JP3408409B2 - Semiconductor device manufacturing method and reaction chamber environment control method for dry etching apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing method and a reaction chamber environment control method for a dry etching apparatus.

[0002]

2. Description of the Related Art Recent improvements in the integration of semiconductor devices are remarkable. In the lithography technology, which has been the driving force for high integration of devices, it is necessary to form finer patterns in order to improve the degree of integration. For this reason, the wavelength of the light source is shortened. At present, a lithography process using an excimer laser using krypton fluoride (KrF) is predominant. As described above, in order to obtain high resolution in the photolithography process, it is necessary to thin the photoresist film formed on the substrate to be processed.

When opening a contact hole in a silicon oxide film, it is necessary to selectively etch the partially exposed silicon oxide film with a photoresist pattern formed on the silicon oxide film. When using a thin photoresist film as a photoresist pattern for the purpose of achieving high resolution, it is necessary to prevent the plasma for etching the silicon oxide film from also etching the thin photoresist film. . The fluorocarbon gas (gas containing carbon and fluorine) used for etching the silicon oxide film contains fluorine that contributes to etching of the photoresist film. Therefore, for example, a fluorocarbon gas having a relatively low ratio of fluorine to carbon contained in one molecule (for example, C ₄
F ₈ ) is attracting attention as an etching gas.

[0004]

[Problems to be Solved by the Invention] However, C ₄ F ₈
When a contact hole is formed in a silicon oxide film by using a fluorocarbon gas such as, for example, the depth of the contact hole that can be formed under the same etching conditions (hereinafter, referred to as “etching depth”) increases the number of etching processes. There is a problem that it becomes shallow.

The present invention has been made in view of the above points, and its main purpose is to provide a method of manufacturing a semiconductor device including a step of stably and stably opening a contact hole, and a necessary method therefor. Another object of the present invention is to provide a method for controlling a reaction chamber environment of a dry etching apparatus.

[0006]

A method of manufacturing a semiconductor device according to the present invention comprises a step of forming a semiconductor element on a substrate, a step of depositing a silicon oxide film on the substrate, and a photolithography process on the silicon oxide film. A step of forming a resist pattern, a step of etching the silicon oxide film using plasma of a gas having a ratio of fluorine to carbon of 2 or less in a reaction chamber of an etching apparatus, and a polymer formed on an inner wall of the reaction chamber. Reaction chamber environment control step of oxidizing the membrane.

The reaction chamber environment control step preferably includes a step of performing oxygen plasma treatment.

[0008] It is preferable that the oxygen plasma treatment is performed in a state where high frequency power is not supplied to the substrate.

After the step of etching the silicon oxide film, a step of removing the polymer film formed on the etching termination surface may be performed.

A step of removing the polymer film formed on the etching termination surface may be performed after the step of etching the silicon oxide film and before the step of controlling the reaction chamber environment.

After the step of etching the silicon oxide film, a step of removing the polymer film formed on the etching termination surface may be performed after the step of controlling the reaction chamber environment.

The step of removing the polymer film formed on the etching termination surface is preferably performed while supplying high frequency power to the substrate.

The flow rate of the oxygen plasma treatment is 200 s.
It is preferable that oxygen of ccm or more is supplied into the reaction chamber and the gas pressure in the reaction chamber is set to 20 mTorr or more.

In the oxygen plasma treatment, the total flow rate is 2
Carbon monoxide and oxygen of 00 sccm or more were supplied into the reaction chamber, and the gas pressure in the reaction chamber was set to 20 mTorr.
It is preferable to execute the above.

The gas having a ratio of fluorine to carbon of 2 or less preferably contains a molecule selected from the group consisting of C ₄ F ₈ , C ₅ F ₈ , C ₃ F ₆ O, and C ₄ F _6. .

It is preferable to include a monitoring step of monitoring the environment inside the reaction chamber using the emission of C ₂ , oxygen or fluorine inside the reaction chamber.

As the C ₂ light emission, light emission with a wavelength of 516 nm may be used.

As the emission of oxygen, emission of wavelength 777 nm may be used.

The wavelength of light emitted from the fluorine is 704 nm.
Alternatively, emission of 685 nm may be used.

The reaction chamber environment control step may be performed after the etching process is completed.

The reaction chamber environment control step may be performed before the etching process.

The reaction chamber environment control method of the present invention is a method for controlling the reaction chamber environment of a dry etching apparatus in which the etching process of a silicon oxide film is performed in the reaction chamber using plasma of a gas having a ratio of fluorine to carbon of 2 or less. Then, the oxygen plasma treatment is performed on the polymer film formed on the inner wall of the reaction chamber while the dry etching process is not performed.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION When a plasma having a ratio of fluorine to carbon of 2 or less than 2 (hereinafter referred to as "carbon-rich plasma") is used for the purpose of improving an etching selection ratio with respect to a photoresist, a reaction chamber is used. A polymer film is easily deposited on the inner wall of the. On the other hand, even when a conventional plasma of fluorocarbon gas having a ratio of fluorine to carbon of more than 2, a polymer film may be formed on the inner wall of the reaction chamber. It has no effect.

The polymer film deposited on the inner wall of the reaction chamber is mainly formed of carbon (C) and fluorine (F).
As the proportion of carbon in the fluorocarbon used to etch silicon oxide increases, the deposition rate of the polymer film increases. When a silicon oxide film is etched using a fluorocarbon gas having a ratio of fluorine to carbon of 2 or less, the thickness of the polymer film deposited in the reaction chamber along with the number of etching processes (the number of wafers to be etched) Will increase. The inventor of the present application, when the etching process is repeated by using the plasma of gas having a ratio of fluorine to carbon of 2 or less, carbon contained in the polymer film on the inner wall of the reaction chamber is supplied into the plasma during the etching process, As a result, they found that the amount of carbon in the plasma increased. Further, the inventors of the present application have found that when the amount of carbon in the plasma is increased in this way, the polymer film deposited on the bottom of the contact hole where etching is progressing becomes thicker. It was observed by an experiment that the film tends to become shallower as the number of etching processes increases.

The present invention prevents the deposition of the polymer film on the side wall of the reaction chamber from changing the environment inside the reaction chamber, and realizes a stable etching process.

(First Embodiment) A first embodiment of the method for manufacturing a semiconductor device according to the present invention will be described below.

First, the dry etching apparatus used in this embodiment will be described with reference to FIG.

FIG. 1 shows a schematic diagram of a dry etching apparatus using inductively coupled plasma. The dry etching apparatus in FIG. 1 includes a reaction chamber 7 in which a dry etching process is performed. The outer wall of the reaction chamber 7 is the reaction chamber 7
It is surrounded by an induction coil 1 for forming plasma inside. The induction coil 1 is connected to a high frequency power source 2 and receives high frequency power (frequency 1.8 MHz) from the high frequency power source 2.

A lower electrode 3 that supports a substrate (silicon substrate) 6 to be processed is provided below the reaction chamber 7, and the lower electrode 3 is connected to a high frequency power source 4 via a matcher 14.
A high-frequency current is supplied from the high-frequency power source 4. A quartz ring 12 is arranged in the peripheral region of the upper surface of the lower electrode 3. An upper silicon electrode 5 is provided above the reaction chamber 7. Further, a heater 11 capable of heating the reaction chamber is provided above the reaction chamber 7 as needed.

A pressure control valve 8 and an exhaust pump 9 are inserted between the exhaust port of the reaction chamber 7 and the outside. CO in fluorocarbon gas C ₄ F ₈ and CH ₂ F ₂
And a mixed gas containing Ar (C ₄ F ₈ / CH ₂ F ₂ / CO /
Ar) is introduced into the reaction chamber 7 via the mass flow controller 13. Various gases forming the etching gas are stored in the plurality of cylinders 15 to 17. The etching gas is exhausted from the exhaust port to the outside of the apparatus via the pressure control valve 8 and the exhaust pump 9. The pressure control valve 8 controls the pressure inside the reaction chamber 7 from 1 mTorr to 5
It operates to maintain the set constant value within the range of 00 mTorr.

Next, with reference to FIG. 2 and FIG. 3 in addition to FIG. 1, a method of manufacturing a semiconductor device including a dry etching step performed using the above-mentioned device will be described. FIG. 3 shows a process procedure.

First, as shown in FIG. 2A, a silicon substrate 20 on which a semiconductor element (not shown) such as a transistor is formed or a silicon substrate 20 on which a semiconductor element is being formed is prepared. Next, using a known thin film deposition technique, silicon oxide (Si
The O ₂ ) film 21 is deposited. After that, as shown in FIG. 2B, a photoresist pattern 22 is formed on the silicon oxide film 21 by the photolithography technique. In order to obtain high resolution, the photoresist pattern 22 has a relatively small thickness of 0.5 μm to 1.0 μm. The photoresist pattern 22 has an opening 23 that defines the shape of the position of the contact hole to be formed.

Next, a photoresist pattern 22 is formed on the surface.
The silicon substrate 20 in which the is formed is set in the reaction chamber 7 of the dry etching apparatus shown in FIG. Then, a mixed gas of C ₄ F ₈ / CH ₂ F ₂ / CO / Ar is added to the reaction chamber 7.
(Step S1 in FIG. 3) and the gas pressure is 1 mTorr.
Control from r to 50 mTorr (step S
2).

Next, the induction coil 1 is applied with a high frequency power of 1000 watts (W) to 3000 W to generate plasma (step S3). In the plasma, other types of molecules formed from the mixed gas,
Excited atoms and ions are included. In this embodiment, high density plasma having a plasma density of 10 ¹¹ cm ⁻³ or more is formed.

Next, the lower electrode 3 is provided with 100 W to 2000
Applying high frequency power up to W, thereby applying a self-negative bias to the substrate 6 (silicon substrate 20 of FIG. 2),
The silicon oxide film 21 is etched (step S
4). Thus, as shown in FIG. 2C, the contact hole 24 is formed in the silicon oxide film 21. The contact hole 24 reaches an impurity diffusion layer (not shown) formed in the silicon substrate 20, and the silicon oxide film 21.
It enables electrical contact between the wiring formed above and the impurity diffusion layer in the silicon substrate 20. The impurity diffusion layer may be a silicide layer or the like.

After the contact etching is completed, oxygen gas is introduced into the reaction chamber 7 (step S5). The flow rate of the oxygen gas to be introduced is preferably 100 sccm or more from the viewpoint of increasing the polymer removal efficiency. Practically, it is more preferably 200 sccm or more.
While controlling the gas pressure to 20 mTorr or more (step S6), high frequency power between 1000 W and 3000 W is applied to the induction coil 1 to generate oxygen plasma.
(Step S7). The gas pressure is set to 20 mTorr or higher in order to stabilize discharge and improve polymer removal efficiency. Then, the polymer film attached to the inner wall of the reaction chamber 7 is oxidized by oxygen plasma and removed (step S8).
The high frequency power is not supplied to the lower electrode 3 while the oxygen plasma is formed. If high frequency power is supplied to the lower electrode 3, positively charged ions will irradiate the silicon substrate in the oxygen plasma. In the present embodiment, the oxygen plasma functions to decompose the polymer film on the inner wall of the reaction chamber 7, so it is not necessary to supply positively charged ions to the silicon substrate. It should be noted that the polymer film does not have to be a continuous film having a uniform thickness, as long as it is a polymer attached on the inner wall of the reaction chamber, it may be a polymer in a discontinuous or porous state. In the present specification, the term "polymer film" is used.

The above steps S5 to S8 are steps for controlling the environment in the reaction chamber.

Next, as shown in FIG. 2D, the photoresist pattern 22 is removed. The removal of the photoresist pattern 22 may be performed using oxygen plasma in the reaction chamber 7. In that case, it is preferable to apply a negative bias to the substrate by supplying high frequency power to the lower electrode 3. This is because the time required for removing the photoresist pattern can be shortened by ion irradiation. After that, a semiconductor device is manufactured through a known manufacturing process.

The graph of FIG. 4 shows the emission intensity of C ₂ (wavelength 516 nm) in the reaction chamber environment control process when the dry etching process is performed according to the process procedure shown in FIG. The horizontal axis of the graph in FIG. 4 indicates the discharge time in the reaction chamber environment control process. Oxygen flow rate is 80sc
It can be seen from FIG. 4 that in the case of cm, it takes about 80 seconds until the emission intensity of C ₂ is lowered to a sufficiently low level. The time when the emission intensity falls to a sufficiently low level corresponds to the time when the polymer film deposited on the wall of the reaction chamber is substantially removed.

The graph of FIG. 5 shows C ₂ in the reaction chamber environment control process when only the oxygen flow rate is changed from 80 sccm to 300 sccm in each condition of the dry etching performed to obtain the data of the graph of FIG. (Emission wavelength 5
16 nm) is shown. The horizontal axis of the graph in FIG. 5 indicates the discharge time in the reaction chamber environment control process.

It can be seen from FIG. 5 that the emission intensity decreases about 40 seconds after the start of discharge. Also, due to the increase in oxygen flow rate, the time required for environmental control is about 1/2 of that in the case of FIG.
It can be seen that it has been reduced to. Increasing the oxygen flow rate is effective in controlling the environment in the reaction chamber. As the oxygen flow rate,
It is particularly preferable to set it to 300 sccm or more,
Even at 0 sccm or more, the polymer film can be removed with sufficient efficiency.

FIG. 6 shows the etching characteristics in the case of forming a contact hole with a diameter of about 0.2 μm in a 2.0 μm thick silicon oxide film which is mostly covered with photoresist (the etching depth depends on the number of processed wafers). Sex). The graph of FIG. 6 shows data both when the reaction chamber environment control step was performed (Example) and when it was not performed (Comparative Example). When the etching of 25 wafers is performed, in the comparative example, the etching depth becomes shallower as the number of processed wafers increases, and the contact causes an open defect. However, in the example in which the process of controlling the reaction chamber environment was performed, the amount of carbon in the plasma during each etching process was kept constant, so that a stable etching depth was obtained.

FIG. 7 shows a fluorocarbon gas in which the ratio of fluorine to carbon is greater than 2 (low carbon content ratio gas).
C _{2 in} the case of using oxygen (conventional example) during oxygen plasma treatment
3 shows the change over time in the emission intensity of

The oxide film was etched using C ₂ F ₆ as a low carbon content ratio gas, and then an oxygen flow rate of 300 sccm was introduced in the same reaction chamber to generate oxygen plasma. As can be seen from FIG. 5, carbon emission was not detected from the beginning, and it can be seen that the environmental control step is not necessary.
This is because the gas is not gas rich in carbon because the ratio of fluorine to carbon is larger than 2 (in the case of C ₂ F ₆ , the ratio is 3). Therefore, the present invention is extremely effective for plasma etching using a gas having a ratio of fluorine to carbon of 2 or more.

In this embodiment, the polymer deposited on the inner wall of the reaction chamber is removed after the contact etching is completed. However, the polymer deposited on the inner wall of the reaction chamber may be removed before the contact etching process is performed on the next wafer.

After the contact etching is completed, a special step of removing the polymer film (not shown) formed on the bottom portion (etching end surface) of the contact hole 24 shown in FIG. 2C may be performed. good. This step can be performed, for example, by supplying high frequency power to the lower electrode 3 while forming oxygen plasma. By supplying a high frequency power to the lower electrode 3, a negative bias is applied to the substrate, and the positively charged ions in the oxygen plasma are sufficiently supplied to the bottom of the contact hole 24. As a result, the polymer film on the bottom is smoothed. To be removed. Such removal of the polymer film is extremely effective in preventing contact failure. This step may be performed before or after the reaction chamber environment control step. However, the step of exposing a part of the surface of the silicon substrate 20 by removing the polymer film at the bottom of the contact hole 24 may be performed after the environment in the reaction chamber is controlled to a certain level by the reaction chamber environment control step. preferable.

If the reaction chamber environment control step is performed after the step of removing the polymer film at the bottom of the contact hole 24, the reaction chamber environment control step may be performed after removing the silicon substrate from the reaction chamber. Further, although it is preferable that the reaction chamber environment control step is always performed after the contact etching step, the reaction chamber environment control step may be performed once for a plurality of etching processes. The purpose of performing the reaction chamber environment control step is to decompose and remove the polymer film that is being formed on the inner wall of the reaction chamber before it grows to a thickness that affects plasma during the etching process. Therefore, the timing of performing the reaction chamber environment control step is not necessarily limited to immediately after the contact etching is completed. However, it goes without saying that it is preferable to program such that a series of processes such as the etching process and the reaction chamber environment control process are continuously performed.

(Second Embodiment) A second embodiment of the method for manufacturing a semiconductor device according to the present invention will be described.

FIG. 8 shows a process procedure for implementing the method for manufacturing a semiconductor device according to this embodiment. The dry etching performed in this embodiment can be performed using the apparatus shown in FIG.

First, as in the first embodiment, as shown in FIG.
As shown in (a), a silicon substrate on which a semiconductor element such as a transistor element is formed or a silicon substrate on which a semiconductor element is being formed is prepared.

Next, a silicon oxide film 21 is formed on the silicon substrate 20 by using a known thin film deposition technique. After that, the silicon oxide film 2 is formed by photolithography technology.
A photoresist pattern 22 is formed on the surface 1.

Next, the photoresist pattern 22 is formed on the surface.
The substrate 20 on which is formed is set in the reaction chamber 7 of the dry etching apparatus shown in FIG. After that, C ₄ F ₈ / CH ₂
A mixed gas of F ₂ / CO / Ar was introduced into the reaction chamber (step S1 in FIG. 8), and the gas pressure was changed from 1 mTorr to 50 mTorr.
Control is performed until r (step S2).

Next, the induction coil 1 is changed from 1000 W to 30
High-frequency power is applied up to 00 W to generate plasma (step S3). Then, high frequency power is applied to the lower electrode 3 between 100 W and 2000 W to perform etching (step S4). After the etching is completed, carbon monoxide of 20 sccm or more and oxygen gas of 80 sccm or more are introduced into the reaction chamber 7 (step S15). The gas pressure is controlled to 20 mTorr or more (step S6), and high frequency power is applied to the induction coil between 1000 W and 3000 W to generate oxygen plasma (step S6).
7). Then, the polymer film attached to the reaction chamber wall is removed (step S8).

The above steps S15 and S6
From S8 to S8 is a step of controlling the environment inside the reaction chamber.

Carbon monoxide reacts with the fluorine contained in the polymer film and contributes to the decomposition of the polymer film. The reaction follows the following reaction formula.

CO + F → COF or CO + 2F → COF ₂ (Third Embodiment) Next, a third embodiment of the method for manufacturing a semiconductor device according to the present invention will be described.

FIG. 9 shows an environmental control monitoring method using an emission spectroscope.

The dry etching apparatus using inductively coupled plasma shown in FIG. 9 has basically the same structure as the apparatus shown in FIG. 1, and the same constituent elements as those shown in FIG. 1 are the same. Reference numerals are added.

The dry etching apparatus shown in FIG. 9 also includes a reaction chamber 7 in which a dry etching process is performed. The outer side wall of the reaction chamber 7 is surrounded by an induction coil 1 for forming plasma in the reaction chamber 7. The induction coil 1 is connected to a high frequency power supply 2 and receives high frequency power from the high frequency power supply 2.

A lower electrode 3 that supports a substrate to be processed (silicon substrate 6) is provided below the reaction chamber 7. The lower electrode 3 is connected to a high frequency power source 4 via a matcher 14 , and the high frequency power source 4 outputs a high frequency wave. Receives current supply. A quartz ring 12 is arranged in the peripheral region of the upper surface of the lower electrode 3. An upper silicon electrode 5 is provided above the reaction chamber 7.

A pressure control valve 8 and an exhaust pump 9 are inserted between the exhaust port of the reaction chamber 7 and the outside.
C in C ₄ F ₈ and CH ₂ F ₂ which are fluorocarbon gases
Mixed gas containing O and Ar (C ₄ F ₈ / CH ₂ F ₂ / CO
/ Ar) is introduced into the reaction chamber 7 via the mass flow controller 13 . The etching gas is exhausted from the exhaust port 4 through the pressure control valve 8 and the exhaust pump 9 to the outside of the apparatus. The pressure control valve 8 operates, for example, to maintain the pressure in the reaction chamber 7 at a constant value within the range of 1 mTorr to 500 mTorr.

A light receiving window 15 is provided in the reaction chamber 7, through which light containing the emission of C ₂ , oxygen and fluorine in the plasma is introduced from the light receiving section 16 to the spectroscope 17. The spectroscope 17 separates the emission of C ₂ , oxygen and fluorine and measures the intensity of each emission. Emission altitude measurements are processed by computer 18. When the emission intensity drops below a preset level, the computer 18 sends an off signal to the high frequency power supplies 2 and 4 to end the reaction chamber environment control process.

By doing so, the environment in the reaction chamber 7 can be constantly monitored and the time of the reaction chamber environment control step can be optimized.

In any of the above embodiments,
Although C ₄ F ₈ was used as the gas having a ratio of fluorine to carbon of 2 or less, C ₅ F ₈ , C ₃ F ₆ O, C ₄ F ₆ or a mixed gas thereof may be used.

In any of the above embodiments,
A silicon substrate is used as the substrate on which the silicon oxide film is formed, but another substrate (eg glass substrate)
You may use. However, when a glass substrate is used, the glass substrate itself is also subject to etching because its main component is silicon oxide. After a polycrystalline silicon film or an amorphous silicon film is formed on a glass substrate, a silicon oxide film is formed so as to cover them, and a predetermined area of the silicon oxide film is covered with a resist film. It is quite possible to carry out the invention. A semiconductor device having a thin film transistor formed on a glass substrate or another substrate may be further integrated in the future. Applying the present invention to the manufacture of such a semiconductor device is expected to bring about very favorable effects.

[0066]

As described above, according to the present invention, the step of oxidizing the polymer film formed on the inner wall of the reaction chamber is provided in the plasma etching using the gas having the ratio of fluorine to carbon of 2 or less. As a result, carbon in the polymer film reacts with oxygen and is removed / exhausted from the inner wall. As a result, stable contact etching becomes possible, and the occurrence of open defects can be prevented even if the number of etching processes increases.

If the environment of the reaction chamber is monitored using C ₂ luminescence, oxygen luminescence, or fluorine luminescence,
It is possible to grasp the deposition state of the polymer on the inner wall of the reaction chamber and to optimize the time required for the reaction chamber environment control process for removing or reducing the polymer.

[Brief description of drawings]

FIG. 1 is a schematic view of a dry etching apparatus used in a method of manufacturing a semiconductor device according to the present invention.

2A to 2D are process cross-sectional views showing a process in the middle of the method for manufacturing a semiconductor device according to the present invention.

FIG. 3 is a diagram showing a process procedure of the first embodiment of the present invention.

FIG. 4 is a diagram showing a change in emission intensity according to the first embodiment of the present invention (oxygen flow rate 80 sccm).

FIG. 5 is a diagram showing changes in emission intensity according to the first embodiment of the present invention (oxygen flow rate 300 sccm).

FIG. 6 is a diagram showing a change in etching depth according to the first embodiment of the present invention.

FIG. 7 is a graph showing changes in emission intensity in a comparative example using a low carbon content ratio gas.

FIG. 8 is a diagram showing a process procedure of the second embodiment of the present invention.

FIG. 9 is a schematic diagram showing a configuration of an apparatus used in a third embodiment of the present invention.

[Explanation of symbols]

1 induction coil 2 high frequency power supply 3 Lower electrode 4 high frequency power supply 5 Upper silicon electrode 6 Silicon substrate 7 Reaction chamber 8 Pressure control valve 9 Exhaust pump 15-17 Gas cylinder 11 heater 12 silicone ring 13 Mass flow controller 14 Matcher 15 Light receiving window 16 Light receiving part 17 Spectroscope 18 Computer 20 Silicon substrate 21 Silicon oxide film 22 photoresist 23 opening 24 contact holes

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-6-275568 (JP, A) JP-A-8-124908 (JP, A) JP-A-8-319586 (JP, A) JP-A-9- 129612 (JP, A) JP 7-94470 (JP, A) JP 61-10239 (JP, A) JP 63-5532 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/3065

Claims (10)

(57) [Claims] 1. A process of forming a semiconductor element on a substrate, a process of depositing a silicon oxide film on the substrate, a process of forming a photoresist pattern on the silicon oxide film, and a reaction chamber of an etching apparatus. After the step of etching the silicon oxide film using plasma of a gas having a ratio of fluorine to carbon of 2 or less, and after the step of etching the silicon oxide film, the polymer film formed on the inner wall of the reaction chamber is oxidized. By chance
The reaction chamber environment is controlled by using the
And a step of removing the polymer film formed on the substrate . 2. A step of forming a semiconductor element on a substrate, a step of depositing a silicon oxide film on the substrate, and a step of forming a photoresist pattern on the silicon oxide film.
And the ratio of fluorine to carbon in the reaction chamber of the etching device
Of the silicon oxide film by using plasma of gas of 2 or less
Etching process and carbon monoxide and acid with a total flow rate of 200 sccm or more
Element into the reaction chamber to control the gas pressure in the reaction chamber.
Oxygen plasma treatment is performed at 20 mTorr or more,
The polymer film formed on the inner wall of the reaction chamber is removed.
A method of manufacturing a semiconductor device, comprising: 3. A step of forming a semiconductor element on a substrate, a step of depositing a silicon oxide film on the substrate, and a step of forming a photoresist pattern on the silicon oxide film.
And the ratio of fluorine to carbon in the reaction chamber of the etching device
Of the silicon oxide film by using plasma of gas of 2 or less
Etching process and oxidize the polymer film formed on the inner wall of the reaction chamber
The step of controlling the reaction chamber environment by changing the environment in the reaction chamber to C ₂ or fluorine in the reaction chamber .
Monitoring using luminescence.
Manufacturing method of semiconductor device . 4. A process of performing the reaction chamber environment control, claims, characterized in that it comprises a step of performing an oxygen plasma treatment
4. The method for manufacturing a semiconductor device according to 1 or 3 . 5. The oxygen plasma treatment is performed without supplying high frequency power to the substrate.
A method of manufacturing a semiconductor device according to claim 2 or 4 . 6. The method of manufacturing a semiconductor device according to claim 3, further comprising a step of removing the polymer film formed on the etching termination surface after the step of etching the silicon oxide film. 7. A step of removing the polymer film formed on the etching termination surface, the <br/> claim 1 or 6, characterized in that to perform while supplying high frequency power to the substrate Manufacturing method of semiconductor device. 8. The gas having a ratio of fluorine to carbon of 2 or less contains a molecule selected from the group consisting of C ₄ F ₈ , C ₅ F ₈ , C ₃ F ₆ O, and C ₄ F _6. Claims characterized by
8. The method for manufacturing a semiconductor device according to any one of 1 to 7 . 9. The wavelength of 516 nm as the emission of C ₂
4. The method for manufacturing a semiconductor device according to claim 3, wherein the light emission is used. 10. The wavelength of 704 is emitted as the emission of fluorine.
nm or 685 nm emission is used
The method for manufacturing a semiconductor device according to claim 3 .