JPH06173012A - Gaseous mixed cleaning composition - Google Patents

Abstract

PURPOSE:To easily remove an SiO2 film sticking to the inside of a reactor and an incompletely decomposed product, of alkoxysilane deposited in the reactor and piping by using a compsn. prepd. by mixing gaseous HF with gaseous ClF3 within a specified range. CONSTITUTION:A gaseous mixture of gaseous HF with gaseous ClF3, is prepd. as a mixed cleaning compsn. so as to satisfy the inequality (where (a) is the concn. (vol.%) of ClF3, (b) is the concn. (vol.%) of HF and P is the internal pressure (Torr) of a system). A device for forming a silicon oxide film is cleaned with the gaseous mixture. An SiO2 film sticking to parts at a high temp. is rapidly removed by a reaction with the ClF3 and an incompletely decomposed product of alkoxysilane (starting material) deposited in a low temp. parts such as piping and the flange of a reactor is removed by a reaction with the HF.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the inside of a reactor of a silicon oxide film forming apparatus using alkoxysilane as a raw material,
The present invention relates to a mixed cleaning gas composition for removing an SiO ₂ film attached to a jig, the inside of a reactor, a jig, and a non-complete decomposition product of alkoxysilane deposited in a pipe connected to the device.

[0002]

2. Description of the Related Art When alkoxysilane is used as a raw material and SiO ₂ is deposited by CVD (thermal CVD, plasma CVD), the temperature is high (400 to 900 ° C.) on the reactor wall. SiO ₂ with completely decomposed alkoxysilane has a low temperature (400 ° C
Below) A large amount of a compound containing C, H, O, and Si in which the alkoxysilane is incompletely decomposed adheres to the reactor wall, the apparatus jig, and the inside of the pipe. Accumulation of such a large amount of particles causes generation of particles in the reactor, and the phenomenon that the pressure of the reaction system fluctuates due to clogging of the pipes and the like, making it difficult to maintain normal reaction conditions. Therefore, these deposits must be removed from time to time.

As a current method of removing these deposits, a method of disassembling the apparatus and rubbing it by manpower, a wet cleaning method of removing it with a strong acid aqueous solution such as hydrofluoric acid, and the like are generally performed. However, these methods have a disadvantage that it takes a long time to perform the complicated work such as disassembling, assembling and taking out a jig. Further, as a method for cleaning the SiO ₂ film adhered in the reaction chamber, N
Plasma cleaning with F ₃ is being performed. However, this method cannot clean the outside of the plasma atmosphere, and naturally cannot clean the inside of the piping. Further, a film forming apparatus that does not have a device for generating plasma cannot be cleaned.

On the other hand, plasma rescreening using F ₂ , ClF ₃ and hydrofluoric acid vapor is also conceivable.
_{If 2} or ClF ₃ is used, the SiO ₂ film inside the reactor can be removed, but when it is brought into contact with the incompletely decomposed product of alkoxysilane in the pipe, a powder of SiO ₂ composition is produced and the number of particles in the reactor increases. Further, when hydrofluoric acid vapor is used, the metal such as stainless steel and quartz, which are the materials of the pipes and the reactor, are severely damaged, which is not preferable.

Further, plasma re-screening using hydrogen fluoride can be considered. With this method, the deposits in the piping can be completely removed without damaging the material of the equipment, but the etching rate for the SiO ₂ film deposited inside the reactor is very slow, and the SiO ₂ film inside the reactor can be removed. It is not practical to remove it.

[0006] Therefore, using alkoxysilane, Si
SiO ₂ attached inside the reactor of the apparatus for forming the O ₂ film
Incomplete decomposition products of alkoxysilane deposited in the membrane and piping or in the reactor without damaging the equipment materials,
There is a demand for a simple and simultaneous removal method that does not require complicated operations such as disassembling the apparatus.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors, by using a mixed cleaning gas composition containing HF gas and ClF ₃ gas in a specific range, SiO ₂ using alkoxysilane as a raw material can be used. A method of cleaning the film forming apparatus has been found.

That is, the present invention has the general formula (I)

[0009]

[Equation 2]

The present invention provides a mixed cleaning gas composition containing HF gas and ClF ₃ gas in the range indicated by.
In the present invention, the alkoxysilane used as a raw material has a general formula of (RO) _n SiX _4-n or (RO) _n SiR ′ _4-n [wherein X is a halogen atom and R and R ′ are independent of each other. An alkyl group, an aryl group, a glycidoxyalkyl group,
Acryloxyalkyl group, methacryloxyalkyl group,
Alternatively, it represents a vinyl group, and n is 0 or an integer of 1 to 4. ] A compound represented by, for example, monomethoxytrichlorosilane, dimethoxydichlorosilane, trimethoxymonochlorosilane, monoethoxytrichlorosilane, diethoxydichlorosilane, triethoxymonochlorosilane, monoallyloxytrichlorosilane, diaryloxydiene Chlorosilane, monomethoxytrifluorosilane,
Dimethoxydifluorosilane, trimethoxymonofluorosilane, monoethoxytrifluorosilane, diethoxydifluorosilane, triethoxymonofluorosilane, monoallyloxytrifluorosilane, diaryloxydifluorosilane, tetramethoxysilane, tetraethoxysilane , Tetrapropoxysilane, tetrabutoxysilane, monomethyltrimethoxysilane, monoethyltrimethoxysilane, monoethyltriethoxysilane, monoethyltriethoxysilane, monoethyltributoxysilane, monophenyltrimethoxysilane, monophenyltriethoxysilane, Dimethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diethyldibutoxysilane, vinylmethyldimethoxysilane , Vinylethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, β-methacryloxyethyltrimethoxysilane, β -Methacryloxyethyltriethoxysilane, β-glycyloxyethyltrimethoxysilane,
β-glycyloxyethyltriethoxysilane, γ-propyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and the like can be mentioned.

In the present invention, within the ratio range of the formula (I)
HF gas and ClF₃Device using mixed gas of gas
By cleaning the inside of the reactor and
SiO deposited in the tube₂Membrane and incomplete alkoxysilane
The debris can be completely removed. That is, the temperature is
SiO adhered to the high part (400-900 ° C) ₂
Membrane ClF₃To quickly remove the reaction with a pipe or reactor
Arcoki deposited in low temperature areas (400 ° C or less)
A non-complete decomposition product of silane is removed by reaction with HF.
It In this case, the upper limit of the mixing ratio depends on the pressure.
On the other hand, if the concentration exceeds the ratio range of formula (I), ClF₃With
When cleaning with the added gas,
Incomplete decomposition of orchids could not be completely removed, resulting in residue.
As it causes increase of particles in the reactor,
SiO₂It becomes impossible to form a film.

In the present invention, only ClF ₃ and HF may be used as the cleaning gas, but N ₂ , Ar and H may be appropriately used in consideration of process conditions such as exhaust gas treatment and a supply device.
The reaction gas may be diluted with an inert gas such as e.
In addition to the inert gas as the diluent gas, other fluoride gas such as F ₂ and other halogen gas, oxygen, etc. for the purpose of improving the etching rate of the SiO ₂ film which is a completely decomposed product adhered to the reactor wall. , Hydrogen or the like may be added.

In the present invention, the cleaning temperature is preferably higher considering the removal rate of deposits. Therefore, the cleaning temperature may be appropriately determined in consideration of the corrosion resistance of the device material to ClF ₃ . However, when the pipe is heated, the temperature is preferably 100 ° C. or lower from the viewpoint of work safety (however, this is not the case when a heat insulating material is used).

Next, the system pressure is not particularly limited, and normal pressure or reduced pressure is usually applied. From the viewpoint of the deposit removal rate, it is preferable that it is high, but it may be appropriately selected in consideration of the device structure and the like. Further, a higher HF concentration is more advantageous in terms of removal rate, but it may be selected in consideration of the relationship with other conditions. For example, the system internal pressure during cleaning is 100 Torr
In case of 700 Torr, the HF concentration is diluted to 50 vol% or less with an inert gas such as nitrogen or argon, and the superficial velocity is 0.1 SL.
Cleaning with M-100 SLM is preferred.
However, when cleaning can be performed only at a pressure of 100 Torr or less due to the structure of the film forming apparatus, the cleaning conditions may be selected within a range of a concentration of 1 to 100 vol% and a superficial velocity of 0.1 SLM to 100 SLM. In addition, the higher the mixing ratio, the higher the ClF ₃ concentration, but within the range of the formula (I) in consideration of the amount of deposited SiO ₂ film, the amount of incomplete decomposition products, the equipment conditions, and the process conditions (time, pressure, temperature). You can select with time.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 73, Comparative Examples 1 to 56 Thermal CVD using TEOS (tetraethoxysilane) as a raw material.
Transparent glass-like substances, semi-transparent glass-like substances, and white cullet-like substances were attached to the exhaust pipe of the apparatus at (800 ° C.). When this deposit was subjected to elemental analysis using a fluorescent X-ray analyzer, an elemental analyzer and ICP, each of the compounds contained Si, C, H, and O It was found that the composition was SiCH ₁₂ O ₃ , the translucent glass-like material was SiCH ₁₀ O ₂ , and the white material was SiC _0.5 H ₂ O. When these were reacted with HF gas and the reaction products were identified, H ₂ O, CH ₄ ,
It was confirmed that H ₂ and SiF ₄ were present.

The compounds containing these three kinds of Si, C, H and O (TEOS incompletely decomposed products) were placed in separate nickel boats under the conditions shown in Tables 1 to 8 and HF gas and ClF _{3 were used.}
Attempted reaction removal in mixed gas atmosphere of gas (total flow rate 1
0SLM). The reaction gas was used after diluting it with N _{2 as} needed. As a result, within the mixing ratio region shown in FIG.
It was found that incomplete decomposition products of OS can be completely removed by reaction regardless of the cleaning temperature. The results are shown in FIGS. 1 to 3 (in the figure, ◯ indicates a good cleaning portion, and x indicates a defective portion).

Elemental analysis of the residue revealed that it had a SiO ₂ composition containing almost no C or H.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

[0024]

[Table 6]

[0025]

[Table 7]

[0026]

[Table 8]

Comparative Example 57 The above three types of incompletely decomposed TEOS (100 g) were treated with ClF.
_{When three} gases (760 Torr, 100 vol%, 300 ° C.) were tried to be removed by reaction, none of the incomplete decomposed products could be completely removed by reaction, and a residue of 10 to 25 wt% remained. Elemental analysis of this residue revealed a SiO ₂ composition.

Example 74 Using a non-completely decomposed product produced when pyrolyzing monofluorotriethoxysilane and tetramethoxysilane, H
Mixed gas of F gas and ClF ₃ gas or HF gas, C
The results of the reaction removal test performed with a mixed gas of 1F ₃ gas and N ₂ gas are shown in FIGS. 4 and 5 (in the drawings, ◯ indicates a good cleaning portion, and × indicates a defective portion). From this result, it was found that the reaction can be completely removed in the region of the mixing ratio of the formula (I) as in the case of TEOS.

Example 75 A silicon wafer was subjected to thermal CVD using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF1
0 vol%, ClF ₃4vol%, N₂86 vol%), system pressure 7
It was distributed at 60 Torr for 1 hour. Then dismantle the device
On the silicon wafer₂Observation of film thickness and inside of piping
I made SiO₂Complete removal of both film and deposits in piping
I was coming.

Example 76 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF1
0 vol%, ClF ₃1vol%, N₂89vol%), system pressure 7
It was distributed at 60 Torr for 1 hour. Then dismantle the device
On the silicon wafer₂Observation of film thickness and inside of piping
I made SiO₂Complete removal of both film and deposits in piping
I was coming.

Example 77 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF1
0 vol%, ClF ₃9.75vol%, N₂80.25vol
%) And the system pressure was 760 Torr for 1 hour. So
After dismantling the device, SiO on the silicon wafer₂Film thickness and
When observing the inside of the pipe, SiO₂Both membranes and deposits in piping
Was completely removed.

Comparative Example 58 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF1
0 vol%, ClF ₃9.80vol%, N₂80.20vol
%) And the system pressure was 760 Torr for 1 hour. So
After dismantling the device, SiO on the silicon wafer₂Film thickness and
When observing the inside of the pipe, SiO₂The membrane can be completely removed
However, SiO was trapped in the trap attached to the piping.₂set
A residual powdery residue remained (weight <1 mg).

Example 78 A silicon wafer was subjected to thermal CVD using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF2
0 vol%, ClF ₃10vol%, N₂70vol%), system pressure 2
It was circulated at 00 Torr for 1 hour. Then dismantle the device
On the silicon wafer₂Observation of film thickness and inside of piping
I made SiO₂Complete removal of both film and deposits in piping
I was coming.

Example 79 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF2
0 vol%, ClF ₃7vol%, N₂73 vol%), system power 10
It was circulated for 1 hour at 0 Torr. Then dismantle the device,
SiO on silicon wafer₂The film thickness and the inside of the pipe were observed
By the way SiO₂Can completely remove both film and deposits in piping
I was there.

Comparative Example 59 TEOS was used as a raw material and thermal CVD was carried out to deposit a SiO ₂ film (about 1 μm) on a silicon wafer. ClF ₃
Gas and N ₂ gas mixed gas at a flow rate of 10 SLM (HF20
vol%, ClF ₃ 8 vol%, N ₂ 72 vol%), system pressure 10
It was circulated for 1 hour at 0 Torr. Then dismantle the device,
Observation of the SiO ₂ film thickness on the silicon wafer and the inside of the pipe showed that the SiO ₂ film was completely removed, but a powdery residue of the SiO ₂ composition remained in the trap attached to the pipe (weight). <1 mg).

Example 80 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF8
0 vol%, ClF ₃8.95vol%, N₂11.05vol
%) And the system pressure was 10 Torr for 1 hour. That
After dismantling the device, SiO on the silicon wafer₂Film thickness and distribution
When the inside of the tube was observed, SiO₂Both film and deposits in piping
It was completely removed.

Example 81 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF5
0 vol%, ClF ₃5.60vol%, N₂44.40vol
%) And the system pressure was 10 Torr for 1 hour. That
After dismantling the device, SiO on the silicon wafer₂Film thickness and distribution
When the inside of the tube was observed, SiO₂Both film and deposits in piping
It was completely removed.

COMPARATIVE EXAMPLE 60 TEOS was used as a raw material and thermal CVD was carried out to deposit a SiO ₂ film (about 1 μm) on a silicon wafer. ClF ₃
Gas and N ₂ gas mixed gas at a flow rate of 10 SLM (HF50
vol%, ClF ₃ 6 vol%, N ₂ 44 vol%), system pressure 10
It was circulated for 1 hour at Torr. After that, the device was disassembled, and the SiO ₂ film thickness on the silicon wafer and the inside of the pipe were observed. As a result, the SiO ₂ film was completely removed. However, the powdery residue of the SiO ₂ composition remained in the trap attached to the pipe part. Remained (weight <1 mg).

Example 82 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF9
0 vol%, ClF ₃3.20vol%, N₂6.80vol%),
It was circulated for 2 hours at a system pressure of 1 Torr. Then the device
Disassembled, SiO on the silicon wafer₂The film thickness and the inside of the pipe
Observed SiO₂Completely removes both film and deposits in piping
It was gone.

Comparative Example 61 On a silicon wafer, thermal CVD was performed using TEOS as a raw material.
On SiO₂Film forming device (pipe for depositing film (about 1 μm)
HF gas, ClF to the medium deposit average film thickness of about 0.1 mm)₃
Gas, N₂The total flow rate of mixed gas is 10 SLM (HF9
0 vol%, ClF ₃4vol%, N₂6vol%), system pressure 1T
It was circulated at orr for 2 hours. Then dismantle the device and
SiO on conwafer₂The film thickness and the inside of the pipe were observed.
SiO ₂The membrane was completely removed, but
SiO in the attached trap₂The powdery residue of the composition remains
(Weight <1 mg).

Example 83 A film forming apparatus in which thermal CVD was performed using monofluorotriethoxysilane as a raw material and a SiO ₂ film (about 1 μm) was deposited on a silicon wafer (average film thickness of deposits in a pipe was about 0.1 m).
m) mixed gas of HF gas, ClF ₃ gas and N ₂ gas at a total flow rate of 10 SLM (HF 90 vol%, ClF ₃ 3.20 vo).
1%, N ₂ 6.80 vol%) and the system pressure was 1 Torr. Then the device was disassembled, SiO ₂ film was observed with the piping and SiO ₂ film thickness on a silicon wafer,
The deposits in the pipe could be completely removed.

Comparative Example 62 A film forming apparatus in which thermal CVD was performed using monofluorotriethoxysilane as a raw material and an SiO ₂ film (about 1 μm) was deposited on a silicon wafer (average film thickness of deposit in pipe: about 0.1 m)
m) mixed gas of HF gas, ClF ₃ gas and N ₂ gas at a total flow rate of 10 SLM (HF 90 vol%, ClF _{3 4} vol%, N
₂ 6 vol%), was passed through for 2 hours at system pressure 1 Torr.
After that, the device was disassembled, and the SiO ₂ film thickness on the silicon wafer and the inside of the pipe were observed. As a result, the SiO ₂ film was completely removed, but powdery residue of the SiO ₂ composition was found in the trap attached to the pipe part. It remained (weight <1 mg).

Example 84 A film-forming apparatus in which thermal CVD was performed using monofluorotriethoxysilane as a raw material to deposit a SiO ₂ film (about 1 μm) on a silicon wafer (average film thickness of deposits in a pipe was about 0.1 m).
m) is a mixed gas of HF gas, ClF ₃ gas, and N ₂ gas at a total flow rate of 10 SLM (HF 20 vol%, ClF ₃ 19.45).
vol%, N ₂ 60.55 vol%), system pressure 760 Torr
It was distributed for 1 hour. After that, the device was disassembled, and the SiO ₂ film thickness on the silicon wafer and the inside of the pipe were observed.
Both the O ₂ film and the deposit in the pipe could be completely removed.

Comparative Example 63 A film-forming apparatus (average film thickness of deposits in pipes of about 0.1 m) was obtained by depositing a SiO ₂ film (about 1 μm) on a silicon wafer by thermal CVD using monofluorotriethoxysilane as a raw material.
m) is a mixed gas of HF gas, ClF ₃ gas, and N ₂ gas at a total flow rate of 10 SLM (HF 20 vol%, ClF ₃ 20 vol%,
N ₂ 60 vol%) and the system pressure was 760 Torr for 2 hours. After that, the device was disassembled and Si on the silicon wafer was
When the O ₂ film thickness and the inside of the pipe were observed, the SiO ₂ film was completely removed, but a powdery residue of SiO ₂ composition remained in the trap attached to the pipe part (weight <1 m.
g).

Example 85 Tetramethoxysilane was used as a raw material and thermal CVD was performed to
SiO on conwafer ₂Formed by depositing a film (about 1 μm)
HF gas is applied to the membrane device (average thickness of the deposit in the pipe is about 0.1 mm).
Su, ClF₃Gas, N₂Total flow rate of mixed gas is 10S
LM (HF90vol%, ClF₃3.20vol%, N₂6.
And 80% by volume, and the system pressure was 1 Torr for 2 hours.
After that, the device is disassembled, and SiO on the silicon wafer is₂Film thickness
When the inside of the pipe was observed, SiO₂Membrane, pipe deposit
Both were completely removed.

Comparative Example 64 Thermal CVD was performed using tetramethoxysilane as a raw material to
SiO on conwafer ₂Formed by depositing a film (about 1 μm)
HF gas is applied to the membrane device (average thickness of the deposit in the pipe is about 0.1 mm).
Su, ClF₃Gas, N₂Total flow rate of mixed gas is 10S
LM (HF90vol%, ClF₃4vol%, N₂6vol%),
It was circulated for 2 hours at a system pressure of 1 Torr. Then the device
Disassembled, SiO on the silicon wafer₂The film thickness and the inside of the pipe
Observed SiO₂The film was completely removed,
SiO in the trap attached to the pipe₂Composition of powder
Residue remained (weight <1 mg).

Example 86 Thermal CVD was performed using tetramethoxysilane as a raw material to obtain silicon.
SiO on conwafer ₂Formed by depositing a film (about 1 μm)
HF gas is applied to the membrane device (average thickness of the deposit in the pipe is about 0.1 mm).
Su, ClF₃Gas, N₂Total flow rate of mixed gas is 10S
LM (HF20vol%, ClF₃19.45vol%, N₂6
0.55vol%), system pressure 760Torr for 1 hour
Let After that, the device was disassembled and Si on the silicon wafer was
O₂When the film thickness and the inside of the pipe were observed, SiO₂Membrane, piping
The internal deposits were completely removed.

Comparative Example 65 Using tetramethoxysilane as a raw material, thermal CVD was performed to obtain silicon.
SiO on conwafer ₂Formed by depositing a film (about 1 μm)
HF gas is applied to the membrane device (average thickness of the deposit in the pipe is about 0.1 mm).
Su, ClF₃Gas, N₂Total flow rate of mixed gas is 10S
LM (HF20vol%, ClF₃20vol%, N₂60 vol
%) And the system pressure was 760 Torr for 2 hours. So
After dismantling the device, SiO on the silicon wafer₂Film thickness and
When observing the inside of the pipe, SiO₂The membrane can be completely removed
However, SiO was trapped in the trap attached to the piping.₂set
A residual powdery residue remained (weight <1 mg).

[0049]

INDUSTRIAL APPLICABILITY The cleaning gas composition of the present invention containing HF gas and ClF ₃ gas can be used to remove incompletely decomposed products of alkoxysilane deposited or deposited without disassembling thin film forming equipment, jigs, pipes and the like. SiO ₂ can be easily cleaned.

[Brief description of drawings]

FIG. 1 shows the relationship between the system pressure and the gas mixing ratio in the cleaning of TEOS incomplete decomposition products (25 ° C.).

FIG. 2 shows the relationship between the system internal pressure and the gas mixing ratio in cleaning TEOS incomplete decomposition products (100 ° C.).

FIG. 3 shows the relationship between the system internal pressure and the gas mixing ratio in the cleaning of TEOS incomplete decomposition products (200 ° C.).

FIG. 4 shows the relationship between the system internal pressure and the gas mixing ratio in the cleaning of incompletely decomposed monofluorotriethoxysilane (25 ° C.).

FIG. 5: Incomplete decomposition product of tetramethoxysilane (25 ° C)
The relation between the system internal pressure and the gas mixture ratio in the cleaning is shown.

Claims (1)

[Claims] 1. The general formula (I): A mixed cleaning gas composition containing HF gas and ClF ₃ gas in the range shown in FIG.