM to 15 CCM.
Was found to be stable with respect to the number of days elapsed.
When the NH ₃ flow rate is less than 9 CCM or exceeds 15 CCM, the amount of oxygen (atomic%) in the HfN membrane tends to increase with respect to the number of days elapsed, which is not preferable.

FIG. 7 is a diagram of the relationship between the virtual film formation rate and the susceptor temperature in the production of the HfN film of the example. When the susceptor temperature is from 260 ° C. to 400 ° C., the higher the susceptor temperature, the lower the film formation rate. Further, when the NH ₃ flow rate was 9 CCM and 20 CCM, it was found that the film formation rate decreased as the NH ₃ flow rate increased.

Of a series of data of the, for the preparation of HfN film, deposition temperature, 260 ° C., NH ₃ flow rate is more than 9CCM, 15CCM the following deposition conditions were found to be optimal.
Table 1 shows the measurement results of XPS analysis (atomic%) and N / Hf of Inventions 1, 2, 3, 4, 5, and 6.
Table 2 shows the XPS analysis (atomic%) and N / Hf measurement results of the comparative products 1, 2, 3, 4, 5, 6, 7, and 8.

According to the method for producing an HfN film and the HfN film of the present invention, the raw material gas and the thin film-forming raw material react in a reaction vessel serving as a reaction chamber so that the HfN film can be formed, and are stable to the reaction part. It is possible to provide a method for producing an HfN film and an HfN film that can be supplied with various raw materials and can be used for a long period of time, which contributes to the development of the semiconductor industry.

1 Dispersion body,
2 gas passage,
3 carrier gas,
4 Gas inlet,
5 Raw material solution,
6 Raw material supply hole,
7 gas outlet,
8 Dispersed part,
9a, 9b, 9c, 9d screws,
10 rods,
11 Vaporizer,
12 heater,
13 Reaction vessel,
14 plumbing,
15 shower nozzle,
15a outer wall,
15b Nozzle surface,
15c peripheral wall,
16 Reaction gas supply port,
17 heater,
18 Means for cooling (cooling water),
20 vaporization tube,
21 Heating means (heater),
22 Vaporization Department,
23 Connection,
24 fittings,
25 Oxygen introduction means (oxygen supply port),
29 Raw material supply inlet,
31 Vaporizer,
32 Combustion chamber,
33 Reaction vessel,
34 plumbing,
35 Approximately conical shower nozzle,
36 susceptor,
37 heater,
41 Shower head,
42 shower nozzle,
43 Shower plate,
61 board,
62 thin film,
63 thin film.

In the method for producing an HfN film according to claim 1 of the present invention, a raw material gas vaporized by a vaporizer is supplied via a pipe, and the raw material gas is supplied to a substrate to be deposited facing the nozzle surface. A shower nozzle for injecting gas is provided, and the shower nozzle is composed of an outer wall that expands around the introduction port of the pipe, a peripheral wall that rises from the expanded end of the outer wall, and a nozzle surface that covers the end of the peripheral wall. In a film forming apparatus, a gas supply port is provided so as to directly supply the reaction gas to the reaction chamber, a wafer is mounted on the susceptor, and the temperature of the susceptor ranges from 250 ° C. or higher to 270 ° C. or lower. The flow rate of the raw material gas TEMAH is 0.2 CCM,
The reaction chamber pressure 4 Torr, the reaction gas NH ₃ flow rate is 9.0 CCM or more and 15.0 CCM or less , the HfN membrane has an N / Hf in the range of 0.734 or more and 0.757 or less , and the oxygen concentration is high. , 2.5 atomic% or less , which is a method for producing an HfN film.

HfN film according to claim 2 of the present invention, the HfN film, the oxygen concentration in the film, at age 10 days, according to claim 1, wherein a variation width is less than 0.01 atomic% It is an HfN film.

Claims (3)

It is equipped with a shower nozzle in which the raw material gas vaporized by the vaporizer is supplied via a pipe and the raw material gas is injected onto the substrate to be filmed, which is arranged facing the nozzle surface.
An HfN film using a film forming apparatus that comprises an outer wall that expands the shower nozzle around the introduction port of the pipe, a peripheral wall that rises from the expanded end portion of the outer wall, and a nozzle surface that covers the end portion of the peripheral wall. It is a manufacturing method of
A gas supply port is provided so that the reaction gas is directly supplied to the reaction chamber.
The wafer is mounted on the susceptor,
The flow rate of the raw material gas TEMAH is 0.2 CCM,
At a reaction chamber pressure of 4 Torr
The temperature of the susceptor is in the range of 250 ° C or higher and 270 ° C or lower.
A method for producing an HfN film, wherein the flow rate of the reaction gas NH ₃ is in the range of 9.0 CCM or more and 15.0 CCM or less. N / Hf is in the range of 0.734 or more and 0.757 or less.
An HfN film having an oxygen concentration of 2.5 atomic% or less. The HfN membrane according to claim 2, wherein the oxygen concentration in the membrane has a fluctuation range of 0.01 atomic% or less after 10 days have passed.

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