JP2003257946A - Method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device which eliminates process defects on a ferroelectric material due to the peel of a reaction product and is capable of obtaining a semiconductor device having normal characteristics. <P>SOLUTION: The semiconductor device is manufactured using a dry etching unit having a configuration where an upper electrode 8 and a support substrate 1 having an etching film face each other. After the maintenance of the dry etching unit, an adherent layer 11 is formed first on the surface of the upper electrode 8, which faces the etching film. Next, dry etching is performed to the etching film (ferroelectric material 2) to form the reaction product 9 made from etching gas and the ferroelectric material 2 on the adherent layer 11. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In recent years, a semiconductor device having a capacitive element using a ferroelectric material has attracted attention. This is because the ferroelectric material can be used as a non-volatile memory device because of the spontaneous polarization characteristic. Further, in comparison with a flash memory used as a non-volatile memory device in the related art, a semiconductor device having a capacitive element using a ferroelectric material has a low power consumption operation, an increase in the number of rewrites, and a high speed rewrite / read. It is possible, and it is considered that replacement with conventional devices will occur in the future.

Hereinafter, a conventional method of manufacturing a capacitive element using a ferroelectric material will be described with reference to the drawings.

FIG. 7 shows a process of processing a ferroelectric material, which is one of the conventional manufacturing processes of a capacitive element using a ferroelectric material. First, as shown in FIG. 7A, a sputtering method or a metal orga deposition (metal orga) deposition is performed on the supporting substrate 1.
A ferroelectric material 2 is formed by a nic deposition (MOD) method, and a mask 3 for processing the ferroelectric material 2 into a desired shape is formed on the ferroelectric material 2. Then
As shown in FIG. 7B, the ferroelectric material 2 is dry-etched to selectively remove the portion of the ferroelectric material 2 not covered with the mask 3. Finally, Figure 7
As shown in (c), the mask 3 is removed. The ferroelectric material 2 is processed by the above steps.

As described above, the processing of the ferroelectric material 2
When using a dry etching technique, generally,
As shown in FIG. 8, reactive ion etching (reactive i
On etching (RIE) device is used. As shown in FIG. 8, this RIE apparatus includes a lower electrode 6 and an upper electrode 8 arranged in a chamber 7, and a support substrate (film to be processed) having a film to be etched (film to be processed) on the lower electrode 6 ( Figure 7
In, a supporting substrate 1) having a ferroelectric material 2 is placed. Here, the upper electrode 8 is grounded, and the lower electrode 6 is connected to the high frequency (rf) power supply 4.

When dry etching of a ferroelectric material is performed using the RIE apparatus shown in FIG. 8, a reaction product containing the components of the ferroelectric material is generated, but the melting point of the reaction product is high. The reaction product generated during the dry etching is not volatilized and easily adheres to each part inside the chamber, particularly to the upper electrode 8.

FIG. 9 shows a state around the upper electrode 8 when the ferroelectric material 2 is dry-etched by using the RIE apparatus. FIG. 9A shows the upper electrode 8 immediately after the maintenance of the RIE device. When the ferroelectric material 2 is dry-etched after the maintenance, the reaction product 9 adheres to the upper electrode 8 as shown in FIG. 9B.

[0008]

As described above, the reaction product 9 generated during dry etching of the ferroelectric material 2 does not easily melt or volatilize because of its high melting point, and R
It adheres to each part in the IE device, especially the upper electrode 8. In addition, the reaction product 9 is poor in adhesiveness and thus easily peeled from the upper electrode 8. Therefore, the above conventional manufacturing method has the following problems. That is, when the dry etching of the ferroelectric material 2 is repeated, as shown in FIG. 9C, the reaction product 9 is generated during the dry etching in each part in the RIE apparatus, particularly,
It is peeled off from the interface of the upper electrode 8 (reference numeral 1 in FIG. 9C).
0), it adheres to the ferroelectric material 2 which is the film to be etched (processed film), and it becomes difficult to process the ferroelectric material 2 into a desired shape.

The present invention has been made in order to solve the above problems in the prior art, and it is possible to eliminate a processing defect of a ferroelectric material due to peeling of a reaction product and obtain a semiconductor device having normal characteristics. An object of the present invention is to provide a method of manufacturing a semiconductor device that can be manufactured.

[0010]

To achieve the above object, a first method of manufacturing a semiconductor device according to the present invention is a dry etching apparatus having a structure in which an upper electrode and a supporting substrate having a film to be etched face each other. A method of manufacturing a semiconductor device, comprising: a first step of forming an adhesion layer on a surface of the upper electrode facing the film to be etched after maintenance of the dry etching device; and dry etching the film to be etched. Then, a reaction product of the etching gas and the film to be etched is formed on the adhesion layer.
And a process.

According to the first method of manufacturing a semiconductor device, the reaction product generated during dry etching of the film to be etched does not directly adhere to the upper electrode but adheres to the upper electrode via the adhesion layer. Become. As a result, it becomes possible to prevent the conventional peeling at the interface between the upper electrode and the reaction product.

In the first method of manufacturing a semiconductor device of the present invention, it is preferable that the first step and the second step are repeated at least twice. According to this preferable example, the reaction product formed during dry etching of the film to be etched has a structure sandwiched by the adhesion layers,
Since it contributes to the improvement of the adhesion between the reaction products, it is possible to further prevent the conventional peeling at the interface between the upper electrode and the reaction product.

A second method of manufacturing a semiconductor device according to the present invention has a structure in which an upper electrode is opposed to a supporting substrate in which a film containing a material to be an adhesion layer and a film to be etched are laminated in this order from the substrate side. A method of manufacturing a semiconductor device using a dry etching apparatus, comprising: a first step of forming a first adhesion layer on a surface of the upper electrode facing the film to be etched after maintenance of the dry etching apparatus; The second step of dry-etching the etching film to form a reaction product of the etching gas and the film to be etched on the first adhesion layer, and the material to be the adhesion layer are dry-etched to generate the reaction product. And a third step of forming a second adhesion layer on the object.

According to the second manufacturing method of the semiconductor device, the reaction product generated during the dry etching of the film to be etched does not directly adhere to the upper electrode but adheres to the upper electrode via the adhesion layer. Become. Further, the reaction product formed during the dry etching of the film to be etched has a structure sandwiched by the adhesion layers, which contributes to the improvement of the adhesion between the reaction products. For this reason, it becomes possible to reliably prevent the peeling at the interface between the upper electrode and the reaction product, which has conventionally occurred.

A third method of manufacturing a semiconductor device according to the present invention has a structure in which an upper electrode is opposed to a support substrate in which a film containing a material to be an etching target film and an adhesion layer is laminated in this order from the substrate side. A method of manufacturing a semiconductor device using a dry etching apparatus, comprising: after maintenance of the dry etching apparatus, dry-etching a film containing a material to be the adhesion layer, and forming a film on the surface of the upper electrode facing the film to be etched. And a second step of dry etching the film to be etched to form a reaction product of the etching gas and the film to be etched on the adhesion layer. Characterize.

According to the third method of manufacturing a semiconductor device, the reaction product generated during dry etching of the film to be etched does not directly adhere to the upper electrode but adheres to the upper electrode via the adhesion layer. Become. Further, the reaction product formed during the dry etching of the film to be etched has a structure sandwiched by the adhesion layers, which contributes to the improvement of the adhesion between the reaction products. For this reason, it becomes possible to reliably prevent the peeling at the interface between the upper electrode and the reaction product, which has conventionally occurred.

Further, in the first or second method of manufacturing a semiconductor device of the present invention, it is preferable that the first step is performed using dry etching.

In the first to third manufacturing methods of the semiconductor device of the present invention, it is preferable that the adhesion layer contains Ti.

Further, in the first to third manufacturing methods of the semiconductor device of the present invention, the melting point of the reaction product is 50.
It is preferably 0K or more.

In the first to third manufacturing methods of the semiconductor device of the present invention, it is preferable that the film to be etched contains a ferroelectric material. Further, in this case, the ferroelectric material is SrBi ₂ (Ta _x Nb).
_1-x ) ₂ O ₉ , (Ba _x Sr _1-x ) TiO ₃ , Pb (Z
_{r x Ti 1-x) O} 3 or _{(Bi x La 1-x)} 4 Ti 3 O
_It is preferably any of ₁₂ (0 ≦ x ≦ 1).

In the first to third manufacturing methods of the semiconductor device of the present invention, the film to be etched is P
It preferably contains either t, Ir or IrO ₂ .

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to embodiments.

[First Embodiment] In the present embodiment, a method of manufacturing a semiconductor device will be described with reference to FIGS. 7 to 9 used in the description of the prior art.

FIG. 1 shows reactive ion etching (reactive ion etching) when dry etching is performed to process a ferroelectric material, which is a film to be etched on a supporting substrate, into a desired shape in the present embodiment. The state of the upper electrode of a (RIE) apparatus is shown.

FIG. 1A shows a sectional shape of the upper electrode 8 after maintenance of the RIE apparatus. Figure 1
Etched film (processed film) of the upper electrode 8 shown in (a)
Ferroelectric material 2 (see FIG. 7) (in FIG. 8,
The surface of the supporting substrate 5 having the film to be etched facing the film to be etched) is in a state where the upper electrode material is completely exposed and no other foreign matter is attached by wet cleaning or sputter cleaning.

In this state, first, as shown in FIG. 1B, the adhesion layer 1 is formed on the surface of the upper electrode 8 facing the film to be etched.
1 is formed. The adhesion layer 11 is formed by the RIE shown in FIG.
Using the apparatus, dry etching is performed on the supporting substrate 5 or another substrate on which Ti (titanium) having a thickness of 50 nm is deposited on the outermost surface using a gas containing Ar (argon). The etching conditions in this case are Ar flow rate = 30 sccm, pressure = 5 mTorr, rf power =
It is 500W. As a result, the adhesion layer 1 containing Ti and having a thickness of about 20 nm is formed on the surface of the upper electrode 8 facing the film to be etched.
1 is formed.

Then, dry etching for processing the ferroelectric material 2 having a film thickness of 250 nm of the substrate having the structure shown in FIG. 7A is performed using a gas containing Cl (chlorine) and Br (bromine). To do. The etching conditions in this case are Cl ₂ / HBr = 5 sccm / 10 sccm, pressure = 1.7 mTorr, and rf power = 800 W. Here, the ferroelectric material 2 is SrBi ₂ Ta ₂ O ₉ having a perovskite structure containing Sr (strontium), Bi (bismuth), Ta (tantalum), and O (oxygen).
Is used, and a photoresist is used as the mask 3. When dry etching for processing the ferroelectric material 2 of the substrate having the structure shown in FIG.
As shown in (c), the components of the ferroelectric material 2 and the gas used for dry etching are formed on the adhesion layer 11 formed on the surface of the upper electrode 8 facing the film to be etched (ferroelectric material 2). The reaction product 9 having a thickness of about 1 μm and containing the above component adheres.

As described above, according to this embodiment, first, after the maintenance of the RIE apparatus, the adhesion layer 11 is formed on the surface of the upper electrode 8 facing the film to be etched, and then processed into a desired shape. For this reason, by carrying out dry etching of the support substrate 5 having the ferroelectric material 2 which is the film to be etched, the reaction product 9 generated during the dry etching of the ferroelectric material 2 which is the film to be etched is the upper electrode 8 To the upper electrode 8 via the adhesive layer 11. As a result, it becomes possible to prevent the conventional peeling at the interface between the upper electrode 8 and the reaction product 9.

As described above, in the present embodiment, the gas containing Cl and Br is used as the reaction gas (etching gas) during the dry etching of the ferroelectric material 2, and the ferroelectric material is also used. 2 as Sr, Bi,
SrBi ₂ Ta ₂ having a perovskite structure containing Ta and O
O ₉ is used. It is generally known that these Sr, Bi and Ta chlorides and bromides have very high melting points. For example, the melting points of SrCl ₂ and SrBr ₂ are 1146K, 931K, BiCl ₃ and BiB, respectively.
The melting points of r are 507 K, 567 K, TaCl ₄ , and
The melting points of TaBr ₅ are 570K and 513K, respectively.

The method described in this embodiment is an effective means when the reaction product of the etching gas and the film to be etched has a high melting point, and the effect is
It becomes particularly remarkable when the melting point of the reaction product of the etching gas and the film to be etched is 500 K or more.

That is, in the present embodiment, SrBi ₂ Ta ₂ O ₉ is used as the film to be etched and a gas containing Cl and Br is used as the etching gas. The effect of the present invention can be obtained in all cases where the melting point of the reaction product is 500 K or more.

In the Ti used as the adhesion layer 11 in the present embodiment, the adhesion between Pt (platinum) used as an electrode and the oxide film used as an interlayer insulating film in a capacitive element using a ferroelectric material is used. As can be seen from the fact that it is generally used as a layer, there is an effect of improving the adhesion strength between two different materials. As a result, it is possible to prevent the reaction product 9 from peeling, which has conventionally been generated at the interface between the upper electrode 8 and the reaction product 9.

FIG. 2 shows the effect of this embodiment.

FIG. 2A shows the transition of the number of particles due to the exfoliation of the reaction product 9 with the increase in the number of processed substrates when the ferroelectric material 2 is dry-etched by the conventional method. As shown in FIG. 2A, the number of particles generated due to the separation of the reaction product 9 tends to increase as the number of processed sheets increases, and the number of particles finally exceeds 100.

On the other hand, FIG. 2B shows the transition of the number of particles due to the exfoliation of the reaction product 9 with the increase in the number of processed materials when the ferroelectric material 2 is dry-etched by the method of this embodiment. ing. As shown in FIG. 2B, the number of particles generated due to the peeling of the reaction product due to the increase in the number of processed sheets is between 40 and 70, and the peeling of the reaction product 9 is larger than that in the conventional method. It can be seen that processing defects of the ferroelectric material 2 due to particles due to the above can be reduced.

Although the RIE apparatus is used as the dry etching apparatus in the present embodiment, the same effect can be obtained in all the dry etching apparatuses in which the upper electrode and the supporting substrate having the film to be etched face each other. can get.

In this embodiment, the substrate having Ti deposited on the outermost surface is dry-etched to form the adhesion layer 11 containing Ti on the surface of the upper electrode 8 facing the film to be etched. However, the material and forming method of the adhesion layer 11 are not necessarily limited to the above-described materials and forming method. Any material may be used as long as it improves the adhesion strength between the surface of the upper electrode 8 facing the etching target film and the reaction product 9 generated during dry etching of the etching target film. Any method capable of forming the adhesion layer 11 on the opposing surface may be used. For example, Ta (tantalum) may be used as the material of the adhesion layer 11. Alternatively, the upper electrode 8 may be once taken out of the etching apparatus, and the adhesion layer 11 may be formed by directly forming a Ti film by using a sputtering method. Further, the upper electrode 8 may be once taken out of the etching apparatus, and the adhesion layer 11 may be formed by directly coating Ti using a plating method.

[Second Embodiment] In this embodiment as well, a method of manufacturing a semiconductor device will be described with reference to FIGS. 7 to 9 used in the description of the prior art.

FIG. 3 shows the state of the upper electrode of the RIE apparatus when dry etching is performed to process the ferroelectric material, which is the film to be etched on the support substrate, into a desired shape in the present embodiment. .

FIG. 3A shows a sectional shape of the upper electrode 8 after maintenance of the RIE apparatus. Figure 3
Etched film (processed film) of the upper electrode 8 shown in (a)
Ferroelectric material 2 (see FIG. 7) (in FIG. 8,
The surface of the supporting substrate 5 having the film to be etched facing the film to be etched) is in a state where the upper electrode material is completely exposed and no other foreign matter is attached by wet cleaning or sputter cleaning.

In this state, first, as shown in FIG. 3B, the adhesion layer 1 is formed on the surface of the upper electrode 8 facing the film to be etched.
1 is formed. The adhesion layer 11 is formed on the outermost surface with a thickness of 50 nm.
It is performed by dry etching a substrate on which a thick Ti is deposited using a gas containing Ar. This allows
An adhesion layer 11 containing Ti is formed on the surface of the upper electrode 8 facing the film to be etched.

Next, dry etching for processing the ferroelectric material 2 of the substrate having the structure shown in FIG. 7A is performed using a gas containing Cl and Br. Here, SrBi ₂ Ta ₂ O ₉ having a perovskite structure containing Sr, Bi, Ta, and O is used as the ferroelectric material 2, and a photoresist is used as the mask 3. Figure 7 (a)
When dry etching is performed to process the ferroelectric material 2 of the substrate having the structure shown in FIG. 3, as shown in FIG. 3C, the upper electrode 8 faces the film to be etched (ferroelectric material 2). The ferroelectric material 2 is formed on the adhesion layer 11 formed on the surface.
A reaction product 9 containing the above component and the component of the gas used for dry etching is attached.

Then, as shown in FIG.
Reaction product 9 attached on the adhesion layer 11 in the step (c)
A further adhesion layer 11 is formed on top. This adhesion layer 11 is formed on the outermost surface by 50 nm as in the step of FIG.
It is performed by dry etching a substrate on which a thick Ti is deposited using a gas containing Ar. This allows
The reaction product 9 sandwiched by the adhesion layers 11 is formed on the surface of the upper electrode 8 facing the film to be etched (ferroelectric material 2).

Then, again, dry etching for processing the ferroelectric material 2 of the substrate having the structure shown in FIG. 7A is performed using a gas containing Cl and Br.
As shown in (e), the reaction product 9 adheres to the adhesion layer 11 formed in the step of FIG. That is, the adhesion layer 11 and the reaction product 9 are alternately formed (attached) on the surface of the upper electrode 8 facing the film to be etched (ferroelectric material 2).
It will be in the state of being.

As described above, according to the present embodiment, R
After the maintenance of the IE device, the film to be etched is formed by alternately performing the formation of the adhesion layer 11 on the surface of the upper electrode 8 facing the film to be etched and the dry etching of the ferroelectric material 2 as the film to be etched. Ferroelectric material 2
The reaction product 9 generated during the dry etching of the above does not directly adhere to the upper electrode 8 and does not adhere to the upper electrode 8 through the adhesion layer 11.
Adhere to. As a result, the upper electrode 8 that has been conventionally generated
It is possible to prevent peeling at the interface between the reaction product 9 and the reaction product 9. Further, the reaction product 9 generated during the dry etching of the ferroelectric material 2 and attached to the surface of the upper electrode 8 facing the film to be etched (ferroelectric material 2) is the adhesion layer 11
The structure is sandwiched between the two, which contributes to the improvement of the adhesion between the reaction products 9.

The method described in this embodiment is also the first
Similar to the embodiment described above, this is an effective means when the reaction product of the etching gas and the film to be etched has a high melting point, and the effect is particularly remarkable when the reaction products are easily separated from each other. Further, as in the case of the first embodiment, the effect becomes particularly remarkable when the melting point of the reaction product of the etching gas and the film to be etched is 500 K or more.

FIG. 4 shows the effect of this embodiment.
FIG. 4 shows the transition of the number of particles due to the peeling of the reaction product 9 with the increase in the number of processed materials when the ferroelectric material 2 is dry-etched by the method of the present embodiment. As shown in FIG. 4, the number of particles generated due to the peeling of the reaction product due to the increase in the number of processed particles is 50 or less, and the reaction product 9 of It can be seen that the processing defects of the ferroelectric material 2 due to the particles due to the peeling can be reduced.

Although the RIE apparatus is used as the dry etching apparatus in the present embodiment, the same effect can be obtained in all the dry etching apparatuses in which the upper electrode and the supporting substrate having the film to be etched face each other. can get.

In the present embodiment, the substrate having Ti deposited on the outermost surface is dry-etched to form the adhesion layer 11 containing Ti on the surface of the upper electrode 8 facing the film to be etched. However, the material and forming method of the adhesion layer 11 are not necessarily limited to the above-described materials and forming method. Any material may be used as long as it improves the adhesion strength between the surface of the upper electrode 8 facing the etching target film and the reaction product 9 generated during dry etching of the etching target film. Any method capable of forming the adhesion layer 11 on the opposing surface may be used.

[Third Embodiment] FIG. 5 shows a step of processing a ferroelectric material in the manufacturing steps of the capacitive element using the ferroelectric material according to the present embodiment.

First, as shown in FIG. 5A, the adhesion layer 13 is formed on the supporting substrate 1 including the MOS transistor, the lower electrode of the capacitive element and the like by the sputtering method. Next, the ferroelectric material 2 is formed on the adhesion layer 13 by a sputtering method or a metal organic deposition (MOD) method, and the ferroelectric material 2 is formed on the ferroelectric material 2 as desired. A mask 3 for processing into a shape is formed. Here, Ti is used as the material of the adhesion layer 13, and the structure thereof is Ti alone or Pt, Ir, IrO ₂
It is a laminated body of a material selected from and Ti. As the ferroelectric material 2, SrBi ₂ Ta ₂ O ₉ having a perovskite structure containing Sr, Bi, Ta, and O is used, and as the mask 3, a photoresist is used.

Next, using the RIE apparatus shown in FIG. 8 which has been subjected to maintenance, the substrate with Ti having a thickness of 50 nm deposited on the outermost surface was dry-etched using a gas containing Ar, and then, as shown in FIG. The dry etching for processing the ferroelectric material 2 of the substrate having the structure shown is performed with Cl and B
It is performed using a gas containing r. As a result, as shown in FIG. 5B, the ferroelectric material 2 is completely dry-etched in the opening region of the mask 3 and the adhesion layer 13 is exposed. Then, an adhesion layer 11 is formed on the surface of the upper electrode 8 facing the film to be etched, and the reaction product 9 of the ferroelectric material 2 and the gas used for dry etching adheres to the adhesion layer 11. .

Next, as shown in FIGS. 5B and 5C, dry etching of the adhesion layer 13 is performed using a gas containing Ar. As a result, the adhesive layer 13 is selectively removed, and the state shown in FIG. 5C is obtained. Then, the removed adhesion layer 13 adheres to the reaction product 9 on the surface of the upper electrode 8 facing the film to be etched to form the adhesion layer 11.

Finally, as shown in FIG. 5 (d), the mask 3 is removed. The ferroelectric material 2 is processed by the above steps.

As described above, in the present embodiment,
After maintenance of the RIE device, first, 50n on the outermost surface
The substrate on which m-thick Ti is deposited is dry-etched using a gas containing Ar, whereby the adhesion layer 11 is formed on the surface of the upper electrode 8 facing the etching target film (ferroelectric material 2).
(See FIGS. 1 (b) and 3 (b)), and then, as shown in FIGS. 5 (a) and 5 (b), the ferroelectric material 2 as the film to be etched is formed on the adhesion layer 13. Support substrate 1 formed
Was dry-etched using a gas containing Cl and Br. As a result, the adhesion layer 11 is formed on the surface of the upper electrode 8 of the RIE device facing the etching target film (ferroelectric material 2).
Then, the reaction product 9 of the ferroelectric material 2 and the gas used for the dry etching and the adhesion layer 11 are alternately formed (adhered) (see FIG. 3E).

This means that the adhesion layer 11, the reaction product 9 and the adhesion layer 11 are alternately arranged on the surface of the upper electrode 8 of the RIE apparatus facing the film to be etched as described in the second embodiment. It is the same as forming (attaching). Therefore,
Also according to the method of the present embodiment, it is possible to prevent the conventional peeling at the interface between the upper electrode 8 and the reaction product 9 and reduce the processing defect of the ferroelectric material 2.

In this embodiment, the supporting substrate 1
And Ti as the material of the adhesion layer 13 between the ferroelectric material 2 and
However, the material of the adhesion layer 13 is not necessarily limited to Ti. Any material may be used as long as it is an adhesion layer between the supporting substrate 1 and the ferroelectric material 2 and improves the adhesion strength between the reaction products 9 generated during the dry etching of the ferroelectric material 2.

Further, in the present embodiment, the RIE apparatus is used as the dry etching apparatus, but the upper electrode, the film containing the material to be the adhesion layer and the film to be etched are laminated in this order from the substrate side. The same effect can be obtained in all dry etching apparatuses having a structure facing the substrate.

[Fourth Embodiment] FIG. 6 shows a step of processing a ferroelectric material in the manufacturing steps of the capacitive element using the ferroelectric material according to the present embodiment.

First, as shown in FIG. 6A, the ferroelectric material 2 is deposited on the supporting substrate 1 including the MOS transistor, the lower electrode of the capacitive element and the like by the sputtering method or the organic metal deposition method (MOD method). Form. Next, the ferroelectric material 2
An adhesion layer 14 is formed thereon by a sputtering method, and a mask 3 for processing the ferroelectric material 2 into a desired shape is formed on the adhesion layer 14. Here, Ti is used as the material of the adhesion layer 14, and the structure thereof is Ti alone or a laminated body of Ti and a material selected from Pt, Ir, and IrO ₂ . Further, as the ferroelectric material 2, Sr, Bi,
SrBi ₂ Ta ₂ having a perovskite structure containing Ta and O
O ₉ is used, and a photoresist is used as the mask 3.

Then, the adhesion layer 14 of the substrate having the structure shown in FIG. 6A is dry-etched using a gas containing Ar by using the RIE apparatus shown in FIG. As a result, the adhesion layer 14 is selectively removed, and the state shown in FIG. 6B is obtained. Then, the removed adhesion layer 14 adheres to the surface of the upper electrode 8 facing the film to be etched to form the adhesion layer 11.

Next, dry etching for processing the ferroelectric material 2 of the substrate having the structure shown in FIG. 6B is performed using a gas containing Cl and Br. This allows
As shown in FIG. 6C, the support substrate 1 is exposed in the opening region of the mask 3. And the upper electrode 8
The reaction product 9 of the ferroelectric material 2 and the gas used for dry etching adheres on the adhesion layer 11 adhered to the surface facing the film to be etched.

Finally, as shown in FIG. 6D, the mask 3 is removed. The ferroelectric material 2 is processed by the above steps.

As described above, in the present embodiment,
After the maintenance of the RIE device, the support substrate 1 having the adhesion layer 14 formed on the ferroelectric material 2 as shown in FIG.
Of the adhesion layer 11 (formed by the adhesion layer 14 formed on the ferroelectric material 2) on the surface facing the film to be etched, and the reaction product 9 of the ferroelectric material 2 and the gas used for the dry etching. Then, a state in which the adhesion layers 11 are alternately formed (attached) is obtained. Here, the third adhesion layer 11 is the adhesion layer 14 of the next substrate having the structure shown in FIG.
It is formed when dry etching is performed using a gas containing Ar.

This means that the adhesion layer 11, the reaction product 9 and the adhesion layer 11 are alternately arranged on the surface of the upper electrode 8 of the RIE apparatus facing the film to be etched as described in the second embodiment. It is the same as forming (attaching). Therefore,
Also according to the method of the present embodiment, it is possible to prevent the conventional peeling at the interface between the upper electrode 8 and the reaction product 9 and reduce the processing defect of the ferroelectric material 2.

Although Ti is used as the material of the adhesion layer 14 on the ferroelectric material 2 in the present embodiment,
The material of the adhesion layer 14 is not necessarily limited to Ti, and may be any material that improves the adhesion strength between the reaction products 9 generated during dry etching of the ferroelectric material 2.

Further, in the present embodiment, the RIE apparatus is used as the dry etching apparatus. However, the upper electrode, the film to be etched and the film containing the material to be the adhesion layer are laminated in this order from the substrate side. The same effect can be obtained in all dry etching apparatuses having a structure facing the substrate.

Further, in the above embodiment, the ferroelectric
SrBi as body material₂ Ta₂ O₉Is used
But besides this, SrBi₂ (Ta_x Nb_1-x )₂ O
₉ , (Ba_x Sr_1-x ) TiO₃ , Pb (Zr_x Ti
_1-x ) O₃ Or (Bi_x La_1-x ) _Four Ti₃ O₁₂(0 ≦
x ≦ 1) or the like can be used.

[0069]

As described above, according to the present invention,
The reaction product generated during dry etching of the film to be etched does not directly adhere to the upper electrode but adheres to the upper electrode via the adhesion layer. Further, the reaction product that is generated during dry etching of the film to be etched and adheres to the surface of the upper electrode facing the film to be etched has a structure sandwiched between the adhesion layers, which contributes to the improvement of the adhesion between the reaction products. It will be. Therefore, it is possible to prevent the peeling at the interface between the upper electrode and the reaction product, which has been conventionally generated. As a result, it is possible to surely obtain a semiconductor device having normal characteristics without processing defects of the ferroelectric material.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state of an upper electrode of a reactive ion etching (RIE) apparatus when dry etching for processing a film to be etched on a supporting substrate into a desired shape is performed in an embodiment of the present invention. Figure

FIG. 2 is a diagram showing a transition of the number of particles due to the peeling of the reaction product with the increase in the number of processed sheets in the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state of an upper electrode of an RIE device when dry etching for processing a film to be etched on a supporting substrate into a desired shape is performed in a second embodiment of the present invention.

FIG. 4 is a diagram showing a transition of the number of particles due to the separation of reaction products with the increase in the number of processed sheets in the second embodiment of the invention.

FIG. 5 is a process sectional view showing a method of manufacturing a semiconductor device according to a third embodiment of the invention.

FIG. 6 is a process sectional view showing a method of manufacturing a semiconductor device according to a fourth embodiment of the invention.

7A to 7C are process cross-sectional views showing a method for manufacturing a semiconductor device in the prior art.

FIG. 8 is a sectional view showing a reactive ion etching (RIE) device.

FIG. 9 is a cross-sectional view showing a state of an upper electrode of a reactive ion etching (RIE) device when dry etching for processing a film to be etched on a supporting substrate into a desired shape is performed in the related art.

[Explanation of symbols]

1 Support Substrate Including Lower Electrodes of MOS Transistor and Capacitance Element 2 Ferroelectric Material 3 Mask 4 Radio Frequency (rf) Power Supply 5 Support Substrate Having Etch Film 6 Lower Electrode of RIE Device 7 Chamber 8 Upper Electrode 9 of RIE Device Reaction product 10 Peeled reaction product 11 Adhesion layer

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Claims (10)

[Claims] 1. A method of manufacturing a semiconductor device using a dry etching apparatus having a structure in which an upper electrode and a supporting substrate having a film to be etched face each other, wherein the maintenance of the dry etching apparatus is followed by the coating of the upper electrode. A first step of forming an adhesion layer on the surface facing the etching film,
A method of manufacturing a semiconductor device, comprising: a second step of dry etching the film to be etched to form a reaction product of an etching gas and the film to be etched on the adhesion layer. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the first step and the second step are repeated at least twice. 3. A method of manufacturing a semiconductor device using a dry etching apparatus in which an upper electrode, a film containing a material to be an adhesion layer, and a film to be etched face a supporting substrate laminated in this order from the substrate side. A first step of forming a first adhesion layer on the surface of the upper electrode facing the film to be etched after maintenance of the dry etching apparatus, and dry etching the film to be etched to obtain the first adhesion layer. A second step of forming a reaction product of an etching gas and the film to be etched on the layer, and a material forming the adhesion layer are dry-etched to form a second layer on the reaction product.
And a third step of forming an adhesion layer. 4. A method of manufacturing a semiconductor device using a dry etching apparatus having a structure in which an upper electrode and a supporting substrate in which a film containing a material to be an etching target film and an adhesion layer is laminated in this order from the substrate side face each other. Then, after the maintenance of the dry etching apparatus, a film including a material to be the adhesion layer is dry-etched to form an adhesion layer on a surface of the upper electrode facing the etching target film, A method of manufacturing a semiconductor device, comprising: a second step of dry-etching a film to be etched to form a reaction product of an etching gas and the film to be etched on the adhesion layer. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the first step is performed using dry etching. 6. The method for manufacturing a semiconductor device according to claim 1, wherein the adhesion layer contains Ti. 7. The method for manufacturing a semiconductor device according to claim 1, wherein a melting point of the reaction product is 500 K or higher. 8. The method of manufacturing a semiconductor device according to claim 1, wherein the film to be etched contains a ferroelectric material. 9. The ferroelectric material is SrBi ₂ (Ta
_x Nb _1-x ) ₂ O ₉ , (Ba _x Sr _1-x ) TiO ₃ , P
_{b (Zr x Ti 1-x} ) O 3 or _{(Bi x La 1- x) 4} T
9. The method for manufacturing a semiconductor device according to claim 8, wherein any one of i ₃ O ₁₂ (0 ≦ x ≦ 1). 10. The method of manufacturing a semiconductor device according to claim 1, wherein the film to be etched contains any one of Pt, Ir and IrO ₂ .