WO2005024926A1

WO2005024926A1 - Substrate treating device and method of manufacturing semiconductor device

Info

Publication number: WO2005024926A1
Application number: PCT/JP2004/012855
Authority: WO
Inventors: Masayuki Asai; Sadayoshi Horii; Hideharu Itatani; Atsushi Sano; Hidehiro Yanai
Original assignee: Hitachi Kokusai Electric Inc.
Priority date: 2003-09-05
Filing date: 2004-09-03
Publication date: 2005-03-17
Also published as: JPWO2005024926A1; JP4356943B2

Abstract

A substrate treating device capable of improving the reproducibility, inplane uniformity, and composition uniformity of a thin-film formed on a substrate. Valves (34) and (35) are installed in a raw material gas supply tube (5b) supplying a raw material gas to a reaction chamber (100), and a valve (33) is installed in a bypass tube (14a) branched from the raw material gas supply tube (5b). An inert gas supply tube (23) is installed between the valves (34) and (35). A control device (250) controls the valves (33) to (35) as follows. In transition from film formation to the stop of the film formation, the valve (34) is closed and both the valves (33) and (35) are opened to bypass the raw material gas through the bypass tube (14a) and to flow the inert gas through the inert gas supply tube (23) to discharge, from the reaction chamber, residual gas in a dead space on the downstream side of the valve (35) in the raw material gas supply tube (5b). When the film formation is stopped, the valve (35) is closed and both the valves (34) and (33) are opened to flow the inert gas through the inert gas supply tube (23) so as to discharge, together with the raw material gas, residual gas in a dead space on the upstream side of an inert gas supply portion in the raw material gas supply tube (5b) through the bypass tube (14a).

Description

Specification

Substrate processing apparatus and method of manufacturing semiconductor device

Technical field

The present invention relates to a substrate processing apparatus for processing a substrate such as a semiconductor wafer and a method for manufacturing a semiconductor device (semiconductor device).

Background art

[0002] One of semiconductor manufacturing processes includes a CVD (Chemical Vapor D mark osition) process of performing a predetermined film forming process on the surface of a substrate. Here, the substrate refers to a substrate on which a fine electric circuit pattern based on a silicon wafer, glass, or the like is formed. In the CVD process, a substrate is loaded into an airtight reaction chamber, the substrate is heated by a heating means provided in the chamber, and a chemical reaction occurs while introducing a reaction gas onto the substrate, thereby forming a fine electric circuit pattern on the substrate. It forms a thin film uniformly. The CVD apparatus shown in FIG. 13 is configured such that a shower plate 2 and a susceptor 4 are provided in a reaction chamber 1, and a substrate 3 is arranged on the susceptor 4. The reaction gas is supplied through a film forming gas supply pipe 8 connected to the shower plate 2, and is introduced onto the substrate 3 via a shower hole 6 provided in the shower plate 2. A part of the film-forming gas introduced onto the substrate 3 is used for depositing a predetermined CVD thin film by causing a decomposition reaction, an adsorption reaction, or a bonding reaction by thermal energy from the substrate. In addition, residual gas and by-products of the film forming gas are exhausted through the exhaust pipe 7. During the deposition of the CVD thin film, the substrate 3 is heated by the heater 5 provided below the susceptor 4.

[0003] As such a CVD apparatus, there are a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus and an ALD (Atomic Layer D mark osition) apparatus. These devices form a hafnium oxide film (hereinafter abbreviated as HfO) or a hafnium silicate film (hereinafter abbreviated as HfSif) using an organic metal material as a film forming material.

For example, when HfO is deposited, Hf [OC (CH 2)] (tetra-sharov

3 3 4

Traxie hafnium, abbreviated as Hf_〇tBu), Hf [〇C (CH) CH〇CH] (tetrakis (1_methoxy

3 2 2 3 4

2-methyl-2-propoxy) hafnium, abbreviated as Hf-MMP), Hf [〇-Si- (CH 2)], HfCl, etc.

4 3 4 4 Various organic Hf metal raw materials are used. When HfSiO is deposited, Si [OC (CH 2) 2] (tetra-

3 3 4 Sharybutroxy silicon, abbreviated as S〇tBu), Si [〇C (CH) CH〇CH] (tetrakis (1_

3 2 2 3 4

Methoxy-1-methyl-2-propoxy) silicon, abbreviation Si-MMP), Si (〇C H) (abbreviation TEOS)

4 2 5 4

Organic Si metal raw materials such as are used. This organic Si metal raw material is used by being mixed with the above organic Hf metal material.

Many of such organometallic materials are liquid or solid at normal temperature and normal pressure in order to ensure easy transportation and supply. For this reason, most raw materials are heated and raised in vapor pressure to be converted into gas for use.

FIG. 12 is a configuration diagram of a typical conventional MOCVD apparatus. The liquid raw material 9 filled in the film forming raw material container 10 is pushed by an inert gas under pressure from an inert gas inlet 11 and guided to a vaporizer 13 via a liquid supply pipe 12. The liquid raw material is heated by a heater disposed inside the vaporizer 13 and is converted from liquid to gas. In this way, the liquid source 9 becomes a film forming gas, and is guided to the gas supply control pipe 15 through the vaporized gas supply pipe 14.

When a film is formed on a substrate in the gas supply control pipe 15, the film formation gas is guided to the film formation gas supply pipe 8. When the film formation is not performed, or when the film formation is stopped, the film formation gas is led to the bypass pipe 16. Regardless of which route the film forming gas passes through, the film forming gas is guided to the exhaust treatment device 17 via the exhaust pipe 7 and is subjected to the exhaust treatment.

The gas supply control pipe 15 includes a valve 31, a valve 32, and a dilution gas supply pipe 19, as shown in FIG. The valve 31 is provided in a bypass pipe 16 branched from the vaporized gas supply pipe 14. The valve 32 is provided on the film forming gas supply pipe 8 communicating with the vaporized gas supply pipe 14. The dilution gas supply pipe 19 is provided in the film formation gas supply pipe 8 downstream of the valve 32. The gas control pipe 15 controls the opening / closing of the valves 31 and 32 to control whether or not to form a film. The diluent gas is introduced from the diluent gas inlet 20 regardless of whether or not to form a film, and is always supplied to the reaction chamber via the diluent gas supply pipe 19. By constantly supplying a diluting gas to the reaction chamber, pressure fluctuations in the reaction chamber due to opening and closing of the valves 31 and 32 are suppressed, and the deposition gas is diluted to reduce the deposition rate of the thin film Or control the degree.

Disclosure of the invention

Problems to be solved by the invention

Here, the problems of the conventional gas supply control pipe 15 will be described with reference to FIGS.

FIG. 9 shows a state in which the film forming gas is flown into the bypass pipe 16 by using the conventional gas supply control pipe 15, that is, a state in which the film formation is stopped. At this time, the valve 31 is open and the valve 32 is closed. The piping in which the film forming gas exists is indicated by a thick line. Hereinafter, in FIGS. 10 and 11, the pipes indicated by thick lines also indicate that a film forming gas is present. FIG. 10 shows a state in which the film formation is stopped, the state in which the film formation gas is supplied to the film formation gas supply pipe 8 by using the gas supply control pipe 15, that is, the state in which the film formation is started, is shifted. expressed. At this time, the valve 31 is closed and the valve 32 is open, and a film forming gas is introduced into the reaction chamber, and a film is formed.

[0006] FIG. 11 shows a state in which the state is shifted from this state to the state at the moment when the film formation is stopped. At this time, the valve 31 is open and the valve 32 is closed. However, since the film formation gas remains in the dead space 18 in the film formation gas supply pipe 8, the film formation is not stopped. Here, the dead space 18 refers to a portion between the valve 32 in the film forming gas supply pipe 8 and the dilution gas supply point. Therefore, in the gas supply control pipe 15 having the conventional structure, the state of stopping the film formation becomes ambiguous, and it is difficult to stop the film formation immediately and completely. For this reason, conventionally, the deposited film thickness of the thin film fluctuates, and it is difficult to obtain uniformity of the film thickness in the substrate surface. The above-mentioned worrisome events, especially when two-element CVD thin films (HfSiO, AlSi〇, ZrSi〇, HfAlO, etc.) are formed using two types of liquid materials, This is a serious problem because it makes it difficult to obtain uniform composition.

[0007] It is also conceivable to remove the film forming gas remaining in the dead space by evacuating the nozzle after closing the knob. However, since the deposition gas sticks to the wall, the deposition gas cannot be completely removed by the method.

[0008] The present invention solves the conventional problem that it is difficult to purge a deposition gas staying in a dead space, and improves the reproducibility, in-plane uniformity, and composition uniformity of a thin film formed on a substrate. An object of the present invention is to provide a substrate processing apparatus and a semiconductor device manufacturing method which can be improved. It has been the target.

Means for solving the problem

[0009] The first invention is directed to a reaction chamber for processing at least a substrate, a source gas supply unit for supplying a source gas into the reaction chamber, and a source connecting the reaction chamber and the source gas supply unit. A source gas supply line, a bypass line provided to branch off from the source gas supply line, and a source gas, which is exhausted so as to bypass the reaction chamber, and a downstream side of a branch point between the source gas supply line and a bypass line of the source gas supply line. A first valve provided on the bypass line, a second valve provided on the source gas supply line downstream of the first valve, a third valve provided on the bypass line, A substrate processing apparatus comprising: a first inert gas supply line that supplies an inert gas into a raw gas supply line between a first valve and the second valve. .

When a first inert gas supply line for supplying an inert gas is provided in a source gas supply line between the first valve and the second valve, a film forming gas supply line near the first valve ( A dead space) and a film forming gas that is retained in a film forming gas supply line (dead space) near the second vanoleb can be flushed with an inert gas. Therefore, it is possible to effectively purge the deposition gas staying in the dead space.

[0010] In a second aspect, in the first aspect, when processing the substrate in the reaction chamber, the first valve is opened, the second valve is opened, and the third valve is closed. After that, close the first valve, open the second valve, open the third valve, and then open the first valve, close the second valve, open the third valve. A substrate processing apparatus characterized by having control means for controlling the substrate processing.

At the time of substrate processing, when the first valve is opened, the second valve is opened, and the third valve is closed, a source gas is supplied into the reaction chamber to form a film. After the substrate processing, when the first valve is closed, the second valve is opened, and the third valve is opened, the source gas is exhausted from the bypass line so as to bypass the reaction chamber, and the film formation is stopped. At the same time, the deposition gas staying in the dead space near the second valve is flushed into the reaction chamber. Thereafter, when the first valve is opened, the second valve is closed, and the third valve is opened, the deposition gas staying in the dead space near the first valve is exhausted from the bypass line. Therefore, stop film formation The later ambiguous state is eliminated, and the film formation can be stopped immediately.

[0011] In a third aspect based on the second aspect, after the substrate processing, the first valve is closed, the second valve is opened, and the third valve is opened. An operation of opening, closing the second valve, and opening the third valve is a substrate processing apparatus having control means for controlling the operation to be repeated a plurality of times.

After processing the substrate, the first valve is closed, the second valve is opened, and the third valve is opened.The first valve is opened, the second valve is closed, and the third valve is opened. Is repeated several times, the purging effect is enhanced, and even when the source gas remains in the film forming gas supply line, the degree of dilution of the source gas is increased to increase the concentration of the source gas. The force S can be reduced.

[0012] In a fourth aspect based on the second aspect, the source gas supply unit is configured to always supply a constant flow rate of the source gas to the source gas supply line at least during and after the substrate processing. The substrate processing apparatus is characterized in that:

If a constant flow of the source gas is always supplied to the source gas supply line, the source gas can be supplied stably.

[0013] In a fifth aspect based on the fourth aspect, the first inert gas supply line is configured to always supply a constant flow rate of the inert gas at least during the substrate processing and after the substrate processing. The substrate processing apparatus is characterized in that:

By continuously supplying a constant flow of the inert gas, it is possible to prevent the source gas from flowing back to the first inert gas supply line.

[0014] A sixth invention is characterized in that, in the first invention, a second inert gas supply line for supplying an inert gas into a source gas supply line downstream of the second valve is provided. Is a substrate processing apparatus.

When a second inert gas supply line for supplying an inert gas is provided in a source gas supply line downstream of the second valve, the pressure in the reaction chamber is adjusted by adjusting the flow rate of the second inert gas. Variations can be suppressed.

[0015] In a seventh aspect based on the sixth aspect, the supply flow rate of the source gas supplied from the source gas supply unit and the supply flow rate of the inert gas supplied from the first inert gas supply line are different from each other. A substrate processing apparatus characterized in that the supply flow rate of the inert gas supplied to the second inert gas supply line is made variable while being constant.

The supply flow rate of the source gas supplied from the source gas supply unit and the supply flow rate of the inert gas supplied from the first inert gas supply line are fixed, and the inert flow supplied from the second inert gas supply line is maintained. By making the gas supply flow variable, it is possible to adjust the total gas flow introduced into the reaction chamber (total flow of the raw material gas and the inert gas) to be always constant, and to suppress pressure fluctuations in the reaction chamber be able to.

[0016] In an eighth aspect based on the seventh aspect, the total flow rate of the source gas and the inert gas supplied into the reaction chamber is constant before, during, and after the substrate processing. A substrate processing apparatus comprising a control unit for adjusting a supply flow rate of an inert gas flowing from a second inert gas supply line.

Supply of the inert gas flowing from the second inert gas supply line so that the total flow rate of the source gas and the inert gas supplied into the reaction chamber becomes constant before, during, and after the substrate processing. Since the flow rate is adjusted, pressure fluctuations in the reaction chamber can be suppressed before, during, and after substrate processing.

[0017] In a ninth aspect based on the eighth aspect, before processing the substrate in the reaction chamber, the first valve is opened, the second valve is closed, the third valve is opened, and the substrate is removed. When processing, the first valve is opened, the second valve is opened, and the third valve is closed. After the substrate is processed, the first valve is closed, the second valve is opened, and the third valve is opened. A substrate processing apparatus characterized by having control means for controlling a valve to be opened, a first valve to be opened, a second valve to be closed, and a third valve to be opened thereafter.

By controlling each valve as in the present invention, it is possible to remove the film-forming gas staying in the dead space near the first valve and near the second valve, and before, during, and after the substrate processing. After that, pressure fluctuation in the reaction chamber can be suppressed.

[0018] In a tenth aspect based on the first aspect, a power for connecting at least two source gas supply units for supplying at least two types of source gas to the source gas supply line, at least A substrate processing apparatus characterized in that at least one raw material supply unit that supplies a mixed gas of two types of raw materials is connected. In the case of forming a multi-element thin film for supplying two types of source gases as described above, the present invention is particularly concerned with the fact that the lighter the source material, the more the source material adheres to the center of the substrate, the more likely it is for the phenomenon to occur. According to the method, any type of residual gas remaining in the dead space can be effectively purged, so that such a phenomenon can be effectively prevented, and the composition uniformity in the substrate surface can be improved. .

[0019] In an eleventh aspect, at least a step of loading a substrate having a size of at least one substrate into the reaction chamber, and supplying a source gas into the reaction chamber from a source gas supply unit through a source gas supply line and transporting the source gas into the reaction chamber. A step of processing the substrate, a step of exhausting the source gas from the bypass line provided to branch off from the source gas supply line before or after the substrate processing so as to bypass the reaction chamber, and a step of processing the substrate. Discharging the source gas from the bypass line after the substrate processing, wherein the step of discharging the source gas from the bypass line after the substrate processing is performed on a downstream side of a branch point of the source gas supply line with the bypass line. The first valve is closed, the second valve provided downstream of the first valve of the source gas supply line is opened, and the third valve provided in the bypass line is opened. And in a state, a method of manufacturing a semiconductor device comprising a call including a first valve and a step of supplying a raw material gas supply line in the inert gas between the second valve.

In the step of exhausting the source gas from the bypass line after the substrate processing, the first valve is closed, the second valve is opened, and the third valve is opened. Since the inert gas is supplied into the source gas supply line between the second valve and the source valve, the source gas is exhausted from the bypass line and the source gas remaining in the source gas supply line downstream of the second valve is purged. be able to.

[0020] In a twelfth aspect based on the eleventh aspect, the step of exhausting the source gas from the bypass line after the substrate processing further comprises opening the first valve, closing the second valve, and closing the third valve. A step of supplying an inert gas into a source gas supply line between the first valve and the second valve while the other valve is open. .

In the step of exhausting the source gas from the bypass line after the substrate processing, the first valve is opened, the second valve is closed, and the third valve is opened. Since the inert gas is supplied into the source gas supply line between the first valve and the inert gas supply point, the source gas is exhausted from the bypass line and stays in the source gas supply line between the first valve and the inert gas supply point. Source gas can be purged.

[0021] In a thirteenth aspect based on the eleventh aspect, the step of exhausting the source gas from the bypass line after the substrate processing is performed by closing the first valve, opening the second valve, and removing the third valve. A step of supplying an inert gas into the source gas supply line between the first valve and the second valve while the valve is open; and opening the first valve and closing the second valve. The step of supplying an inert gas into the source gas supply line between the first valve and the second valve while the third valve is open is repeated a plurality of times. This is a method of manufacturing a semiconductor device.

[0022] In a fourteenth aspect based on the eleventh aspect, the step of exhausting the source gas from the bypass line after the substrate processing includes closing the first valve, opening the second valve, and removing the third valve. A step of supplying an inert gas into the source gas supply line between the first valve and the second valve while the valve is open, so that the inert gas flows toward the second valve; With the first valve open, the second valve closed, and the third valve open, an inert gas is introduced into the source gas supply line between the first valve and the second valve. Supplying a gas to allow the inert gas to flow toward the first valve side.

In the step of causing the inert gas to flow toward the second valve, the source gas retained in the source gas supply line downstream of the second valve can be purged. Further, in the step of causing the inert gas to flow toward the first valve, the source gas remaining in the source gas supply line between the first valve and the inert gas supply point is purged. it can. Therefore, the source gas retained in the source gas supply line is effectively purged. S power

According to a fifteenth invention, in the twelfth invention, at least the step of processing the substrate and the step of exhausting the source gas from the bypass line before or after the substrate processing are always performed at a constant flow rate from the source gas supply unit. A method for manufacturing a semiconductor device, comprising continuously supplying a source gas to a source gas supply line.

[0024] In a sixteenth aspect based on the fifteenth aspect, at least the step of processing the substrate and the step of exhausting the source gas from the bypass line before or after the substrate processing are performed by the first valve and the second valve. A method for manufacturing a semiconductor device, characterized in that a constant flow of an inert gas is continuously supplied into a source gas supply line between the semiconductor device and the valve.

[0025] In a seventeenth aspect based on the twelfth aspect, in the step of exhausting the source gas from the bypass line before the substrate processing, the first valve is opened, the second valve is closed, and the third valve is closed. A method of manufacturing a semiconductor device, comprising: a step of supplying an inert gas into a source gas supply line between a first valve and a second valve while the valve is open. Even before the substrate processing, the first valve is opened, the second valve is closed, and the third valve is opened in the step of exhausting the source gas from the no-pass line. Since the inert gas is supplied into the source gas supply line between the first valve and the second valve, the source gas between the first valve and the inert gas supply point is discharged while exhausting the source gas from the nozzle line. The source gas retained in the gas supply line can be purged.

According to an eighteenth aspect based on the seventeenth aspect, before the substrate processing, during the substrate processing, and after the substrate processing, the supply flow rate of the source gas supplied from the source gas supply unit, the first valve and the The supply flow rate of the inert gas supplied into the source gas supply line between the second valve and the second valve is always kept constant, and the total flow rate of the source gas and the inert gas supplied into the reaction chamber is always kept constant. 2. A method for manufacturing a semiconductor device, characterized in that an inert gas is supplied into a source gas supply line downstream of a second valve, and the supply flow rate is adjusted. Supply of the inert gas flowing from the second inert gas supply line so that the total flow rate of the source gas and the inert gas supplied into the reaction chamber becomes constant before, during, and after the substrate processing. Since the flow rate is adjusted, pressure fluctuations in the reaction chamber can be suppressed before, during, and after substrate processing.

[0027] In a nineteenth aspect based on the twelfth aspect, the raw material gas supplied into the reaction chamber via the raw material gas supply line includes at least two types of raw material gas or a mixed gas of at least two types of raw material gas. A method for manufacturing a semiconductor device, comprising:

In the case of forming a multi-element thin film for supplying two types of source gases as described above, the present invention is particularly concerned with the fact that the lighter the source material, the more the source material adheres to the center of the substrate, the more likely it is for the phenomenon to occur. According to the method, any type of residual gas remaining in the dead space can be effectively purged, so that such a phenomenon can be effectively prevented, and the composition uniformity in the substrate surface can be improved. .

The invention's effect

According to the present invention, it is possible to effectively purge a film formation gas staying in a dead space by flushing it with an inert gas. For this reason, the variation in the deposited film thickness of the thin film can be suppressed, and the reproducibility of the thin film formed on the substrate and the uniformity of the film thickness and composition in the substrate surface can be improved. Since there is no dead space where the deposition gas stays, it is possible to suppress the generation of particles due to the self-decomposition of the deposition gas.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the HfO film, which is particularly an amorphous HfO film, is formed by using the CVD method, more specifically, the MOCVD method.

2

(Hereinafter simply abbreviated as HfO film)

2

Will be explained.

FIG. 1 is a schematic diagram showing an example of a single-wafer MOCVD apparatus in which a remote plasma unit as a substrate processing apparatus according to an embodiment is incorporated. Single wafer MOCVD equipment is configured to process at least one substrate.

As shown in the figure, a hollow heater unit 180 is provided in the reaction chamber 100. The heater unit 180 has an upper opening covered by a susceptor 200 as a substrate holding means. . Inside the heater unit 180, a heater 300 power S is provided as a calorie heating means. The substrate 400 mounted on the susceptor 200 can be heated by the heater 300. The heater 300 is controlled by the temperature control means 51 so that the temperature of the substrate 400 becomes a predetermined temperature. The substrate 400 mounted on the susceptor 200 is, for example, a semiconductor silicon wafer, a glass substrate, or the like.

A substrate rotation unit 120 as a rotation unit is provided outside the reaction chamber 100. The heater unit 180 in the reaction chamber 100 is rotated by the substrate rotating unit 120 so that the substrate 400 on the susceptor 200 can be rotated. The reason why the substrate 400 is rotated is that processing on the substrate in a film forming step and a reforming step, which will be described later, is quickly and uniformly performed on the substrate surface. The substrate rotation unit 120 is controlled by the drive control means 54.

Further, a shower head 600 having a large number of holes 800 is provided above the susceptor 200 in the reaction chamber 100. A raw material supply pipe 500 for supplying a film forming gas and a radical supply pipe 130 for supplying radicals are commonly connected to the shower head 600, so that the film forming gas or radicals are supplied to the shower head 600 in a shower-like reaction chamber. It can squirt into 100. Here, the shower head 600 constitutes the same supply port for supplying a film formation gas supplied to the substrate 400 in the film formation step and a radical supplied to the substrate 400 in the modification step.

A raw material supply unit 900 for supplying an organic liquid raw material as a film forming raw material to the outside of the reaction chamber 100, a liquid flow control device 280 as flow control means for controlling a liquid supply flow rate of the film forming raw material, A vaporizer 290 for vaporizing the film raw material is provided. Further, an inert gas supply unit 10a for supplying an inert gas as a diluting gas, mass flow controllers 460a and 460b as flow control means for controlling a supply flow rate of the inert gas, and a force S are provided. The mass flow controllers 460a and 460b are provided in the first inert gas supply pipe 23 and the second inert gas supply pipe 24 connected to the inert gas supply unit 10a, respectively. Hf— (MMP) or the like is used as the organic liquid raw material. In addition, Ar,

Four

He, N, etc. are used.

2

[0034] The raw material gas supply pipe 5b provided in the raw material supply unit 900, the first inert gas supply pipe 23 provided in the inert gas supply unit 10a, and the second inert gas supply pipe 24 are provided. A single raw material supply pipe 500 connected to the shower head 600 is provided. The raw material supply pipe 500 is formed in the shower head 600 in a film forming process for forming an Hf〇 film on the substrate 400.

2

A mixed gas of a film gas and an inert gas is supplied. The source gas supply pipe 5b and the inert gas supply pipes 23 and 24 are both connected to a gas supply control pipe 36. The gas supply control pipe 36 has a function of controlling whether or not to form a film, and will be described in detail later. The first valve 34, the second knob 35, and the third knob 35 33, a first inert gas supply pipe 23, a second inert gas supply pipe 24, and a source gas bypass pipe 14a. The supply of the mixed gas of the film forming gas and the inert gas can be controlled by the gas supply control pipe 36.

The source gas supply line is composed of the source gas supply pipe 5b and the source gas supply pipe 500 described above. Further, the first inert gas supply line 23 and the second inert gas supply line 24 constitute a first inert gas supply line and a second inert gas supply line, respectively.

Further, a reactant activating unit (remote plasma unit) 110 serving as a plasma source for activating a gas by plasma to form radicals as a reactant is provided outside the reaction chamber 100. Radicals used in the reforming step described below are used as raw materials such as Hf— (MMP).

4 When an organic material is used, for example, an oxygen radical is preferable. This is because oxygen radicals can efficiently remove impurities such as C and H immediately after HfO film formation.

2

Power. The radical used in the self-cleaning step described later is preferably a C1F radical. In the reforming process, oxygen-containing gas (O, N〇, NO, etc.) is separated by plasma.

twenty two

In the dissolved oxygen radical atmosphere, the process of oxidizing the film is referred to as remote plasma oxidation (RPO).

[0036] A gas supply pipe 370 is provided upstream of the reactant activation unit 110. The gas supply pipe 370 has an oxygen supply unit 470 for supplying oxygen (O 2), and a plasma is generated.

2

Ar supply unit 480 for supplying gaseous argon (Ar) and chlorine fluoride (C1F)

3 Supply C1F supply units 490 are connected via supply pipes 520, 530, and 540, respectively.

Three

It is. Oxygen supply unit 470, Ar supply unit 480, C1F supply unit 490

Three

Between Ar used in the quality process and Ar and C1F used in the self-cleaning process

twenty three It is supplied to the product activation unit 110. Supply pipes 520, 530, 540 connected to oxygen supply unit 470, Ar supply unit 480, and C1F supply unit 490

Three

Are provided with mass flow controllers 550, 560, and 570 as flow control means for controlling the supply flow rates of the respective gases. Supply pipes 520, 530, and 540 are provided with vanolebs 580, 590, and 600, respectively, and by opening and closing these vanolebs 580, 590, and 600, O

It is possible to control the supply of 2 gas, Ar gas and C1F.

Three

A radial supply pipe 130 connected to the shower head 600 is provided downstream of the reactant activation unit 110, and oxygen (O 2) is supplied to the shower head 600 in the reforming step or the self-cleaning step. To supply radicals or chlorine fluoride (C1F) radicals

twenty three

Yes. Further, a valve 240 is provided in the radical supply pipe 130, and the supply of radicals can be controlled by opening and closing the valve 240.

[0038] An exhaust port 7a is provided in the reaction chamber 100, and an exhaust pipe 700 is connected to the exhaust port 7a. The exhaust pipe 700 is provided with a pressure regulator 61 for controlling the pressure in the reaction chamber 100 and a material recovery trap 160 for recovering a film forming material. This raw material recovery trap 160 is used commonly for the film forming step, the reforming step, and the self-cleaning step. The exhaust pipe 700 is further provided with a vacuum pump 62 and an abatement device 63 as an exhaust device. The exhaust port 7a and the exhaust pipe 700 constitute an exhaust line.

A source gas bypass pipe 14 a and a radical bypass pipe 14 b connected to a source recovery trap 160 provided in the exhaust pipe 700 are respectively branched and connected to the source gas supply pipe 5 b and the radical supply pipe 130. The valve 33 described above is provided on the raw material gas bypass pipe 14a, and the valve 230 is provided on the radical bypass pipe 14b. When the film forming gas is supplied to the substrate 400 in the reaction chamber 100 in the film forming step by opening and closing the valves 33 and 230, the radicals used in the reforming step are supplied to the reaction chamber 100 without stopping the supply. The gas is exhausted through the radial bypass pipe 14b and the raw material recovery trap 160 so as to bypass the air. Also, when supplying radicals to the substrate 400 in the reforming step, the source gas bypass pipe 14a and the source recovery trajectory are used to bypass the reaction chamber 100 without stopping the supply of the film forming gas used in the film forming step. Exhaust through top 160.

Note that the bypass line is connected to the above-described raw material gas bypass pipe 14a and the radical bypass pipe 14b. Is configured.

[0040] The single-wafer MOCVD apparatus is provided with a control device 250. The control device 250 includes a film forming step for forming an Hf〇 film on the substrate 400 in the reaction chamber 100, and removing impurities such as C and H which are specific elements in the Hf〇 film formed in the film forming step. The reforming step of removing by plasma treatment using the reactant activation unit 110 is controlled so as to be continuously repeated a plurality of times. This control controls the opening and closing of the valves 33, 34, 35 provided in the gas supply control pipe 36, the valve 230 provided in the radial bypass pipe 14b, and the valve 240 provided in the radical supply pipe 130. It is done by doing.

In the control device 250, the temperature control means 51 for controlling the heater 300, the liquid flow control device 280, the flow control means 52 for controlling the mass flow controllers 460a, 460b, 550, 560 and 570, and the control of the pressure regulator 61 And a drive control unit 54 for controlling the substrate rotation unit 120.

Next, a procedure for depositing a high-quality HfO film using the single-wafer CVD apparatus configured as shown in FIG. 1 will be described. This procedure includes a temperature raising step, a film forming step, a purging step, and a reforming step.

First, at least one substrate 400 is carried into the reaction chamber 100 shown in FIG. 1, and the substrate 400 is placed on the susceptor 200 in the reaction chamber 100. While rotating the substrate 400 by the substrate rotation unit 120, power is supplied to the heater 300 to raise the temperature of the substrate 400 to 350-500. Heat uniformly to C (heating step). The substrate temperature varies depending on the reactivity of the organic material used. For Hf- (MMP), the temperature is preferably in the range of 390-450 ° C. In addition, when transporting the substrate 400 or heating the substrate, if an inert gas such as Ar, He, or N is constantly flowed into the reaction chamber 100 from the inert gas supply pipes 23 and 24, particles and metal contamination may occur. An object can be prevented from adhering to the substrate 400.

After the completion of the temperature raising step, a film forming step is started. In the film forming process, the flow rate of the organic liquid raw material, for example, Hf- (MMP), supplied from the raw material supply unit 900 is controlled by the liquid flow controller 280.

, And supplied to a vaporizer 290 to be vaporized. By opening the valves 34 and 35 provided on the source gas supply pipe 5b, the vaporized source gas is supplied onto the substrate 400 via the shower head 600. Also at this time, the inert gas supply unit 10a connects the inert gas An inert gas (such as N) is always flowed into the reaction chamber 100 to agitate the deposition gas.

. When the film forming gas is diluted with an inert gas, stirring becomes easier. The film forming gas supplied from the source gas supply pipe 5b and the inert gas supplied from the inert gas supply pipes 23 and 24 are mixed by the gas supply control pipe 36, and the mixed gas is showered from the source supply pipe 500 through the gas supply control pipe 36. It is guided to the head 600 and supplied through a large number of holes 800 onto the substrate 400 on the susceptor 200 in the form of a shower. At this time, gas containing oxygen atoms such as O is not supplied, and only Hf— (MMP) gas is supplied as the reactive gas.

By performing the supply of the mixed gas for a predetermined time, an interface layer with the substrate is formed on the substrate 400.

A 0.5 A 30 A, for example, 15 A, HfO film is formed as the (first insulating layer). During this time, the substrate 400 is kept at a predetermined temperature (film formation temperature) by the heater 300 while rotating, so that a uniform film can be formed in the surface of the substrate. Next, the supply of the source gas to the substrate 400 is stopped by closing the valve 34 or the valve 35 provided on the source gas supply pipe 5b. At this time, the valve 33 provided in the source gas bypass pipe 14a is opened, and the supply of the deposition gas is exhausted by bypassing the reaction chamber 100 by the source gas bypass pipe 14a, and the deposition gas supplied from the source supply unit 900 is discharged. Do not stop the supply of water. Since it takes a long time to vaporize the liquid raw material and stably supply the vaporized raw material gas, if the flow of the reaction chamber 100 is bypassed without stopping the supply of the film forming gas, In the film forming process, the film forming gas can be supplied to the substrate 400 immediately by simply switching the flow.

After the completion of the film forming step, a purging step is started. In the purge step, the inside of the reaction chamber 100 is purged with an inert gas to remove residual gas. In the film forming process, since the inert gas (N or the like) is constantly flowing from the inert gas supply unit 10a into the reaction chamber 100, the valve 34 or 35 is closed to supply the source gas to the substrate 400. Is stopped and purge is performed at the same time.

After the purging step, the reforming step is started. The reforming process is performed by RPO (remote plasma oxidation) treatment. Here, the RPO treatment is a remote plasma oxidation treatment that oxidizes the film using oxygen radicals as reactants generated by activating the oxygen-containing gas (〇, N〇, NO, etc.) with plasma. It is. In the reforming process, open the vanoleb 590 provided in the supply pipe 530, and supply the Ar supply unit 480 with Ar, which also supplied 480 power, to the mass flow controller 560. Then, the flow rate is controlled to supply the reactant activation unit 110 to generate Ar plasma. After the Ar plasma is generated, the valve 580 provided in the supply pipe 520 is opened, and the amount supplied from the oxygen supply unit 470 is controlled by the mass flow controller 550 to the reactant activation unit 110 which is generating the Ar plasma. Supply and activate o. This produces oxygen radicals. The valve 240 provided on the radical supply pipe 130 is opened, and a gas containing oxygen radicals is supplied from the reactant activation unit 110 onto the substrate 400 via the shower head 600. During this time, the substrate 400 is kept at a predetermined temperature (the same temperature as the film formation temperature) by the heater 300 while rotating, so that the C, H And other impurities can be quickly and uniformly removed.

Thereafter, the valve 240 provided on the radical supply pipe 130 is closed to stop the supply of oxygen radicals to the substrate 400. At this time, by opening the valve 230 provided in the radical bypass pipe 14b, the supply of gas containing oxygen radicals is exhausted by bypassing the reaction chamber 100 by the radical bypass pipe 14b, and the supply of oxygen radicals is not stopped. To do. Oxygen radicals require a certain amount of time S from generation to stable supply, so if the oxygen radicals are not stopped and flowed so as to bypass the reaction chamber 100, the flow will be reduced in the next reforming step. By simply switching, radicals can be supplied to the substrate 400 immediately.

[0048] After the reforming step, the purge step is started again. In the purge step, the inside of the reaction chamber 100 is purged with an inert gas to remove residual gas. In the reforming process, since the inert gas (N or the like) always flows from the inert gas supply unit 10a into the reaction chamber 100, the supply of the oxygen radical to the substrate 400 is stopped and the purge is performed at the same time. Will be done.

After the purging step is completed, the film forming step is started again, the valve 33 provided in the source gas bypass pipe 14a is closed, and the valves 34 and 35 provided in the source gas supply pipe 5b are opened, thereby forming the film forming gas. Is supplied onto the substrate 400 via the shower head 600, and a 15A Hf 15 film is deposited on the thin film formed in the previous film forming step.

[0050] As described above, the cycle process of repeating the film formation process → the purge process → the reforming process → the purge process a plurality of times enables the formation of a thin film having a predetermined film thickness with extremely little CH and ΔH contamination. it can. The processed substrate 400 is carried out of the reaction chamber 100.

Here, preferable film forming conditions when Hf— (MMP) is used are as follows. temperature The range is 400-450 ° C, and the pressure range is less than about 100Pa. As for the temperature, when the temperature is lower than 400 ° C., the amount of impurities (C, H) taken into the film increases rapidly. At 400 ° C. or higher, impurities are easily released, and the amount of impurities taken into the film decreases. Further, when the temperature is higher than 450 ° C, the step coverage becomes worse. When the temperature is 450 ° C or less, good step coverage can be obtained and the amorphous state can be maintained.

When the pressure is set to a high pressure of, for example, 1 Torr (133 Pa) or more, the gas becomes a viscous flow, so that the gas does not enter the depth of the pattern groove. However, by setting the pressure to less than about lOOPa, a molecular flow without flow can be obtained, and the gas reaches the depth of the pattern groove.

[0053] In addition, the RPO (reforming process) which is a reforming process performed continuously to the film forming process using Hf— (MMP)

Four

Preferred conditions for the remote plasma oxidation treatment are a temperature range of about 390-450 ° C (approximately the same as the film formation temperature), and a pressure range of about 100-100OOOPa. The O flow rate for radicals is 100 sccm, and the inert gas Ar flow rate is lslm.

2

It is preferable that the film forming step and the reforming step are performed at substantially the same temperature. That is, it is preferable that the set temperature of the heater be kept constant without being changed. This is because, by not causing temperature fluctuations, particles are generated due to thermal expansion of peripheral members such as the shower head and the susceptor, and it is possible to suppress the projection of metal from metal parts (metal contamination). is there.

In order to perform the self-cleaning step of the accumulated film adhering to the reaction chamber, the reactant activation unit 110 converts the cleaning gas (C1 or C1F) into a radical to form the reaction chamber 100

twenty three

To be introduced. That is, the valve 590 provided on the supply pipe 530 is opened, and the Ar supply unit 480 supplies the supplied Ar to the reactant activation unit 110 by controlling the flow rate by the mass flow controller 560 to generate Ar plasma. After generating the Ar plasma, open the vanoleb 600 provided in the supply pipe 540, and use the 490 C1F supply unit to supply the supplied C1F to the mass flow controller.

3 3

The flow rate is controlled by the roller 570 and supplied to the reactant activation unit 110 which generates Ar plasma to activate C1F. This produces C1F radicals. Radical supply

3 3

Open the valve 240 provided in the pipe 130, and supply the C1F radical from the reactant activation unit 110.

Three

Is supplied onto the substrate 400 through the shower head 600. This self-cleaning In the reaction chamber 100, the cleaning gas reacts with the accumulated film in the reaction chamber 100, and the accumulated film is converted into a metal chloride or the like and volatilized, and the gas is exhausted. Thereby, the accumulated film in the reaction chamber is removed.

According to the above-described embodiment, since the cycle process of repeating the HfO film formation → reforming process (RP〇 process) → HfO film formation →... Is repeated a plurality of times, mixing of CH and OH is prevented. It is possible to form an Hf〇 film having a very small thickness and a predetermined thickness.

Incidentally, a film formation gas is introduced into the reaction chamber 100 to form a film. To stop the film formation, the film formation gas remaining in the dead space of the source gas supply pipe 5b is sufficiently purged. What has to be done is as described above. In the present embodiment, the film formation gas staying in the dead space is effectively purged by controlling the gas supply control pipe 36.

Hereinafter, the configuration and operation of the gas supply control pipe 36 in the present embodiment will be described in detail. The features of the gas supply control pipe 36 of the present invention are as follows. That is, first, one dilution gas supply pipe and one valve are added to the conventional gas supply control pipe 15. That is, the number of connecting points of the dilution gas pipe and the valve connected to the vaporized gas supply pipe is arranged in two or more straight lines on one supply path to the shower plate.

Specifically, as shown in FIG. 2, the gas supply control pipe 36 has a vaporized gas supply pipe 14, a film formation gas supply pipe 8, and a bypass pipe 16. In the drawing, the vaporized gas supply pipe 14 and the film forming gas supply pipe 8 which are connected in an inverted L-shape correspond to the source gas supply pipe 5b shown in FIG. 1, and supply the source gas into the reaction chamber 100. A source gas supply line to be used. The bypass pipe 16 corresponds to the source gas bypass pipe 14a shown in FIG. 1 and is provided so as to branch off from a connection point between the vaporized gas supply pipe 14 and the film formation gas supply pipe 8, so that the raw material bypasses the reaction chamber 100. Construct a bypass line to exhaust gas.

A first valve 34 is provided downstream of the branch point of the film forming gas supply pipe 8 from the bypass pipe 16, and is provided downstream of the film forming gas supply pipe 8 downstream of the first valve 34. Is provided with a second valve 35 force S. A third valve 33 is provided in the bypass pipe 16. Each of these valves 33-35 uses a two-way valve.

The first dilution gas supply line for supplying the first dilution gas is connected to the film formation gas supply line 8. A pipe 27 and a second dilution gas supply pipe 28 for supplying a second dilution gas are provided. The first dilution gas supply pipe 27 corresponds to the first inert gas supply pipe 23 shown in FIG. 1, and the first dilution gas supply pipe 27 is provided in the source gas supply line between the first valve 34 and the second valve 35. A first inert gas supply line for supplying the inert gas is constituted. The second dilution gas supply pipe 28 corresponds to the second inert gas supply pipe 24 shown in FIG. 1, and supplies the second inert gas into the source gas supply line downstream of the second valve 35. A second inert gas supply line.

The first dilution gas supply pipe 27 and the second dilution gas supply pipe 28 have a first dilution gas inlet 25 for introducing a dilution gas as an inert gas and a second dilution gas introduction 26, respectively. Provided.

[0062] The role of the first and second inert gas supply lines is as follows. The first inert gas supply line 27 has a role of purging a first dead space 21 of a film formation gas supply line 8 described later (film formation stopped state). Further, it has a role of purging a second dead space 21 of a film formation gas supply line 8 described later (film formation stop transition state). In the second inert gas supply line 28, the flow rate of the second inert gas is adjusted so that the total flow rate of the gas introduced into the reaction chamber (total flow rate of the source gas and the dilution gas) is always constant. It has a role in suppressing pressure fluctuations.

An example of a method (process) for stopping film formation is described below with reference to FIGS. In the present invention, the gas supply control pipe 36 is in a state where film formation is stopped → a state during film formation → a state where film formation is stopped → a state where film formation is stopped → a state during film formation → a state where film formation is stopped. → ······ Change. The operation of the gas supply control pipe 36 for each of the above-described states will be described after the substrate 400 has been installed and heated in the reaction chamber 100 in advance. In the illustration, the vaporizer 290 is always supplied with the film forming gas, and the first diluent gas inlet 25 and the second diluent gas inlet 2

It is assumed that the diluent gas (Ar, N, 〇, etc., gas that does not have a film forming function alone) is always supplied to 6, respectively. The flow rates of the film forming gas and the dilution gas may be controlled by a flow control device or the like.

Here, the reason why the film formation gas is always supplied from the vaporizer 290 is as follows. If the raw material is vaporized in the vaporizer, not vaporized, or if the vaporization is stopped, the heat of vaporization May or may not be taken away, and the temperature of the vaporizer may become unstable. Then, it takes time from the start of raw material vaporization to the stable supply of raw material gas. Therefore, in order to constantly stabilize the temperature of the vaporizer and stably supply the raw material gas, the vaporizer power and the raw material gas are continuously supplied without stopping the vaporization.

[0065] The reason why the diluent gas is always supplied to the diluent gas supply line is as follows. When the supply of the diluent gas from the diluent gas supply line is stopped, it is conceivable that the source gas and the like will flow back to the diluent gas supply line. To prevent this, the dilution gas is always supplied to the dilution line.

[0066] (State of film formation stop)

Fig. 3 shows the state in which film formation is stopped. In this state, both the valve 33 and the valve 34 are opened and the valve 35 is closed. 3 indicates that the film forming gas supplied from the vaporizer 290 flows in the bold line pipes, that is, in the vaporized gas supply pipe 14 and the bypass pipe 16. Further, the first diluent gas passes through the first dead space 21, the valve 34, the valve 33, and the bypass pipe 16 in the film forming gas supply pipe 8 and is combined with the film forming gas as indicated by an arrow. To the exhaust treatment device. Here, the first dead space 21 refers to a portion between the first valve 34 in the film forming gas supply pipe 8 and the first dilution gas supply point. Further, a second dead space 22, which will be described later, refers to a portion between the second valve 35 in the film forming gas supply pipe 8 and a second dilution gas supply point.

Thus, the film forming gas staying in the first dead space 21 and the valve 34 can be purged by flushing with the diluent gas.

In the state where the film formation is stopped, the backflow of the dilution gas (the film formation) occurs between the first dilution gas supply point in the film formation gas supply pipe 8 and the connection point between the vaporization gas supply pipe 14 and the film formation gas supply pipe 8. Flow in the opposite direction to time). Since the bypass pipe 16 is directly connected to the vacuum pump 62, simply switching the valves 33, 34, and 35 allows the first dilution gas supply point in the deposition gas supply pipe 8, the vaporized gas supply pipe 14, and the A backflow due to the dilution gas can be quickly generated between the gas supply pipe 8 and the connection point.

The state in which the film formation is stopped is a state before the start of film formation on the substrate 400, and is a process necessary for stabilizing the flow rate of the film formation gas. The state shifts from this state to the state at the time of film formation. (State at the time of film formation)

Figure 4 shows the state during film formation. In this state, the valve 33 is closed, and both the valve 34 and the valve 35 are open. In the same manner as described above, the bold gas pipes, that is, the vaporized gas supply pipe 14 and the film formation gas supply pipe 8 indicate that the film formation gas is flowing. Therefore, a film forming gas is introduced into the reaction chamber 100, and a film forming process is performed on the substrate 400. At this time, the first and second dilution gases are also supplied into the film forming gas supply pipe 8. After maintaining this state for a predetermined time, the state shifts to the next film formation stop transition state.

(Transition stop state)

Fig. 5 shows the state of the film formation stop transition. In this state, both the valve 33 and the valve 35 are opened and the valve 34 is closed. Similarly to the above, it is shown that the film forming gas flows in the thick line pipe, that is, the vaporized gas supply pipe 14 and the bypass pipe 16, but in the first dead space 21 in the film formation gas supply pipe 8, This indicates that the membrane gas has accumulated. In this state, the film formation gas staying in the first dead space 21 is supplied to the reaction chamber 100 by a diffusion phenomenon, so that the film formation on the substrate 400 is not completely stopped. Further, in this state, the film forming gas existing in the second dead space 22 is swept away by the first diluent gas and the force S capable of purging, and the film forming gas existing in the first dead space 21 is swept away. Have difficulty. However, by shifting from the state of the film formation stop transition to the state of the film formation stop of FIG. 3, the film formation gas in the first dead space 21 can be pushed into the bypass pipe 16 with the first dilution gas. it can.

[0069] Therefore, by using the structure and the process of the present embodiment, it is possible to eliminate the conventional problem that the deposition gas remains in the dead space. The opening and closing of the first valve 34, the second valve 35, and the third valve 33 for performing the above operation is controlled by the control device 250.

Here, an example of a method for controlling the flow rate of the dilution gas will be specifically described with reference to FIG. The raw material gas flow rate A supplied from the vaporizer to the vaporized gas supply pipe 14 is always constant. The first dilution gas flow rate B supplied from the first dilution gas supply pipe 27 is also constant. The second dilution gas flow rate C supplied from the second dilution gas supply pipe 28 is adjusted so that the total gas flow rate D introduced into the reaction chamber 100 through the film formation gas supply pipe 8 is always constant. Pressure inside reaction chamber 100 This is to prevent force fluctuation.

That is, D = A + B + C at the time of film formation (FIG. 14 (b)) so that D = C in the film formation stopped state (FIG. 14 (a)). As described above, in the film formation stop transition state (FIG. 14 (c)), the flow rate of C is adjusted so that D = B + C. For example, if A = 0.5 slm, B = 0.5 slm, and D = l. 5 slm, C is adjusted as follows. In the film formation stopped state, C = l.5slm, in film formation, C = 0.5slm, and in the film formation stop transition state, C = l.Oslm.

As described above, in the present embodiment, the film forming gas staying in the dead space, which has been a conventional problem, is purged by flushing with the diluent gas. The film forming gas can be easily removed. Therefore, fluctuations in the deposited film thickness of the thin film can be suppressed, and uniformity of the film thickness and composition on the substrate surface can be easily obtained. In addition, there is no dead space where the film forming gas stays. It is possible to suppress the occurrence of partake-out due to the self-decomposition of water.

In the above embodiment, the case where the gas supply control pipe 36 of FIG. 2 is provided in the raw material supply pipe 500 has been described, but it may be provided in the radical supply pipe 130.

In the above-described embodiment, when processing the substrate 400 in the reaction chamber 100, the first valve 34 is opened, the second valve 35 is opened, and the third valve 33 is closed. After the substrate processing, the first valve 34 is closed, the second valve 35 is opened, the third knob 33 is opened, and then the first valve 34 is opened and the second valve 35 is closed. The control device 250 controls the valves 33-35 so as to open the third valve 33, thereby purging the deposition gas remaining in the dead space. In this case, the control device 250 controls the first valve 34, the second vane valve 35, and the third valve 33 to close the first valve 34 and open the second valve 35 after the substrate processing. The operation of opening the third valve 33 and the operation of opening the first valve 34, closing the second valve 35, and opening the third valve 33 may be controlled a plurality of times. . According to this, the “film formation stop state” in FIG. 3 and the “film formation stop transition state” in FIG. 5 are repeated a plurality of times.

The merits of repeating the “film formation stop transition state” → “film formation stop state” are as follows. When the film formation is stopped, the flow of the diluent gas is formed from the first diluent gas supply point to the bypass pipe 16 side, and the raw material gas remaining in the first dead space 21 is pushed into the bypass pipe 16. However, even in this case, the raw material gas that has stayed in the first dead space 21 due to diffusion may be supplied from the first dilution gas supply point to the reaction chamber side, that is, the first dilution gas supply point and the second dilution gas supply point. There is a possibility of getting out between the valve 35. In such a case, the source gas remains in the film forming gas supply pipe 8. However, if the “film forming stop transition state” → “film forming stop state” is repeated, the purging effect increases, and (1) The degree of dilution of the residual source gas that escapes from the dead space 21 can be increased, and the concentration of the source gas can be reduced.

In the above-described embodiment, a two-way valve is used for the first valve 34 and the second valve 35 constituting the gas supply control pipe 36. A three-way valve may be used for these forces. is there. FIG. 6 shows a gas supply control pipe 36 using such a three-way valve. The film forming gas supply pipe 8 constituting the gas supply control pipe 36 and the first dilution gas supply pipe 27 are connected by a first three-way valve 40. That is, the film forming gas supply pipe 8 is connected to the first and second ports of the first three-way valve 40, and the first dilution gas supply pipe 27 is connected to the third port. Further, the film forming gas supply pipe 8 and the second dilution gas supply pipe 28 are connected by a second three-way valve 41. That is, the deposition gas supply pipe 8 is connected to the first and second ports of the second three-way valve 41, and the second dilution gas supply pipe 28 is connected to the third port. By connecting the dilution gas supply pipe to the third port, a three-way valve can be used as the first valve and the second valve of the gas supply control pipe 36.

When a three-way valve is used, there is no dead space outside the valve. There is a dead space inside the knob. That is, as shown in FIG. 7, a dead space 43 always exists inside the three-way valve 40 or 41. Therefore, even when a three-way valve is used, the film forming gas remaining in the dead space 43 needs to be flushed with a diluent gas (indicated by an arrow) as in the above-described embodiment.

In the above embodiment, one source element supply unit 900 for supplying one type of organic Hf metal source is connected to the source gas supply line to form an Hf 1 film by a one-element CVD thin film.

2

The case of the film forming apparatus has been described. However, the present invention is not limited to this. For example, a source gas supply line must have at least two sources that supply at least two types of sources. The present invention can also be applied to a multi-element CVD thin film forming apparatus to which a material supply unit is connected or at least one material supply unit for supplying a mixed material in which at least two kinds of materials are mixed in a liquid state is connected.

This multi-element thin film forming apparatus will be described by taking a two-element CVD thin film forming apparatus, for example, an HfSi〇 film forming apparatus as an example. The HfSi〇 film forming apparatus includes, for example, the following two types of apparatuses. One is a type in which two types of raw materials are mixed in a liquid state in a raw material tank, and the other is a type in which a raw material tank and a vaporizer are separately provided for each raw material. The type in which two types of raw materials are mixed in the raw material tank is the same as the configuration shown in FIG. 1, and the Hf raw material and the Si raw material are mixed in the raw material supply unit 900. The type in which a raw material tank and a vaporizer are separately provided for each raw material is configured as shown in FIG.

The configuration of the substrate processing apparatus shown in FIG. 15 is basically the same as the configuration shown in FIG.

Portions corresponding to 1 are denoted by the same reference numerals and description thereof is omitted. The difference is that two kinds of film forming material supply systems are provided in parallel, and they are combined into one supply system by a downstream material gas supply pipe 5b. One of the Hf source supply systems includes a source supply unit 900a for supplying the Hf source, a liquid flow controller 28 Oa for controlling the liquid supply flow rate of the deposition source, and a vaporizer 290a for vaporizing the deposition source. It is composed of The other Si source supply system is composed of a source supply unit 900b for supplying an S source material, a liquid flow controller 280b for controlling the liquid supply flow rate of the film forming material, and a vaporizer 290b for vaporizing the film forming material. You. The output ports of these vaporizers 290a and 290b are unified and connected to the source gas supply pipe 5b. The respective gases sent from the respective film forming source supply systems are mixed in a source gas supply pipe 5b and supplied to the reaction chamber via a gas supply control pipe 36.

The present invention is particularly effective when forming such a multi-element thin film. When forming a multi-element CVD thin film, a plurality of types of elements have different diffusing powers depending on their masses. The lighter the element, the greater the diffusing power. That is, of the plurality of elements staying in the dead space, the one with the smaller mass is diffused first and supplied to the reaction chamber. For example, when forming the above-mentioned HfSiO film, which is a two-element system CVD thin film, an Hf raw material and an S source material are used. Due to the difference, the timing of supply into the reaction chamber is shifted. Then, first The supplied material adheres more to the center of the substrate, which affects the composition uniformity within the substrate surface. Note that this problem does not become a problem particularly when the supply amount of the raw material is large, such as at the time of film formation. From the above, the present invention is particularly effective when forming a multi-element CVD thin film. It is needless to say that the present invention is also effective when a multi-element thin film is formed by ALD.

Brief Description of Drawings

FIG. 1 is a schematic sectional view showing a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a gas supply control pipe according to the first embodiment.

FIG. 3 is an explanatory diagram of a gas supply control pipe according to the first embodiment.

FIG. 4 is an explanatory diagram of a gas supply control pipe according to the first embodiment.

FIG. 5 is an explanatory diagram of a gas supply control pipe according to the first embodiment.

FIG. 6 is a view showing a gas supply control pipe according to a second embodiment.

FIG. 7 is an explanatory view of a three-way valve according to a second embodiment.

FIG. 8 is a view showing a conventional gas supply control pipe.

FIG. 9 is an explanatory view showing a problem of a conventional gas supply control pipe.

FIG. 10 is an explanatory diagram showing a problem of a conventional gas supply control pipe.

FIG. 11 is an explanatory diagram showing a problem of a conventional gas supply control pipe.

FIG. 12 is a schematic configuration diagram of a conventional CVD apparatus.

FIG. 13 is a structural view of a conventional reaction chamber.

FIG. 14 is an explanatory diagram showing a method for controlling a flow rate of a dilution gas according to an embodiment.

FIG. 15 is a schematic sectional view showing another substrate processing apparatus according to the embodiment.

Explanation of symbols

[0080] 5b Source gas supply pipe (source gas supply line)

14a Source gas bypass pipe (bypass line)

14b Radical bypass pipe (bypass line)

23 First inert gas supply pipe (inert gas supply line)

24 Second inert gas supply pipe (inert gas supply line)

33 Third valve 1st valve

Second valve

Reaction chamber

Substrate

Raw material supply pipe (raw gas supply line) Raw material supply unit

Claims

The scope of the claims

[1] a reaction chamber for processing a small number of substrates,

A source gas supply unit for supplying a source gas into the reaction chamber,

A source gas supply line connecting the reaction chamber and the source gas supply unit,

A bypass line that is provided to branch off the source gas supply line power and exhausts the source gas to bypass the reaction chamber;

A second valve provided downstream of the first valve of the source gas supply line provided downstream of a branch point of the source gas supply line with the bypass line;

A third valve provided in the bypass line,

A first inert gas supply line for supplying an inert gas into a source gas supply line between the first valve and the second valve;

A substrate processing apparatus comprising:

[2] When processing a substrate in the reaction chamber, the first valve is opened, the second valve is opened, and the third valve is closed. After the substrate is processed, the first valve is closed, and the second valve is closed. Control means for opening the first valve, opening the third valve, and thereafter controlling the first valve to open, the second valve to close, and the third valve to open. 2. The substrate processing apparatus according to claim 1,

[3] After processing the substrate, the first valve is closed, the second valve is opened, and the third valve is opened. The first valve is opened, the second valve is closed, and the third valve is opened. 3. The substrate processing apparatus according to claim 2, further comprising control means for controlling the operation of opening the valve to be repeated a plurality of times.

[4] The source gas supply unit according to claim 2, wherein the source gas supply unit is configured to continuously supply a constant flow rate of the source gas to the source gas supply line at least during and after the substrate processing. The substrate processing apparatus according to any one of the preceding claims.

[5] The method according to claim 4, wherein the first inert gas supply line is configured to always supply a constant flow of the inert gas at least during and after the substrate processing. The substrate processing apparatus according to any one of the preceding claims.

6. The substrate processing apparatus according to claim 1, further comprising a second inert gas supply line for supplying an inert gas into a source gas supply line downstream of the second valve.

[7] With the supply flow rate of the source gas supplied from the source gas supply unit and the supply flow rate of the inert gas supplied from the first inert gas supply line kept constant, the second inert gas supply line power supply 7. The substrate processing apparatus according to claim 6, wherein a supply flow rate of the inert gas is variable.

[8] Flow from the second inert gas supply line so that the total flow rate of the source gas and the inert gas supplied into the reaction chamber is constant before, during, and after the substrate processing. 8. The substrate processing apparatus according to claim 7, further comprising control means for adjusting a supply flow rate of the inert gas.

[9] Before processing the substrate in the reaction chamber, the first valve is opened, the second valve is closed, the third valve is opened, and when processing the substrate, the first valve is opened. Open the second valve, close the third valve, and after processing the substrate, close the first valve, open the second valve, open the third valve, and then open the first valve. 9. The substrate processing apparatus according to claim 8, further comprising control means for controlling to open the second valve, close the second valve, and open the third valve.

[10] At least two source gas supply units that supply at least two types of source gas or at least one source supply unit that supplies a mixed gas of at least two types of source gas are connected to the source gas supply line. The base according to claim 1, wherein the base is connected.

[11] A step of loading at least one substrate into the reaction chamber, and a step of supplying a source gas from the source gas supply unit to the reaction chamber via a source gas supply line and processing the substrate loaded into the reaction chamber. When,

Before or after the substrate processing, a step of exhausting the source gas to bypass the reaction chamber from a bypass line provided to branch off from the source gas supply line, and carrying out the processed substrate from the reaction chamber And a step of

The step of exhausting the source gas from the bypass line after the substrate processing includes the step of supplying the source gas. The first valve provided downstream of the branch point of the supply line with the bypass line is closed, and the second valve provided downstream of the first valve of the source gas supply line is opened. A step of supplying an inert gas into a source gas supply line between the first valve and the second valve with the third valve provided in the bypass line opened. Semiconductor device manufacturing method.

[12] In the step of exhausting the source gas from the bypass line after the substrate processing, the first valve is opened, the second valve is closed, and the third valve is opened. 12. The method for manufacturing a semiconductor device according to claim 11, further comprising a step of supplying an inert gas into a source gas supply line between the first valve and the second valve.

[13] In the step of exhausting the source gas from the bypass line after the substrate processing, the first valve is closed, the second valve is opened, and the third valve is opened. Supplying an inert gas into the source gas supply line between the second valve and the first valve, opening the first valve, closing the second valve, and opening the third valve; 12. The method of manufacturing a semiconductor device according to claim 11, wherein the step of supplying an inert gas into a source gas supply line between the first valve and the second valve is repeated a plurality of times.

[14] In the step of exhausting the source gas from the bypass line after the substrate processing, the first valve is closed, the second valve is opened, and the third valve is opened. Supplying an inert gas into the source gas supply line between the second valve and the inert gas so as to flow toward the second valve; and opening the first valve, and With the third valve closed and the third valve open, an inert gas is supplied into the source gas supply line between the first valve and the second valve, and the inert gas is supplied to the first valve side. 12. The method for manufacturing a semiconductor device according to claim 11, further comprising a step of causing an inert gas to flow.

[15] At least in the step of processing the substrate and in the step of exhausting the source gas from the bypass line before or after the substrate processing, a constant flow of the source gas is always supplied to the source gas supply line from the source gas supply unit. 13. The method for manufacturing a semiconductor device according to claim 12, wherein the method is continued.

[16] at least a step of processing the substrate, and before or after the substrate processing The method according to claim 15, wherein in the step of further exhausting the source gas, a constant flow of the inert gas is continuously supplied into the source gas supply line between the first valve and the second valve. Manufacturing method of a semiconductor device.

[17] In the step of exhausting the source gas from the bypass line before the substrate processing, the first valve is opened, the second valve is closed, and the third valve is opened. 13. The method of manufacturing a semiconductor device according to claim 12, further comprising a step of supplying an inert gas into a source gas supply line between the first valve and the second valve.

[18] Before, during, and after substrate processing, the supply flow rate of the source gas supplied from the source gas supply unit and the source gas supply line between the first valve and the second valve. In the source gas supply line downstream of the second valve, the supply flow rate of the inert gas supplied into the reaction chamber is always constant, and the total flow rate of the source gas and the inert gas supplied into the reaction chamber is always constant. 18. The method for manufacturing a semiconductor device according to claim 17, wherein an inert gas is supplied to the semiconductor device and the supply flow rate is adjusted.

[19] The semiconductor according to claim 12, wherein the source gas supplied into the reaction chamber via the source gas supply line includes at least two types of source gases or a mixed gas of at least two types of source gases. Device manufacturing method.