JP2022015035A - Chloride gas supply method, chloride gas supply device and chloride gas supply system - Google Patents

Abstract

To provide a chloride gas supply method with which the mass flow of chloride gas can be controlled using conventional mass flow controllers and also system simplification can be achieved by limiting the handling range of chloride gas to just before a reaction chamber.SOLUTION: A chloride gas supply method is characterized to include: introducing reaction gas, which comprises chlorine gas or hydrogen chloride gas and the mass flow of which is controlled, into heated reaction tube made of quartz glass; reacting a solid raw material for forming an insulation film, the solid raw material filling the inside of the reaction tube, with the reaction gas to generate chloride gas; and supplying the generated chloride gas to the reaction chamber for forming an insulation film.SELECTED DRAWING: Figure 1

Description

INDUSTRIAL APPLICABILITY The present invention supplies chloride gas, which is an insulating film-forming element mainly composed of a gate insulating film such as aluminum, zirconium, and hafnium, to, for example, an atomic layer deposition (ALD) device in semiconductor manufacturing. Regarding the method, its device and its system.

In semiconductor manufacturing, monoatomic layer growth equipment (ALD equipment), which is one of the film formation technologies using vacuum, is becoming the mainstream of film formation equipment. For example, when creating a High-k metal gate insulating film (high dielectric constant gate insulating film) for a CMOS device with this device, a compound of elements such as aluminum, zirconium, and hafnium (solid at room temperature) is used. A method of heating to a high temperature to vaporize the film, introducing it into a reaction chamber of an ALD apparatus, and forming a film on a silicon wafer is becoming mainstream.

As one of the methods for extracting a compound gas from the above compound, there is a method using an organic compound (solution heating method for a solid raw material compound). In this method, an organic compound (solid) of the above elements (aluminum, zirconium, hafnium) is dissolved in a solvent to change it into a liquid, which is controlled by the next liquid mass flow controller and vaporized by the vaporizer. It is a method of letting it supply.

The problems of this method are as follows.
1) Since the boiling points of the dissolved organic compound and the solvent are different, the solvent preferentially evaporates inside the vaporizer, and the remaining solid component blocks the liquid inlet inside the vaporizer.
2) Many of these organic compounds are denatured by heating, and multimeric products such as dimers and trimers are produced, which adversely affects the formation of thin films.
3) The organic substance used as a solvent generally contains carbon, and this carbon remains in the thin film due to thermal decomposition and adversely affects the formation of the semiconductor thin film.

Therefore, the use of carbon-free raw materials has been considered. Among them, chloride is taken up, and a part of it is used as a raw material for film formation. The chlorides currently targeted are aluminum trichloride (AlCl ₃ ), zirconium tetrachloride (ZrCl ₄ ), hafnium tetrachloride (HfCl ₄ ) and the like. As a method of utilizing these chlorides, there is a solid chloride high temperature heating method.
In this method, granules of these solid chloride raw materials Mc, which are solid at room temperature, are placed in a raw material container 100, heated to a high temperature to sublimate, and the sublimated chloride gas G150 is used as a mass flow controller (mass flow controller). This is a process (solid chloride high temperature heating method) in which the mass flow rate is controlled at 200 and the chloride gas G300 whose mass flow rate is controlled is supplied to the reaction chamber 700 (FIG. 8).

SEMICONDUCTOR INTERNATIONAL Japanese Edition, June 2008, P.19-P.24

In the solid chloride high temperature heating method shown in FIG. 8, a mass flow controller 200 including a raw material container 100 housed in a constant temperature bath 110, a mass flow meter 210, and a control valve 220 is used. These devices are connected by pipes and are connected to the reaction chamber 700 of the film forming apparatus. Then, the solid chloride raw material Mc stored in the raw material container 100 as described above is heated in the raw material container 100 and sublimated to generate chloride gas G150. The chloride gas G150 is sent to the reaction chamber 700 by controlling the mass flow rate by the mass flow controller 200.

However, this process also has the following problems.
1) These solid chloride raw materials Mc are extremely reactive, react with oxygen and moisture in the atmosphere, and are toxic. Therefore, it is necessary to fill the raw material container 100 in a vacuum or in an atmosphere of an inert gas. There is. Since it is difficult to handle, equipment and labor are required and the cost is high.
2) These solid chloride raw materials Mc are solid at room temperature, have high melting points and boiling points, and a constant temperature bath 110 is used as an apparatus for vaporization, and the raw material container 100 containing these solid chloride raw materials Mc is heated to a high temperature. It is necessary to heat and maintain this high temperature. At the same time, the piping system connecting the equipment from the raw material container 100 to the reaction chamber 700 must be heated and kept warm to a high temperature in order to keep the vapor pressure of the vaporized chloride gas G150 / G300 above a certain level. It is necessary to install heaters and heat insulating materials in all piping routes from the raw material container 100 to the reaction chamber 700. At the same time, the mass flow controller 200 installed in the middle of the piping system must also be heated and kept warm to a high temperature. In other words, in this process, heaters and insulation must be installed in the entire path from the raw material container 100 to the reaction chamber 700.
3) Moreover, these solid chloride raw materials Mc and the generated chloride gases G150 and G300 are extremely corrosive to metals. Therefore, a material that is not corroded by the chloride gas G150 / G300 must be used for at least the gas contact portion of the entire path from the raw material container 100 to the reaction chamber 700, including the mass flow controller 200. Such materials are limited and expensive, and very difficult to process. The mass flow controller 200 is a special specification device that is not corroded by the chloride gases G150 and G300 and uses a heat-resistant material.
When the gas contact portion constituting these devices is a metal material conventionally used for these devices, the chloride gases G150 and G300 react with the metal materials at high temperatures to cause metal corrosion. The resulting metallic chlorine compound flows into the reaction chamber 700 of the semiconductor film forming apparatus and causes fatal contamination (metal contamination) for the semiconductor film forming.

The present invention has been made to solve such a problem, and the first object thereof is to be able to control the mass flow rate of chloride gas by using a conventional mass flow controller. Moreover, it is an object of the present invention to provide a chloride gas generation method capable of simplifying the system by limiting the handling range of the chloride gas immediately before the reaction chamber, and the second object is to enable the method. It is an object of the present invention to provide a chloride gas generator, and a third object thereof is to provide a system which enables the implementation of the above method by using the chloride gas generator.

The method of the present invention relates to a chloride gas supply method for forming an insulating film of a semiconductor device.
A reaction gas G2 composed of chlorine gas or hydrogen chloride gas and whose mass flow rate was controlled was introduced into a heated quartz glass reaction tube 41.
The solid raw material M for forming an insulating film filled in the reaction tube 41 and the reaction gas G2 are reacted to generate chloride gas G3.
It is a chloride gas supply method characterized by supplying the generated chloride gas G3 toward a reaction chamber 70 for forming an insulating film.

In the method of the present invention, the reaction gas G2 is characterized in that the mass flow rate is controlled so that an amount of chloride gas G3 required for forming an insulating film in the reaction chamber 70 is generated in the reaction tube 41.

The solid raw material M for forming an insulating film used in the method of the present invention is characterized by being aluminum, zirconium or hafnium.

The chloride gas generator 40 used in the method of the present invention is an apparatus used in the chloride gas supply process in forming an insulating film of a semiconductor device.
A reaction gas G2 filled with a solid raw material M for forming an insulating film, composed of chlorine gas or hydrogen chloride gas, and whose mass flow rate is controlled flows, and the solid raw material M and the reaction gas G2 react with each other to form chloride. A reaction tube 41 made of quartz glass that generates a physical gas G3 and supplies the generated chloride gas G3 toward a reaction chamber 70 for forming an insulating film, and a reaction tube heating unit 50 that heats the reaction tube 41 are provided. It is characterized by including.

In the chloride gas generator 40 of the present invention, the reaction tube heating unit 50 is arranged so as to surround the outer surface of the reaction tube 41, and the gap between the reaction tube heating unit 50 and the reaction tube 41 is filled with graphite powder. It is characterized in that the heat transfer filling layer 49 is provided.

In the chloride gas generator 40 of the present invention, the reaction gas G2 is mass flow controlled so that an amount of chloride gas G3 required for forming an insulating film in the reaction chamber 70 is generated in the reaction tube 41. It is characterized by that.

The chloride gas supply system A of the present invention in forming an insulating film of a semiconductor device is
The gas supply source 1 of the controlled gas G1 to be controlled by the mass flow rate composed of chlorine gas or hydrogen chloride gas, and
A mass flow controller 10 that is connected to the gas supply source 1 and controls the mass flow rate of the controlled gas G1 so as to generate a required amount of chloride gas G3 in the reaction chamber 70 for forming an insulating film.
The reaction gas G2, which is filled with the solid raw material M for forming an insulating film and is connected to the mass flow controller 10 and whose mass flow rate is controlled, flows through the reaction gas G2 to react with the solid raw material M. Chloride gas composed of a reaction tube 41 made of quartz glass that generates chloride gas G3 and supplies the chloride gas G3 to the reaction chamber 70, and a reaction tube heating unit 50 that heats the reaction tube 41. Generator 40 and
The chloride gas G3 provided around the chloride gas supply pipe 61 connecting the outlet 41b of the reaction pipe 41 and the inlet 70a of the reaction chamber 70 and the chloride gas supply pipe 61 and flowing through the chloride gas supply pipe 61. It is characterized by including a pipe temperature maintaining portion 67 for heating or retaining heat in order to maintain the vapor pressure of the above.

An inlet side filter 45a is installed between the inlet 41a of the reaction tube 41 and the solid raw material M of the chloride gas generator 40 according to the present invention, and between the outlet 41b of the reaction tube 41 and the solid raw material M. The outlet side filter 47b is installed in the air.

In the present invention, in the chloride gas supply in forming the insulating film of the semiconductor device, the reaction gas G2 whose mass flow rate is controlled is introduced into the reaction tube 41 made of quartz glass, so that the chloride gas generated by reacting with the solid raw material M is introduced. The amount of G3 generated corresponds to the reaction gas G2 whose mass flow rate is controlled. In other words, if the mass flow rate of the reaction gas G2 introduced into the reaction tube 41 is controlled to an amount that generates only the required amount of the chloride gas G3 in the reaction chamber 70 for forming the insulating film, the highly corrosive chloride There is no need to control the mass flow rate of the gas G3, and there is an advantage that the portion that must correspond to the highly corrosive chloride gas G3 is only a short portion from the reaction tube 41 to the reaction chamber 70.

It is a schematic flow chart of the whole system which concerns on this invention. It is a schematic sectional drawing of the mass flow controller used in this invention. It is a top view of the 1st Embodiment of the chloride gas generator used in this invention. It is a vertical sectional view of FIG. It is a top view of the 2nd Embodiment of the chloride gas generator used in this invention. It is a vertical sectional view of FIG. It is a vertical sectional view of the 3rd Embodiment of the chloride gas generator used in this invention. It is a schematic flow chart of the whole conventional system.

Hereinafter, the present invention will be described with reference to the drawings. The chloride gas supply system A according to the present invention includes a gas supply source 1, a mass flow controller 10, and a chloride gas generator 40 as equipment, and a gas supply source 1 and a mass flow controller 10 as piping systems. Includes a first pipe line 5 connecting the above, a second pipe line 30 connecting the mass flow controller 10 and the chloride gas generator 40, and a third pipe line 60 connecting the chloride gas generator 40 and the reaction chamber 70. ..

The gas supply source 1 is, for example, a gas cylinder made of chrome molybdenum steel filled with high-purity chlorine gas or hydrogen chloride gas containing no water. The chlorine gas and hydrogen chloride gas are the gas G1 to be controlled by the mass flow controller 10. The controlled gas G1 is sent from the gas supply source 1 to the inlet 41a of the chloride gas generator 40 described later in the state of high-purity chlorine gas or hydrogen chloride gas. Therefore, a material (for example, stainless steel) that is not affected by the controlled gas G1 is selected for at least the passage path (contact part) of the controlled gas G1 from the gas supply source 1 to the inlet 41a of the chloride gas generator 40 described later. Will be done.

The mass flow controller 10 measures not the volumetric flow rate of the controlled target gas G1 (the chlorine gas or hydrogen chloride gas) but the mass flow rate by the measuring unit 15, and controls the opening degree of the control valve unit 25 to control the inside. It is a device that controls and supplies the gas G1 to be controlled that flows so as to flow out with a constant mass flow rate.

An example of the mass flow controller 10 will be described with reference to FIG. The mass flow controller 10 includes a body 11, a measuring unit 15, a bypass element 20, and a control valve unit 25. At least the gas contact member of the mass flow controller 10 is made of a material (stainless steel) that is not affected by the controlled gas G1.
A cylindrical hole 12 that opens at one end of the body 11 is bored, and a primary valve flow path 24 that communicates with the valve chamber 26 of the control valve portion 25 and a valve chamber are formed in the center of the hole of the cylindrical hole 12. A secondary valve flow path 27 communicating with the other end of the body 11 from 26 is bored.

The measurement unit 15 is composed of a sensor tube 16, a sensor housing 17, and a calculation unit 18, and the sensor housing 17 is mounted and fixed on the upper surface of the body 11.
Two pipelines (primary side pipeline 17a and secondary side pipeline 17b) are bored in the sensor housing 17, and are provided so as to straddle the bypass element 20 described later. The open end of the sensor tube 16 is connected to the primary side pipeline 17a and the secondary side pipeline 17b, respectively, and two heaters Hu and Hd are left and right (in other words, the upstream side and the downstream side) around the opening end. It is wound apart. The heaters Hu and Hd are connected to the calculation unit 18.
As will be described later, the calculation unit 18 detects the mass flow rate of the controlled gas G1 flowing through the sensor tube 16 as a flow rate signal, converts the detected flow rate signal into a voltage signal by an internal electronic circuit, and converts this into a voltage signal, which is a control valve. It is given to the drive unit 29 of the unit 25. It is a controlled target gas G1 that is the target of mass flow rate control.

The bypass element 20 is, for example, a bundle of a large number of capillaries, and is used by being fitted into a cylindrical hole 12. The primary side pipeline 17a is connected to the inlet side space 12a of the bypass element 20 in the cylindrical hole 12, and the secondary side pipeline 17b is connected to the outlet side space 12b. The number of bypass holes is appropriately selected according to the flow rate.

The control valve unit 25 includes a valve housing 28, a drive unit 29, a valve chamber 26, and a control valve 26b. The valve housing 28 is installed on the upper surface of the body 11 so as to match the concave holes constituting the valve chamber 26. The control valve 26b is a thin film-like diaphragm, and is arranged in the concave hole so as to cover the entire surface of the concave hole. The space below the control valve 26b is the valve chamber 26.

A vertical hole of the secondary side valve flow path 27 formed in an L shape is opened in the center of the bottom of the valve chamber 26, and a control valve 26b is brought into contact with and separated from the opening to adjust the valve opening. 26c is formed. Around the valve seat 26c is a primary side chamber 26a in the valve chamber 26, and a primary side valve flow path 24 through which the controlled target gas G1 whose mass flow rate is controlled passes is open.

The drive unit 29 expands and contracts toward the control valve 26b by the output from the calculation unit 18, controls the valve opening degree of the control valve 26b with respect to the valve seat 26c, and controls the controlled gas G1 according to the output from the calculation unit 18. The mass flow rate is controlled. Although the drive unit 29 in the figure is normally open, the valve opening can be controlled by normal closing by changing the valve structure.

The chloride gas generator 40 is composed of a quartz glass reaction tube 41, a cylindrical reaction tube heating unit 50 provided so as to surround the reaction tube 41, its accessories, and a solid raw material M which is a filling material. ing.

As shown in FIGS. 3 and 4, the first embodiment of the reaction tube 41 is a tube body 42 made of straight tube quartz glass, an inlet member 45 attached to one opening as an accessory thereof, and the other. It is composed of an outlet member 47 attached to the opening of the above, an inlet side filter 45a provided inside the inlet member 45, and an outlet side filter 47b provided inside the outlet member 47. The inlet member 45 and the outlet member 47 are made of, for example, quartz glass or polytetrafluoroethylene.
Then, the tube main body 42 is filled with the granular solid raw material M between the inlet side filter 45a and the outlet side filter 47b.
High-purity aluminum, high-purity zirconium, or high-purity hafnium is used as the solid raw material M for forming an insulating film mainly composed of a gate insulating film.

Although the reaction tube heating unit 50 is not shown, for example, a cylindrical aluminum casing 51, a plurality of rod-shaped heaters 53 embedded in the casing 51 in the longitudinal direction, and a thermocouple (not shown). It is composed of a lid member 58a / 58b provided above and below the temperature control device and the casing 51 through which an inlet member 45 and an outlet member 47 penetrate, respectively, and a fastening member 57 for fastening the lid members 58a / 58b. Has been done.
The casing 51 of the reaction tube heating unit 50 repeats thermal expansion and contraction by heating and cooling. On the other hand, since the thermal expansion rate of the quartz glass tube body 42 is almost zero and brittle fracture occurs, it is necessary to provide a gap between the quartz glass tube body 42 and the casing 51 of the reaction tube heating unit 50. be. Since air has entered this gap, heat conduction is poor. In the chloride gas generator 40 of the present invention, the gap is filled with graphite powder. This portion is referred to as a heat transfer packed bed 49.
The thermal conductivity of graphite powder is about 1/3 that of aluminum, and about 3 times that of stainless steel.

The piping system includes a first piping line 5 connecting the gas supply source 1 and the mass flow controller 10, a second piping line 30 connecting the mass flow controller 10 and the chloride gas generator 40, and a chloride gas generator 40. A third piping line 60 connecting the reaction chamber 70 and the reaction chamber 70 is included.

Since the first piping line 5 is a gas G1 to be controlled at room temperature such as high-purity chlorine gas and high-purity hydrogen chloride gas emitted from the gas supply source 1, a material that can withstand high-purity chlorine gas and high-purity hydrogen chloride gas. For example, it is composed of stainless steel pipe. This portion does not need to be heated because the controlled gas G1 is only sent to the mass flow controller 10, and is kept at room temperature.

Since the second pipe line 30 is a pipe line connecting the mass flow controller 10 and the chloride gas generator 40 that requires heating, it is preferable to heat the second pipe line 30 for preheating. Of course, it does not have to be heated.
In the case of heating, structurally, for example, a nichrome wire is wound around a pipe and the circumference thereof is covered with a heat insulating material. Further, in this case, the second piping line 30 is adjusted to a preferable temperature. Further, since the reaction gas G2 whose mass flow rate is controlled only flows in the pipe used in the second pipe line 30, the same material (stainless steel pipe) as the pipe in the first pipe line 5 is used.

On the other hand, in the third pipe line 60, the highly corrosive chloride gas G3 emitted from the chloride gas generator 40 needs to pass through as it is while maintaining the gaseous state, so that the chloride gas supply pipe 61 has. It is made of quartz glass, and a chloride wire is wound around it, and the structure is such that the surrounding area is covered with a heat insulating material. The temperature control is performed by the temperature control device of the reaction tube heating unit 50 or the original thermocouple and temperature control device. These nichrome wires, heat insulating thermocouples, and temperature control devices constitute the pipe temperature maintenance unit 67.

Next, the operation of the present invention will be described. Generally, the controlled target gas G1 emitted from the gas supply source 1 is mass flow controlled by the mass flow controller 10 and sent to the chloride gas generator 40.
In the mass flow controller 10, in the chloride gas generator 40, the gas G1 to be controlled is controlled so that the required amount of the chloride gas G3 in the reaction chamber 70 for forming the insulating film mainly composed of the gate insulating film is generated. Is mass flow controlled.
In the chloride gas generator 40, the high-purity, granular solid raw material M reacts with the reaction gas G2 whose mass flow rate is controlled to generate the chloride gas G3 corresponding to the reaction gas G2 whose mass flow rate is controlled. Then, it is sent to the reaction chamber 70. The reaction is as follows.
Here, a high-purity hydrogen chloride gas containing no water is brought into contact with the heated solid raw material M (granule) to generate a chloride gas G3 corresponding to the reaction gas G2 whose mass flow rate is controlled.
Reaction equation 1) For aluminum: 6HCl + 2Al = 2AlCl ₃ + 3H ₂
2) For zirconium: 4HCl + Zr = ZrCl ₄ + 2H ₂
3) For hafnium: 4HCl + Hf = HfCl ₄ + 2H ₂
In this case, hydrogen (H ₂ ) is generated as a reaction product, but normally, the reaction chamber 70 is exhausted by a vacuum pump, so there is no problem. However, if there is concern about the effect, the method using chlorine gas may be adopted.

As described above, in the mass flow controller 10, in the chloride gas generator 40, the controlled gas G1 is the mass flow rate so that the required amount of the chloride gas G3 in the reaction chamber 70 for forming the insulating film is the amount to be generated. It will be controlled, and in the present invention, it is not necessary to control the mass flow rate of the chloride gas G3. Hereinafter, it will be described in more detail.
In the mass flow controller 10, the high-purity controlled gas G1 sent from the gas supply source 1 enters the cylindrical hole 12 of the body 11, a part of the gas is diverted and flows into the sensor tube 16, and most of it (sensor). (N times the tube 16) flows through the bypass element 20.

The controlled target gas G1 flowing through the sensor tube 16 takes heat from the upstream heater Hu and flows to the downstream side to suppress the heating amount of the downstream heater Hd. In the upstream heater Hu, the control circuit controls the upstream heater Hu so that the deprived heat is replenished and the equilibrium temperature is reached. As a result, the balance of the power supplied to both heaters Hu and Hd is lost, and the mass flow rate of the fluid flowing through the sensor tube 16 is detected by detecting and calculating this difference.

On the other hand, since the flow rate of the controlled target gas G1 flowing through the bypass element 20 is proportional to the flow rate of the sensor tube 16, the total gas flow rate can be known by multiplying the flow rate of the sensor tube 16 by a predetermined coefficient. Then, this output is fed back to the control valve unit 25, and the control valve 26b is driven by the drive unit 29 to accurately control the mass flow rate of the fluid flowing through the valve chamber 26.

The controlled target gas G1 exiting the bypass element 20 merges with the controlled target gas G1 that has passed through the sensor tube 16 and enters the primary valve flow path 24. At this time, the drive unit 29 operates in proportion to the signal voltage from the calculation unit 18, and the gap between the control valve 26b and the valve seat 26c is strictly adjusted to move from the primary side chamber 26a to the secondary side valve flow path 27. The mass flow rate of the flowing controlled gas G1 is strictly controlled. The accurately controlled reaction gas G2 flows out through the secondary valve flow path 27 and is sent to the chloride gas generator 40 in the next step.

The reaction gas G2 exiting the mass flow controller 10 is sent to the chloride gas generator 40 via the second piping line 30 as described above, but the chloride gas generator 40 generates the chloride gas G3. Therefore, it is heated to a high temperature. Therefore, it is preferable that the second piping line 30 is also preheated.

The reaction gas G2 whose mass flow rate is controlled to a required amount and is preheated (or remains at room temperature) is introduced into the reaction tube 41 made of quartz glass heated to a high temperature of the chloride gas generator 40 through the inlet member 45. Will be done. The introduced reaction gas G2 passes through the inlet side filter 45a and enters the packed bed of the solid raw material M. As the heating temperature of the reaction tube 41, a region in which the yield due to the above reaction is 100% or close to 100% is selected. The chloride gas G3 generated thereby is equivalent to the case where the mass flow rate is controlled, and the mass flow rate control of the chloride gas G3 becomes unnecessary. As the solid raw material M, granules having good air permeability are used. The appropriate particle size is selected based on the air permeability and reaction rate. As the heating temperature, a temperature at which a reaction rate of 100% or a value close to 100% can be obtained is selected from the reaction characteristics of the reaction gas G2 which is chlorine gas (hydrogen chloride gas) and each metal. The generated chloride gas G3 flows through the outlet side filter 47b to the third piping line 60. Since the generated chloride gas G3 corresponds to the reaction gas G2 whose mass flow rate is controlled, the mass flow rate control of the chloride gas G3 becomes unnecessary. The outlet-side filter 47b serves to collect droplets so as not to flow to the reaction chamber 70 side as the chloride gas G3 flows out. If it is desired to supply the chloride gas G3 to the reaction chamber 70 in a short time, a carrier gas (not shown) may be introduced from a key point.

The chloride gas generator 40 is heated to a high temperature as described above, but a heat transfer filling layer 49 of graphite powder having good thermal conductivity is provided between the reaction tube 41 and the reaction tube heating unit 50. Therefore, the heat of the reaction tube heating unit 50 is transferred to the reaction tube 41 through the heat transfer filling layer 49, and the temperature of the solid raw material M inside is smoothly raised to a predetermined temperature.
At this time, the inner diameter of the reaction tube heating unit 50, which thermally expands with respect to the reaction tube 41 which does not thermally expand or contract when the temperature rises, increases and the gap expands. Graphite powder moves downwards to fill the widened gaps.
On the contrary, when the temperature of the reaction tube heating unit 50 drops in the non-energized state, the inner diameter thereof becomes smaller and the gap is reduced. The graphite powder that is filled in the gap and constitutes the heat transfer packed bed 49 slides and lifts each other as the gap shrinks, automatically responds to the shrinkage of the gap, and is excessive in the reaction tube 41 that does not expand or contract. Do not apply compression pressure. As a result, when the temperature rises, the heat from the reaction tube heating unit 50 is transferred to the reaction tube 41 due to good heat conduction, and the reaction tube 41 made of quartz glass is damaged by the thermal expansion and contraction of the reaction tube heating unit 50. Never.

The chloride gas G3 generated in a state equivalent to mass flow rate control leaving the chloride gas generator 40 is supplied to the reaction chamber 70 through the third piping line 60. In the third pipe line 60, the flowing chloride gas G3 is heated so as to be cooled and its vapor pressure is maintained so as not to adhere to the inner surface of the chloride gas supply pipe 61.

To summarize this system A as above,
1) Since the temperature from the gas supply source 1 such as a gas cylinder to the inlet 41a of the reaction tube 41 may be normal temperature (partially preheated), the metal constituting the device by the controlled gas G1 such as chlorine gas or hydrogen chloride gas (1) There is virtually no corrosion of the mass flow controller 10 and the pipes of the first and second pipe lines 5 and 30).
2) The reaction tube 41 is a chlorine compound (AlCl ₃ , Zrcl ₄ ) which is a reaction product with the reaction gas G2 in which the inflow mass flow control is controlled under high temperature, in which the whole or the tube body 42 is made of quartz glass. , HfCl ₄ ) and the reaction with the chloride gas G3 generated by sublimation from these can be ignored. Therefore, in this system A, the contact portions of the chlorine compounds (AlCl ₃ , Zrcl ₄ , HfCl ₄ ) and the chloride gas G3 are limited, so that corrosion due to these and metal contamination in the insulating film due to the corrosion are caused. There is no fear.
3) The size and filling amount of the granules of the solid raw material M and the amount of the solid raw material M were charged so that the reaction rate between the reaction gas G2 whose mass flow rate was controlled and the raw material metal could be 100% to nearly 100% in the reaction tube 41. The mass flow rate of the reaction gas G2, the cross-sectional area of the reaction tube 41, the length, the heating temperature, and the like are set to the optimum values.

The second embodiment of the chloride gas generator 40 (FIGS. 5 and 6)
The longer the reaction tube 41 of the chloride gas generator 40 is, the more preferable it is. Here, a U-shaped tube is used as the reaction tube 41. The casing 51 of the reaction tube heating unit 50 is provided with a storage hole for the upper surface opening, and the metal sheath tube 51a constituting the inner surface portion of the casing 51 is fitted in the storage hole. The reaction tube 41 is housed in the sheath tube 51a. The sheath tube 51a is filled with graphite powder so as to surround the U-shaped reaction tube 41 to form a heat transfer packed bed 49. The lid member 58 is provided with an insertion hole for the reaction tube 41, and is attached so as to close the storage hole so that the graphite powder does not leak.

Third Embodiment of the chloride gas generator 40 (FIG. 7)
Here, a spiral tube is used for the reaction tube 41, and graphite powder is filled so as to surround the reaction tube 41 to form a heat transfer packed bed 49.

A: Chloride gas supply system, G1: Control target gas, G2: Mass flow controller controlled reaction gas, G3: Chloride gas, G150: Chloride gas, G300: Mass flow controller controlled chloride gas, Hu: Upstream Side heater, Hd: Downstream heater, M: Solid raw material, Mc: Solid chloride raw material, 1: Gas supply source, 5: First pipe line, 10: Mass flow controller, 11: Body, 12: Cylindrical hole, 12a : Inlet side space, 12b: Exit side space, 15: Measurement unit, 16: Sensor pipe, 17: Sensor housing, 17a: Primary side pipe, 17b: Secondary side pipe, 18: Calculation unit, 20: Bypass Element, 24: 1 primary side valve flow path, 25: control valve section, 26: valve chamber, 26a: 1 primary side chamber, 26b: control valve, 26c: valve seat, 27: secondary side valve flow path, 28: valve Housing, 29: Drive unit, 30: Second piping line, 40: Chloride gas generator, 41: Reaction tube, 41a: Inlet, 41b: Outlet, 42: Pipe body, 45: Inlet member, 45a: Inlet side filter 47: Outlet member, 47b: Outlet side filter, 49: Heat transfer packing layer, 50: Reaction pipe heating part, 51: Casing, 51a: Sheath pipe, 53: Heater, 57: Fastening member, 58, 58a, 58b : Lid member, 60: Third piping line, 61: Chloride gas supply piping, 67: Piping temperature maintenance unit, 70: Reaction chamber, 70a: Inlet, 100: Raw material container, 110: Constant temperature bath, 200: Mass flow controller Instrument (mass flow controller), 210: Mass flow meter, 220: Control valve, Reaction chamber: 700

Claims (8)

In the chloride gas supply method in forming the insulating film of a semiconductor device,
A reaction gas composed of chlorine gas or hydrogen chloride gas and whose mass flow rate is controlled is introduced into a heated quartz glass reaction tube.
The solid raw material for forming the insulating film filled in the reaction tube and the reaction gas are reacted to generate chloride gas.
A chloride gas supply method comprising supplying the generated chloride gas to a reaction chamber for forming an insulating film. The chloride gas supply according to claim 1, wherein the reaction gas is mass-flow controlled so that an amount of chloride gas required for forming an insulating film in the reaction chamber is generated in the reaction tube. Method. The chloride gas supply method according to claim 1 or 2, wherein the solid raw material is aluminum, zirconium, or hafnium. A chloride gas generator for supplying chloride gas in the formation of an insulating film of a semiconductor device.
A reaction gas filled with a solid raw material for forming an insulating film, composed of chlorine gas or hydrogen chloride gas, and whose mass flow rate is controlled flows, and the solid raw material reacts with the reaction gas to generate chloride gas. Chloride gas generation, which comprises a reaction tube made of quartz glass for supplying the generated chloride gas to a reaction chamber for forming an insulating film, and a reaction tube heating unit for heating the reaction tube. Device. The reaction tube heating section is arranged so as to surround the outer surface of the reaction tube, and a heat transfer packing layer filled with graphite powder is provided in the gap between the reaction tube heating section and the reaction tube. The chloride gas generator according to claim 4, wherein the device is characterized by the above. The chloride according to claim 4 or 5, wherein the reaction gas is mass-flow controlled so that an amount of chloride gas required for forming an insulating film in the reaction chamber is generated in the reaction tube. Gas generator. 4. The present invention is characterized in that an inlet side filter is installed between the inlet of the reaction tube and the solid raw material, and an outlet side filter is installed between the outlet of the reaction tube and the solid raw material. The chloride gas generator according to any one of 6. The gas supply source of the controlled gas to be controlled by the mass flow rate composed of chlorine gas or hydrogen chloride gas,
A mass flow controller that is connected to the gas supply source and controls the mass flow rate of the gas to be controlled so as to generate a required amount of chloride gas in the reaction chamber for forming an insulating film.
The reaction gas, which is filled with a solid raw material for forming an insulating film and is connected to the mass flow controller and whose mass flow rate is controlled, flows through the reaction gas and reacts with the solid raw material to generate chloride gas. A chloride gas generator composed of a reaction tube made of quartz glass for supplying the chloride gas to the reaction chamber and a reaction tube heating unit for heating the reaction tube.
In order to maintain the vapor pressure of the chloride gas flowing through the chloride gas supply pipe, which is provided around the chloride gas supply pipe connecting the outlet of the reaction pipe and the inlet of the reaction chamber and the chloride gas supply pipe. A chloride gas supply system for forming an insulating film of a semiconductor device, which comprises a pipe temperature maintaining portion for heating or retaining heat.

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