JP2004342786A - Method of manufacturing semiconductor device, and dry etching equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device wherein a High-k film can be selectively etched with respect to an SiO<SB>2</SB>film of ground, and a dry etching equipment. <P>SOLUTION: In the dry etching equipment 300, an upper electrode 303 has a hollow part inside, and a plurality of gas jetting ports are arranged on a surface of the upper electrode 303 which surface faces a semiconductor substrate 306. Etching gas G is introduced from the gas jetting ports into a vacuum chamber 301 through an etching gas supply pipe 308 and the hollow part in order. Plate type members 403 composed of silicon are arranged at peripheries of the gas jetting ports. A lower ring 307 composed of silicon is arranged at periphery of the semiconductor substrate 306. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor device and a dry etching apparatus, and more particularly, to a method for manufacturing a semiconductor device having a high dielectric constant insulating film and a dry etching apparatus for performing desired etching on the high dielectric constant insulating film.
[0002]
[Prior art]
2. Description of the Related Art In recent years, high integration of a semiconductor integrated circuit device has been greatly advanced, and in a MOS (Metal Oxide Semiconductor) type semiconductor device, elements such as a transistor and the like for responding to high integration have been miniaturized and improved in performance. I have. In particular, the thickness of a gate insulating film, which is one of the elements constituting a MOS structure, has been rapidly reduced in order to cope with miniaturization, high-speed operation, and low voltage of the transistor.
[0003]
As a material for forming the gate insulating film, a silicon oxide film (SiO ₂ Membrane) has been used. On the other hand, when the gate insulating film is made thinner with the miniaturization of the gate electrode, a tunnel current, that is, a gate leak current, generated by carriers (electrons and holes) directly tunneling through the gate insulating film increases. . For example, the thickness of a gate insulating film required for a device of a 130 nm node is SiO ₂ Although the thickness of the film is about 2 nm, this region is a region where the tunnel current starts to flow. Therefore, SiO 2 is used as the gate insulating film. ₂ When a film is used, the gate leakage current cannot be suppressed, resulting in an increase in power consumption.
[0004]
Therefore, SiO ₂ Studies have been made to use a material having a higher dielectric constant as a gate insulating film instead of a film. Conventionally, as a high dielectric constant insulating film (hereinafter, referred to as a High-k film), TiO ₂ Membrane, Ta ₂ O ₅ Film and Al ₂ O ₅ Films have been studied, but recently, HfO ₂ Membrane, HfAlO _x Film and HfSiO _x Attention has been paid to films and the like because of their excellent stability on silicon.
[0005]
[Problems to be solved by the invention]
FIG. 5 is a cross-sectional view showing a manufacturing process of a conventional field-effect transistor (Field Effect Transistor) using a High-k film as a gate insulating film.
[0006]
After forming element isolation regions 502 and 503 on a silicon substrate 501 using a known method, SiO 2 is formed by thermal oxidation. ₂ A film 504 is formed. Next, a High-k film 505, a polycrystalline silicon film 506 as a gate electrode, and SiO 2 as a mask material ₂ The film 507 is grown in order. After that, an anti-reflection film 508 is formed for the purpose of improving the dimensional uniformity of the gate electrode, and then a resist pattern 509 is formed by photolithography (FIG. 5A).
[0007]
Next, using the resist pattern 509 as a mask, the anti-reflection film 508, SiO 2 ₂ The film 507 is dry-etched, ₂ A film pattern 510 is formed (FIG. 5B).
[0008]
Next, SiO 2 ₂ The polycrystalline silicon film 506 is dry-etched using the film pattern 510 as a mask to form a polycrystalline silicon film pattern 511 (FIG. 5C).
[0009]
Finally, the High-k film 505 and SiO ₂ The gate electrode is completed by etching the film 504, but there are the following problems at this time.
[0010]
In the structure of FIG. 5C, when the High-k film 505 does not exist, the polycrystalline silicon film pattern 511 and the underlying SiO ₂ Since the selectivity with the film 504 is large, SiO 2 ₂ Etching stops when the film 504 is exposed. Then, wet etching using dilute hydrofluoric acid or the like ₂ By removing the film 504, a gate electrode can be formed.
[0011]
On the other hand, if there is a High-k film 505, after forming the polycrystalline silicon film pattern 511 as described above, ₃ , HBr, O ₂ Alternatively, a High-k film pattern is formed by a dry etching method using an etching gas such as fluorocarbon or a wet etching method using an appropriate etching solution.
[0012]
However, when forming the High-k film pattern, the High-k film 505 and the underlying SiO ₂ Since the selectivity with the film 504 can be obtained only at a value of about 0.5 to 0.8, ₂ There is a problem that it is difficult to selectively etch the High-k film 505 with respect to the film 504. Further, since the selectivity between the High-k film 505 and the silicon substrate 501 is smaller than the above selectivity, the silicon substrate 501 is also etched (FIG. 5D). This impedes the formation of desired extensions and source / drain regions.
[0013]
The present invention has been made in view of such a problem. That is, an object of the present invention is to provide a base SiO 2 ₂ It is an object of the present invention to provide a method for manufacturing a semiconductor device capable of selectively etching a High-k film with respect to a film.
[0014]
Other objects and advantages of the present invention will become apparent from the following description.
[0015]
[Means for Solving the Problems]
The present invention provides a method for manufacturing a semiconductor device in which a high-dielectric-constant insulating film formed on a semiconductor substrate through an oxide film containing silicon is etched using a dry etching apparatus, wherein a gas containing bromine and oxygen is used as an etching gas. The method is characterized in that a silicon supply source is provided in a dry etching apparatus, and silicon is supplied into an etching atmosphere by etching the silicon supply source when etching a high dielectric constant insulating film. The silicon supply source may be a silicon member provided on at least one of the ejection port of the etching gas and the periphery of the semiconductor substrate. Here, the silicon member provided at the ejection port of the etching gas can be a plate-like member made of silicon. Further, the silicon member provided around the semiconductor substrate may be a silicon ring. The etching gas is HBr gas and O ₂ Mixed gas with gas or SiBr ₄ Gas and O ₂ It is preferable to use a mixed gas with a gas.
[0016]
Further, the present invention provides a method of manufacturing a semiconductor device for dry-etching a high dielectric constant insulating film formed on a semiconductor substrate via an oxide film containing silicon, wherein a gas containing silicon, bromine and oxygen is used as an etching gas. It is characterized in that it is used. Etching gas is SiBr ₄ Gas and O ₂ It is preferable to use a mixed gas with a gas.
[0017]
In the method of manufacturing a semiconductor device according to the present invention, the high dielectric constant insulating film is made of HfO. ₂ Membrane, HfAlO _x Film and HfSiO _x It is preferable to use one film selected from the group consisting of films.
[0018]
Further, the dry etching apparatus of the present invention converts the etching gas introduced into the vacuum chamber into plasma, and performs desired etching on the high dielectric constant insulating film formed on the semiconductor substrate via the oxide film containing silicon. An apparatus, wherein a first electrode on which a semiconductor substrate is mounted, and a second electrode provided at a predetermined interval at a position facing a surface of the semiconductor substrate on which the high dielectric constant insulating film is formed, An etching gas supply pipe for supplying an etching gas into the vacuum chamber, the second electrode has a hollow portion inside, and a plurality of gas ejection ports are provided on a surface of the second electrode facing the semiconductor substrate. The etching gas is introduced into the vacuum chamber from the gas outlet through the etching gas supply pipe and the hollow part in this order, and the gas outlet and the semiconductor substrate are reduced. It is characterized in that silicon member is also provided on the periphery of one. Here, the silicon member provided around the gas ejection port can be a plate-like member made of silicon. The silicon member provided around the substrate to be processed may be a silicon ring.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The present inventor has conducted intensive studies and found that while using an etching gas containing bromine and oxygen and supplying silicon into an etching atmosphere, the etching rate of the High-k film was increased, ₂ It has been found that the selectivity with the film (silicon oxide film) can be made larger than 1. This will be described in detail below.
[0020]
FIG. 1 shows that the etching rate of the High-k film is set to SiO 2 when silicon is supplied in an etching atmosphere and when silicon is not supplied. ₂ 3 shows the results of comparison with the etching rates of the film and the polycrystalline silicon film. In the example of FIG. 1, HfO is used as the High-k film. ₂ Uses a membrane. Specifically, a silicon substrate is made of SiO ₂ HfO through the membrane ₂ Film formed (sample A), SiO2 on silicon substrate ₂ A film having only a film formed thereon (sample B) and a silicon substrate on which SiO ₂ A sample in which a polycrystalline silicon film is formed through a film (sample C) is prepared, and these are formed on a silicon substrate or a SiO2 film formed on a silicon substrate. ₂ Each of the films was attached on the film, and the etching rate was measured. The etching gas used was HBr and O ₂ Was used. In the figure, a sample obtained by attaching samples A to C on a silicon substrate corresponds to a case where silicon is supplied. In addition, SiO formed on a silicon substrate ₂ Samples obtained by attaching samples A to C on the film correspond to a case where silicon is not supplied.
[0021]
As can be seen from FIG. ₂ The etching rate of the film is SiO ₂ It is about 18 times larger on a silicon substrate than on a film. In addition, SiO ₂ HfO for membrane ₂ The etching selectivity of the film was about 2.22 on the silicon substrate, and it was recognized that the etching selectivity was about three times as large as that of the related art.
[0022]
The above fact is considered to be due to the fact that Si is combined with the etching gas to generate a substance that contributes to the improvement of the etching rate. For example, in the example of FIG. 1, silicon reacts with bromine and oxygen in the etching gas to form SiO 2. _x Br, thereby producing HfO ₂ It is considered that the etching rate of the film is improved. On the other hand, SiO _x Br is SiO ₂ It is known as a material having selectivity to the film, and it is considered that the etching selectivity is increased.
[0023]
From the above findings, the present inventors have thought of supplying silicon in an etching atmosphere, and have reached the present invention. Hereinafter, embodiments of the present invention will be described while specifically showing a method of supplying silicon.
[0024]
Embodiment 1 FIG.
This embodiment is characterized in that a silicon supply source is provided in a dry etching apparatus.
[0025]
2A to 2E are cross-sectional views illustrating the steps of manufacturing the semiconductor device according to the present embodiment. First, device isolation regions 202 and 203 are formed on a silicon substrate 201 by a known method, and then a region sandwiched between the device isolation region 202 and the device isolation region 203 is formed by thermal oxidation. ₂ A film 204 is formed. SiO ₂ The thickness of the film 204 can be, for example, about 1 nm. Where SiO ₂ The film 204 may be formed not only by the thermal oxidation method but also by another method.
[0026]
Next, element isolation regions 202 and 203 and SiO ₂ A High-k film 205 is formed on the film 204. As the High-k film 205, for example, HfO ₂ Membrane, HfAlO _x Film or HfSiO _x A film or the like can be used. Note that the thickness of the High-k film 205 can be, for example, about 2 nm to 3 nm.
[0027]
After the High-k film 205 is formed, a polycrystalline silicon film 206 serving as a gate electrode and SiO 2 serving as a mask material are formed thereon. ₂ The film 207 is formed in order. The thickness of the polycrystalline silicon film 206 can be, for example, about 150 nm. In addition, SiO ₂ The thickness of the film 207 can be, for example, about 100 nm.
[0028]
SiO ₂ After forming the film 207, an anti-reflection film 208 is formed thereon. The anti-reflection film 208 plays a role in eliminating exposure light reflection at an interface between the resist film and the anti-reflection film by absorbing exposure light transmitted through the resist film when patterning a resist film to be formed next. . As the antireflection film 208, a film containing an organic substance as a main component can be used, and for example, can be formed by a spin coating method or the like. In the present invention, the anti-reflection film may not be provided.
[0029]
Next, a resist film (not shown) is formed on the antireflection film 208, and a resist pattern 209 having a desired line width is formed by photolithography. Through the above steps, the structure of FIG. 2A is obtained.
[0030]
Next, as shown in FIG. ₂ A film pattern 210 is formed.
[0031]
First, using the resist pattern 209 of FIG. ₂ The film 207 is etched. After that, the unnecessary resist pattern 209 is removed. Note that the etching of the antireflection film 208 progresses and SiO 2 ₂ The etching conditions may be set so that the resist pattern 209 disappears by etching almost immediately when the film 207 is exposed. In this case, SiO ₂ The etching of the film 207 is performed using an antireflection film pattern (not shown) as a mask. SiO ₂ After the film pattern 210 is formed, the anti-reflection film pattern can be removed by, for example, performing a plasma treatment using oxygen gas.
[0032]
Next, SiO 2 ₂ The structure shown in FIG. 2C is obtained by etching the polycrystalline silicon film 206 using the film pattern 210 as a mask. In the figure, a polycrystalline silicon film pattern 211 is a gate electrode.
[0033]
Next, SiO 2 ₂ The High-k film 205 is etched using the film pattern 210 as a mask. The etching can be performed by, for example, low-pressure high-density plasma by inductive coupling. This embodiment is characterized in that silicon is supplied in an etching atmosphere by providing a material capable of supplying silicon in a dry etching apparatus.
[0034]
FIG. 3 is an example of a dry etching apparatus according to the present embodiment. As shown in the figure, a dry etching apparatus 300 includes a lower electrode 302 as a first electrode and a second electrode disposed at a position facing the lower electrode 302 at a predetermined interval in a vacuum chamber 301. And an upper electrode 303 as an electrode. The lower electrode 302 is connected to a radio frequency (RF) power supply 304, and the upper electrode 303 is connected to a radio frequency (RF) power supply 305.
[0035]
The lower electrode 302 also serves as a substrate mounting table, and the semiconductor substrate 306 is mounted on the lower electrode 302 while being surrounded by a lower ring 307. At this time, the semiconductor substrate 306 is placed so that the surface on which the High-k film (not shown) is formed faces the upper electrode 303. The lower ring 307 has a role of positioning the semiconductor substrate 306 on the lower electrode 302. In the present embodiment, the lower ring 307 is a silicon ring formed of silicon. Also have a role.
[0036]
An etching gas supply pipe 308 for supplying an etching gas G is connected to the vacuum chamber 301. In this embodiment, a method for introducing the etching gas G into the vacuum chamber 301 will be specifically described with reference to FIGS. In these drawings, the portions denoted by the same reference numerals indicate the same portions.
[0037]
FIG. 4 is an enlarged view of a portion of the upper electrode 303 in FIG. The upper electrode 303 has a hollow portion 401 inside, and the etching gas G is introduced into the hollow portion 401 from the etching gas supply pipe 308. A plurality of gas outlets 402 are provided on a surface 303 a of the upper electrode 303 facing the semiconductor substrate, and the etching gas G in the hollow portion 401 is introduced into the vacuum chamber 301 from the gas outlets 402. You. The present embodiment is characterized in that a plate-shaped member 403 made of silicon is provided around the gas outlet 402 and inside the upper ring 404. The plate member 403 has a role as a silicon supply source similarly to the lower ring 307.
[0038]
As described above, the present embodiment is characterized in that the lower ring 307 and the plate member 403 are formed of silicon. Thus, the lower ring 307 and the plate member 403 can function as a silicon supply source. In the present embodiment, it is sufficient that the silicon member is provided in a region near the semiconductor substrate and exposed to plasma, and the shape is not particularly limited. That is, a silicon member having a shape other than the ring shape may be provided around the semiconductor substrate. Further, a silicon member having a shape other than the plate shape may be provided around the gas outlet.
[0039]
The process of etching the High-k film will be described with reference to FIGS.
[0040]
First, the semiconductor substrate 306 is mounted on the lower electrode 302. At this time, since the lower ring 307 is placed near the semiconductor substrate 306 so as to surround the periphery of the semiconductor substrate 306, silicon can be effectively supplied to the etched portion. Here, the semiconductor substrate 306 is made of SiO 2 formed according to the present embodiment. ₂ Film (not shown) and this SiO ₂ And a High-k film (not shown) formed on the film. Also, a polycrystalline silicon film pattern (not shown) and SiO 2 are formed on the High-k film. ₂ A film pattern (not shown) is formed. The semiconductor substrate 306 is placed so that the surface on which these films are formed faces the upper electrode 303 side.
[0041]
Next, an etching gas G is introduced into the vacuum chamber 301 at a predetermined flow rate. In the present embodiment, the etching gas G passes through the etching gas supply pipe 308, passes through the hollow portion 401 provided inside the upper electrode 303, and enters the vacuum chamber 301 from the gas outlet 402. As the etching gas G, a gas containing bromine and oxygen is preferably used. For example, HBr (hydrogen bromide) gas and O ₂ A mixed gas with an (oxygen) gas can be used.
[0042]
Next, when a high frequency is applied to each of the upper electrode 303 and the lower electrode 302, the etching gas reaching the plasma discharge region 309 is turned into plasma. At this time, silicon is present in the plasma atmosphere together with bromine and oxygen derived from the etching gas. Here, two silicon sources are the plate-like member 403 attached to the gas ejection port 402 and the lower ring 307. That is, since the gas ejection port 402 is provided on the surface of the upper electrode 303 facing the lower electrode 302, the plate-like member 403 is etched by the active species (such as Br radical and O radical) generated from the etching gas G. To generate silicon. Similarly, lower ring 307 is also etched to generate silicon. Here, in particular, since the lower ring 307 is provided around the semiconductor substrate 306, silicon can be supplied at a high concentration near the etched portion.
[0043]
The generated silicon combines with bromine and oxygen to form SiO 2 _x Generate Br. Therefore, SiO ₂ The High-k film can be selectively etched with respect to the film.
[0044]
The gas generated by the etching and the surplus etching gas G are exhausted from the exhaust port 310 to the outside of the vacuum chamber 301.
[0045]
Thus, by etching the High-k film 205, the structure shown in FIG. 2D can be obtained. Thereafter, the SiO 2 is formed by a known wet etching method using an appropriate etching solution. ₂ By removing the film 204, the gate electrode shown in FIG. 2E is completed.
[0046]
According to the present embodiment, silicon can be supplied into the etching atmosphere by providing a plate-shaped member made of silicon at the outlet of the etching gas and placing it in a region exposed to plasma. Further, by providing a lower ring made of silicon around the semiconductor substrate, it is possible to supply silicon to the vicinity of the etched portion. Therefore, by using a gas containing bromine and oxygen as an etching gas, SiO _x Br can be produced, thereby increasing the etch rate of the High-k film and the SiO 2 ₂ The etching selectivity with respect to the film can be increased.
[0047]
Further, according to the present embodiment, the silicon supply source is provided not on the semiconductor substrate but at a location other than the semiconductor substrate. Here, when a silicon supply source is provided on a semiconductor substrate, a new mask for forming a silicon supply source pattern is required. However, according to the present embodiment, such a mask is not required, and a pattern can be created using a conventional mask. Therefore, the object of the present invention can be easily achieved without increasing the cost.
[0048]
Note that only one of the gas ejection port and the lower ring may be formed of silicon as long as a necessary amount of silicon can be supplied into the etching atmosphere to obtain the above effect. However, considering that silicon can be supplied in the vicinity of the etched portion, it is more effective to form the lower ring with silicon. In addition, another silicon supply source may be provided as long as it can be installed near the semiconductor substrate and in a region exposed to plasma.
[0049]
Embodiment 2 FIG.
This embodiment is characterized in that a gas containing silicon is used as an etching gas.
[0050]
After forming element isolation regions 202 and 203 on a semiconductor substrate 201 according to the method shown in FIGS. ₂ The polycrystalline silicon film pattern 211 and the SiO 2 film ₂ A film pattern 210 is formed. Here, as in the first embodiment, the high-k film 205 is made of HfO ₂ Membrane, HfAlO _x Film or HfSiO _x A film or the like can be used.
[0051]
Next, the High-k film 205 is etched. In the present invention, a general-purpose dry etching apparatus can be used. Further, the dry etching apparatus described in Embodiment 1 may be used. However, in the apparatus shown in FIGS. 3 and 4, it is not necessary to provide a member made of silicon at the outlet of the etching gas, and it is not necessary to form the lower ring with silicon.
[0052]
The method for etching the High-k film according to the present embodiment will be described with reference to FIGS.
[0053]
First, the semiconductor substrate 306 is mounted on the lower electrode 302. In this embodiment, the lower ring 307 provided around the semiconductor substrate 306 can be formed of a material other than silicon. For example, the lower ring 307 can be formed of quartz. The semiconductor substrate 306 is made of SiO ₂ A film pattern (not shown) is placed so as to face the upper electrode 303.
[0054]
Next, an etching gas G is introduced into the vacuum chamber 301 at a predetermined flow rate. This embodiment is characterized in that a gas containing silicon, bromine and oxygen is used as the etching gas G. For example, silicon tetrabromide (SiBr) ₄ ) Gas and oxygen (O ₂ ) A gas mixture with a gas can be used.
[0055]
As shown in FIG. 4, the etching gas G passes through the etching gas supply pipe 308, passes through the hollow portion 401 provided inside the upper electrode 303, and enters the vacuum chamber 301 from the gas ejection port 402. In the present embodiment, the plate member 403 provided around the gas ejection port 402 can be formed of a material other than silicon. For example, the plate member 403 can be formed of quartz. In the present embodiment, the plate member 403 may not be provided.
[0056]
Next, when a high frequency is applied to each of the upper electrode 303 and the lower electrode 302, the etching gas reaching the plasma discharge region 309 is turned into plasma. At this time, silicon, bromine and oxygen derived from the etching gas are present in the plasma atmosphere. These are combined to form SiO 2 _x By producing Br, SiO ₂ The High-k film can be selectively etched with respect to the film.
[0057]
As described above, in the present embodiment, since the High-k film is etched using the etching gas containing silicon, it is not necessary to provide a silicon supply source in the dry etching apparatus. That is, there is no need to provide a silicon member as a silicon supply source around the ejection port of the etching gas or around the semiconductor substrate. Therefore, etching can be performed using an existing dry etching apparatus. Further, when a component of the dry etching apparatus is used as a silicon supply source, the component is rapidly consumed by etching. According to the present embodiment, the component is not consumed without causing such component consumption. Etching can be performed.
[0058]
The gas generated by the etching and the excess etching gas G are exhausted from the exhaust port 310 shown in FIG.
[0059]
Through the above steps, the structure shown in FIG. 2D can be obtained. Thereafter, the SiO 2 is etched by a wet etching method using an appropriate etching solution. ₂ The gate electrode structure is completed by removing the film 204 (FIG. 2E).
[0060]
According to the present embodiment, by using a gas containing silicon, bromine and oxygen as an etching gas, SiO _x By generating Br, the etching rate of the High-k film can be improved and SiO ₂ It is possible to increase the selectivity for the film. Therefore, the High-k film is selectively etched, so that the semiconductor device can be manufactured stably.
[0061]
Embodiment 1 and Embodiment 2 may be performed in combination. That is, after the structure shown in FIG. 2C is formed according to the method described in Embodiment 1, the High-k film is etched by a method combining Embodiment 1 and Embodiment 2. Specifically, in the dry etching apparatus shown in FIGS. 3 and 4, the plate member 403 provided around the gas outlet 402 and the lower ring 307 provided on the lower electrode 302 are formed of silicon, respectively. In addition, a gas containing silicon, bromine and oxygen is used as an etching gas. As a result, a large amount of silicon is supplied and SiO 2 in the etching atmosphere is supplied. _x The concentration of Br can be increased. Therefore, the etching rate of the High-k film and SiO ₂ It is possible to further increase the selectivity for the film.
[0062]
In the first and second embodiments, SiO 2 is used as a base film of the High-k film. ₂ Although an example using a film has been described, the present invention is not limited to this. The base film of the High-k film may be an oxide film containing silicon, and for example, a silicon oxynitride film or a silicate film may be used.
[0063]
Further, in the first and second embodiments, an example in which a polycrystalline silicon film is used as a gate electrode material has been described, but the present invention is not limited to this. Any film containing silicon such as amorphous silicon or silicon germanium can be used as a gate electrode material.
[0064]
Further, in Embodiments 1 and 2, an example in which a High-k film is used for a gate insulating film of a transistor has been described; however, the present invention is not limited to this. For example, the present invention can be applied to an example in which a High-k film is used as a capacitor film as a passive element.
[0065]
【The invention's effect】
According to the present invention, by providing a silicon supply source in a dry etching apparatus and using a gas containing bromine and oxygen as an etching gas, the etching rate of a High-k film can be improved and SiO ₂ It is possible to increase the selectivity for the film.
[0066]
Further, according to the present invention, by using a gas containing silicon, bromine and oxygen as an etching gas, the etching rate of the High-k film can be improved and SiO ₂ It is possible to increase the selectivity for the film.
[Brief description of the drawings]
FIG. 1 shows a High-k film, SiO ₂ FIG. 4 is a diagram comparing the etching rates of a film and a polycrystalline silicon film.
FIGS. 2A to 2E are cross-sectional views illustrating a process for manufacturing a semiconductor device according to the present invention.
FIG. 3 is an example of a dry etching apparatus used in the present invention.
FIG. 4 is a partially enlarged view of the dry etching apparatus of FIG. 3;
FIGS. 5A to 5D are cross-sectional views illustrating a process for manufacturing a conventional semiconductor device.
[Explanation of symbols]
201, 501 semiconductor substrate, 202, 203, 502, 503 element isolation region, 211, 511 polycrystalline silicon film pattern, 204, 207, 504, 507 SiO ₂ Film, 205,505 High-k film, 206,506 polycrystalline silicon film, 208,508 antireflection film, 209,509 resist pattern, 210,510 SiO ₂ Film pattern, 300 dry etching apparatus, 301 vacuum chamber, 302 lower electrode, 303 upper electrode, 304, 305 high frequency power supply, 306 semiconductor substrate, 307 lower ring, 308 etching gas supply pipe, 309 plasma discharge area, 310 exhaust port, 401 Hollow part, 402 gas outlet, 403 plate-like member, 404 upper ring.

Claims (11)

In a method for manufacturing a semiconductor device, a high-dielectric-constant insulating film formed on a semiconductor substrate through an oxide film containing silicon is etched using a dry etching apparatus.
Using a gas containing bromine and oxygen as an etching gas,
A method of manufacturing a semiconductor device, comprising: providing a silicon supply source in the dry etching apparatus; and supplying silicon in an etching atmosphere by etching the silicon supply source when etching the high dielectric constant insulating film. Method. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the silicon supply source is a silicon member provided on at least one of an outlet of the etching gas and a periphery of the semiconductor substrate. 3. 3. The method according to claim 2, wherein the silicon member provided at the etching gas outlet is a plate-like member made of silicon. 3. The method according to claim 2, wherein the silicon member provided around the semiconductor substrate is a silicon ring. 5. The method according to claim 1, wherein the etching gas is a mixed gas of HBr gas and O ₂ gas or a mixed gas of SiBr ₄ gas and O ₂ gas. 6. In a method of manufacturing a semiconductor device for dry-etching a high dielectric constant insulating film formed through an oxide film containing silicon on a semiconductor substrate,
A method for manufacturing a semiconductor device, wherein a gas containing silicon, bromine and oxygen is used as an etching gas. The method according to claim 6, wherein the etching gas is a mixed gas of a SiBr ₄ gas and an O ₂ gas. The method of manufacturing a semiconductor device according to claim 1, wherein the high dielectric constant insulating film is one film selected from the group consisting of a HfO ₂ film, a HfAlO _x film, and a HfSiO _x film. A dry etching apparatus for converting an etching gas introduced into a vacuum chamber into plasma, and performing desired etching on a high dielectric constant insulating film formed on a semiconductor substrate via an oxide film containing silicon,
A first electrode on which the semiconductor substrate is mounted;
A second electrode provided at a predetermined interval at a position facing the surface of the semiconductor substrate on which the high dielectric constant insulating film is formed;
An etching gas supply pipe for supplying the etching gas into the vacuum chamber,
The second electrode has a hollow portion inside, and a plurality of gas ejection ports are provided on a surface of the second electrode facing the semiconductor substrate,
The etching gas is introduced into the vacuum chamber from the gas outlet through the etching gas supply pipe and the hollow portion in order,
A dry etching apparatus, wherein a silicon member is provided around at least one of the gas outlet and the semiconductor substrate. The dry etching apparatus according to claim 9, wherein the silicon member provided around the gas outlet is a plate-like member made of silicon. The dry etching apparatus according to claim 9, wherein the silicon member provided around the substrate to be processed is a silicon ring.

Images