JP3362333B2 - Dry etching method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus and a dry etching method used for microfabrication of a semiconductor device, and more particularly to a dry etching apparatus and a dry etching method for realizing highly accurate dry etching processing of a silicon oxide film.

[0002]

2. Description of the Related Art In a semiconductor device, in order to electrically connect a transistor formed on a wafer to metal wiring and between metal wiring, an insulating film (SiO ₂ A contact hole is formed in a thin film as a main component (hereinafter referred to as an oxide film) by a dry etching method, and the contact hole is filled with an electric conductor. In dry etching, an etching gas is introduced into a vacuum container, a high frequency bias or μ wave is applied to this gas to generate plasma, and the oxide film is selectively etched by active species and ions generated in the plasma to form a contact hole. Form. At the time of this etching, a resist thin film to which the hole pattern is transferred is formed on the oxide film. In this contact hole processing, it is necessary to selectively etch the oxide film with respect to the resist film, the wiring layer below the contact hole, and the silicon forming the transistor. In addition, in the dry etching method in which the gate electrode of the field effect transistor formed on the wafer is covered with a second insulating film made of a material different from that of the wiring layers and the source and drain regions and the wiring layer are connected, Since the second insulating film appears in the holes, selectivity for the second insulating film is also required. This contact processing is called self-aligned contact (SAC) processing, and a silicon nitride film is used as the second insulating film.

[0003] Processing of the contact hole, introducing _{CF 4,} CHF _3, fluorocarbon gas and Ar gas such as C 4 _{F 8} in the etching apparatus, 10 Pa from 4Pa
High-frequency plasma discharge is performed under the gas pressure condition of 1), and etching is performed under the condition that a Vpp voltage of 1.5 to 2.0 kV is applied to the wafer. When the oxide film between the wiring layers is thick and the aspect ratio (depth / diameter) of the contact hole is high, oxygen gas is added to improve hole opening property, and SAC is used.
In processing, in order to increase the selectivity for the nitride film, C
The addition of O gas has been performed.

[0004]

However, in the conventional etching apparatus, when the etching conditions such as the gas pressure and the high frequency power required for plasma generation are determined, the plasma density and the electron temperature are determined. And the amount of CF ₂ and ions produced is fixed. In plasma, in addition to CF ₂ , CF, CF ₃ , C ₂
Although the like exists, in the present specification, C, CF, and CF ₂ or the like is represented by CF ₂ radical, the CF ₂ radicals in CF _2,
The F radical is denoted by F. For this reason, it was difficult to change the amount of ions generated while keeping the amounts of F and CF ₂ generated constant, or to change the amounts of incident F and CF ₂ under the conditions where the amount of ions generated was constant. For example, in the case of a parallel plate type etching apparatus, the higher the high frequency bias power for plasma generation increased ion generation amount for the plasma density is increased, at the same time, the amount of F with respect to CF ₂ for dissociation by a plasma progresses Will also change.

In such a conventional etching apparatus, the following problems occur. When contact processing with a high aspect ratio is performed, fluorine radicals F are reduced on the bottom surface of the contact hole under conditions where the resist selection ratio is high.
A polymer is formed by CF-based radicals, and etching stops in the middle of the hole. On the contrary, under the condition that the etching is not stopped, oxygen gas is added or fluorine is excessive, and the resist mask is etched by oxygen or fluorine, so that a sufficient selection ratio with respect to the resist cannot be obtained. In the conventional technique, gas dissociation in plasma is fixed, and this problem cannot be addressed.

In addition, when a contact hole having a high aspect ratio is etched under a condition of high gas pressure (4 Pa or more), collision with gas molecules causes ions to be incident on the wafer in a tilting direction. Is partially etched laterally, which makes vertical processing difficult. The collision with gas molecules can be reduced by lowering the gas pressure, but in the conventional device, the plasma density and electron temperature change when the gas pressure is lowered, so the ratio of F increases and the ratio of F to the resist or nitride film increases. A sufficient selection ratio could not be obtained, which was an obstacle to lowering the gas pressure.

In the etching of the oxide film, as the semiconductor device becomes finer, the processing accuracy, the selection ratio to the nitride film (selection ratio to the nitride film) and the selection ratio to the resist are improved, and the semiconductor device is flattened. With the increase in the number of wiring layers and wiring, it has become necessary to process contact holes having a high depth / hole diameter ratio (aspect ratio).

The problem to be solved by the present invention is to control the generation amount of F and ions with respect to CF2 in plasma, and to oxidize a contact hole having a high aspect ratio or a silicon nitride film which requires a high selection ratio. It is to realize the processing of the film.

[0009]

[Means for Solving the Problems] Two or more having different electron temperatures
In the plasma by forming a plasma region of
Independent control of F and ion production for CF ₂
You can do it .

In oxide film etching using fluorocarbon gas, the amount of F produced with respect to CF ₂ depends on the plasma temperature, and the amount of ions produced is determined in proportion to the power introduced for plasma production. For _{C 4 F 8, C 4 F} 8
To F has a threshold energy of about 6 eV, whereas CF _{2 has} a threshold energy of about 12 eV. Therefore, when the electron temperature is low (1-4 eV), F is easily generated and F
The / CF ₂ production ratio becomes large. Electron temperature is 5-20eV
Then, since the production of CF ₂ is promoted, the F / CF ₂ production ratio becomes smaller than that at the low electron temperature. Therefore, when two kinds of electron temperatures are used, F and CF _{2 in the} high electron temperature region
And F in the low temperature region. The F / CF ₂ ratio is controlled by changing the sizes of these two electron temperature regions. The difference between these electron temperatures is 1 eV or more, preferably 5 eV or more.

The production amount of F and ions with respect to CF _{2 in} plasma should be controlled independently for the following reasons. The introduced fluorocarbon gas is dissociated into CF ₂ radicals, F radicals and ions in plasma, and is incident on the wafer. The etching of the oxide film proceeds by the ions entering the surface to which CF ₂ and F are attached. On the other hand, the resist and the silicon nitride film are mainly etched by F and ions, and CF ₂ forms a polymer on the surface, and thus acts as an etching resistant film on the resist and the silicon nitride film. Therefore, C
When etching is performed under the condition that the amount of incident ions or F is smaller than that of F ₂ , a high selection ratio can be obtained with respect to a resist or a silicon nitride film. However, when the amount of incident ions is reduced, the etching rate of the oxide film is slowed, and when the amount of incident F is reduced, there is a problem that etching is stopped in holes having a high aspect ratio. In this way, the etching process of the oxide film is roughly C
It depends on the incidence of F ₂ , F, and ions, and particularly depends on the incident amount of ions and the incident amount of F with respect to the incident amount of CF ₂ . Therefore, if the production amounts of F and ions with respect to CF _{2 in} plasma can be controlled independently, the process conditions are broadened, and as a result, finer and deeper oxide films can be processed.

However, since F is generated in both of the two electron temperature regions, F is excessively large under the condition that F is excessive as a whole.
/ CF ₂ will be controlled. To selectively exclude F, a gas containing hydrogen atoms (H ₂ , CH ₂ F ₂ , CH ₄
Etc.) and F is reacted with H radicals to be excluded. Besides, F can be consumed by the reaction with the inner wall material. Specifically, Si is formed on the inner wall surface of the etching apparatus.
A material that reacts with F, such as a plate or a SiC plate, is installed, and F is excluded by applying a high frequency bias to the plate to promote F consumption. In addition, F can be excluded by reacting F with a polymer formed by CF ₂ adhering to the wall. When the distance between the wafer and the inner wall portion is reduced, the area of the inner wall surface with respect to the volume of the plasma increases, so that the ratio of F generated by the plasma in the etching apparatus to the inner wall portion increases. That is, when the wafer and the inner wall are brought close to each other, F efficiently reacts with the polymer and is eliminated.
Specifically, it is possible to shorten the distance between the wafer and the wafer facing surface of the etching apparatus. These methods and 2
By using a plasma with different electron temperatures, F
It becomes possible to control the / CF ₂ ratio in a wide range.

On the other hand, the amount of generated ions is determined by the electron density in the plasma, and the electron density is almost proportional to the input high frequency power. Since F / CF ₂ dissociation is generated by electron collision with gas molecules, it depends on the power of the high frequency, but by changing the two electron temperature regions, the generation of F / CF ₂ is independent of the ion production amount. The ratio can be controlled.

As a concrete method for generating two kinds of electron temperature regions, in the case of an etching apparatus using electron cyclotron resonance (ECR) as shown in FIG.
The electron temperature is high in the CR region (high electron temperature region 103), and the low electron temperature region 102 is formed in the other portions.
The ECR region becomes narrower as the magnetic field gradient of the magnetic field applied from the outside is increased. Therefore, the F / CF ₂ production ratio can be varied by controlling the magnetic field gradient in the ECR region. As shown in FIG. 2, under the condition that the magnetic field gradient is small, the high electron temperature region widens, so F / CF
_{As the 2} production ratio becomes smaller and the magnetic field gradient becomes larger, the high electron temperature region becomes narrower, so that the F / CF ₂ production ratio can be made larger. In addition to this, the ECR region is roughly inversely proportional to the frequency of the introduced high frequency. For example, when the frequency is changed from 2.45 GHz to 450 MHz, the ECR area is expanded about 5 times. Therefore, the high electron temperature region is widened by lowering the frequency of the high frequency to be introduced, and F /
The CF ₂ production ratio can be reduced.

When the ECR region 101 is fixed, the size of the low electron temperature region 102 can be changed by changing the distance between the wafer 6 and the wafer facing surface 103. As shown in FIG. 2, when the distance between the wafer 6 and the wafer facing surface 103 is shortened, the low electron temperature region 102 is narrowed, so that the F / CF ₂ generation ratio can be reduced.

FIG . 3 shows the control of the distance between the wafer and the surface facing the wafer.
Formation of two types of electron temperature regions and F / CF ₂ generation
It is a figure which shows the relationship of ratio. In the figure, 301 is a high electron
Temperature region, and 302 indicates a wafer pair of the etching apparatus.
Shows the relationship between the distance between the facing surface and the wafer and the F / CF ₂ production ratio.
Curve that is out of the high electron temperature region 301
When the distance between the facing surface and the wafer is 40 to 150 mm, F
It can be seen that the effect of / CF ₂ generation is remarkable.

As described above, in the case of the ECR etching apparatus, by controlling the magnetic field gradient, the frequency of the high frequency to be introduced, and the distance between the wafer and the wafer facing surface, the F / CF ₂ production ratio can be set independently of the amount of ions produced. Can be controlled.

The present invention specifically provides the following methods.
To serve.

According to the present invention, a semiconductor device is manufactured by generating a high frequency and a magnetic field in an etching processing chamber to generate plasma.
In the dry etching method for etching the wafer for the disposed etching chamber, to set the distance between the antenna and the wafer for radiating electromagnetic waves into 20mm or 150mm or less, the etching
Reduce the pressure in the processing chamber to a low gas pressure in the range of 1 Pa to 4 Pa
The high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is 4 Gcm ^-1 to 50 Gcm.
Set a low gradient of ^-1 and set the value of magnetic field gradient / magnetic field strength to 0.
The temperature is set in the range of ¹ cm ⁻¹ to 0.01 cm ⁻¹ , and a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer. A dry etching method for dry etching the wafer is provided.

The present invention is a dry process for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching process chamber in which C and F are present. in the etching method, the edge
Low gas pressure in the ching process chamber in the range of 1 Pa to 4 Pa
The pressure is set, the distance between the antenna, which is placed in the etching chamber and emits electromagnetic waves, and the wafer is 20 mm.
Above 150mm and below, the high frequency is 300MH
The magnetic field gradient is set to 4 Gcm or more by setting z to 600 MHz or less.
^-1 to 50 Gcm ^-1 Set to a low gradient, magnetic field gradient /
The value of the magnetic field intensity from 0.1 cm ^-1 of 0.01 cm ^-1
The first magnetic field gradient is set to a range, and a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer by the magnetic field gradient, and F for CF2 radicals in the plasma is generated. A dry etching method is provided in which the respective amounts of radicals and ions are independently generated and the wafer is dry-etched.

The present invention is a method for manufacturing a semiconductor device in which an insulating film is formed by generating a high frequency and a magnetic field to generate plasma in an etching processing chamber in which C and F are present.
In the dry etching method of performing an etching treatment on the roof, the pressure in the etching treatment chamber is changed from 1 Pa to 4 Pa.
The pressure is set to a low gas pressure within the range of Pa, the distance between the antenna disposed in the etching chamber and emitting the electromagnetic wave and the wafer is set to 20 mm or more and 150 mm or less, and the high frequency is set to 300 MHz or more and 600 MHz or less. ,
The magnetic field gradient 4Gcm ^-1 to a low gradient of 50Gcm ^-1
Set the value of magnetic field gradient / magnetic field strength from 0.1 cm ^-1
The first high temperature electron temperature region and the second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer in the range of 0.01 cm ⁻¹ , and the insulating film etching process is performed. Correspondingly, there is provided a dry etching method for dry etching the insulating film while independently controlling the production amount of F radicals and ions with respect to CF2 radicals in the plasma.

The present invention is a dry process for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching process chamber in which C and F are present. in the etching method, the edge
Low gas pressure in the ching process chamber in the range of 1 Pa to 4 Pa
The pressure is set, and the distance between the antenna, which is placed in the etching chamber and emits electromagnetic waves, and the wafer is 20 m.
m to 150 mm, and the high frequency is 300M
Hz to 600 MHz or less, and the magnetic field gradient during the etching process is as low as 4 Gcm ^-1 to 50 Gcm ^-1 .
Set, or 0.1 cm ^-1 the value of the magnetic field gradient / field strength
Was controlled in the range of Luo 0.01 cm ^-1, between the antenna and the wafer, the first hot electronic temperature region and a second low electron temperature region generated in the vertical direction, the first hot collector There is provided a dry etching method for dry etching the wafer by varying the size of the child temperature region and controlling the production ratio of CF2 / F radicals independently of the ion production amount.

In the present invention, the plasma is generated by electron cyclotron resonance, and the magnetic field gradient is
The value of magnetic field gradient / magnetic field strength is from 0.1 m ⁻¹ to 0.01 c
Provided is a dry etching method which controls in the range of m ⁻¹ .

According to the present invention, a high frequency and a magnetic field are generated in an etching processing chamber to generate a plasma and a semiconductor device is installed.
In a dry etching method of etching a wafer for manufacturing, the pressure of the etching chamber is
The force is set to a low gas pressure in the range of 1 Pa to 4 Pa , and the distance between the antenna disposed in the etching chamber and emitting electromagnetic waves and the wafer is 20 mm or more and 150 mm.
Set the following to the high frequency above 300MHz and 600M
Set the magnetic field gradient to 4 Gcm ^-1 to 50 G with the frequency set to Hz or less.
Set a low gradient of cm- ¹ and set the value of magnetic field gradient / magnetic field strength.
Control in the range of 0.1 cm ⁻¹ to 0.01 cm ⁻¹ ,
A vertical first line is provided between the antenna and the wafer.
Generate a high temperature electron temperature region and a second low temperature electron temperature region,
A dry etching method is provided in which the electron temperature near the wafer is changed with the elapse of etching time for the contact hole of the wafer.

According to the present invention, a high frequency and a magnetic field are generated in the etching processing chamber to generate plasma, and a semiconductor device is installed.
In a dry etching method of etching a wafer for manufacturing, the pressure of the etching chamber is
The force is set to a low gas pressure in the range of 1 Pa to 4 Pa , the distance between the facing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is 4 Gcm. ^-1
To 50 Gcm ^-1 low gradient, magnetic field gradient / magnetic field
Strength values in the range of 0.1 cm ^-1 to 0.01 cm ^-1
Set, between the wafer and the facing surface of the wafer,
A dry etching method is provided in which a first high temperature electron temperature region and a second low temperature electron temperature region are generated in a vertical direction to dry etch the wafer.

The present invention is a dry process for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching process chamber in which C and F are present. in the etching method, the edge
Low gas pressure in the ching process chamber in the range of 1 Pa to 4 Pa
The pressure is set, the distance between the facing surface of the wafer and the wafer is set to 20 mm or more and 150 mm or less, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is set.
Set a low gradient of 4Gcm- ¹ to 50Gcm- ¹
Then, the value of the magnetic field gradient / magnetic field strength is changed from 0.1 cm ⁻¹ to 0.
01 cm ^−1, a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the facing surface of the wafer and the wafer, and CF _{2 in the} plasma is There is provided a dry etching method for independently etching F wafers and ions to radicals and dry etching the wafer.

The present invention is a method for manufacturing a semiconductor device in which an insulating film is formed by generating a high frequency and a magnetic field to generate plasma in an etching processing chamber in which C and F are present.
In the dry etching method of performing an etching treatment on the roof, the pressure in the etching treatment chamber is changed from 1 Pa to 4 Pa.
The pressure is set to a low gas pressure in the range of Pa, the distance between the facing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is 4 Gcm ^-1 to 50 Gcm.
Set a low gradient of ^-1 and set the value of magnetic field gradient / magnetic field strength to 0.
It is set in the range of ¹ cm ⁻¹ to 0.01 cm ⁻¹ , and a first vertical direction is provided between the facing surface of the wafer and the wafer.
To generate a high temperature electron temperature region and a second low temperature electron temperature region, and independently control the respective amounts of F radicals and ions with respect to CF ₂ radicals in the plasma according to the insulating film etching process. A dry etching method for dry etching an insulating film is provided.

The present invention is a method for manufacturing a semiconductor device in which an insulating film is formed by generating a high frequency and a magnetic field to generate plasma in an etching processing chamber in which C and F are present.
In the dry etching method of performing an etching treatment on the roof, the pressure in the etching treatment chamber is changed from 1 Pa to 4 Pa.
The pressure is set to a low gas pressure in the range of Pa, the distance between the facing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is 4 Gcm ^-1 to 50 Gcm.
Set a low gradient of ^-1 and set the value of magnetic field gradient / magnetic field strength to 0.
It is controlled in the range of ¹ cm ⁻¹ to 0.01 cm ⁻¹ , and the first vertical direction is provided between the facing surface of the wafer and the wafer.
A high temperature electron temperature region and a second low temperature electron temperature region are generated, and the size of the first high temperature electron temperature region is changed by the control of the magnetic field gradient to be independent of the amount of ions generated in the plasma. And a dry etching method for controlling the production ratio of CF2 / F radicals.

The present invention is a method for manufacturing a semiconductor device in which an insulating film is formed by generating a high frequency and a magnetic field to generate plasma in an etching processing chamber in which C and F are present.
In the dry etching method of performing an etching treatment on the roof, the pressure in the etching treatment chamber is changed from 1 Pa to 4 Pa.
The pressure is set to a low gas pressure in the range of Pa, the distance between the facing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is 4 Gcm ^-1 to 50 Gcm.
Set a low gradient of ^-1 and set the value of magnetic field gradient / magnetic field strength to 0.
It is controlled in the range of ¹ cm ⁻¹ to 0.01 cm ⁻¹ , and the first vertical direction is provided between the facing surface of the wafer and the wafer.
The generated hot electrons temperature region and a second low electron temperature region, provides a dry etching method of changing the electron temperature in the vicinity of the wafer over the etching time for the contact hole of the wafer.

The present invention relates to a dry etching method of converting an etching gas into plasma and utilizing the plasma to dry-etch a workpiece.
The antenna installed in the processing chamber and emitting electromagnetic waves
Set the distance from the wafer to 20 mm or more and 150 mm or less
The pressure in the etching chamber from 1 Pa to 4 Pa.
Set to a low gas pressure in the range and set the high frequency to 300 MHz.
More than 600MHz and the magnetic field gradient is 4Gcm
^-1 to 50 Gcm ^-1 Set to a low gradient, magnetic field gradient /
The value of the magnetic field intensity from 0.1 cm ^-1 of 0.01 cm ^-1
Set to the range, and hang between the antenna and the wafer.
A first high-temperature electron temperature region and a second low-temperature electron temperature in the direct direction
A region is generated, and the plasma has a first high temperature electron temperature region and a second low temperature electron temperature region, and the workpiece is processed while changing the first high temperature electron temperature region. A dry etching method for dry etching a silicon oxide film formed on a wafer is provided.

In the present invention, the first high-temperature electron temperature region is a region for selectively producing CF-based radicals, and the second low-temperature electron temperature region is for selectively producing F-based radicals. A dry etching method that is a region to be generated is provided.

The present invention further provides the dry etching
Provided is a dry etching method performed at a pressure of 0.1 Pa or more and 4 Pa or less.

In the present invention, the dry etching further comprises
A dry etching method performed by adding a gas containing hydrogen.

The present invention further provides a dry etching method in which the first high temperature electron temperature is 2 eV or higher and 4 eV or lower and the second low temperature electron temperature is 5 eV or higher.

The present invention, a magnetic field is applied to the processing chamber, the etching gas into plasma, by using the plasma, in the dry etching process for dry-etching a workpiece, is disposed in the etching chamber, the electromagnetic wave Let go
The distance between the radiating antenna and the wafer is 20 mm or more 1
The pressure in the etching chamber is set to 50 mm or less.
Set to a low gas pressure in the range of 1 Pa to 4 Pa,
Set the frequency above 300MHz and below 600MHz,
The field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1.
The value of magnetic field gradient / magnetic field strength from 0.1 cm ⁻¹
It is set in the range of 0.01 cm ⁻¹ , and the antenna and the
A first hot electron temperature region in the vertical direction between the wafer and
A dry etching method is provided in which a second low-temperature electron temperature region is generated and the magnetic field gradient of the magnetic field is changed while dry etching the workpiece.

The present invention further provides a dry etching method, wherein the workpiece is a silicon oxide film formed on a wafer.

In the present invention, the magnetic field gradient is such that the value of magnetic field gradient / magnetic field strength is 0.1 cm ^-1 or less and 0.01 cm ^-1.
A dry etching method controlled within the above range is provided.

In the present invention, the dry etching further comprises
Provided is a dry etching method performed at a pressure of 0.1 Pa or more and 4 Pa or less.

In the present invention, the dry etching further comprises
A dry etching method performed by adding a gas containing hydrogen.

The present invention further provides a dry etching method in which the first high temperature electron temperature is 2 eV or higher and 4 eV or lower and the second low temperature electron temperature is 5 eV or higher.

The present invention provides a high frequency and high frequency etching chamber.
Semiconductor devices are manufactured by generating a magnetic field to generate plasma
Dryer for etching the wafer
In the etching method, the
The distance between the antenna that radiates electromagnetic waves and the wafer.
The etching is set to 20 mm or more and 150 mm or less.
Reduce the pressure in the processing chamber to a low gas pressure in the range of 1 Pa to 4 Pa
Set the high frequency to 300MHz or more and 600MHz or less
Set to below, magnetic field gradient from 4Gcm- ¹ to 50Gcm
Set a low gradient of ^-1 and set the value of magnetic field gradient / magnetic field strength to 0.
It is set in the range of ¹ cm ⁻¹ to 0.01 cm ⁻¹ , and
A first high temperature vertically between the antenna and the wafer.
An electron temperature region and a second low temperature electron temperature region are generated, a gas containing fluorocarbon is introduced into the processing chamber, the gas is turned into plasma, and the production amount of fluorine radicals, fluorocarbon radicals, and ions in the plasma is controlled. independently controlled during the etching of the workpiece, the workpiece providing a de dry etching how to dry etching.

The present invention further provides a dry etching method in which the amounts of the fluorine radicals and fluorocarbon radicals are changed during the etching of the workpiece.

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) FIG. 4 shows a dry etching apparatus used in the present invention. In this apparatus, an etching gas is introduced into the etching processing chamber 1 and the microwave generator 2 is operated from 900 MHz to 2.
A high frequency of 45 GHz is generated, and the high frequency is transported to the etching processing chamber 1 through the waveguide 3 to generate a gas plasma. The vertical magnetic field gradient in the ECR region is E
Four solenoid coils for magnetic field generation are installed around the etching processing chamber so that the magnetic field strength in the CR region can be controlled in a wide range. These solenoid coils 4 control the four coil currents so that the magnetic field between 0 and 875 Gauss is almost directly above the processing table, and the electron density is adjusted to 10 by using electron cyclotron resonance (ECR).
A high density plasma of ¹¹ pieces / cm ³ or more is generated.

The magnetic field gradient in the ECR region is controlled in the range of the value of magnetic field gradient / magnetic field strength from 0.1 cm ^-1 to 0.01 cm ^-1 . The etching processing chamber 1 has a processing table 5, on which an object 6 to be processed is placed, and etching processing is performed by gas plasma. The etching gas is introduced into the etching processing chamber 1 through the gas flow rate control device, and the exhaust pump 7
Thus, the gas is exhausted to the outside of the etching processing chamber 1. The processing table 5 on which the object to be processed is installed is equipped with a high-frequency power source 12,
A high frequency bias from KHz to 13.56 MHz can be applied. The position of the processing table can be fixed within a range of 20 mm to 150 mm from the facing surface (gas introduction port 11) of the processing table.

An 8-inch silicon wafer is transferred to this apparatus as an object to be processed. An oxide film having a thickness of 2 mm is formed on the silicon wafer, and a resist mask to which a mask pattern is transferred is formed on the oxide film. Holes having a diameter of 200 nm are formed in the resist mask.

Ar 400 sccm, C ₄ F ₈ of 10 sccm, and CH ₂ F ₂ of 5 sccm are introduced into the processing chamber into the processing chamber, and the gas pressure is set to 2 Pa. 2.45 GHz, 1k
Generate high frequency of W from the microwave generator and
A bias of 00 KHz and 1000 W is applied to etch the oxide film. The position of the processing table is set to 100 mm from the microwave introduction window, and the coil current is adjusted so that the magnetic field strength is 875 gauss at a position 6 cm above the wafer and the magnetic field gradient at that position is 50 gauss / cm. Under that condition, the ECR region has a thickness of about 10 mm and an electron temperature of about 10 eV. Electron temperature outside ECR region is 3e
It will be about V. That is, a high electron region having a thickness of about 10 mm and a low electron region having a thickness of about 90 mm are formed. A part of F is excluded by reacting with H generated from CH ₂ F ₂ . _Therefore, although the amount of F from C 4 _{F 8} is two times with respect to CF _2, the ratio of F / CF ₂ incident on the wafer can be estimated to be around 0.6. Electron density is 3
Ion current density is 5 mA at about 10 ¹¹ cells / cm ^3.
/ Cm ² or so. Under this condition, the etching rate of the oxide film is about 700 nm / min, and the selection ratio for the resist is 5. Although the processed shape is almost vertical, when the gas pressure is increased up to 5 Pa under the same conditions, a 20 nm lateral shaving is observed in the hole due to obliquely incident ions. When the gas pressure is 4 Pa or less, the processed shape becomes almost vertical.

When the magnetic field gradient is set to 15 G / cm, ECR
The thickness of the region spreads to about 20 mm. As a result, the F / CF ₂ ratio incident on the wafer is reduced to about 0.3.
On the other hand, the plasma density hardly changes even if the magnetic field gradient is changed, and in both cases, the ion current density is about 5 mA / cm ² . For this reason, the etching rate of the oxide film is almost unchanged, and is about 700 nm / min in the flat portion. In contrast, resist selectivity for the ratio of F decreases is better and 30, since the CF ₂ is excessive, oxide film is stopped is etched to a depth of about 1 mm.

A magnetic field gradient of 15 Gauss /
When changing from cm to 50 G / cm at 12 G / cm / min, the etching rate is 700 nm / min.
The etching is completed in about 3 minutes without stopping. The selectivity with respect to the resist is about 20, and the resist selectivity is greatly improved as compared with etching with a magnetic field gradient of 50 G / cm.

By controlling the magnetic field gradient in this way, the F / CF ₂ ratio can be changed while keeping the ion current constant. By reducing the magnetic field gradient, the selectivity to resist is increased. However, making the magnetic field gradient smaller means forming a uniform magnetic field in the etching apparatus, and in order to achieve this with the same magnetic field strength, it is necessary to install many coils around the etching apparatus. There is. On the other hand, when the magnetic field strength is reduced, the magnetic field gradient is also reduced in proportion thereto, so that the magnetic field gradient can be easily reduced. Since the magnetic field strength that forms the ECR depends on the frequency of the microwave,
To reduce the magnetic field strength and magnetic field gradient, it is advantageous to lower the microwave frequency.

(Example 2) Next, using the same apparatus, the microwave frequency was set to 900 MHz.
The case of using z will be described. 60 mm above the wafer
The coil current is adjusted so that the magnetic field strength is 320 gauss at the position and the magnetic field gradient is 20 gauss / cm at that position. Under this condition, the thickness of the ECR region is about 20 mm, and under the condition that the magnetic field gradient / magnetic field strength is almost constant, 2.
The ECR region is approximately doubled as compared with the case of 45 GHz. Therefore, when the gas is introduced under the same conditions, the ion current density is about 5 mA / cm ² , which is almost the same as 2.45 GHz, but the ratio of F / CF ₂ incident on the wafer is 0.
It can be estimated to be about 7. Therefore, the etching rate of the oxide film is about 700 nm / min, and the selection ratio to the resist is 15.

Example 3 Next, another embodiment using the apparatus of FIG. 5 will be described. In this device, an etching gas was introduced into the etching processing chamber 1 to generate 300 M in the high frequency power source 503.
A high frequency between Hz and 900 MHz is introduced from the antenna 502 into the etching processing chamber 1 to generate gas plasma. Three solenoid coils 4 for generating a magnetic field are arranged around the etching chamber for high-efficiency discharge.
2 so that the magnetic field between 0 gauss is almost right above the processing table.
The electron density is 1011 electrons / cm ³ by controlling two coil currents and using electron cyclotron resonance (ECR).
The above high-density plasma is generated. The etching processing chamber 1 has a processing table 5, on which an object 6 to be processed is placed, and etching processing is performed by gas plasma. The etching gas is introduced into the etching process chamber 1 through the gas flow rate control device, and the exhaust pump 7 drives the etching gas into the etching process chamber 1.
Exhausted outside. The processing table 5 on which the object to be processed is installed is equipped with a high frequency power source 12, and 400 KHz to 13.56 MH
A high frequency bias up to z can be applied. The position of the processing table is 20 mm to 150 m from the microwave introduction window.
It can be fixed within the range of m.

An 8-inch silicon wafer is transferred to this apparatus as an object to be processed. A silicon nitride film having a thickness of 0.1 mm is formed on the silicon wafer, an oxide film having a thickness of 1.5 mm is formed on the silicon nitride film, and a resist mask to which a mask pattern is transferred is formed on the silicon nitride film. A hole having a diameter of 150 nm is formed in the resist mask.

Ar 200 sccm and 10 sccm of C ₄ F ₈ were introduced into the processing chamber through the gas introduction port and the gas pressure was set to 1 in this apparatus.
Set to Pa. Gas plasma is generated with a high frequency of 450 MHz and 1 kW, and a bias of 800 KHz and 800 W is applied to the processing table to etch the oxide film. The position of the processing table is set to 60 mm from the antenna 502, and the coil current is adjusted so that the magnetic field strength is 160 gauss at a position 40 mm directly above the wafer and the magnetic field gradient at that position is 4 gauss / cm. Under this condition, the thickness of the ECR region is 50
The electron temperature is about 8 eV in mm. The electron temperature outside the ECR region is about 2 eV. Although the generation ratio of F / CF ₂ becomes about 1.0 due to the dissociation of C ₄ F _8, the amount of F incident on the wafer decreases due to the reaction between the polymer on the wafer facing surface and F. Therefore, the F / CF incident on the wafer
The ratio of ₂ is estimated to be about 0.5. The ion current density is about 5 mA / cm ² . Under this condition, the etching rate of the oxide film is about 700 nm / min, the selection ratio to the resist is 20, and the selection ratio to the underlying nitrogenized film is 30.

Under this condition, if etching is performed with a film thickness of the oxide film of 3 mm and a contact hole diameter of 150 nm, the etching stops at a depth of about 2 mm. In the prior art, in such a case, it was necessary to add oxygen gas to prevent the etching stop. When oxygen gas is added, the selection ratio of the resist is reduced to about 5 under the condition that etching stop does not occur. On the other hand, the magnetic field gradient from 4 gauss / cm to 10
When the amount of F generated is increased to Gauss / cm, the oxide film thickness is 3 mm and the contact hole diameter is 150 nm.
In the above etching, a substantially vertical processed shape can be obtained without stopping halfway. At this time, the selection ratio for the resist is reduced to about 10, but it is higher than that for the addition of oxygen.

As described above, by changing the magnetic field gradient and controlling the F / CF ₂ ratio even under the same gas condition, it becomes easy to deal with different etching conditions, and addition of oxygen gas or the like becomes unnecessary.

The frequency of the high frequency power source for plasma formation is set to 3
Even if it is changed within the range of 00 MHz to 900 MHz, the same result as 450 MHz can be obtained by controlling the magnetic field gradient. When the frequency is lowered, the size of the solenoid coil is reduced and the condition of the low magnetic field gradient is easily realized. Therefore, the frequency of 300 MHz to 600 MHz is particularly desirable. Regarding the gas pressure, when the gas pressure is increased to about 5 Pa, the oxide film is seen to be scraped in the lateral direction, and at a low gas pressure of 0.1 Pa or less, the incident amount of CF ₂ is small, so the high selection ratio is maintained. It becomes difficult to obtain a sufficient etching rate. Therefore, the gas pressure is particularly preferably 0.1 Pa to 4 Pa.

The distance between the wafer and the antenna was changed from 60 mm to 100 mm under the same etching conditions that the frequency of the high frequency applied to the antenna was 450 MHz and the magnetic field gradient was 4 gauss / cm, and a 1.5 mm silicon oxide film and a contact hole were used. Is processed to a diameter of 150 nm. By increasing the distance, the low electron temperature region is increased, and the influence of F consumption on the wafer facing surface is reduced.
The relative incident amount of is increased. Therefore, the selection ratios for the resist and the nitrided film are as small as 10 and 12, respectively. No change in the selection ratio was observed when the distance between the wafer and the antenna was 100 mm or more. Under this condition, CH ₂ F ₂
When gas is added at about 5 sccm, the resist selectivity is 20,
The selection ratio of the nitriding film is about 25, but since CH ₂ F ₂ has a strong deposition property and adheres to the inner wall surface, the frequency of cleaning increases and the throughput decreases. That is, it is more advantageous in terms of throughput to shorten the distance between the wafer and the antenna to 60 mm and improve the selection ratio. On the contrary, when the distance between the wafer and the antenna is shortened to 40 mm, the incident amount of F decreases and the selection ratio increases, but etching stops at a depth of about 1.2 mm 2. Thus, by controlling the relative incident amount of F by controlling the distance between the wafer and the antenna and the magnetic field gradient, desired etching conditions can be achieved without adding gas.

Next, another embodiment using the apparatus of FIG. 6 will be described. In this apparatus, an etching gas is introduced into the etching processing chamber 1 to generate a high frequency between 10-100 MHz in the first high frequency power source 601 and the second high frequency power source 602, and the high frequency is generated by the ring antenna 60.
Gas plasma is generated by introducing gas plasma into the etching chamber 1 from 3, 604 respectively. The electron density of plasma is 10
It becomes a high density plasma of ¹¹ pieces / cm ³ or more. The etching processing chamber 1 has a processing table 5, on which an object 6 to be processed is placed, and etching processing is performed by gas plasma. The etching gas is introduced into the etching processing chamber 1 through the gas flow rate control device, and is exhausted outside the etching processing chamber 1 by the exhaust pump 7. Processing table 5 for setting the object to be processed
Equipped with a high-frequency power source 12 from 400 KHz to 13.5
High frequency bias up to 6MHz can be applied.

An 8-inch silicon wafer is transferred to this apparatus as an object to be processed. An oxide film having a thickness of 2 mm is formed on the silicon wafer, and a resist mask to which a mask pattern is transferred is formed on the oxide film. Holes having a diameter of 200 nm are formed in the resist mask.

Ar 400 sccm and 10 sccm of C ₄ F ₈ were introduced into the processing chamber through the gas introduction port, and the gas pressure was set to 3 in this apparatus.
Set to Pa. A high frequency of 1500 W of 13.56 MHz is applied to the first ring antenna 603, and 13.56 MH
The high frequency of 1000 W of z is applied to the second ring antenna 60.
4 to generate a gas plasma, 800 on the processing table
A bias of kHz and 1200 W is applied to etch the oxide film. Under this condition, the electron temperature near the height of the first ring antenna is about 10 eV and 4 eV near the wafer.
become. The etching rate of the oxide film is about 700 nm / mi
The selection ratio of n to the resist is about 25, but the etching is stopped in the middle of the contact hole.

When the high frequency power applied to the second ring antenna 604 is set to 500 W, the electron temperature near the wafer is reduced to about 2 eV. Since the plasma density is almost determined by the first ring antenna, the ion current density does not change, and the etching rate of the oxide film is 700 nm / min, but the selection ratio of the resist is 10 due to the decrease in electron temperature.
It becomes small. However, under this condition, the etching does not stop.

During etching, the second ring antenna 6
High frequency power applied to 04 from 1000W to 500W
When the etching time is changed, the contact hole is formed without stopping the etching, and the average resist selection ratio during etching becomes about 20.

[0082]

According to the present invention, since the production ratio of F / CF ₂ can be arbitrarily controlled, the oxide film etching which has a high selectivity with respect to the resist and the nitriding film can be performed without largely depending on the gas pressure and the gas flow rate. It will be possible. By using the present invention, it is possible to process a contact hole having a high aspect ratio and an oxide film with a high selection ratio with respect to a resist and a silicon nitride film. Since the etching can be performed even under a low gas pressure condition of 1 Pa to 4 Pa, a vertically processed shape can be obtained with a contact hole having a high aspect ratio.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing formation of two kinds of electron temperature regions of the present invention.

FIG. 2 is a diagram showing the relationship between the formation of two types of electron temperature regions and the F / CF ₂ production ratio by controlling the magnetic field gradient of the present invention.

FIG. 3 is a diagram showing the relationship between the formation of two types of electron temperature regions and the F / CF ₂ production ratio by controlling the distance between the wafer and the surface facing the wafer according to the present invention.

FIG. 4 is a sectional view of a dry etching apparatus used in the present invention.

FIG. 5 is a sectional view of another dry etching apparatus used in the present invention.

FIG. 6 is a sectional view of another dry etching apparatus used in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Etching processing chamber, 2 ... Microwave generator, 3 ... Waveguide, 4 ... Solenoid coil, 5 ... Processing base, 6 ... Processing base, 7 ... Exhaust pump, 8 ... Exhaust valve, 9 ... Conductance valve, 10 ... Gas flow controller, 11, 50
1 ... Gas inlet, 12 ... High-frequency power source for processing table, 13 ...
Quartz chamber, 101 ... high electron temperature region, 102 ... low electron temperature region, 103 ... wafer facing surface 201 ... curve showing the relationship between the magnetic field gradient and F / CF ₂ generation ratio, 301 ... high electron temperature region, 302 ... etching A curve showing the relationship between the distance between the wafer facing surface of the apparatus and the wafer and the F / CF ₂ production ratio, 502 ... Antenna, 503 ... High frequency power supply, 601 ...
First high frequency power source, 602 ... Second high frequency power source, 603
... first ring antenna, 604 ... second ring antenna.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Yamamoto 1-280, Higashi Koikeku, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Nobuyuki Negishi, 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi, Ltd. (56) References JP-A-9-120957 (JP, A) JP-A-6-224155 (JP, A) JP-A-9-161993 (JP, A) JP-A-5-198533 (JP, A) JP-A-8-64585 (JP, A) JP-A-62-7131 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/3065

Claims (24)

(57) [Claims] 1. A dry etching method in which a high frequency and a magnetic field are generated in an etching processing chamber to generate plasma to perform etching processing on a wafer for manufacturing a semiconductor device, wherein the etching processing chamber is provided with an electromagnetic wave. The distance between the antenna that radiates the light and the wafer is 20 mm or more and 150 mm
The following is set, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1. Set the value of the magnetic field gradient / magnetic field strength from 0.1 cm ⁻¹ to 0.01
set in the range of cm ^-1, between the antenna and the wafer, the first hot electronic temperature region and a second low electron temperature region generated in the vertical direction, characterized in that dry etching the wafer And a dry etching method. 2. A dry etching method for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching treatment chamber in which C and F are present. The pressure of the chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, and the distance between the antenna arranged in the etching chamber and radiating electromagnetic waves and the wafer is 20 mm or more and 150 mm.
The high frequency is set to 300 MHz or more and 600 MHz or less, the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1 , and the value of the magnetic field gradient / magnetic field strength is 0.1 cm ^-1 to 0.01
cm ⁻¹ , and by the magnetic field gradient, a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer, A dry etching method, characterized in that respective amounts of F radicals and ions with respect to CF 2 radicals are independently generated, and the wafer is dry-etched. 3. Dry etching for etching a wafer for producing a semiconductor device having an insulating film formed by generating a high frequency and a magnetic field to generate plasma in an etching processing chamber in which C and F are present. In the method, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, and the distance between the wafer and the antenna that is disposed in the etching processing chamber and emits electromagnetic waves is 20 mm or more and 150 mm.
The high frequency is set to 300 MHz or more and 600 MHz or less, the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1 , and the value of the magnetic field gradient / magnetic field strength is 0.1 cm ^-1 to 0.01
set in the range of cm ^-1, between the antenna and the wafer to produce a first hot electron temperature region and a second low electron temperature region in the vertical direction,
Corresponding to the etching process of the insulating film, dry etching is performed on the insulating film while independently controlling the production amounts of F radicals and ions with respect to CF2 radicals in the plasma. . 4. A dry etching method for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching treatment chamber in which C and F are present. The chamber pressure is set to a low gas pressure in the range of 1 Pa to 4 Pa, and the distance between the antenna disposed in the etching processing chamber and radiating electromagnetic waves and the wafer is 20 mm or more and 150 m.
m or less, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is 4 Gcm ^-1 to 50 G during the etching process.
The magnetic field gradient / magnetic field strength value is controlled within a range of 0.1 cm ⁻¹ to 0.01 cm ⁻¹ by setting a low gradient of cm ⁻¹ , and a first vertical direction is provided between the antenna and the wafer. Generate a high temperature electron temperature region and a second low temperature electron temperature region of
A dry etching method characterized in that the size of the first high-temperature electron temperature region is varied to control the CF2 / F radical generation ratio independently of the amount of generated ions to dry-etch the wafer. 5. The plasma is generated by electron cyclotron resonance, and the magnetic field gradient is 0.1 m-
The dry etching method according to claim 4, wherein the dry etching method is controlled in the range of 1 to 0.01 cm ^-1 . 6. A dry etching method in which a high frequency and a magnetic field are generated in the etching processing chamber to generate plasma to perform etching processing on a wafer for manufacturing a semiconductor device, wherein the pressure in the etching processing chamber is from 1 Pa. The low gas pressure in the range of 4 Pa is set, and the distance between the antenna arranged in the etching chamber and radiating electromagnetic waves and the wafer is 20 mm or more and 150 m.
m or less, the high frequency is set to 300 MHz or more and 600 MHz or less, the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1 , and the value of the magnetic field gradient / magnetic field strength is 0.1 cm ^-1 to 0. 01
controlling to a range of cm ⁻¹ , and generating a first high temperature electron temperature region and a second low temperature electron temperature region in the vertical direction between the antenna and the wafer,
A dry etching method characterized in that the electron temperature near the wafer is changed with the lapse of etching time for the contact hole of the wafer. 7. A dry etching method in which a high frequency and a magnetic field are generated in an etching processing chamber to generate plasma to perform etching processing on a wafer for manufacturing a semiconductor device, wherein the pressure in the etching processing chamber is from 1 Pa. The pressure is set to a low gas pressure in the range of 4 Pa, the distance between the opposing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is 4 Gcm ^-1 to 50 Gcm. ^-1 is set to a low gradient, and the value of magnetic field gradient / magnetic field strength is set from 0.1 cm ^-1 to 0.01
set in the range of cm ^-1, between the counter surface and the wafer of the wafer, the first hot electronic temperature region and a second low electron temperature region generated in the vertical direction, dry etching the wafer A dry etching method characterized by the above. 8. A dry etching method for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field to generate plasma in an etching treatment chamber in which C and F are present. The chamber pressure is set to a low gas pressure in the range of 1 Pa to 4 Pa, the distance between the facing surface of the wafer and the wafer is set to 20 mm to 150 mm, the high frequency is set to 300 MHz to 600 MHz, and the magnetic field gradient is set. Is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1 , and the value of magnetic field gradient / magnetic field strength is set from 0.1 cm ^-1 to 0.01
cm ^−1, a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the facing surface of the wafer and the wafer, and CF 2 radicals in the plasma are generated. A dry etching method, characterized in that respective amounts of F radicals and ions are independently generated and the wafer is dry-etched. 9. A dry etching process for etching a wafer for producing a semiconductor device in which an insulating film is formed by generating a high frequency and a magnetic field to generate plasma in an etching process chamber in which C and F are present. In the method, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, the distance between the opposing surface of the wafer and the wafer is set to 20 mm or more and 150 mm or less, and the high frequency is 300 MHz or more and 600 MHz or less. And set the magnetic field gradient to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1 , and set the value of the magnetic field gradient / magnetic field strength to 0.1 cm ^-1 to 0.01
set in the range of cm ^-1, between the counter surface and the wafer of the wafer, the first hot electronic temperature region and a second low electron temperature region generated in the vertical direction, the etching process of the insulating film Correspondingly, the dry etching method is characterized in that the amounts of F radicals and ions with respect to CF2 radicals in the plasma are independently controlled, and the insulating film is dry-etched. 10. An etching treatment chamber in which C and F are present,
In a dry etching method of etching a wafer for producing a semiconductor device in which a high frequency and a magnetic field are generated to generate plasma to form an insulating film, the pressure in the etching processing chamber is in the range of 1 Pa to 4 Pa. The low gas pressure is set, the distance between the wafer facing surface and the wafer is set to 20 mm or more and 150 mm or less, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is low from 4 Gcm ^-1 to 50 Gcm ^-1 . The gradient is set and the value of the magnetic field gradient / magnetic field strength is set from 0.1 cm ⁻¹ to 0.01
By controlling the magnetic field gradient, a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the facing surface of the wafer and the wafer by controlling the range of cm ⁻¹ . The dry etching method is characterized in that the size of the first high temperature electron temperature region is changed to control the production ratio of CF2 / F radicals independently of the amount of ions produced in the plasma. 11. An etching treatment chamber in which C and F are present,
In a dry etching method of etching a wafer for producing a semiconductor device in which a high frequency and a magnetic field are generated to generate plasma to form an insulating film, the pressure in the etching processing chamber is in the range of 1 Pa to 4 Pa. The low gas pressure is set, the distance between the wafer facing surface and the wafer is set to 20 mm or more and 150 mm or less, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is low from 4 Gcm ^-1 to 50 Gcm ^-1 . The gradient is set and the value of the magnetic field gradient / magnetic field strength is set from 0.1 cm ⁻¹ to 0.01
The first high temperature electron temperature region and the second low temperature electron temperature region are generated in the vertical direction between the facing surface of the wafer and the wafer by controlling to a range of cm ⁻¹ , and A dry etching method characterized in that an electron temperature near the wafer is changed with the lapse of etching time. 12. A dry etching method in which an etching gas is converted into plasma and the plasma is utilized to dry-etch a workpiece, and a gap between an antenna arranged in the etching chamber and radiating an electromagnetic wave and the wafer. 20 mm or more and 150 mm
The following is set, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1. Set the value of the magnetic field gradient / magnetic field strength from 0.1 cm ⁻¹ to 0.01
The first high temperature electron temperature region and the second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer by setting the range of cm ^−1. It has a temperature region and a second low temperature electron temperature region, and dry-etches the silicon oxide film formed on the wafer as the workpiece while varying the first high temperature electron temperature region. And a dry etching method. 13. The first high temperature electron temperature region is a region for selectively generating CF type radicals, and the second low temperature electron temperature region is a region for selectively generating F type radicals. The dry etching method according to claim 11, wherein: 14. The dry etching is performed under a pressure of 0.1.
14. The dry etching method according to claim 11, wherein the dry etching is performed at Pa or more and 4 Pa or less. 15. The dry etching method according to claim 11, wherein the dry etching is performed by adding a gas containing hydrogen. 16. The first high temperature electron temperature is 2 eV or higher 4
16. The dry etching method according to claim 11, wherein the second low temperature electron temperature is eV or lower and the second low temperature electron temperature is 5 eV or higher. 17. A dry etching method in which a magnetic field is applied to a processing chamber to convert an etching gas into plasma, and the plasma is used to dry-etch a workpiece, the method being provided in the etching processing chamber and radiating electromagnetic waves. The distance between the antenna and the wafer is 20 mm or more and 150 mm
The following is set, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1. Set the value of the magnetic field gradient / magnetic field strength from 0.1 cm ⁻¹ to 0.01
set in the range of cm ^-1, between the antenna and the wafer, the first hot electronic temperature region and a second low electron temperature region generated in the vertical direction, while changing the magnetic field gradient of the magnetic field A dry etching method, characterized in that the workpiece is dry-etched. 18. The dry etching method according to claim 17, wherein the workpiece is a silicon oxide film formed on a wafer. 19. The dry etching according to claim 17, wherein the magnetic field gradient is controlled such that the value of magnetic field gradient / magnetic field strength is 0.1 cm-1 or less and 0.01 cm-1 or more. Method. 20. The dry etching has a pressure of 0.1.
20. The dry etching method according to claim 17, wherein the dry etching is performed at Pa or more and 4 Pa or less. 21. The dry etching method according to claim 17, wherein the dry etching is performed by adding a gas containing hydrogen. 22. The first high-temperature electron temperature is 2 eV or higher 4
22. The dry etching method according to claim 17, wherein the second low temperature electron temperature is eV or lower and the second low temperature electron temperature is 5 eV or higher. 23. A dry etching method for etching a wafer for producing a semiconductor device by generating a high frequency and a magnetic field in the etching processing chamber to produce plasma, wherein the etching processing chamber is provided with an electromagnetic wave. The distance between the antenna that radiates the light and the wafer is 20 mm or more and 150 mm
The following is set, the pressure of the etching processing chamber is set to a low gas pressure in the range of 1 Pa to 4 Pa, the high frequency is set to 300 MHz or more and 600 MHz or less, and the magnetic field gradient is set to a low gradient of 4 Gcm ^-1 to 50 Gcm ^-1. Set the value of the magnetic field gradient / magnetic field strength from 0.1 cm ⁻¹ to 0.01
The temperature is set to a range of cm ^−1, a first high temperature electron temperature region and a second low temperature electron temperature region are generated in the vertical direction between the antenna and the wafer, and a gas containing fluorocarbon is introduced into the processing chamber. Then, the gas is made into plasma, and the production amount of fluorine radicals, fluorocarbon radicals, and ions in the plasma is independently controlled during etching of the workpiece, and the workpiece is dry-etched. Dry etching method. 24. The dry etching method according to claim 23, wherein the amounts of the fluorine radicals and fluorocarbon radicals are changed during the etching of the workpiece.