JP3484317B2 - Method for manufacturing semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device such as a semiconductor IC (integrated circuit), and more particularly to a method for manufacturing a semiconductor device using a lithography technique.

[0002]

2. Description of the Related Art There is a lithography method as a manufacturing technology of a semiconductor IC. The lithography method is a technical method for transferring a device pattern or a circuit pattern onto a semiconductor substrate.
It is used for forming a conductive portion such as a gate of a semiconductor element such as a transistor or a word line or a bit line forming a matrix of a DRAM. In this lithography method, generally, a conductive layer is formed on a semiconductor substrate, and an organic photoresist layer is formed on this conductive layer. The photoresist layer is selectively exposed to light through a photomask and then developed to form a resist pattern having a predetermined shape on the conductive layer. By the etching process using this resist pattern as a mask,
A desired conductive part is formed.

By the way, as the demand for integration increases,
For example, it is required to process a fine gate width of 0.2 to 0.23 μm. In the lithography technology that requires such fine processing, the light reflected from the conductive layer below the photoresist layer causes the exposure resolution to decrease when the photoresist layer is selectively exposed using a photomask. This reflected light hinders fine processing.

Therefore, an amorphous carbon layer is interposed between the conductive layer and the photoresist layer, the amorphous carbon layer is used as an antireflection film, and the amorphous carbon is used as an etching mask for an underlying conductive layer. Technologies to be used have been proposed.

According to this conventional technique, when the resist pattern is formed on the amorphous carbon layer by the organic photoresist layer, the amorphous carbon under the photoresist layer effectively absorbs the exposure, so that the amorphous carbon itself. The reflection of the exposure light is prevented and the reflection of the light from the conductive layer thereunder is prevented, thereby preventing the deterioration of the resolution due to the reflected light during the exposure. Therefore, a high resolution resist pattern can be obtained with the photoresist layer. The conductive layer is etched to form a conductive part having a desired shape by using the part of the amorphous carbon layer corresponding to the resist pattern as a mask, and then the mask part remaining on the conductive part of the amorphous carbon is removed. Therefore, the substantial height dimension of the conductive portion is not increased by the residue on the conductive portion. Therefore, it is advantageous in flattening the interlayer insulating film formed on the conductive portion.

[0006]

In the conventional method using the amorphous carbon layer as an antireflection film as described above, the amorphous carbon layer is formed by a dry etching process using a resist pattern made of a photoresist layer as a mask. The selective removal is performed according to the desired pattern.

However, as the etching gas used in this dry etching, conventionally, an F-based etching gas such as SF ₆ , a Cl-F-based etching gas such as CClF ₃ or a Cl-based etching gas such as HCl has been used. . Such etching gas has an extremely small etching rate ratio (amorphous carbon layer / photoresist layer) of 0.3, which is an etching rate ratio of the amorphous carbon layer to be removed with respect to the resist pattern formed of the photoresist layer. Is only shown.

The larger this selection ratio is, the easier the amorphous carbon layer to be removed is to be removed as compared with the photoresist layer serving as a mask, and therefore the etching process with high accuracy is facilitated. Therefore, etching the amorphous carbon layer with a higher selection ratio,
Due to this, there has been a demand for a method of manufacturing a semiconductor device that can perform highly accurate processing relatively easily.

[0009]

The present invention adopts the following constitution in order to solve the above points. <Structure> According to the present invention, a conductive layer is formed on a semiconductor substrate, an antireflection film layer containing carbon is formed on the conductive layer, and an organic photoresist layer is formed on the antireflection film. ,
By selectively exposing and developing the photoresist layer to form a resist pattern of a predetermined shape composed of the photoresist layer, using the resist pattern as a mask,
By selectively etching the antireflection film using an etching gas, the conductive layer is selectively etched using the remaining portion of the antireflection film as a mask to form a desired conductive portion on the semiconductor substrate. In a method for manufacturing a semiconductor device including forming, HBr , CF 4 and He are included as an etching gas for etching the antireflection film.
It is characterized by using an etching gas .

In the manufacturing method according to the present invention, an etching gas for etching the antireflection film containing carbon is used.
To, use an etching gas containing HBr and CF 4
The selection ratio (antireflection film / photoresist layer) of the antireflection film to be removed with respect to the resist pattern formed of the photoresist layer is larger than the conventional value of 0.3.

Therefore, by using such an etching gas, a highly accurate etching mask corresponding to the resist mask made of a photoresist layer can be easily formed by the antireflection film as compared with the conventional case.

As an antireflection film containing carbon, BARC (bottom) containing carbon in addition to conventional amorphous carbon is used.
Although an antireflection film called an anti reflective coat can be used, in order to easily manufacture the antireflection film,
It is desirable to use amorphous carbon (corresponding to claim 2).

[0013]

When an etching gas containing HBr, CF ₄ and He is used as the etching gas for the antireflection film, the flow rates of HBr, CF ₄ and He are set to 30 sccm, 100 sccm and 100 sccm, respectively.
(Corresponding to claim 3 ). In this condition, by the proper setting of the operating condition according to the type of similar dry etching apparatus and described above, as the same selection ratio as described above, it is possible to obtain a large value called 0.6.

[0015]

Using the remaining portion of the antireflection film layer left corresponding to the resist pattern as a mask, the conductive layer is subjected to etching treatment to form a conductive portion having a desired shape, and then the antireflection film remaining on the conductive portion. The remaining part of is removed. For removal of this remaining portion, normal ashing, that is, ashing treatment can be applied. In this ashing process,
It is desirable to use an etching gas containing O ₃ (corresponding to claim 4 ).

In order to ash the remaining portion of the antireflection film on the conductive portion, an etching gas containing only O ₂ can be used. This O ₂ gas is used for the semiconductor substrate and for the antireflection film. Since it has the same etching characteristics as described above, the semiconductor substrate may be damaged when the remaining portion of the antireflection film is ashed. On the other hand, the etching gas containing O ₃ effectively peels off the mask portion remaining on the conductive portion, so that the unnecessary antireflection film, that is, the conductive portion, is not seriously damaged to the semiconductor substrate. The remaining mask portion can be effectively removed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. <Specific Example> FIG. 1 shows an example in which the method for manufacturing a semiconductor device according to the present invention is applied to the manufacture of a MOS transistor. For example, on a semiconductor substrate 10 made of silicon, as shown in FIG.
As shown in, the active region 11 for forming the element is divided by the element isolation region 12. The active region 11 and the element isolation region 12 are the well-known LOCOS.
It can be formed by a method. A gate oxide film for a gate, which will be described later, is formed on the active region 11, but this gate oxide film is omitted for simplification of the drawing.

A conductive layer 13 (14) for a gate is formed on the active region 11 and the element isolation region 12 of the semiconductor substrate 10.
And 15) are formed. In the illustrated example, FIG.
As shown in FIG. 1, the conductive layer 13 includes, for example, a polysilicon layer 14 having a thickness dimension of about 1000 A ° to which phosphorus is added, and a 1000 A layer formed on the polysilicon layer 14.
And a tungsten silicide layer 15 having a thickness of 0 °. The polysilicon layer 14 and the tungsten silicide layer 15 can be formed by a chemical vapor deposition method and a sputtering method, respectively, as is well known in the art.

An amorphous carbon layer 16 having a thickness of about 2000 A ° is formed on the conductive layer 13 by, for example, a sputtering method. Further, on the amorphous carbon layer 16, for example, by spin coating, about 6
A well-known organic photoresist layer 17 having a thickness of 000 A ° is formed. With the photomask 18 having a desired resist pattern placed on the photoresist layer 17, the photoresist layer 17
Is exposed by using, for example, an excimer laser device as a light source.

During the selective exposure of the photoresist layer 17 using the photomask 18, the amorphous carbon layer 16 effectively absorbs the laser light due to the exposure and the reflected light from the tungsten silicide layer 15 effectively. Function as an antireflection film. Therefore, the photoresist layer 17 is exposed with high resolution without causing blur due to scattering due to reflected light or the like.

After the selective exposure of the photoresist layer 17 using the photomask 18, the photomask 18 on the photoresist layer 17 is removed. Then, the photoresist layer 17 is subjected to a well-known development process in the related art. By this development process, as shown in FIG. 1C, a resist wiring pattern 17a of, eg, about 0.25 μm is formed on the amorphous carbon layer 16 by the remaining part of the photoresist layer 17. After that, resist wiring pattern 1
Using 7a as an etching mask, the antireflection film 16 made of an amorphous carbon layer is selectively removed.

FIG. 2 schematically shows an example of a dry etching device 19 used for selectively removing the antireflection film 16. Dry etching apparatus 1 shown in FIG.
Reference numeral 9 denotes a magnetron RIE (reactive ion etching) device which is well known in the related art, and a reaction chamber 21 defined by a housing 20 thereof has a structure similar to that in the conventional case.
The upper electrode 22 and the lower electrode 23 are spaced apart from each other.

An introduction pipe 24 for introducing an etching gas is connected to the reaction chamber 21, and an exhaust pipe 25 is connected to the reaction chamber 21. The reactive etching gas introduced from the introduction pipe 24 into the reaction chamber 21 is activated by the high frequency power 26 applied to the lower electrode 23. The activating gas causes the antireflection film 16 of the semiconductor substrate 10 arranged on the lower electrode 23 to be etched. Magnetron RIE
In the device 19, as is well known in the art, the rotating magnetic field of the rotating magnet device 27 arranged around the housing 20 is used to confine the plasma of the activated gas in the central portion of the reaction chamber 21.

In the manufacturing method according to the present invention, as the etching gas introduced into the reaction chamber 21 through the introduction pipe 24,
An etching gas consisting of C ₄ F ₈ and O ₂ was used. This etching gas has a flow rate of C ₄ F ₈ and O ₂ of 1 each.
It is introduced into the reaction chamber 21 for about 120 seconds so as to be 0 sccm and 20 sccm. At this time, the dry etching apparatus 19 has, for example, a pressure of 2 in the reaction chamber 21.
0 mTorr, high frequency power 26 is 1400 W, rotation speed of rotating magnet device 27 is 20 rpm, temperature of lower electrode 23 is 2
It was operated under operating conditions of 0 ° C.

The etching gas consisting of C ₄ F ₈ and O ₂ is
Under the above operating conditions, the antireflection film 16 to be removed,
Resist pattern 17a made of photoresist layer 17
Selection ratio (antireflection film 16 / photoresist layer 1
7) showed a value of 0.4, which is larger than the conventional value of 0.3. This large selection ratio enables the selective removal of the antireflection film 16 along the resist wiring pattern 17a more easily and with higher accuracy than in the conventional case. Therefore, FIG.
As shown in (d), the remaining portion 1 of the antireflection film 16 corresponding to the resist wiring pattern 17a is formed under the resist wiring pattern 17a more easily and with higher accuracy than before.
6a can be left.

The resist wiring pattern 17a on the remaining portion 16a of the antireflection film 16 has, for example, this remaining portion 17a.
Can be removed by immersing it in a mixed solution of sulfuric acid and hydrogen peroxide for about 20 minutes, and then by washing with water,
As shown in FIG. 1E, an appropriate etching mask made of the remaining portion 16a of the antireflection film 16 can be formed on the conductive layer 13.

FIG. 3 shows the remaining portion 16a of the antireflection film 16.
An example of the dry etching apparatus 28 suitable for partially removing the conductive layer 13 using the mask as a mask is shown. The dry etching apparatus 28 shown in FIG. 3 is a conventionally well-known magnetic field microwave plasma etching apparatus. According to this dry etching apparatus 28, the etching gas introduced into the reaction chamber 29 through the introduction pipe 24 is not affected by the waveguide 3
The microwaves introduced through 0 and the magnetic field generated by the pair of solenoid coils 31A and 31B arranged around the reaction chamber 29 and supplied with the direct current are activated by high-frequency power. It is effectively directed to the semiconductor substrate 10 on the stage 33 which receives the supply of 32.

In the selective etching of the tungsten silicide layer 15 using the remaining portion 16a of the antireflection film 16 as a mask, the pressure in the reaction chamber 29 is 5 mTorr and the high frequency power 32 is applied.
Is 50 W and the supply current to the solenoid coil 31A is 20
A, the supply current to the solenoid coil 31B was 5 A, and the temperature of the stage 33 was 20 ° C., the etching gas consisting of Cl ₂ was introduced into the reaction chamber 29 for about 20 seconds. In this first step, the tungsten silicide layer 15 of the conductive layer 13 is partially removed corresponding to the mask 16a.

Then, in the second step, the pressure in the reaction chamber 29 is 5 mTorr, the high frequency power 32 is 30 W, the supply current to the solenoid coil 31 A is 20 A, the supply current to the solenoid coil 31 B is 5 A, and the stage 33 is in the stage 33. The temperature is 2
Under the operating condition of 0 ° C., the etching gas composed of Cl ₂ and O ₂ is about 20 at a flow rate of 95 sccm and 5 sccm, respectively.
It was introduced into the reaction chamber 29 for a second. In this second step, the polysilicon layer 14 under the tungsten silicide layer 15 is partially removed corresponding to the mask 16a. Further, in a third step, the polysilicon layer 14 is overetched. An example of the condition is high frequency power 3
Same as the second step, except that 2 is 20W.

By the first to third steps, the selective removal of the conductive layer 13 is completed. After the mask 16a remaining on the conductive layer 13 is removed, the semiconductor substrate 10 is washed with, for example, a mixed solution of sulfuric acid and hydrogen peroxide water, and then washed with, for example, 1% hydrofluoric acid water for about 30 seconds. As a result, the gate 13a formed of the remaining portions 14a and 15a of the polysilicon layer 14 and the tungsten silicide layer 15, respectively, is received as shown in FIG.
Is formed.

Mask 1 which is the remaining portion of antireflection film 16
For removing 6a, for example, a downflow type ashing device 34 as shown in FIG. 4 can be used. In the downflow type ashing device 34, as is well known in the art, the etching gas guided into the reaction chamber 36 through the gas supply pipe 35 supplies the high frequency power supplied between the high frequency electrode 37 and the ground electrode 38. The electric field of 39 effectively directs the semiconductor substrate 10 on the grounded stage 40. O ₂ as an etching gas, for example, 1
It can be supplied to the reaction chamber 36 at a flow rate of 00 sccm for about 60 seconds, at which time the pressure in the reaction chamber 36 is 500 mTorr.
r and the high frequency power 39 can be set to 600W.

As shown in FIG. 1F, after forming the gate 13a which is a conductive portion on the semiconductor substrate 10, the gate 13a of the semiconductor substrate 10 is formed by, for example, ion implantation.
Source and drain are formed on both sides of the
Each part required for S is assembled on the semiconductor substrate 10, and MO
The S transistor is completed.

In the manufacturing method according to the present invention, as shown in FIG.
As shown in (c), when selectively removing the antireflection film 16 by dry etching using the resist wiring pattern 17a made of the photoresist layer 17 as a mask, the photoresist of the antireflection film 16 to be partially removed is used. Layer 1
The selection ratio for the resist pattern 17a composed of 7 is
Since the etching gas composed of C ₄ F ₈ and O ₂ showing the value of 0.4 is used, the selective reflection of the antireflection film 16 along the resist wiring pattern 17a can be performed easily and with high accuracy as compared with the conventional case. The etching mask 16a that can be removed can be formed easily and with high precision. Therefore, since the gate 13a can be formed with high accuracy relatively easily by using the etching mask 16a with high accuracy, the MOS having excellent reliability can be relatively easily prepared.
A transistor can be formed.

As an etching gas for the antireflection film 16 made of amorphous carbon, an etching gas containing HBr, CF ₄ and He can be used. This HBr, CF
_As the dry etching apparatus using the etching gas containing ₄ and He, the dry etching apparatus 19 shown in FIG. 2 or the dry etching apparatus 28 shown in FIG. 3 can be used. Further, instead of these, an inductive coupling type dry etching device 41 as shown in FIG. 5 can be used.

In FIG. 5, the same functional portions as those of the inductively coupled dry etching apparatus 41 shown in FIG. 3 are designated by the same reference numerals. In the inductively coupled dry etching apparatus 41, alternating current power 42
The magnetic field generated by the spiral coil 27 arranged on the transmission window 43 made of quartz in response to the supply of the magnetic field is used to confine the plasma.

In the example using the inductively coupled dry etching apparatus 41, the flow rates of HBr, CF ₄ and He are 30 respectively.
The mixed gas thereof was introduced into the reaction chamber 29 for about 140 seconds so as to have sccm, 100 sccm and 100 sccm. The operating conditions of the dry etching apparatus 41 at this time are that the pressure in the reaction chamber 29 is 10 mTorr, and the high frequency power 42
Is 500 W, high frequency power 32 is 100 W, stage 33
Was 20 ° C.

At this time, the etching gas composed of HBr, CF ₄ and He has a selection ratio of the antireflection film 16 to be removed with respect to the resist pattern 17a composed of the photoresist layer 17 (antireflection film 16 / photoresist layer 17). As a result, a larger value of 0.6 was shown.

Further, in order to selectively remove the antireflection film 16 using the inductively coupled dry etching apparatus 41 shown in FIG. 5, it is possible to use an etching gas containing CH ₂ F ₂ , CF ₄ and He. it can. The flow rates of CH ₂ F ₂ , CF ₄ and He are 30 sccm, 100 sccm and 100 sccm, respectively.
And the mixed gas thereof is used for about 140 seconds in the reaction chamber 29.
Was introduced in. Inductively coupled dry etching device 41
Other operating conditions of are the same as in the example of the etching gas composed of HBr, CF ₄ and He described above.

The etching gas composed of CH ₂ F ₂ , CF ₄ and He exhibits a large selection ratio of 0.6 with respect to the photoresist layer 17 when the antireflection film 16 is selectively removed using this etching gas. It was

When the mask 16a is obtained by selectively removing the antireflection film 16, the end point of the etching operation can be determined by observing the gas in the reaction chamber with a monochromator. The end point of this etching can be determined by the disappearance of carbon emission by observation of a monochromator, but the emission waveform of carbon does not show a remarkable peak,
Clear judgment is not easy. Therefore, it is desirable to finish the etching operation of the antireflection film 16 by observing the emission of light having a wavelength of 405 nm, which is the emission from the tungsten silicide layer 15 that is the base of the antireflection film 16.
Thereby, the uniform mask 16a can be formed with high reproducibility.

After the mask 16a is formed by the etching gas composed of HBr, CF ₄ and He using the inductively coupled dry etching apparatus 41 shown in FIG. 5, the inductively coupled dry etching apparatus 41 is continuously used. ,
In the reaction chamber 29, the tungsten silicide layer 15 and the polysilicon layer 14 can be etched.

In etching the tungsten silicide layer 15 and the polysilicon layer 14 using the inductively coupled dry etching apparatus 41, the pressure in the reaction chamber 29 is 3 mTo.
rr, high frequency power 43 is 300 W, high frequency power 32 is 25
0W, the temperature of the stage 33 is 20 ℃
_The etching gas consisting of ₂ and O ₂ is 18 sc
It was introduced into the reaction chamber 29 at a flow rate of cm and 2 sccm for about 30 seconds.

The introduction of this etching gas causes the tungsten silicide layer 15 and the polysilicon layer 14 to be etched, and subsequently, for over-etching of the polysilicon layer 14 below the conductive layer 13, the reaction chamber 2
Under the operating conditions where the pressure inside 9 is 5 mTorr, the high frequency power 42 is 250 W, the high frequency power 32 is 80 W, and the temperature of the stage 33 is 20 ° C., the etching gas consisting of Cl ₂ and O ₂ is 16 sccm and 4 sccm, respectively. Was introduced into the reaction chamber 29 for about 30 seconds. This polysilicon layer 14
The gate 13a is formed by over-etching.

As described above, by changing the operating conditions and the etching gas, the mask 16a made of the antireflection film 16 and the gate 13a made of the conductive layer 13 can be formed by the single inductively coupled dry etching apparatus 41. It will be possible. Therefore, productivity can be improved by shortening the work time required for manufacturing the semiconductor device.

Mask 1 which is the remaining portion of antireflection film 16
For the removal of 6a, an example in which O ₂ is used as an etching gas is shown in accordance with the description of the downflow type ashing device 34 shown in FIG. As this etching gas, a mixed gas of O ₂ and O ₃ can be used.

FIG. 6 is a sectional view schematically showing an example of an ashing device 44 using a mixed gas of O ₂ and O ₃ . The ashing device 44 shown in FIG. 6 is an ashing device 44 which is a so-called ozone asher. In the ashing device 44, the inside of the reaction chamber 36 which is defined by the housing 20 and receives exhaust gas through the exhaust pipe 25. Toward the semiconductor substrate 10 arranged on the stage 40,
A mixed gas of O ₂ and O ₃ is blown from the gas shower head 45. At this time, the temperature of the stage 40 is about 300.
Kept at ℃. When the mixed gas is supplied at a flow rate of 20 torr / min, the ratio of O _{3 in} the mixed gas is 100.
The mixed gas is g / m ³ and is sprayed toward the semiconductor substrate 10 for about 120 seconds.

After the mask 16a remaining on the semiconductor substrate 10 is removed by spraying a mixed gas of O ₂ and O ₃ , the semiconductor substrate 10 is dipped in a mixed solution of sulfuric acid and hydrogen peroxide as a cleaning treatment. And then 0.3%
Immerse in hydrofluoric acid water for about 20 seconds.

The etching gas containing O ₃ used for ashing the mask 16a effectively peels off the mask 16a remaining on the gate 13a which is the conductive portion. Therefore, after the ashing of the mask 16a, the concentration of hydrofluoric acid water used for cleaning the semiconductor substrate 10 and the treatment time with hydrofluoric acid water can be shortened.

The treatment with hydrofluoric acid water is carried out on the active region 11 by
There is a risk that the gate oxide film (not shown) formed under the gate 13a may be corroded or damaged. However, by using an etching gas containing O ₃ for ashing the mask 16a, it is possible to shorten the concentration of hydrofluoric acid water used for the purification treatment and the treatment time with hydrofluoric acid water. Can be reliably prevented, and thus the reliability of the operation of the semiconductor device including the gate film can be improved.

In the above description, each device 19, 28,
34, 41 and 44 and their operating conditions have been described as an example, the method according to the present invention is not limited to these devices, and various dry etching devices can be used under various proper operating conditions. Can be implemented. Further, various additive components can be added to the components of the etching gas, if necessary. Further, the example of forming the gate of the MOS transistor on the semiconductor substrate has been described, but the present invention is not limited to this, and for example, a word line of a semiconductor memory device, a bit line or a single layer of polysilicon, aluminum, tungsten and titanium. It can be applied to the formation of various metal wirings such as nickel or conductive portions such as multilayer wiring.

[0052]

As described above, in the manufacturing method according to the present invention, the etching gas for the etching treatment of the antireflection film containing carbon is applied to the resist pattern of the antireflection film to be removed, which is composed of the photoresist layer. Since the selection ratio shows a larger value than the conventional one, it becomes possible to easily form a mask with higher precision than the conventional one when forming the etching mask by the antireflection film. Therefore,
According to the present invention, a conductive portion such as a gate or a multi-layer wiring can be formed on a semiconductor substrate more easily and with higher accuracy than in the conventional case, thereby improving the reliability of a semiconductor device. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing each step of a method for manufacturing a semiconductor device according to the present invention.

FIG. 2 is a cross-sectional view schematically showing an etching apparatus used for etching an antireflection film in the method for manufacturing a semiconductor device according to the present invention.

FIG. 3 is a cross-sectional view schematically showing another etching apparatus used for etching a conductive layer in the method for manufacturing a semiconductor device according to the present invention.

FIG. 4 is a cross-sectional view schematically showing an ashing device used for removing the antireflection film by ashing in the method for manufacturing a semiconductor device according to the present invention.

FIG. 5 is a cross-sectional view schematically showing still another etching apparatus used for etching the antireflection film in the method for manufacturing a semiconductor device according to the present invention.

FIG. 6 is a cross-sectional view schematically showing another ashing device used for removing the antireflection film by ashing in the method for manufacturing a semiconductor device according to the present invention.

[Explanation of symbols]

10 Semiconductor substrate 13 Conductive layer 16 Antireflection film (amorphous carbon layer) 16a mask 17 Photoresist layer 17a Resist wiring pattern

Claims (5)

(57) [Claims] 1. Forming a conductive layer on a semiconductor substrate,
Forming an antireflection film layer containing carbon on the conductive layer;
Forming an organic photoresist layer on the antireflection film, forming a resist pattern of a predetermined shape composed of the photoresist layer by selective exposure and development of the photoresist layer, and using the resist pattern as a mask A selective etching process is performed on the antireflection film using an etching gas, and the conductive layer is selectively etched on the semiconductor substrate using the remaining portion of the antireflection film as a mask. A method of manufacturing a semiconductor device, the method comprising: forming an electrically conductive portion, wherein an etching gas containing HBr , CF 4 and He is used as an etching gas for etching the antireflection film. A method for manufacturing a semiconductor device, comprising: 2. The method for manufacturing a semiconductor device, wherein the antireflection film layer is amorphous carbon. 3. A flow rate of HBr, CF ₄ and He is 30 sccm and 1 respectively for the etching treatment of the antireflection film.
2. The method for manufacturing a semiconductor device according to claim 1, wherein the size is 00 sccm and 100 sccm. 4. After formation of the conductive portion, the manufacturing method of the anti-reflection film remaining on the conductive portion, the semiconductor device according to claim 2, wherein the ashing with an etching gas containing O ₃ . 5. As an etching apparatus of the antireflection film, a reactive ion etching apparatus using a rotating magnetic field,
2. The method for manufacturing a semiconductor device according to claim 1, wherein one of a magnetic field microwave plasma etching apparatus and an inductively coupled dry etching apparatus for generating a magnetic field by a coil is used.