JPH08255792A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE: To enable high-speed formation of a silicon oxide film excelling in step coverage by using a gas of compounds containing siloxane as a raw material gas of a silicon oxide film and rotating a workpiece at the time of silicon oxide film formation. CONSTITUTION: A susceptor 5 is set on a silicon substrate 6 and the inside of a chamber 1 is subjected to N2 substitution. Next, while the silicon substrate 6 is heated by a resistance heating heater 7 to a film-forming temperature of 800 deg.C, the silicon substrate 6 is rotated. TEDS [(C2 H5 O)2 CH3 Si)2 O], O2 , and N2 are introduced to the chamber 1 at respective flow rates of 20scm for TEDS [(C2 H5 O)2 CH2 Si)2 O], 1slm for O2 , and 10slm for N2 . At this time, the total gas pressure is set to 100Torr. Such film-forming method enables a silicon oxide film having an excellent step coverage and maintaining an in-plane uniformity to be formed at high speed on the silicon substrate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device having a step of forming a silicon oxide film by a vapor phase growth method.

[0002]

2. Description of the Related Art A vapor phase growth method (CVD method) has been conventionally known as one of LSI manufacturing technologies. The CVD method is used, for example, for forming an insulating film such as a silicon oxide film that insulates between wirings.

For forming a silicon oxide film, the film thickness uniformity within the wafer (in-plane film thickness uniformity) is used as a source gas.
Further, a batch type low pressure CVD method is known in which a plurality of silicon oxide films are formed at one time by using TEOS (tetraethoxysilane: Si (0C ₂ H ₅ ) ₄ ) capable of enhancing step coverage.

By the way, recently, there has been a shift from a batch type film forming apparatus for processing a plurality of wafers to a single wafer type film forming apparatus for processing one wafer at a time, and a single wafer type low pressure CVD using TEOS is performed. The law is also being considered.

However, in the single-wafer type low pressure CVD method, since the film forming rate is as slow as 10 n / min, it is difficult to increase the film forming throughput. Such problems are caused by single-wafer type low pressure CVD.
It is an obstacle to the practical application of the law.

Further, recently, in order to improve the productivity of LSI, a wafer having a large diameter of 8 inches, 12 inches or the like has been used. Therefore, there is a need for a method capable of forming a silicon oxide film on a large-area wafer with good uniformity.

There is a high-speed rotation type CVD method as a CVD method having a high film forming rate. This high-speed rotation type CVD method improves the film thickness uniformity within the wafer surface. The high-speed rotation type CVD method is a kind of thermal CVD method, in which a substrate is rotated around its center, and a reactive gas (raw material gas) is uniformly distributed on the entire surface of the substrate in parallel with the substrate rotation axis. It is a laminar flow.

The fact that the film formation rate can be increased and the film thickness uniformity within the wafer surface can be improved is, for example, in the case of Si epitaxial growth, Y. Sato et al. , Extended A
btracts of 1991 Internet
Ion al conference on Soli
d State Device and Material
als, Yokohama, 1991, p717. Is shown in.

However, the conventional high-speed rotation type CVD method has the following problems. That is, future CVD
The single-wafer film formation method of a silicon oxide film by the method needs to have a high film formation rate and high step coverage like the batch method, but the conventional high-speed rotary CVD method has a high performance. It was not possible to satisfy the conditions of film speed and high step coverage at the same time.

Further, there is a large flow rate type CVD method as a CVD method with a high film forming rate and a high uniformity of the in-plane film thickness. I couldn't.

[0011]

As mentioned above, the future C
The single-wafer film-forming method of the silicon oxide film by the VD method requires a high film-forming rate and a high step coverage, but a CVD method that can simultaneously satisfy these requirements has not been realized yet.

The present invention has been made in view of the above circumstances, and an object thereof is to manufacture a semiconductor device which has excellent step coverage on the surface of a substrate to be processed and which can form a silicon oxide film at high speed. To provide a method.

[0013]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention (claim 1).
Uses a gas of a substance containing siloxane as a source gas of the silicon oxide film when forming a silicon oxide film on a substrate to be processed by a vapor phase epitaxy method, and the substrate to be processed at the time of forming the silicon oxide film. It is characterized by rotating.

Here, the rotation of the substrate to be processed is preferably a high-speed rotation in which the peripheral speed of the outer periphery of the substrate to be processed is equal to or higher than the linear speed of the source gas (claim 2). The gas of the substance containing siloxane as the raw material gas is, for example, hexamethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-methyldisiloxane, hexaethoxydisiloxane, or cyclosiloxane. , For example, octamethylcyclotetrasiloxane or 1,3,5,
A gas such as 7-tetramethylcyclotetrasiloxane is preferable (claim 3).

[0015]

According to the research conducted by the present inventors, when a silicon oxide film is formed on a substrate to be processed by a vapor phase growth method, a gas of a substance containing siloxane is used as a raw material gas for the silicon oxide film, and It was found that by rotating the substrate to be processed during film formation, it is possible to form a film that simultaneously satisfies the conditions of high film formation rate and high step coverage.

Therefore, according to the method of manufacturing a semiconductor device according to the present invention based on such knowledge, a silicon oxide film having excellent step coverage can be formed at high speed on a substrate to be processed.

[0017]

Embodiments will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a schematic diagram showing a schematic structure of a high-speed rotary CVD apparatus according to the first embodiment of the present invention.

In the figure, reference numeral 1 denotes a chamber which is a film forming chamber, and an exhaust pump 2 is provided at the bottom of the chamber 1. The exhaust pump 2 is for exhausting gas and the like in the chamber 1 to the outside.

A substrate 6 to be processed is provided on the bottom of the chamber 1.
There is provided a susceptor 5 for mounting. The susceptor 5 is configured to rotate about the center of the substrate 6 to be processed by a rotating means such as a motor. Further, the susceptor 5 is provided with a resistance heater 7 for heating the substrate 6 to be processed from its back surface.

On the other hand, gas supply pipes 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ are provided above the chamber 1, and each gas supply pipe 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ is TEDS
(1,1,3,3-tetramethyl-ethoxy-1,3-dimethyl Siji _{siloxane: ((C 2 H 5 O} ) 2 CH 3 Si) 2
O), TEOS (raw material gas), O ₂ and N ₂ (carrier gas) are supplied into the chamber 1. The above-mentioned gases introduced from the respective gas supply pipes join together before the straightening plate 4 provided above the chamber 1 and then the substrate 6 to be treated.
Is supplied to.

Next, a high speed rotating CV constructed as described above.
A method of forming a silicon oxide film using the D device will be described. First, after setting the silicon substrate as the substrate 6 to be processed on the susceptor 5, the inside of the chamber 1 is replaced with N ₂ .

Next, the resistance heater 7 heats the silicon substrate 6 to a film forming temperature of 800 ° C. and rotates the silicon substrate 6. This rotation is preferably a high-speed rotation in which the peripheral speed of the outer periphery of the silicon substrate 6 is higher than the linear speed of the raw material gas.

Next, TEDS is 20 sccm and O ₂ is 1 s.
1m (1slm = 1000sccm), N ₂ for 10s1
It is introduced into the chamber 1 at a flow rate of m. At this time, the total pressure of the above three gases is set to 100 Torr.

The silicon substrate 6 is formed by such a film forming method.
A silicon oxide film having high in-plane film thickness uniformity and excellent step coverage can be formed at a high speed. FIG. 2 is a characteristic diagram showing the relationship between the number of rotations of the substrate to be processed (silicon substrate) and the film forming rate according to the present invention and the conventional film forming method. The conventional film forming method uses TEOS as a source gas,
This is a method in which the TEOS partial pressure is the same as that of the source gas (TEDS) of the present invention.

From FIG. 2, when the source gas is TEOS (conventional), the film formation rate is decreased by increasing the rotation speed, whereas when the source gas is TEDS (the present invention), the rotation speed is changed. It can be seen that the film formation rate increases when the temperature is increased.

FIG. 3 is a characteristic diagram showing the relationship between the number of revolutions of the substrate to be processed and the step coverage according to the present invention and the conventional film forming method. In the conventional film forming method, TEOS is used as a raw material gas, and the partial pressure of the TEOS is used as the raw material gas (TED of the present invention).
This is the same method as the partial pressure of S).

In order to evaluate the step coverage, a silicon oxide film is formed on a substrate to be processed having a via hole having a hole diameter of 0.5 μm and a depth of 1 μm, and is formed on a flat portion of the substrate to be processed outside the via hole. The thickness B of the formed silicon oxide film is compared with the thickness A of the silicon oxide film formed at the bottom of the groove of the via hole (100 B / A). The same applies to the evaluation of step coverage (step coverage) in other figures.

From FIG. 3, when the raw material gas is TEOS (conventional), the step coverage is deteriorated when the rotation speed is increased, whereas when the raw material gas is TEDS (the present invention), the rotation speed is changed. It can be seen that when the temperature is raised, the step coverage is improved.

From FIGS. 2 and 3, it can be seen that by increasing the number of rotations, both the deposition rate of the silicon oxide film and the step coverage can be improved at the same time. The rotation speed is, for example,
500 rpm or more, particularly 1000 rpm or more is preferable.

FIG. 4 is a characteristic diagram showing the relationship between the rotational speed of the substrate to be processed (6 inch wafer) and the in-plane distribution of the film thickness at the film forming temperature of 800 ° C. From FIG. 4, when the rotation speed is 0 rpm, that is, when the substrate to be processed is not rotated, the uniformity of the in-plane film thickness is as high as 8% or more, whereas when the substrate to be processed is rotated. , The in-plane film thickness uniformity increases until the rotation speed increases to 1000 rpm, and
When the rpm is exceeded, the uniformity of the in-plane film thickness gradually increases, but the in-plane uniformity value itself is as low as 4% or less. That is,
A characteristic that a minimum is obtained when the rotation speed is 1000 rpm.

From FIG. 2, FIG. 3, and FIG. 4, it can be seen that by increasing the rotation speed to an appropriate level, the deposition rate of the silicon oxide film, the step coverage, and the in-plane film thickness uniformity can all be improved at the same time. .

In this embodiment, the pressure during film formation is set to 10
Although the film forming temperature was set to 0 Torr and 800 ° C., the film forming condition is not limited to this. For example, it was confirmed that even when the pressure during film formation was changed, by rotating the substrate at a speed equal to or higher than the linear velocity of gas, the same effect as in the case of the above film formation conditions was obtained.

It was also confirmed that there is a region where the number of rotations can be increased to the extent that convection is prevented even when the film forming temperature is changed. Furthermore, as a carrier gas, N
Instead of ₂ , another inert gas such as Ar or He may be used.

Further, as source gas, hexamethyldisiloxane, hexamethoxydisiloxane, octamethylcyclotetrasiloxane or 1,3,5,7-
Si-like tetramethylcyclotetrasiloxane
A compound having an O-Si bond may be used.

Next, the experimental results and the like that triggered the creation of the present invention will be described. The present inventors have tried to form a silicon oxide film by a high-speed rotation CVD method using TEOS as a source gas for the silicon oxide film. The results of this experiment are shown in FIGS.

FIG. 9 shows the film forming temperatures (800 ° C., 900 ° C.).
FIG. 9 is a characteristic diagram showing the relationship between the substrate rotation speed and the film formation rate at (° C.). From FIG. 9, when the film forming temperature is 800 ° C.,
It can be seen that when the substrate rotation speed is increased, the film formation rate becomes slower, while when the film formation temperature is 900 ° C., the film formation rate becomes faster when the substrate rotation speed is increased. It was also found that the in-plane film thickness uniformity was improved by increasing the rotation speed at any temperature.

FIG. 10 shows the film forming temperatures (800 ° C., 900 ° C.).
FIG. 9 is a characteristic diagram showing the relationship between the substrate rotation speed and the step coverage at (° C.). From FIG. 10, it is understood that when TEOS is used as the source gas, the step coverage deteriorates at any temperature.

The present inventors consider the reason why good step coverage cannot be obtained when TEOS is used as the source gas in this way. That is, according to the research conducted by the present inventors, whether or not the step coverage of the silicon oxide film formed by using TEOS is good or bad depends on the adsorption probability of the intermediate product reacted with TEOS in the gas phase on the substrate surface. it seems to do.

The step coverage is improved as the sticking probability decreases. In the case of TEOS, it is considered that its thermal decomposition process first becomes molecules having a silanol group in the gas phase and then further changes to a polymer such as hexaethoxydisiloxane (hereinafter referred to as HMOS).

Then, in the case of the high-speed rotation CVD method using TEOS as a raw material gas, a molecule having a silanol group is considered to be a reaction precursor. It is considered that the attachment probability of the molecule having this silanol group is four orders of magnitude or more higher than that of HMOS. This is because in the case of the high speed rotation CVD method, the temperature boundary layer having a temperature gradient existing on the substrate surface becomes thin, and TEOS
It is thought that it is difficult for the reaction from to HMOS to occur.

Therefore, in the case of the high-speed rotation CVD method using TEOS as the source gas for the silicon oxide film, the main reaction precursor contributing to film formation is a molecule having a silanol group with a high sticking probability, which causes a step difference. It is considered that the covering property is deteriorated.

On the other hand, in the case of the present invention, siloxane, which is an organic compound having a silicon-oxygen bond-silicon bond having a structure close to that of TEOS having a high degree of polymerization and having a low adsorption probability, is used as a source gas for the silicon oxide film. It is considered that the step coverage is improved due to the progress of film formation while suppressing the vapor phase growth because the substance containing is used. (Second Embodiment) By the way, according to the above consideration, TEO
It should be possible to improve the step coverage by controlling the reaction of S to generate only an intermediate product having a low adsorption probability in the gas phase.

In fact, the inventors of the present invention used TE as a source gas by using the following high-speed rotation CVD apparatus.
It was confirmed that a silicon oxide film having excellent step coverage can be formed even when OS is used.

That is, as the high-speed rotary CVD apparatus, one capable of keeping the flow of the raw material gas (TEOS) in the vapor phase in a laminar state and changing only the gas temperature distribution of the raw material was used. Specifically, a high-speed rotation CVD apparatus provided with a heating mechanism around the chamber was used.

According to such a high speed rotary CVD apparatus,
Since the amount of heat and the time that the source gas (TEOS) receives before reaching the substrate can be controlled, the TEOS polymerization reaction can be optimally controlled.

Therefore, only an intermediate product having a low adsorption probability can be produced, and a silicon oxide film excellent in step coverage can be formed. Further, it is possible to simultaneously realize the improvement of the film formation speed, which is an advantage of the high speed rotation, and the improvement of the in-plane uniformity of the film thickness.

Even when another organic silicon compound described later is used instead of TEOS, the reaction in the gas phase is controlled, and only an intermediate product having a low adsorption probability is generated, so that the step The coatability can be improved.

FIG. 5 shows a second embodiment of the present invention based on the above findings.
It is a schematic diagram which shows schematic structure of the vapor phase growth apparatus which concerns on the Example of this. In the figure, reference numeral 11 denotes a quartz chamber, and an exhaust pump 12 is provided above the chamber 11. The exhaust pump 12 is for exhausting the gas in the chamber 11.

A susceptor 15 for mounting a substrate 16 to be processed is provided in the upper part of the chamber 11. The susceptor 15 can be rotated about the center of the substrate 16 to be processed by a rotating means (not shown) such as a motor. Further, the susceptor 15 is provided with a resistance heater 17 for heating the substrate 16 to be processed from its back surface. Furthermore, the susceptor 15 has a vacuum chuck structure for fixing the substrate 16 to be processed facedown. That is, in the present embodiment, the generation of thermal convection is suppressed by fixing the substrate 16 to be processed facedown.

On the other hand, gas supply pipes 14 ₁ , 14 ₂ and 14 ₃ are provided in the lower part of the chamber 11. These three gas supply pipes 14 ₁ , 14 ₂ and 14 ₃ respectively supply TEOS, O ₂ and N ₂ gases into the chamber 11, and these gases are provided below the susceptor 15 inside the chamber 11. Is supplied to the substrate 16 to be processed, etc. Although the area of the clear stream plate 13 is the same as the area of the substrate 16 to be processed,
For example, it is preferable that the area of the substrate 16 to be processed is twice or less in terms of operability and gas flow characteristics.

A side heater 18 is provided outside the side surface of the chamber 11 so as to surround the chamber 11. The side heater 28 can heat the inner surface of the chamber 11 to a predetermined temperature.

Next, the high speed rotation CV constructed as described above.
A method of forming a silicon oxide film using the D device will be described. First, a silicon substrate as the substrate 16 to be processed is set on the susceptor 15, the inside of the chamber 11 is replaced with N ₂ gas, and then the side surface of the chamber 11 is heated to 500 to 900 ° C. by the side surface heater 28.

Next, the resistance heating heater 17 heats the silicon substrate 16 to a film forming temperature of about 650 to 950 ° C. and rotates the silicon substrate 16 at 0 to 2000 rpm.

Next, 20 sccc of TEOS is used as a source gas.
m and O ₂ are introduced into the chamber 11 at a flow rate of ₁ s1 m and N ₂ at a flow rate of 10 s1 m. At this time, the total pressure of the above three gases is set to 100 Torr.

The silicon substrate 1 is formed by such a film forming method.
It is possible to form a silicon oxide film having high in-plane film thickness uniformity and excellent step coverage on the film 6 at high speed. FIG.
It is a characteristic view which shows the relationship between the temperature of the side heater 18 and the step coverage. This is a case where the surface temperature of the silicon substrate 16 is set to 800 ° C. by the resistance heater 17 and the silicon substrate 16 is rotated at 1000 rpm.

From FIG. 6, it is understood that when the side wall heater 17 does not heat the side wall of the chamber 11, that is, in the case of the conventional method, the step coverage is as low as 75%. Further, it can be seen that when the heater temperature is in the range of 500 to 750 ° C., the higher the temperature is, the higher the step coverage is. And, a peak value of 95% or more is obtained near 800 ° C,
It can be seen that when the temperature exceeds about 800 ° C., the step coverage is lowered. The film formation rate was as large as 30 nm / min regardless of the temperature of the side heater 17.

It is considered that the experimental results were obtained because the side heater 28 heated the chamber 11 to a temperature at which an intermediate product of TEOS having a low adsorption probability was likely to be produced. In addition, when the temperature of the side heater 28 is lower than the substrate temperature, the result that the step coverage is generally good was obtained.

FIG. 7 is a characteristic diagram showing the relationship between the rotation speed of the silicon substrate 16 and the step coverage. The surface temperature of the silicon substrate 16 is set to 800 by the resistance heater 17.
This is the case where the temperature of the side heater 17 is set to 750 ° C. and the temperature of the side heater 17 is set to 750 ° C.

From FIG. 7, in the rotation speed range of 0 to 1000 rpm, the higher the rotation speed, the higher the step coverage ratio, and when the rotation speed exceeds 1000 rpm, the higher the rotation speed, the lower the step coverage ratio. I understand. 500-20
It can be seen that particularly preferable step coverage is obtained when the rotation speed is 00 rpm.

The results of such an experiment can be explained as follows. That is, when the rotation speed is too low, TEOS and the polymer are mixed in the gas phase in the turbulent state to reach the substrate, and it is considered that the step coverage is deteriorated. On the other hand, if the rotation speed is too high, the amount of gas drawn by the rotation of the substrate increases, and turbulent flow occurs, which may deteriorate the step coverage.

In this embodiment, TE is used as the source gas.
Although OS was used, other source gases such as tetramethoxysilane, tetrapropoxysilane, hexamethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-
Dimethyldisiloxane, hexaethoxydisiloxane,
Octamethylcyclotetrasiloxane, 1,3,5,7
-Using an organic silicon compound such as tetramethylcyclotetrasiloxane, fluorotriethoxysilane, fluorotrimethoxysilane, and fluorotriisopropoxysilane, a high film formation rate, high step coverage, as in the present embodiment.
High in-plane film thickness uniformity can be realized.

Even when fluorotriethoxysilane, fluorotrimethoxysilane or fluorotriisopropoxysilane and H ₂ O are used, by increasing the rotation speed, a high film formation rate, high step coverage, and high in-plane coverage can be obtained. Uniformity of film thickness can be realized.

Further, even when TEOS / O ₃ is used, by increasing the number of rotations, similarly, a high film forming rate,
High step coverage and high in-plane film thickness uniformity can be realized. In addition,
Although TEOS is used in the present embodiment, similar to the first embodiment, even if TEDS and a gas (a gas containing a siloxane-containing substance) similar to TEDS are used, a high film formation rate, a high step coverage, and a high surface area can be obtained. Uniform inner film thickness can be realized. (Third Embodiment) FIG. 8 is a schematic diagram showing a schematic structure of a high speed rotation CVD apparatus according to a third embodiment of the present invention. The portion corresponding to the high-speed rotation CVD apparatus of FIG.
Are denoted by the same reference numerals, and detailed description will be omitted.

The high-speed rotation CVD apparatus of this embodiment is different from that of the second embodiment in that the source gas can be made to flow while the purge gas such as N ₂ is being made to flow into the chamber 11. In order to realize this, in the high speed rotation CVD apparatus of the present embodiment, the purge pipe 19 that is a dedicated pipe for introducing the purge gas is provided on the lower side wall of the chamber 11.
Is provided.

Further, the partition plate 20 is provided below the chamber 11 so that the purge gas supplied from the purge pipe 19 and the source gas are not mixed in the lower portion of the chamber 11.
Is provided. As a result, the source gas is supplied to the chamber 1
1, the purge gas is supplied from the central portion of the lower portion of the chamber 1, and the purge gas is introduced from the peripheral portion of the lower portion of the chamber 11.

The flow velocity of the purge gas is approximately the same as the flow velocity of the source gas. At this time, if the silicon substrate material 16 rotates at a peripheral speed faster than the introduced gas such as the purge gas and the raw material gas, the purge gas and the raw material gas reach the silicon substrate 16 in a laminar state, so that the raw material is supplied to the inner wall of the chamber 11. It becomes difficult for the gas to reach, the consumption of the raw material gas on the inner wall becomes small, and particles are reduced. Therefore, the number of times of cleaning the inner wall can be reduced, and the efficiency of use of the device can be improved. (Fourth Embodiment) FIG. 11 is a schematic view showing the schematic arrangement of a high speed rotation CVD apparatus according to the fourth embodiment of the present invention.
FIG. 12 is a plan view of the same device as seen from above inside.

This high-speed rotary CVD apparatus is roughly divided into a load lock chamber 32 and a chamber 33 which is a film formation chamber connected to the load lock chamber 32 via a gate valve 39. The bottoms of the load lock chamber 32 and the chamber 33 are connected to an exhaust pump (not shown).

A susceptor 35 for mounting the substrate 31 to be processed is provided at the bottom of the chamber 33. The susceptor 35 can be rotated about the center of the substrate 31 to be processed by a motor 38. further,
The susceptor 35 is provided with a resistance heater 34 for heating the substrate 31 to be processed from its back surface.

On the other hand, nitrogen gas (purge gas) and oxygen gas (raw material gas) are introduced into the upper portion of the chamber 33,
A perforated plate 36 for gas introduction having a large number of nozzles is provided.

A linear nozzle 37 for introducing a raw material gas and having a linear nozzle is provided between the gas introducing porous plate 36 and the substrate 31 to be treated. This linear nozzle 37
It is arranged in a substantially parallel relationship (including a parallel relationship) with the substrate 31 to be processed.

As shown in FIG. 12, the gas-introducing porous plate 36 is a circular porous plate having a size that completely covers the entire surface of the circular substrate 31 to be processed. Further, as shown in FIG. 12, the linear nozzle 37 is a linear nozzle that passes through the rotation center of the substrate 31 to be processed and has a length larger than the diameter of the substrate 31 to be processed.

Further, the linear nozzle 37 is heated to a predetermined temperature by the resistance heater 34 or a heating means (not shown) provided outside the chamber 33.

Next, the high speed rotation CV constructed as described above.
A method of forming a silicon oxide film using the D device will be described. First, a silicon substrate as the substrate 33 to be processed is introduced into the chamber 33 through the load lock chamber 32, and then the silicon substrate 33 is held on the susceptor 35.

Next, about 20 slm of nitrogen gas and oxygen gas are introduced from the porous plate 36 for introducing gas, and the susceptor 35 is rotated at a speed of about 1000 rpm. The nitrogen gas and the oxygen gas are mixed by the gas introducing porous plate 36 and supplied to the silicon substrate 33.

Next, the resistance heater 34 raises the temperature of the silicon substrate 31 to about 700.degree. At this time, chamber 3
The temperature of 3 and the porous plate 36 for introducing gas is room temperature. Next, with the linear nozzle 371 heated to about 150 ° C., TEOS gas is introduced from the linear nozzle 37 at about 100 sccm.

If the TEOS gas is supplied while the linear nozzle 37 is heated in this manner, the TEOS gas having a low vapor pressure will not condense inside the linear nozzle 37, so that the silicon substrate 31 will not be condensed. It becomes possible to supply the TEOS gas uniformly.

FIG. 13 shows the film thickness distribution of the silicon oxide film (SiO ₂ ) obtained by the method of this embodiment in the plane of the 8-inch substrate in comparison with that of the conventional method. In the conventional method, since the raw material gas is condensed, it is impossible to uniformly supply the gas, the uniformity of the film thickness is extremely low, and at the same time, a sufficient film formation rate cannot be obtained.

On the other hand, in the case of the method of the present embodiment, the in-plane variation is as small as 5% or less, and a highly uniform film formation can be realized. Furthermore, it has been found that high-speed deposition of 10 times or more as compared with the conventional method is possible.

Further, in the method of this embodiment, an experiment was conducted without rotating the substrate to be processed (silicon substrate). As a result, film thickness unevenness occurred corresponding to the position of the linear nozzle, and the accurate film thickness was obtained. It turned out to be out of control.

When the rotation speed of the substrate to be treated is 100 rpm or more, good film deposition can be started, and particularly 500 is possible.
In the case of rpm or more, it was possible to achieve both a high film formation rate and a high in-plane film thickness uniformity. On the other hand, it has been found that it is difficult to obtain a sufficient film formation speed when the rotation speed is low. The upper limit of the rotation speed is preferably 10,000 rpm.

In this example, a linear nozzle having a length larger than the diameter of the substrate to be processed was used.
As shown in FIG. 5, it was confirmed that even if the linear nozzle 37a having the same length as the radius of the substrate 31 to be processed is used, the film can be formed at a high film forming speed and a high in-plane film thickness uniformity. The linear nozzle 37a does not have to have the same length as the radius of the substrate 31 to be processed, but may be disposed so that at least a part thereof is in contact with the extension line of the rotation center axis.

In this case, as shown in FIG. 14, it was found that good in-plane film thickness uniformity can be obtained especially when the number of revolutions of the substrate to be treated is 700 revolutions or more. It is considered that this is because the influence of the linear nozzle being asymmetrical with respect to the rotation axis can be eliminated by increasing the rotation speed and increasing the flow velocity parallel to the substrate to be processed. Further, it can be seen from FIG. 14 that both the film formation rate and the in-plane film thickness uniformity can be improved by further increasing the rotation speed.

Further, as shown in FIG. 15 (b), a plurality of linear nozzles 37b are installed radially from the central axis of rotation, and
More than one kind of gas may be supplied independently. It should be noted that the plurality of linear nozzles 37b need not be radial and may be installed symmetrically with respect to the rotation center axis.

Even if such a linear nozzle 37b is used, the same effect as that of the above-described linear nozzles 37a and 37b can be obtained. Furthermore, the reaction of the raw material gases (reactive gases) in the linear noise in the gas phase can be suppressed, and the effect of eliminating clogging of the nozzle and generation of dust can be obtained.

For example, each gas of tungsten hexafluoride (WF ₆ ) gas and silane (SiH ₄ ) gas is supplied from an independent linear nozzle, and hydrogen (H ₂ ) gas is supplied from a gas introducing porous plate. By supplying, it is possible to prevent the generation of tungsten silicide (WSix) in the linear gas when forming the tungsten (W) film on the substrate to be processed, and to prevent clogging of the nozzle and generation of dust.

Up to now, the source gases have been supplied independently,
As a means for suppressing the reaction in the gas phase (nozzle), WF
_An attempt to supply ₆ gas and SiH ₄ gas from nozzles arranged alternately has been reported. However, in this case, in order to obtain uniformity in the surface of the substrate, it is necessary to install complicated alternate nozzles on the entire surface of the substrate, and it is impossible to eliminate the influence of thermal convection. No such effect was obtained. (Fifth Embodiment) In the fourth embodiment, the film formation of the silicon oxide film which is the insulating film has been described, but the present invention can also be applied to the film formation of a conductive film, for example, a boron-doped polycrystalline silicon film. . As the film forming apparatus, a high-speed rotation CVD apparatus similar to that of the fourth embodiment is used, but the introduced gas is different.

That is, from the gas introducing porous plate 36, S
While introducing iH ₄ gas and H ₂ gas, diborane (B ₂ H ₆ ) gas is introduced from a linear nozzle to form a boron-doped polycrystalline silicon film.

At this time, the flow rate of the SiH ₄ gas is, for example, 5
The flow rate of the H ₂ gas is, for example, 20 slm.
And the mixed gas pressure of SiH ₄ gas and H ₂ gas in the chamber is 100 Torr. The flow rate of B ₂ H ₆ gas is, eg, 100 sccm. The substrate temperature is, for example, 600 ° C., and the substrate rotation speed is, for example, 1000 r.
pm.

According to such a film forming method, the in-plane uniformity of the resistivity of the boron-doped polycrystalline silicon film can be suppressed within 5%. That is, the in-plane uniformity of boron concentration in the boron-doped polycrystalline silicon film was sufficiently high. further,
The in-plane uniformity of the thickness of the boron-doped polycrystalline silicon film was also sufficiently high.

On the other hand, the conventional film forming method (without the linear nozzle,
High-speed CVD that introduces all gases from the perforated plate for gas introduction
It was confirmed that the boron concentration in the boron-doped polycrystalline silicon film has a concentration distribution corresponding to the position of the nozzle (the porous hole from which the gas is ejected) of the porous plate for introducing gas. Similarly, it was confirmed that the film thickness of the boron-doped polycrystalline silicon film also varies depending on the position of the nozzle of the porous plate for gas introduction. These means that the gas introduction porous plate alone produces a concentration distribution in the source gas containing boron that reaches the substrate surface.

In the fourth and fifth embodiments, the case of film formation has been described, but it can be easily applied to etching by introducing the etching gas or the like from the gas introducing porous plate or the linear nozzle. .

Further, the high-speed rotary CVD apparatus of the fourth and fifth embodiments, which is characterized by adding a linear nozzle, and the first to third embodiments, which are characterized by the raw material gas, are appropriately combined. Is also good. In addition, various modifications can be made without departing from the scope of the present invention.

[0093]

As described in detail above, according to the present invention, when a silicon oxide film is formed on a substrate to be processed by a vapor phase growth method, a gas of a substance containing siloxane is used as a source gas for the silicon oxide film. By rotating the substrate to be processed during film formation, a silicon oxide film having excellent film thickness uniformity and step coverage can be formed on the substrate to be processed at high speed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a high-speed rotation CVD apparatus according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between the number of rotations of a substrate to be processed and a film forming speed.

FIG. 3 is a characteristic diagram showing the relationship between the number of revolutions of the substrate to be processed and the step coverage.

FIG. 4 is a characteristic diagram showing the relationship between the rotational speed of the substrate to be processed and the in-plane distribution of film thickness.

FIG. 5 is a schematic diagram showing a schematic configuration of a vapor phase growth apparatus according to a second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a relationship between temperature and step coverage.

FIG. 7 is a characteristic diagram showing the relationship between the number of rotations of the substrate to be processed and the step coverage.

FIG. 8 is a schematic diagram showing a schematic configuration of a high speed rotation CVD apparatus according to a third embodiment of the present invention.

FIG. 9 is a characteristic diagram showing the relationship among the substrate rotation speed, the film formation rate, and the film formation temperature.

FIG. 10 is a characteristic diagram showing the relationship between the substrate rotation speed, step coverage and film formation temperature.

FIG. 11 is a high-speed rotation CVD according to a fourth embodiment of the present invention.
Schematic diagram showing the schematic configuration of the device

FIG. 12 is a plan view of the high-speed rotation CVD apparatus of FIG. 11 seen from above inside.

FIG. 13 is a characteristic diagram showing the relationship between the distance from the center and the film thickness variation.

FIG. 14 is a characteristic diagram showing the relationship between the rotation speed, the in-plane variation, and the deposition rate.

FIG. 15 is a diagram showing an example of another linear nozzle.

[Explanation of Codes] 1 ... Chamber 2 ... Exhaust Pump 3 _{1 to} 3 ₄ ... Gas Supply Pipe 4 ... Rectifier Plate 5 ... Susceptor 6 ... Substrate (Si Substrate) 7 ... Resistance Heater 11 ... Chamber 12 ... Exhaust Pump 13 ... Rectifier plate 14 _{1 to} 14 ₃ ... Gas supply pipe 15 ... Susceptor 16 ... Substrate (silicon substrate) 17 ... Resistance heating heater 18 ... Side heater 19 ... Purge pipe 20 ... Partition plate 31 ... Substrate (silicon) Substrate) 32 ... Load lock chamber 33 ... Chamber 34 ... Resistance heater 35 ... Susceptor 36 ... Gas introduction perforated plate 37, 37a, 37b ... Linear nozzle 38 ... Motor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Iwao Kunishima 1 Komukai Toshiba-cho, Kouki-ku, Kawasaki-shi, Kanagawa Prefecture Corporate Research & Development Center

Claims (3)

[Claims] 1. When forming a silicon oxide film on a substrate to be processed by a vapor phase epitaxy method, a gas of a substance containing siloxane is used as a source gas of the silicon oxide film, and at the time of forming the silicon oxide film. A method of manufacturing a semiconductor device, comprising rotating a substrate to be processed. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the rotation of the substrate to be processed is such that the peripheral speed of the outer periphery of the substrate to be processed is equal to or higher than the linear velocity of the raw material gas. . 3. The raw material gas is hexamethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, hexaethoxydisiloxane, octamethylcyclotetrasiloxane or 1,3,5. , 7-
The method for manufacturing a semiconductor device according to claim 1, wherein the gas is tetramethylcyclotetrasiloxane.