JP4273628B2 - Dry etching method and dry etching apparatus used in this method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry etching method and a dry etching apparatus used in the method, and is particularly suitable for use in a semiconductor dynamic quantity sensor such as a semiconductor acceleration sensor or a semiconductor angular velocity sensor.
[0002]
[Prior art]
In recent years, an SOI substrate is increasingly used for manufacturing a semiconductor sensor. This is because the buried oxide film (insulating film) of the SOI substrate can be used as a sacrificial layer for etching removal in the process of making a fine structure (sensing part) composed of a movable electrode, a fixed electrode, and the like.
[0003]
Conventionally, wet etching using hydrofluoric acid or the like has been mainly used for removing an oxide film from an SOI substrate. However, wet etching causes so-called sticking (adhesion) that structures adhere to each other due to liquid surface tension. ) The phenomenon is easy to occur.
[0004]
In order to avoid the occurrence of this sticking phenomenon, dry etching using plasma has recently been used to remove the oxide film of the SOI substrate. In this dry etching, an apparatus having a processing chamber provided with parallel plate electrodes is prepared, an SOI substrate is disposed on one of the plate electrodes, an etching gas is introduced into the processing chamber, and high frequency power is applied to the parallel electrodes. This is applied to generate plasma and remove the oxide film.
[0005]
[Problems to be solved by the invention]
However, when the oxide film is removed from the SOI substrate by dry etching, there arises a problem that the etching rate becomes nonuniform within the surface of the SOI substrate.
[0006]
When such an etching rate non-uniformity occurs, even if a sufficient etching selection ratio between silicon and oxide film is taken, silicon is etched, so that the structure is partially over-etched, and the movable electrode and the fixed electrode And the capacitance determined by the distance between the movable electrode and the fixed electrode changes from the design position.
[0007]
The present invention has been made in view of the above points, and an object of the present invention is to improve the uniformity of the etching rate in the substrate surface when the insulating film of the substrate is removed by dry etching.
[0008]
[Means for Solving the Problems]
The present inventors considered that the charge accumulated on the wafer is involved as a factor for making the etching rate non-uniform, and examined the charge accumulated during dry etching. FIG. 3 shows a schematic diagram of a dry etching apparatus. Hereinafter, the dry etching method will be described with reference to FIG.
[0009]
First, an SOI substrate 100 to be dry-etched, that is, an active layer 100a is selectively etched to form a structure including a movable electrode and a fixed electrode, and a support layer 100b is selectively etched to form an oxide film 100c. An SOI substrate 100 in which an opening 1 10 d reaching up to 10 mm is formed is prepared.
[0010]
This SOI substrate 100 is placed in a counterbore formed on the quartz plate 101. At this time, the support layer 100b side faces the upper electrode 102 side. Then, an etching gas is introduced into the apparatus, and high-frequency power is applied to the lower electrode 103 from a high-frequency power source (RF power source) 104 to generate plasma 105. Thereby, the etching gas is decomposed into ions and radicals (active species), and the oxide film 100c is dry-etched.
[0011]
Although dry etching is performed by such a method, when the SOI substrate 100 is etched, the active layer 100 a and the support layer 100 b are insulated by the oxide film 100 c, and the SOI substrate 100 is separated from the lower electrode 103. Since the contact is made only at the outer edge portion of the SOI substrate 100, the charges accumulated in the SOI substrate 100 are difficult to escape and charge up is easy.
[0012]
Further, in a fine structure such as an acceleration sensor or an angular velocity sensor, since the insulating separation is performed by the trench 100e in order to form a capacitor by insulating the movable electrode and the fixed electrode, an island-shaped minute region is formed by the trench 100e. Insulated.
[0013]
Therefore, the equivalent circuit of the dry etching apparatus of FIG. 3 is shown by the circuit configuration of FIG. That is, a circuit configuration in which the plasma 105 corresponds to the resistor R1, the so-called sheath 106 that serves as a boundary between the plasma 105 and the SOI substrate 100 is a parallel circuit of the capacitor C1 and the diode D1, the oxide film 100c corresponds to the capacitor C2, and the trench 100e corresponds to the capacitor C3. It becomes.
[0014]
Due to such a circuit configuration, when the capacitance by the trench 100e (capacitor C3 equivalent to the trench 100e) is charged up, the in-plane of the SOI substrate 100 is caused by the bias of positive charge and negative charge generated by plasma. It is considered that the distribution of charge-up (charge charging) occurs, the incident amount of ions decomposed by the plasma 105 varies in the plane of the SOI substrate 100, and the etch rate uniformity deteriorates.
[0015]
Therefore, in the invention described in claim 1, the insulating film (20c) is formed on one electrode (3) among the parallel plate electrodes in the processing chamber (2) provided with the parallel plate electrodes (3, 4). In a dry etching method in which an etching gas is introduced into a processing chamber and an insulating film is removed by applying high-frequency power to parallel plate electrodes while arranging the substrate (20) provided, the etching gas is introduced into the processing chamber and the high-frequency power is introduced. Including an etching process for controlling power and dry etching the insulating film, and a charge distribution control process for controlling the distribution of charges charged on the substrate during dry etching , and alternately repeating the etching process and the charge distribution control process, The etching process and the charge distribution control process are characterized in that the distribution of the magnetic flux density in the plane parallel to the substrate between the parallel plate electrodes is changed.
[0016]
This makes it possible to control the distribution of the amount of ions in the plasma by changing the distribution of the magnetic flux density and to partially control the amount of charge charged to the substrate, so that the etching rate is uniform within the substrate surface. Can be improved.
[0017]
Here, it is assumed that the magnetic flux density has changed even when the magnetic field is applied from a state where it is not applied or when the application is stopped after the magnetic field is applied.
[0018]
The magnetic flux density distribution in the etching step and the charge distribution control step can be determined based on the distribution of charges charged on the substrate during dry etching, as in the second aspect of the invention.
[0019]
Specifically, since charges are difficult to escape at the central portion of the substrate and the amount of charge at the central portion of the substrate tends to increase, the surface parallel to the substrate in the etching step as in the invention according to claim 3. The magnetic flux density of the portion facing the central portion of the substrate is larger than the magnetic flux density of the portion facing the peripheral portion of the substrate in the plane parallel to the substrate. It is preferable that the magnetic flux density of the portion facing the central portion of the substrate in the parallel plane is smaller than the magnetic flux density of the portion facing the peripheral portion of the substrate in the plane parallel to the substrate.
[0020]
Thereby, in the etching process, the density of ions and radicals in the central portion of the substrate is increased, but the etching rate of the central portion of the substrate can be increased until the substrate is charged to some extent. Thereafter, in the charge distribution control step, by reducing the density of ions and radicals in the central portion of the substrate, the charge increased in the central portion of the substrate by performing the etching step can be reduced.
[0021]
In general, since the charge on the substrate is often different between the central portion and the peripheral portion of the substrate, as in the invention according to claim 4, concentric circles in a plane parallel to the substrate centering on the central portion of the substrate. By arranging the magnets in such a manner, different magnetic flux densities can be generated from each magnet, and the magnetic flux density can be suitably changed in the central part and the peripheral part of the substrate, and the magnetic flux density in the etching process and the charge distribution control process can be changed. The distribution can be controlled.
[0022]
Further, as in the invention described in claim 5, when the magnet is disposed on the side opposite to the substrate on the side of the parallel plate electrode on which the substrate is disposed, the distance between the substrate and the magnet is reduced. This is preferable because the upper magnetic flux density can be increased.
[0023]
Further, in the dry etching method according to any one of claims 1 to 5, as shown in claim 6, the active layer (20a) is disposed on one surface side of the insulating film (20c), and the other After preparing the SOI substrate (20) having the support layer (20b) disposed on the surface side, the active layer is selectively etched to form a trench (20e), which is fixed to the movable electrode for mechanical quantity measurement. A step of forming a structure having electrodes, a step of selectively etching the support layer to form an opening (20d) reaching the insulating film, and dry-etching the insulating film to release the structure. In the method of manufacturing a semiconductor dynamic quantity sensor comprising the steps, it is preferable to apply the method when dry-etching the insulating film.
[0024]
The invention described in claim 7 is a dry etching apparatus used in the dry etching method shown in claim 1, wherein the parallel plate electrodes (3, 4) and the processing chamber (2) provided with the parallel plate electrodes are provided. The quartz plate (3a) is disposed on the other electrode (4) side of one electrode (3) among the parallel plate electrodes in the processing chamber, and one of the quartz plates (3a) ( The substrate (20) provided with the insulating film (20c) is disposed on the opposite side to 3), and the insulating film is removed by introducing an etching gas into the processing chamber and applying high-frequency power to the parallel plate electrodes. In the dry etching apparatus, when the insulating film is dry etched, magnets (91 to 93) for controlling the distribution of electric charges charged to the substrate by the dry etching are arranged in the processing chamber. With features To have. If this dry etching apparatus is used, the dry etching shown in claims 1 to 3 can be suitably performed.
[0025]
The invention according to claim 8 is characterized in that, in the invention according to claim 7, the magnets are arranged so as to be concentric in a plane parallel to the substrate centering on the central portion of the substrate. Thus, the same effect as that attained by the 4th aspect can be attained.
[0026]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments shown in the drawings will be described below. FIG. 1 shows a cross-sectional configuration of an etching apparatus 1 used for carrying out the dry etching method. 2 shows a cross-sectional configuration of the SOI substrate 20 to be dry-etched, where (a) shows a state before dry etching and (b) shows a state after dry etching. Indicates.
[0028]
The SOI substrate 20 shown in FIG. 2A is in the process of manufacturing a semiconductor dynamic quantity sensor (for example, a semiconductor acceleration sensor or a semiconductor angular velocity sensor). That is, the SOI substrate 20 includes a step of forming a structure composed of a movable electrode and a fixed electrode in the active layer 20a in the manufacturing process of the semiconductor dynamic quantity sensor, and an oxide film (insulating film) 20c in the support layer 20b. And a step of forming the reaching opening 20d.
[0029]
For example, the structure is formed by selectively etching the active layer 20a and forming the trench 20e reaching the oxide film 20c, and by selectively etching the support layer 20b with a KOH aqueous solution or the like, the oxide film 20c is reached. A reaching opening 20d is formed. The oxide film 20c of the SOI substrate 20 having such a structure is dry-etched by the etching apparatus 1 shown in FIG.
[0030]
As shown in FIG. 1, the etching apparatus 1 includes a processing chamber 2. Dry etching of the SOI substrate 20 is performed in the processing chamber 2. Parallel plate electrodes 3 and 4 are disposed in the processing chamber 2, and the parallel plate electrodes 3 and 4 are disposed with an SOI substrate 20 (SOI substrate 20 shown in FIG. 2A) on which dry etching is performed. The lower electrode (one electrode in the claims) 3 and the upper electrode 4 arranged to face the lower electrode 3.
[0031]
The lower electrode 3 is provided with a quartz plate 3a on the upper electrode 4 side, and an SOI substrate 20 is disposed in a counterbore 3b formed on the quartz plate 3a. For example, a high frequency power (RF power) of 13.56 MHz can be applied to the lower electrode 3 from a high frequency power source 5. The upper electrode 4 has a plurality of gas supply holes 4a arranged at equal intervals on the side facing the SOI substrate 20, and is configured to allow an etching gas to flow in a shower shape. These lower electrode 3 and upper electrode 4 can be cooled by cooling water (not shown).
[0032]
The etching apparatus 1 is provided with a gas inlet 6 for supplying various gases. The gas introduction port 6 is disposed above the upper electrode 4, and various gases supplied from the gas introduction port 6 are supplied into the processing chamber 2 through the gas supply holes 4 a of the upper electrode 4. A gas introduction pipe 7 is connected to the gas introduction port 6, and a plurality of gas supply pipes 8 (this embodiment) are connected to a plurality of types (three kinds in this embodiment) of gas supply sources 8. In this case, three gas introduction pipes 8a are connected. Each of these gas introduction pipes 8a is provided with a mass flow controller 8b for adjusting the gas flow rate.
[0033]
On the other hand, in the lower part of the processing chamber 2, magnets 91 to 93 are arranged on the side opposite to the side on which the SOI substrate 20 is arranged in the lower electrode 3. The magnets 91 to 93 are not particularly limited to be disposed at this position. However, if the magnets 91 to 93 are disposed at this position, the magnetic flux density on the SOI substrate 20 is reduced because the distance between the SOI substrate 20 and the magnets 91 to 93 is short. Can be bigger.
[0034]
Further, these magnets 91 to 93 are arranged so as to be concentric in a plane parallel to the SOI substrate 20 with the central portion of the SOI substrate 20 as the center, and each of the magnets 91 to 93 independently has the strength of the magnetic field. (Magnetic flux density) can be changed. Specifically, a columnar magnet 91 is disposed at the center, and two magnets 92 and 93 having different cylindrical diameters are disposed around the magnet 91. In general, since the charge on the SOI substrate is often different between the central portion and the peripheral portion of the SOI substrate, by disposing the magnets 91 to 93 in this way, different magnetic flux densities are generated from the respective magnets 91 to 93, and the SOI substrate is charged. The magnetic flux density can be changed between the central portion and the peripheral portion of the substrate 20. In the present embodiment, electromagnets are used as the magnets 91 to 93.
[0035]
An exhaust pipe 11 is connected to the lower part of the processing chamber 2. Through this exhaust pipe 11, the inside of the processing chamber 2 can be depressurized by a vacuuming means 12 such as a vacuum pump. With such a configuration, the inside of the processing chamber 2 can be maintained at a degree of vacuum of, for example, about 1.33 Pa to 133 Pa (10 mTorr to 1 Torr) while the gas is supplied from the gas supply source 8.
[0036]
Using the dry etching apparatus configured as described above, dry etching is performed as follows. Dry etching is performed by alternately repeating the etching process and the charge distribution control process.
[0037]
[Etching process]
First, an etching gas is introduced into the processing chamber 2 from various gas supply sources 8. At this time, the flow rate of each gas is controlled by the mass flow controller 8b. Further, the gas pressure in the processing chamber 2 is set to a desired value by the vacuuming means 12.
[0038]
Further, the magnets 91 to 93 are operated to provide a magnetic flux density distribution in a plane parallel to the SOI substrate 20 between the upper electrode 4 and the lower electrode 3. The distribution of the magnetic flux density is determined based on the distribution of charges charged on the SOI substrate 20 (charge-up distribution). In this embodiment, the distribution of the central portion of the SOI substrate 20 (hereinafter simply referred to as the substrate central portion) Since the charge-up distribution differs from the peripheral portion (hereinafter simply referred to as the peripheral portion of the substrate) in the SOI substrate, the following magnetic flux density distribution is used.
[0039]
Of the plane parallel to the SOI substrate 20, the magnetic flux density between the electrodes in the portion facing the central portion of the substrate (hereinafter simply referred to as the magnetic flux density in the central portion of the substrate) is the magnetic flux between the electrodes in the portion facing the peripheral portion of the substrate. The density is made larger than the density (hereinafter simply referred to as the magnetic flux density around the substrate). Specifically, since the magnets 91 to 93 are independently arranged concentrically, the magnetic field strength of the central magnet 91 may be made stronger than the other magnets 92 and 93. At this time, it is desirable to increase the difference in magnetic flux density between the central portion of the substrate and the peripheral portion of the substrate, particularly on the SOI substrate 20 among the electrodes.
[0040]
Then, high frequency power of 13.56 MHz, for example, is applied to the lower electrode 3 from the high frequency power supply 5 so that the RF power becomes 2.5 kW, for example. As a result, plasma is generated between the upper electrode 4 and the lower electrode 3, and various gases are decomposed into ions and radicals by the plasma, and the oxide film 20c of the SOI substrate 20 is dry etched. Such an etching process is performed for several minutes.
[0041]
In general, as the magnetic flux density of plasma in a magnetic field increases, the plasma density increases. As the plasma density increases, the amount of ions and radicals in the plasma increases. Further, the amount of charge charged on the substrate is determined by the balance between the amount of ions in the plasma that reach the substrate and the amount of charge that escapes to the plasma.
[0042]
In this etching process, since the magnetic flux density at the central portion of the substrate is made larger than the magnetic flux density at the peripheral portion of the substrate, the amount of ions and radicals generated at the central portion of the substrate increases, and the etching rate at the central portion of the substrate increases. However, with the passage of time, the amount of ions that reach the SOI substrate 20 increases, so that the charge-up proceeds. In particular, the charge at the central portion of the substrate is difficult to escape, so the charge-up at the central portion of the substrate increases. The etching rate at the center is slow. Therefore, in order to control the charge-up distribution and make it uniform (cancel), the following charge distribution control process is performed.
[0043]
[Charge distribution control process]
In this process, only the magnetic flux density distribution in the etching process is changed. The distribution in this process is also determined based on the distribution of charge-up charged on the SOI substrate 20, and the charge-up in the central part of the substrate is increased in the etching process. To be smaller than the magnetic flux density. Specifically, the magnetic field strength of the central magnet 91 may be made weaker than those of the other magnets 92 and 93. At this time, as in the etching step, it is desirable that the difference in magnetic flux density between the central portion of the substrate and the peripheral portion of the substrate is increased between the electrodes, particularly on the SOI substrate 20. Such a charge distribution control step is performed for several minutes.
[0044]
Thus, by reducing the magnetic flux density in the central portion of the substrate, contrary to the magnetic field distribution in the etching process, the plasma density in the central portion of the substrate is reduced and the amount of ions in the plasma is reduced. As a result, the amount of ions reaching the SOI substrate 20 in the central portion of the substrate is reduced, and the charge-up increased in the central portion of the substrate in the etching process can be reduced.
[0045]
The charge distribution control step is mainly intended to control the charge-up distribution, and dry etching is also performed.
[0046]
Thereafter, the etching process and the charge distribution control process are alternately repeated to perform dry etching until the oxide film 20c is removed while uniformizing the charge-up distribution. As a result, as shown in FIG. 2B, the structure composed of the movable electrode and the fixed electrode formed in the active layer 20a is released, and the semiconductor dynamic quantity sensor is manufactured.
[0047]
In this way, by alternately performing the etching process and the charge distribution control process, the etching rate uniformity within the surface of the SOI substrate 20 can be improved, and dry etching with very small variations in the etching rate can be performed. For this reason, the distance between the movable electrode and the fixed electrode is uniform, and a semiconductor dynamic quantity sensor having good characteristics can be manufactured.
[0048]
In the charge distribution control process, the distribution of charge-up is controlled by reducing the magnetic flux density at the center of the substrate and reducing the plasma density, but reducing the plasma density also reduces the amount of radicals generated. There is a possibility that the etching rate in the central part of the substrate is lowered. However, in the etching process, since the plasma density in the central portion of the substrate is increased, the amount of radicals generated in the central portion of the substrate is increased, and the etching rate until the charge-up progresses is increased. An etching rate can be suitably secured.
[0049]
In addition, since electromagnets are used as the magnets 91 to 93, a magnetic field suitable for etching in the etching process and a magnetic field suitable for controlling the charge distribution in the charge distribution control process are easily generated alternately as described above. Can be made.
[0050]
(Other embodiments)
Although the magnetic field is always applied in the first embodiment, a method of applying a magnetic field in one of the etching process and the charge distribution control process may be employed.
[0051]
For example, first, an etching process is performed without applying a magnetic field. As a result, the charge-up in the central portion of the substrate where it is difficult for the charge to escape is particularly increased. After that, in the charge distribution control process, by applying a magnetic field so that the magnetic flux density in the central part of the substrate is smaller than the magnetic flux density in the peripheral part of the substrate, the charge-up distribution is reduced so that the increased charge-up in the central part of the substrate is reduced. To control. If necessary, the SOI substrate is etched by repeating such an etching process and a charge distribution control process.
[0052]
As another method, first, the etching process is performed in a state where a magnetic field is applied so that the magnetic flux density at the center of the substrate is larger than the magnetic flux density at the periphery of the substrate. As a result, the etching rate at the center of the substrate is initially high, but the charge-up at the center of the substrate gradually increases, and the etching rate at the center of the substrate decreases. After that, by stopping the application of the magnetic field in the charge distribution control step, the magnetic flux density at the central portion of the substrate is relatively lowered, so that the charge-up distribution can be controlled.
[0053]
As described above, even if a step of not applying a magnetic field is included, the charge-up distribution can be controlled to improve the uniformity of the etching rate in the SOI substrate surface. It is assumed that the magnetic flux density is changed when the magnetic field is applied from a state where the magnetic field is not applied or when the application is stopped after the magnetic field is applied.
[0054]
In the etching method including the first embodiment and the above-described step of not applying the magnetic field, the etching rate is uniformed when the charge-up increases in the central portion of the substrate. However, this is not the only case. Regardless of the distribution of charge-up, the distribution of magnetic flux density is determined based on the distribution of charge-up to control the distribution of charge-up and improve the uniformity of the etching rate. Can do.
[Brief description of the drawings]
FIG. 1 is a diagram showing a cross-sectional configuration of an etching apparatus used for dry etching according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a cross-sectional configuration of an SOI substrate subjected to dry etching.
FIG. 3 is a diagram showing an outline of conventional dry etching.
FIG. 4 is a diagram showing an equivalent circuit when the dry etching shown in FIG. 3 is performed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Etching apparatus, 2 ... Processing chamber, 3 ... Lower electrode, 4 ... Upper electrode,
5 ... high frequency power supply, 6 ... gas introduction port, 7 ... gas introduction pipe, 8 ... gas supply source,
8a ... gas introduction pipe, 8b ... mass flow controller, 11 ... exhaust pipe,
12 ... Vacuum evacuation means, 20 ... SOI substrate, 20a ... Active layer, 20b ... Support layer,
20c ... oxide film, 20d ... opening, 20e ... trench, 91-93 ... magnet.

Claims (8)

A substrate (20) provided with an insulating film (20c) is disposed on one electrode (3) among the parallel plate electrodes in the processing chamber (2) provided with parallel plate electrodes (3, 4). In the dry etching method of removing the insulating film by introducing an etching gas into the processing chamber and applying high frequency power to the parallel plate electrodes,
An etching step of introducing an etching gas into the processing chamber and controlling the high-frequency power to dry-etch the insulating film;
A charge distribution control step of controlling the distribution of charges charged on the substrate during the dry etching,
The etching step and the charge distribution control step are alternately repeated,
In the etching step and the charge distribution control step, a distribution of magnetic flux density in a plane parallel to the substrate between the parallel plate electrodes is changed. 2. The dry etching method according to claim 1, wherein the distribution of magnetic flux density in the etching step and the charge distribution control step is determined based on a distribution of electric charges charged on the substrate during dry etching. In the etching step, the magnetic flux density of the portion facing the central portion of the substrate in the plane parallel to the substrate is greater than the magnetic flux density of the portion facing the peripheral portion of the substrate in the plane parallel to the substrate. To be bigger,
In the charge distribution control step, the magnetic flux density of the portion facing the central portion of the substrate in the plane parallel to the substrate is the magnetic flux of the portion facing the peripheral portion of the substrate in the plane parallel to the substrate. The dry etching method according to claim 1, wherein the dry etching method is performed so as to be smaller than the density. A magnet is arranged so as to be concentric in a plane parallel to the substrate with the central portion of the substrate as a center, and the magnetic flux density distribution in the etching step and the charge distribution control step is controlled by the magnet. The dry etching method according to any one of claims 1 to 3. The said magnet is arrange | positioned on the opposite side to the said board | substrate with respect to the electrode of the side in which the said board | substrate is arrange | positioned among the said parallel plate electrodes. Dry etching method. After preparing the SOI substrate (20) in which the active layer (20a) is disposed on one side of the insulating film (20c) and the support layer (20b) is disposed on the other side,
Forming a trench (20e) by selectively etching the active layer, and forming a structure having a movable electrode and a fixed electrode for measuring a mechanical quantity;
Forming an opening (20d) reaching the insulating film by selectively etching the support layer;
A step of dry etching the insulating film and releasing the structure, and a method of manufacturing a semiconductor dynamic quantity sensor comprising:
6. A method of manufacturing a semiconductor dynamic quantity sensor, wherein the dry etching method according to claim 1 is applied when dry-etching the insulating film. A parallel plate electrode (3, 4) and a processing chamber (2) provided with the parallel plate electrode;
A quartz plate (3a) is disposed on the other electrode (4) side of one electrode (3) between the parallel plate electrodes in the processing chamber, and the one electrode (3) of the quartz plate (3a) is disposed. The substrate (20) provided with the insulating film (20c) is disposed on the opposite side of the insulating film (20c), the etching gas is introduced into the processing chamber and high frequency power is applied to the parallel plate electrodes, whereby the insulating film is formed. In a dry etching apparatus designed to be removed,
A magnet (91-93) is disposed in the processing chamber for controlling the distribution of charges charged on the substrate by dry etching when the insulating film is dry etched. Etching equipment. The dry etching apparatus according to claim 7, wherein the magnet is disposed so as to be concentric with respect to a central portion of the substrate in a plane parallel to the substrate.

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