JP2000269434A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor of stable device characteristics by suppressing the movement of water or hydrogen in an insulating film for covering a capacitor element to a capacitor insulating film. SOLUTION: This semiconductor device is provided with a first electrode 30 formed on a substrate 10, a capacitor insulating film 22 formed on the upper layer of the first electrode 30 and a second electrode 31 formed on the upper layer of the capacitor insulating film 22, and films 30a and 31b for preventing the transmission of the hydrogen are formed at least on the upper surface of the second electrode, preferably further on the lower surface of the first electrode 30. Furthermore, the capacitor element is covered with the laminated insulating film of the insulating films 21b and 23b for preventing transmission of moisture, and insulating films 21a and 23c for storing moisture and insulating films 21c and 23a are further provided with a reduction preventing function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to a semiconductor device having a capacitor using an insulating film having a high relative dielectric constant such as a tantalum oxide film as a capacitor insulating film and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in semiconductor devices such as VLSI, miniaturization and miniaturization of 70% have been realized in three years, and high integration and high performance have been achieved. With the miniaturization and miniaturization of the semiconductor device described above, the occupied area of the capacitor element, which is one of the semiconductor elements, has also been reduced.

For example, a DRAM (Dynamic Random Acceses)
Memory) is a field-effect transistor (MOSFE) having a metal-oxide-semiconductor stack for switching.
T) and a memory capacitor, and a DRAM with a storage capacity of 1 Gb has been announced at the academic level as a process driver for semiconductor devices. And large capacity and high integration are being promoted. With the above miniaturization, the memory cell area is reduced,
The area occupied by the memory capacitor, which is a capacitor element, has also been reduced.

However, in order to secure an operation margin and increase the reliability of stored data while securing a soft error resistance by alpha rays, the storage capacitance Cs of the memory capacitor is required to be 20 to 20 bits per bit regardless of the DRAM generation. It is necessary to secure a value of 30 fF or more, which is a certain required amount or more. That is, although the occupied area of the memory capacitor is reduced as the memory capacitor is miniaturized, it is necessary to secure a necessary amount of the storage capacitor Cs, and various devices have been devised for that.

For example, in addition to a method of increasing the storage capacity by reducing the thickness of a capacitor insulating film, an ON film (or ONO film) which is a composite film of a silicon nitride film and a silicon oxide film is used as the capacitor insulating film. By using tantalum oxide (Ta ₂ O ₅ ), BST (barium strontium titanate) or STO (strontium titanate) having a high relative dielectric constant, and improving the material of the capacitor insulating film, the storage capacity of the capacitor can be improved. Methods such as increasing have been developed.

On the other hand, the electrode structure of the capacitor has also been devised, and various structures have been developed. The memory capacitor has a storage node electrode (electrode connected to the transistor of the capacitor), a plate electrode (electrode grounded to the capacitor), and a capacitor insulating film between the storage node electrode and the plate electrode. By increasing the surface area, the storage capacity of the capacitor can be increased. For example, from a planar type having a planar structure, a stack type and a trench type having a three-dimensional shape have been developed.

In a semiconductor device, not only a memory capacitor in a DRAM or the like but also an ordinary capacitor is desired to increase a storage capacity while reducing an occupied area. The technique of increasing the storage capacity by the composition of the insulating film can be widely applied to ordinary capacitors having a structure in which a pair of electrodes face each other via a capacitor insulating film.

A semiconductor device having a planar type capacitor using a high dielectric constant film such as tantalum oxide or BST as a capacitor insulating film will be described. FIG. 12 is a sectional view of a semiconductor device having the above-described capacitor. For example, a semiconductor element (not shown) such as a transistor is formed in an active region (not shown) of the semiconductor substrate 10 separated by an element isolation insulating film formed by a LOCOS method or the like. The semiconductor substrate 10 is covered with a semiconductor element such as a transistor on the semiconductor substrate 10 or is covered with an element isolation insulating film formed on the semiconductor substrate 10 by, for example, TEOS (tetra-ethyl- ortho-sili
cate) as a raw material for plasma CVD (Chemical Vapor D)
An underlying insulating film 20 made of silicon oxide formed by eposition (chemical vapor deposition) or the like is formed. A barrier metal layer 30a made of titanium nitride or the like formed to be connected to a buried plug (not shown) made of, for example, tungsten or polysilicon, and an electrode made of a metal material such as platinum are formed on the base insulating film 20. A first electrode 30 composed of a laminate of layers 30b, a capacitor insulating film 22 composed of a high dielectric constant film such as tantalum oxide, BST or STO, and a second electrode 3 composed of an electrode layer composed of a metal material such as platinum.
1 are stacked to form a capacitor element.

An upper coating insulating film 23 made of silicon oxide formed by a plasma CVD method using TEOS as a raw material is formed so as to cover the above-mentioned capacitor element. Further on top, for example, O ₃ and TEOS
A flattening insulating film 24 made of silicon oxide formed by a CVD method using as a raw material and flattened by a CMP (Chemical Mechanical Polishing) process or the like is formed. Further, an upper insulating film 25 made of silicon oxide formed by, for example, a plasma CVD method using TEOS as a raw material is formed thereon. Upper insulating film 25
A passivation film 26 made of a silicon nitride film (SiN _x : H film) formed by, for example, a plasma CVD method is formed on the uppermost layer which is the upper layer. In the above structure, if necessary, the upper covering insulating film 23 or the upper insulating film 25 may be made of silicon oxide (PSG) containing phosphorus.

[0010] In the capacitor having the above structure, the TEO is arranged so as to be arranged above and below the capacitor element.
A silicon oxide layer formed by a plasma CVD method or the like using S as a raw material or Si as a passivation film
The N _x : H film contains a large amount of moisture (hydroxyl component) or hydrogen. When the moisture (hydroxyl component) or hydrogen moves through the insulating film and is taken into the capacitor insulating film 22, There is a problem that the quality of the capacitor insulating film changes and the high dielectric constant characteristics deteriorate. For example,
A large amount of water is contained in a silicon oxide film formed by a plasma CVD method using TEOS as a raw material, and when water in the film moves and is taken into the capacitor insulating film 22, the capacitor characteristics deteriorate. . Further, for example, a silicon nitride film (Si
(N _x : H film) contains a large amount of hydrogen, for example, about 10 to 25 atom% in the form of a Si—H group or an N—H group, and this hydrogen moves and enters the capacitor insulating film. It is taken in and the capacitor characteristics deteriorate.

In order to avoid the above problem, a structure in which a capacitor element as shown in a sectional view of FIG. 13 is covered with a silicon nitride film formed by a low pressure CVD method is considered. For example, a semiconductor element (not shown) such as a transistor is formed in an active region (not shown) of the semiconductor substrate 10 separated by an element isolation insulating film formed by a LOCOS method or the like. A semiconductor element such as a transistor on the semiconductor substrate 10 is coated on the semiconductor substrate 10 or an element isolation insulating film formed on the semiconductor substrate 10 is coated on the semiconductor substrate 10. A base insulating film 20 made of silicon oxide formed by a CVD method or the like is formed. The above base insulating film 2
0, a lower coating insulating film 21 which is a silicon nitride film (Si ₃ N ₄ film) formed by, for example, a low pressure CVD method.
Are formed. A barrier metal layer 30a made of titanium nitride or the like formed to be connected to a buried plug (not shown) made of, for example, tungsten or polysilicon, and a metal material such as platinum are formed on the lower coating insulating film 21. Electrode 30 made of a laminate of electrode layers 30b made of, for example, a capacitor insulating film 2 made of a high dielectric constant film such as tantalum oxide, BST or STO.
2, and a second electrode 31 made of an electrode layer made of a metal material such as platinum, for example, are laminated to form a capacitor element.

[0012] A silicon nitride film (Si ₃
An upper coating insulating film 23 (N ₄ film) is formed.
Further, the upper layer is made of silicon oxide formed by a CVD method using O ₃ and TEOS as raw materials,
A planarization insulating film 24 that has been planarized by a CMP process or the like is formed. Further, an upper insulating film 25 made of silicon oxide formed by, for example, a plasma CVD method using TEOS as a raw material is formed thereon. For example, the plasma CVD
Silicon nitride film (SiN _x : H film)
A passivation film 26 is formed.

In the capacitor element having the above-described structure, the lower coating insulating film 21 and the upper coating insulating film 23 are formed of a silicon nitride film (Si ₃ N) formed by a low pressure CVD method.
₄ film) does not allow water (hydroxyl groups) to permeate, and can prevent them from being taken into the capacitor insulating film.

[0014]

However, as described above, the lower and upper coating insulating films 21 and 23 are made of a silicon nitride film (Si ₃ N ₄ film) formed by a low pressure CVD method. When forming a structure covered by a pressure reduction,
Silicon nitride film (Si ₃ N) formed by VD method
_{Since the} film formation temperature of the ( ₄ film) is about 700 to 850 ° C., at this film formation temperature, a change in the physical structure of the capacitor insulating film or the electrode or deterioration of the film quality is caused, and the capacitor characteristics are accordingly reduced. Will be deteriorated.

In order to avoid the above problem, the plasma C
Silicon nitride (SiN _x : H) formed by VD method
Lower insulating film 21 and upper insulating film 2
According to 3, a structure that covers the above-mentioned capacitor element can be considered. However, the silicon nitride film (SiN _x : H film) formed by the plasma CVD method contains Si—H
Group (NH) group or a large amount (10-25 atom
%) Contains hydrogen, and the hydrogen moves in the insulating film and is taken into the capacitor insulating film 22, thereby easily causing the above-described problem that the film quality of the capacitor insulating film changes.

Therefore, a method of forming a silicon oxide film having a low content of hydrogen and hydroxyl groups by a plasma CVD method is currently being developed. However, at present, characteristics that can be used as an insulating film in a semiconductor device have not yet been obtained. As described above, in an actual semiconductor device, measures against water (hydroxyl group) and hydrogen in the insulating film are not sufficient, and the device characteristics are not sufficiently stabilized. Water (hydroxyl group) or hydrogen contained in the insulating film is designed with a margin by considering the deterioration of the capacitor characteristics when it moves through the insulating film and is taken into the capacitor insulating film. It cannot be said that the properties of the dielectric film are fully utilized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. Accordingly, an object of the present invention is to provide a capacitor element having a high dielectric constant capacitor insulating film, which is contained in an insulating film covering the capacitor element. Water (hydroxyl group) or hydrogen that is transferred to the capacitor insulating film is suppressed,
An object of the present invention is to provide a semiconductor device capable of stabilizing device characteristics of a capacitor and a method of manufacturing the same.

[0018]

In order to achieve the above object, a semiconductor device according to the present invention comprises a first electrode formed on a substrate, a capacitor insulating film formed on the first electrode, A capacitor element having a second electrode formed on an upper layer of the capacitor insulating film;
A film for preventing permeation of hydrogen is formed on the upper surface of the electrode.

The semiconductor device of the present invention is preferably
Further, a film for preventing permeation of hydrogen is formed on the lower surface of the first electrode. The above-described film that prevents the permeation of hydrogen is formed by a conductive film containing at least one of a titanium nitride film, a titanium oxynitride film, and iridium oxide formed on the upper surface of the second electrode or the surface layer of the lower surface of the first electrode. .

The semiconductor device of the present invention is preferably
A coating insulating film including an insulating film for preventing moisture permeation is formed on at least one, preferably both sides, of the upper layer of the second electrode or the lower layer of the first electrode. More preferably, the insulating film for preventing permeation of moisture is an insulating film containing at least a silicon nitride film or a silicon oxynitride film.

The semiconductor device of the present invention is preferably
At least one, preferably both sides, of the upper layer of the second electrode or the lower layer of the first electrode, an insulating film for preventing the transmission of moisture, and an insulating film for preventing the transmission of the water on the opposite side of the capacitor element. A covering insulating film including a laminated insulating film with the formed insulating film that stores moisture is formed. More preferably, the insulating film that accumulates moisture is an insulating film including a silicon oxide film containing at least phosphorus.

The semiconductor device of the present invention is preferably
An insulating film for preventing the transmission of moisture and an insulating film for preventing the transmission of moisture are formed on at least one of and preferably both sides of the upper layer of the second electrode or the lower layer of the first electrode. A coating insulating film including a laminated insulating film with an insulating film having a reduction preventing function is formed. More preferably, the insulating film having the function of preventing reduction is an insulating film containing at least a silicon oxide film.

The semiconductor device of the present invention is preferably
At least one, preferably both sides, of the upper layer of the second electrode or the lower layer of the first electrode, an insulating film for preventing the transmission of moisture, and an insulating film for preventing the transmission of the water on the opposite side of the capacitor element. A covering insulating film including a laminated insulating film of the formed insulating film for accumulating moisture and an insulating film having a reduction preventing function formed on the capacitor element side of the insulating film for preventing the transmission of the moisture is formed. I have. More preferably, the insulating film that accumulates moisture is an insulating film containing a silicon oxide film containing at least phosphorus, and the insulating film having a reduction preventing function is an insulating film containing at least a silicon oxide film. is there.

The above-described semiconductor device of the present invention is a semiconductor device having a capacitor having a high dielectric constant capacitor insulating film such as tantalum oxide, BST or STO, wherein the capacitor comprises a first electrode, a capacitor insulating film and a second electrode. In the element, at least on the upper surface of the second electrode, preferably on the surface of the upper surface of the second electrode and the lower surface of the first electrode, as a conductive film containing at least one of titanium nitride, titanium oxynitride film, and iridium oxide, A film for preventing permeation of hydrogen is formed. The capacitor having the above structure is contained in an insulating film such as a silicon nitride film formed above or below the film in a state such as a Si—H group or an N—H group by a film that prevents the permeation of hydrogen. Hydrogen can be prevented from moving to the capacitor insulating film. Therefore, it is possible to prevent the hydrogen contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, and to stabilize the device characteristics of the capacitor.

Further, an upper layer of the second electrode or the first electrode
By forming a structure in which a coating insulating film including an insulating film for preventing moisture permeation is formed on at least one of the lower layers of the electrodes, preferably on both sides, the silicon oxide formed on the upper or lower layer of the capacitor element Thus, it is possible to prevent water (hydroxyl group) and the like in the insulating film from migrating to the capacitor insulating film, and to further stabilize the device characteristics of the capacitor. Upper layer of the second electrode or the first layer
By adopting a structure in which a covering insulating film including an insulating film for preventing the transmission of moisture is formed on both sides of the lower layer of the electrode, the device characteristics of the capacitor can be further stabilized.

Further, by forming the covering insulating film to have a laminated insulating film structure of an insulating film for preventing moisture permeation and an insulating film for accumulating moisture, the insulating film for preventing permeation of moisture, such as a silicon nitride film, is made thinner. And the amount of hydrogen supplied from the silicon nitride film can be suppressed.

Further, the covering insulating film has a laminated insulating film structure of an insulating film for preventing the transmission of moisture and an insulating film having a reduction preventing function, so that the insulating film for preventing the transmission of moisture, such as a silicon nitride film, is supplied. The consumed hydrogen is consumed, and the amount of hydrogen moving to the capacitor insulating film can be suppressed.

According to another aspect of the present invention, there is provided a semiconductor device comprising: a first electrode formed on a substrate; a capacitor insulating film formed on the first electrode; A capacitor element having a second electrode formed on an upper layer, wherein at least one of an upper layer of the second electrode and a lower layer of the first electrode, an insulating film for preventing permeation of moisture; A covering insulating film including a laminated insulating film with an insulating film that accumulates moisture formed on the opposite side of the capacitor element from the insulating film for preventing the occurrence of the moisture is formed.

The semiconductor device of the present invention is preferably
On both sides of the upper layer of the second electrode and the lower layer of the first electrode, an insulating film for preventing permeation of moisture, and water formed on the insulating film for preventing permeation of water formed on the opposite side of the capacitor element. A covering insulating film including a laminated insulating film with the insulating film to be formed is formed. More preferably, the insulating film for preventing the transmission of moisture is an insulating film containing at least a silicon nitride film or a silicon oxynitride film, and the insulating film for accumulating moisture is a silicon oxide film containing at least phosphorus. Including an insulating film.

The above-mentioned semiconductor device of the present invention is a semiconductor device having a capacitor having a high dielectric constant capacitor insulating film such as tantalum oxide, BST or STO, wherein the capacitor comprises a first electrode, a capacitor insulating film and a second electrode. In the element, at least one of an upper layer of the second electrode and a lower layer of the first electrode, an insulating film for preventing the transmission of moisture, and a moisture formed on an opposite side of the capacitor element of the insulating film for preventing the transmission of the moisture. A covering insulating film including a laminated insulating film with an insulating film that accumulates the heat is formed.
The capacitor having the above structure has a laminated insulating film structure of an insulating film for preventing the transmission of moisture, an insulating film for preventing the transmission of moisture, and an insulating film for preventing the transmission of moisture and an insulating film for storing moisture. By doing so, it becomes possible to reduce the thickness of an insulating film such as a silicon nitride film which prevents moisture from permeating, so that the amount of hydrogen supplied from the silicon nitride film can be suppressed. Therefore, it is possible to prevent moisture (hydroxyl group), hydrogen, and the like contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, thereby stabilizing the device characteristics of the capacitor.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: forming a first electrode on a substrate; forming a capacitor insulating film on the first electrode; Forming a second electrode on the upper layer of the capacitor insulating film, wherein the steps after the step of forming the second electrode form at least a film for preventing permeation of hydrogen on the upper surface of the second electrode. Process.

The method of manufacturing a semiconductor device according to the present invention is as follows.
Preferably, the step before the step of forming the first electrode includes:
Further, the method includes a step of forming a film for preventing permeation of hydrogen on the lower surface of the first electrode. Forming a conductive film containing at least one of titanium nitride, a titanium oxynitride film, and iridium oxide on the upper surface of the second electrode or the surface portion of the lower surface of the first electrode; I do.

The method for manufacturing a semiconductor device of the present invention described above
Preferably, a covering insulating film including an insulating film for preventing permeation of moisture, at least before the step of forming the second electrode, or at least after the step of forming the first electrode, and preferably both. Further comprising the step of forming More preferably, as an insulating film for preventing the permeation of the water,
An insulating film including at least a silicon nitride film is formed by a low pressure CVD (chemical vapor deposition) method (before the step of forming the first electrode), a plasma CVD method, or a catalytic CVD method.

The method of manufacturing a semiconductor device according to the present invention described above
Preferably, after the step of forming the second electrode, the upper covering insulating film including an insulating film for preventing the permeation of moisture and an insulating film for accumulating moisture in an upper layer of the insulating film for preventing the permeation of the water. The method further includes the step of forming. Or preferably,
Before the step of forming the first electrode, a step of forming a lower coating insulating film including an insulating film that accumulates moisture and an insulating film that prevents the permeation of moisture in an upper layer of the insulating film that accumulates the water is included. Have more. More preferably, an insulating film including a silicon oxide film containing at least phosphorus is formed by a CVD (chemical vapor deposition) method as the insulating film for storing moisture.

The method of manufacturing a semiconductor device according to the present invention described above includes:
Preferably, after the step of forming the second electrode, an insulating film having a reduction preventing function, and an upper covering insulating film including an insulating film for preventing transmission of moisture in an upper layer of the insulating film having the reducing preventing function are provided. The method further includes the step of forming. Alternatively, preferably, before the step of forming the first electrode, an insulating film for preventing the transmission of moisture and a lower side including an insulating film having a function of preventing reduction of an upper layer of the insulating film for preventing the transmission of moisture. The method further includes a step of forming a coating insulating film. More preferably,
An insulating film including at least a silicon oxide film is formed by a CVD (chemical vapor deposition) method as the insulating film having the reduction preventing function.

According to the method of manufacturing a semiconductor device of the present invention described above, in the step of manufacturing a semiconductor device having a capacitor having a high dielectric constant capacitor insulating film such as tantalum oxide, BST or STO, the first electrode, the capacitor, At least one of a titanium nitride, a titanium oxynitride film, and an iridium oxide is formed on at least the upper surface of the second electrode of the capacitor element including the insulating film and the second electrode, and preferably on the surface layer of the upper surface of the second electrode and the lower surface of the first electrode. A film which prevents transmission of hydrogen is formed as a conductive film containing such a material. By forming a film that prevents the above-described permeation of hydrogen, hydrogen contained in a state such as a Si—H group or an N—H group in an insulating film such as a silicon nitride film formed above or below the film is formed. Movement to the capacitor insulating film can be prevented. Therefore, it is possible to prevent the hydrogen contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, and to stabilize the device characteristics of the capacitor.

Further, an upper layer of the second electrode or the first electrode
At least one, and preferably both, of the lower layers of the electrode,
By forming a covering insulating film including an insulating film for preventing the permeation of moisture, water (hydroxyl groups) and the like in an insulating film such as silicon oxide formed on the upper or lower layer of the capacitor element move to the capacitor insulating film. Can be prevented, and the device characteristics of the capacitor can be further stabilized.

Further, by forming the covering insulating film as a laminated insulating film structure of an insulating film for preventing the transmission of moisture and an insulating film for storing the moisture, an insulating film such as a silicon nitride film for preventing the transmission of moisture is formed. The thickness can be reduced, and the amount of hydrogen supplied from the silicon nitride film can be suppressed.

Further, by forming the covering insulating film as a laminated insulating film structure of an insulating film for preventing the transmission of moisture and an insulating film having a reduction preventing function, an insulating film such as a silicon nitride film for preventing the transmission of moisture. Consumes hydrogen supplied from
It is possible to suppress the amount of hydrogen moving to the capacitor insulating film.

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention comprises the steps of: forming a first electrode on a substrate; forming a capacitor insulating film on the first electrode; Forming a second electrode on the upper layer of the capacitor insulating film; insulating the upper layer of the second electrode with an insulating film for preventing the transmission of moisture; and accumulating moisture in the upper layer of the insulating film for preventing the transmission of the water. Forming an upper coating insulating film including the insulating film.

The method of manufacturing a semiconductor device of the present invention described above
Preferably, a plasma CVD (chemical vapor deposition) method or a catalytic CVD method is used as the insulating film for preventing the permeation of moisture.
An insulating film including at least a silicon nitride film or a silicon oxynitride film is formed by a method. Preferably, an insulating film including a silicon oxide film containing at least phosphorus is formed by a CVD method as the insulating film for accumulating moisture.

The method for manufacturing a semiconductor device of the present invention described above
Preferably, before the step of forming the first electrode, the substrate is provided with an insulating film for preventing transmission of moisture, and an insulating film for storing moisture below the insulating film for preventing transmission of the moisture. And forming a lower covering insulating film including the insulating film.

According to the method of manufacturing a semiconductor device of the present invention described above, in the step of manufacturing a semiconductor device having a capacitor having a high dielectric constant capacitor insulating film such as tantalum oxide, BST or STO, the first electrode and the capacitor A second capacitor element comprising an insulating film and a second electrode;
An upper coating insulating film including an insulating film for preventing moisture permeation and an insulating film for accumulating moisture thereon is formed on the upper layer of the electrode. The insulating film that prevents moisture permeation prevents moisture permeation, and the covering insulating film is formed as a laminated insulating film structure of an insulating film that prevents moisture permeation and an insulating film that accumulates moisture. It is possible to reduce the thickness of an insulating film such as a film that prevents moisture from permeating, so that the amount of hydrogen supplied from the silicon nitride film can be suppressed.
Therefore, it is possible to prevent moisture (hydroxyl group), hydrogen, and the like contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, thereby stabilizing the device characteristics of the capacitor.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: an insulating film for accumulating moisture on a substrate; and an insulating film for preventing permeation of moisture in an upper layer of the insulating film for accumulating the moisture. Forming a lower coating insulating film including a film, forming a first electrode on the lower coating insulating film, forming a capacitor insulating film on the first electrode, Forming a second electrode on the capacitor insulating film.

The method of manufacturing a semiconductor device of the present invention described above
Preferably, an insulating film including at least a silicon nitride film or a silicon oxynitride film is formed by a low-pressure CVD (chemical vapor deposition) method, a plasma CVD method, or a catalytic CVD method as the insulating film for preventing the transmission of moisture. . Preferably, the insulating film for storing moisture is CV.
An insulating film including a silicon oxide film containing at least phosphorus is formed by Method D.

According to the method of manufacturing a semiconductor device of the present invention, in the step of manufacturing a semiconductor device having a capacitor having a high dielectric constant capacitor insulating film such as tantalum oxide, BST or STO, the first electrode and the capacitor A first capacitor element comprising an insulating film and a second electrode;
A lower covering insulating film including an insulating film that accumulates moisture and an insulating film that prevents the permeation of moisture is formed below the electrode. The insulating film that prevents moisture permeation prevents moisture permeation, and the covering insulating film is formed as a laminated insulating film structure of an insulating film that prevents moisture permeation and an insulating film that accumulates moisture. It is possible to reduce the thickness of an insulating film such as a film that prevents moisture from permeating, so that the amount of hydrogen supplied from the silicon nitride film can be suppressed.
Therefore, it is possible to prevent moisture (hydroxyl group), hydrogen, and the like contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, thereby stabilizing the device characteristics of the capacitor.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for manufacturing a semiconductor device according to the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 is a sectional view of a semiconductor device according to this embodiment.
For example, LOCOS method or STI (Shallow Trench I
A semiconductor element (not shown) such as a transistor is formed in an active region (not shown) of the semiconductor substrate 10 separated by an element isolation insulating film formed by a solation method or the like. On the semiconductor substrate 10, the semiconductor substrate 10
A semiconductor device such as a transistor above is covered, or an element isolation insulating film formed on the semiconductor substrate 10 is covered, for example, TEOS (tetra-ethyl-ortho-silicat).
e) as raw material for plasma CVD (Chemical Vapor Depo)
A base insulating film 20 made of silicon oxide formed by a sition method or the like is formed. The upper layer of the base insulating film 20 is formed, for example, by a normal pressure CVD method or the like, and contains 100 to 500 n containing 0 to 4.5% by weight of phosphorus.
m silicon oxide film (PSG film) 21a, for example, 0.2 to 20 atm formed by a low pressure CVD method or the like.
A silicon nitride film 21b having a thickness of 50 to 150 nm containing m% of hydrogen and a hydroxyl group (water) of 0.5 to 10% by weight formed by a CVD method using, for example, O ₃ and TEOS as raw materials. A lower coating insulating film 21, which is a laminated insulating film of a silicon oxide film 21c having a thickness of 50 to 150 nm, is formed.

An upper layer of the lower cover insulating film 21 is made of titanium nitride or titanium oxynitride formed by a sputtering method or the like so as to be connected to an embedded plug (not shown) made of, for example, tungsten or polysilicon. A first electrode 30 formed of a laminate of an electrode-coated conductive layer (barrier metal layer) 30a and an electrode layer 30b formed of a conductive material such as platinum or iridium formed by, for example, a sputtering method is formed. On the upper layer of the first electrode 30, for example, tantalum oxide (Ta ₂ O ₅ )
BST (barium strontium titanate) or S
A capacitor insulating film 22 made of a high dielectric constant film such as TO (strontium titanate) or a ferroelectric film such as Y1 is formed. The above capacitor insulating film 22
An electrode layer 31a made of a conductive material such as platinum or iridium formed by a sputtering method or the like, and a titanium nitride or titanium oxynitride formed by a sputtering method or the like,
A second electrode 31 made of a laminate of the electrode-coated conductive layer 31b having a thickness of 150 nm is formed. As described above, a capacitor element having a structure in which a pair of electrodes face each other with a capacitor insulating film interposed therebetween is formed.

The above-mentioned capacitor element is coated and has a hydroxyl group (moisture) content of 0.5 to 10% by weight formed by, for example, a CVD method using O ₃ and TEOS as raw materials.
A silicon oxide film 23a having a thickness of 00 to 500 nm, for example, 1 to 20 atoms formed by a catalytic CVD method or the like.
% Hydrogen-containing silicon nitride film 23b having a thickness of 50 to 150 nm, and a phosphorus-containing silicon oxide film (PSG film) formed by, for example, a normal pressure CVD method or the like.
An upper coating insulating film 23 which is a laminated insulating film of 23c is formed.

For example, O ₃ is formed on the upper coating insulating film 23.
Or IC using TEOS and TEOS as raw materials
P (Inductively Coupled Plasma) plasma CVD
, A silicon oxide formed by a high-density plasma CVD method such as an ECR (Electron Cyclotron Resonance) type plasma CVD method or a helicon wave plasma CVD method, and a CMP (Chemical Mechanical Polishing) method.
g) A planarized insulating film 24 that has been planarized by processing or the like is formed. Further, an upper insulating film 25 made of silicon oxide formed by, for example, a plasma CVD method using TEOS as a raw material is formed thereon. A passivation film 26 made of a silicon nitride film (SiN _x : H film) formed by, for example, a plasma CVD method is formed on the uppermost layer which is an upper layer of the upper insulating film 25.

In the capacitor element having the above structure,
The electrode coating conductive layers 30a and 31b formed on the lower and upper portions of the first electrode 30 and the second electrode respectively function as a barrier metal layer and a passivation film 26.
And has a function of preventing permeation of hydrogen contained in the silicon nitride film.

The silicon nitride films 21b and 23b in the lower coating insulating film 21 and the upper coating insulating film 23 are made of PS.
It has a function of preventing permeation of moisture (hydroxyl group) contained in the G film and the like. In particular, the silicon nitride film 21b in the lower covering insulating film 21 can be formed at a high temperature by a low-pressure CVD method. Can be suppressed.

The PSG films 21a and 23c in the lower coating insulating film 21 and the upper coating insulating film 23 have a function of storing moisture (hydroxyl group) and have a property of hardly releasing moisture (hydroxyl group) to the outside. Prevents excessive moisture permeation, furthermore, sodium ion getter, charge neutralization,
Has functions such as stress relaxation. In the above structure,
If necessary, PSG may be used as a part of the upper coating insulating film 23.
Instead of forming a film, PSG is used as the upper insulating film 25.
It is also possible to use a film, and in this case, the upper insulating film 25 has the above function.

The CVD using O ₃ and TEOS as raw materials in the lower coating insulating film 21 and the upper coating insulating film 23 is performed.
The silicon oxide films 21c and 23a formed by the method
It has a function of supplying an appropriate amount of water (hydroxyl group) to the capacitor element and a function as an oxidizing agent (anti-reduction agent) that consumes hydrogen. Since the above silicon oxide film has moisture in the film, when the film is thickened, a large amount of moisture moves to the capacitor insulating film, and the capacitor insulating film is deteriorated. By forming a thin film on the capacitor element side of the silicon film, only a small amount of water is supplied to the capacitor insulating film, and a film having a function of consuming hydrogen without deteriorating the characteristics of the capacitor element can be obtained. it can.

Therefore, it is possible to prevent water (hydroxyl group), hydrogen, and the like contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, thereby stabilizing the device characteristics (for example, increasing the leakage current). , A reduction in capacitance value, a reduction in breakdown voltage, and a prevention of deterioration in frequency characteristics on the high frequency side).

A method for manufacturing the semiconductor device of the present invention will be described. First, as shown in FIG. 2A, an element isolation insulating film (not shown) is formed on a semiconductor substrate 10 by a LOCOS method or an STI method, and a semiconductor element (not shown) such as a transistor is formed in an active region. , Plasma CVD using TEOS as a raw material
By depositing silicon oxide by a method, a base insulating film 20 is formed.

Next, a normal pressure CVD method, CVD using O ₃ and TEOS as raw materials
Containing 0 to 4.5% by weight of phosphorus by a plasma CVD method using TEOS as a raw material,
Silicon oxide film (PSG) having a thickness of
A film 21a is formed. In general, the PSG film 21a is formed by a normal pressure CVD method.
It can also be formed by a method or a low pressure CVD method. However, it is not preferable to form by a sputtering method from the viewpoint of generation of dust and charge-up damage.
The content of phosphorus in the PSG film 21a is preferably 5% by weight or less from the problem of hygroscopicity in the manufacturing process.

Next, as shown in FIG. 2B, a silicon nitride film (SiN _x : H film) is formed on the PSG film 21a by, for example, a plasma CVD method or a catalytic CVD method.
Silicon nitride film (Si ₃ N ₄ film) by low pressure CVD,
Alternatively, a plasma CVD method, a catalytic CVD method, a reduced pressure CV
A silicon oxynitride film (SiO _x1 N _y1 : H film; x1 = 0 to 50 (ato)
m%), y1 = 100−x1 (atom%))
Deposited at a thickness of 0 to 150 nm, 0.2 to 20 at
A silicon nitride film 21b containing om% of hydrogen is formed. In the catalytic CVD method, a catalytic decomposition reaction between a heating catalyst such as a tungsten wire or the like disposed in the vicinity of a substrate and a raw material gas is used, and 200 to 300 without using plasma.
It is possible to form a film at a low temperature of about ° C. The above-mentioned low-pressure CVD method, plasma CVD method, or sputtering method can be used to form a film under processing conditions in a range usually used, for example, a film forming a silicon nitride film (Si ₃ N ₄ film) by a low-pressure CVD method. Temperature is 700-85
It is about 0 ° C.

Next, the upper layer of the silicon nitride film 21b containing, for example, 0.5 to 10% by weight of a hydroxyl group (moisture) by a CVD method using O ₃ and TEOS as raw materials.
A 150 nm thick silicon oxide film (O ₃ -TEOS
A film 21c is formed. As described above, the PSG film 2
1a, silicon nitride film 21b and O ₃ -TEOS film 2
A lower coating insulating film 21 which is a laminated insulating film of 1c is formed.

Next, as shown in FIG. 2C, titanium nitride, titanium oxynitride or iridium oxide is deposited on the lower coating insulating film 21 by, for example, a sputtering method to form the electrode coating conductive layer 30a. Form. next,
A conductive material such as platinum, iridium, aluminum, or a laminate of platinum / ruthenium is deposited on the upper layer of the electrode coating conductive layer 30a by, for example, a sputtering method to form the electrode layer 30b. As described above, the first electrode 30, which is a laminate of the electrode coating conductive layer 30a and the electrode layer 30b, is formed.

Next, a capacitor insulating film 22 made of a high dielectric constant film such as tantalum oxide, BST or STO is formed on the first electrode 30 by a commonly used method. Next, a conductive material such as platinum, iridium, aluminum, or a platinum / ruthenium laminate is deposited on the upper layer by, for example, a sputtering method in the same manner as the first electrode 30, for example.
To form Next, titanium nitride, titanium oxynitride, or iridium oxide is deposited on the upper layer of the electrode layer 31a by, for example, a sputtering method to form an electrode coating film 31b. As described above, the second electrode 31 which is a laminate of the electrode layer 31a and the electrode coating film 31b is formed. Here, a titanium oxynitride film (TiO _x2 N _y2 film; x2 = 0.1 to 20) is used as the electrode coating conductive layers 30a and 31b.
(Atom%), y2 = 100−x2 (atom%))
Is generally used by a sputtering method, but it is preferable to use a plasma CVD method or an organic metal CV method.
It is also possible to use the D method.

Next, as shown in FIG. 3D, after a resist film R having a pattern of a capacitor element is formed by a photolithography process, the second electrode 3 is formed by an etching process such as RIE (reactive ion etching).
1. The capacitor insulating film 22 and the first electrode 30 are sequentially patterned to form a capacitor element having a structure in which a pair of electrodes face each other via the capacitor insulating film.

Next, as shown in FIG. 3E, after the resist film is removed by ashing or the like, the above-mentioned capacitor element is covered, and the resist is removed by, for example, CVD using O ₃ and TEOS as raw materials. 5-10 wt% of hydroxyl silicon oxide film having a thickness of 100~500nm containing (water) (O ₃ -TEOS film) 23a is formed. Next, a silicon nitride film (SiN _x : H film) by a plasma CVD method or a catalytic CVD method, or a silicon oxynitride film (a SiN _x : H film) by a plasma CVD method or a catalytic CVD method is formed on the O ₃ -TEOS film 23a. SiO _x1 N
_y1 : H film; x1 = 0 to 50 (atom%), y1 = 10
0-x1 (atom%)) is deposited in a thickness of 50 to 150 nm to form a silicon nitride film 23b containing 1 to 20 atom% of hydrogen. In the catalytic CVD method, as in the case of the silicon nitride film 23b, 200 to
It is possible to form a film at a low temperature of about 300 ° C. As the plasma CVD method or the sputtering method, a film can be formed under processing conditions in a range usually used. However, in the low pressure CVD method, the film formation temperature is 700 to 850.
The temperature is as high as about ° C., and changes in the physical structure of the capacitor insulating film and the electrode and deterioration of the film quality are caused at the film forming temperature, and the capacitor characteristics are deteriorated accordingly.

Next, as shown in FIG. 4 (f), C for the upper layer of the silicon nitride film 23b, for example, a SiH ₄ as a raw material
By a VD method, a normal pressure CVD method, a CVD method using O ₃ and TEOS as raw materials, a plasma CVD method using TEOS as a raw material, or the like, a silicon oxide film containing 0 to 4.5% by weight of phosphorus (PSG film) ) 23c is formed. PS
The G film 23c is generally formed by a normal pressure CVD method, but can also be formed by a plasma CVD method or a low pressure CVD method. However, it is not preferable to form by a sputtering method from the viewpoint of generation of dust and charge-up damage. The content of phosphorus in the PSG film 23c is preferably set to 5% by weight or less from the problem of hygroscopicity in the manufacturing process. As described above, O
_3- TEOS film 23a, silicon nitride film 23b and P
An upper coating insulating film 23, which is a laminated insulating film of the SG film 23c, is formed. Next, a CVD method using O ₃ and TEOS as raw materials, or
Silicon oxide is deposited by a high-density plasma CVD method such as an ICP type plasma CVD method, an ECR type plasma CVD method, or a helicon wave plasma CVD method, and an insulating film 24 is formed. As shown in FIG. CM
The surface is planarized by a P process or the like to form a planarized insulating film 24.

Next, silicon oxide is deposited by a plasma CVD method using TEOS as a raw material, for example, to form an upper insulating film 25. A silicon nitride film (SiN _x : H film) or a silicon oxynitride film (SiO _x1 N _y1 : H film) is deposited on the uppermost layer as the upper layer of the upper insulating film 25 by, for example, a plasma CVD method or a catalytic CVD method. ,
A passivation film 26 is formed. Thus, a semiconductor device having the capacitor element illustrated in FIG. 1 can be formed.

According to the above-described method for manufacturing a semiconductor device, the upper surface of the second electrode 31 (upper insulating film side) and the first electrode 3
Electrode coating conductive layers 30a and 31b such as a titanium nitride film and a titanium oxynitride film for preventing permeation of hydrogen are formed on the lower surface (lower coating insulating film side) of the silicon nitride-containing film such as a passivation film. In this case, it is possible to prevent hydrogen contained in a state such as Si-H group or NH group from moving to the capacitor insulating film 22, thereby preventing deterioration of the capacitor element.

The silicon nitride film 2 having a function of preventing the transmission of moisture (hydroxyl group) contained in the PSG film or the like.
Since 1b and 23b are formed, it is possible to prevent moisture (hydroxyl group) from moving to the capacitor insulating film and prevent deterioration of the capacitor element. In particular, the silicon nitride film 21b in the lower coating insulating film 21 can be formed at a high temperature by a low-pressure CVD method. In this case, the hydrogen content in the film can be reduced, so that the deterioration of the capacitor element is further suppressed. can do.

Further, PSG films 21a and 23c having a function of storing moisture (hydroxyl group) and having a property of hardly releasing moisture (hydroxyl group) to the outside are formed, and it is possible to prevent excessive moisture permeation. it can. Furthermore, this PSG film
It has functions such as sodium ion getter, charge neutralization, and stress relaxation. In the above structure, if necessary,
Instead of forming a PSG film as a part of the upper covering insulating film 23, a PSG film can be used as the upper insulating film 25. In this case, the upper insulating film 25 has the above function. .

Further, O ₃ -TEOS films 21 c and 23 a having a function of supplying an appropriate amount of water (hydroxyl group) to the capacitor element and a function as an oxidizing agent (reduction inhibitor) consuming hydrogen are formed. Thus, permeation of hydrogen can be prevented.

Accordingly, it is possible to prevent water, hydrogen, hydroxyl groups, and the like contained in the insulating film covering the capacitor element from migrating to the capacitor insulating film, thereby stabilizing the device characteristics (for example, increasing the leakage current). (A reduction in the capacitance, a reduction in the capacitance value, a reduction in the withstand voltage deterioration, and a deterioration in the frequency characteristics on the high frequency side) can be formed.

In the above structure, the electrode coating films formed on the upper surface (upper coating insulating film side) of the second electrode and the lower surface (lower coating insulating film side) of the first electrode prevent the permeation of hydrogen. Although having a function, an electrode coating film and an electrode layer can also be formed integrally by using an electrode material such as ruthenium oxide formed by a sputtering method or the like that prevents permeation of hydrogen.

Further, the semiconductor device according to the present embodiment can have the structure shown in the sectional view of FIG. For example, a semiconductor element (not shown) such as a transistor is formed in an active region (not shown) of the semiconductor substrate 10 separated by an element isolation insulating film formed by a LOCOS method, an STI method, or the like.
As a drain region or the like, a diffusion layer 11 in which a conductive impurity such as phosphorus is diffused in a semiconductor substrate 10 is formed. The above-mentioned semiconductor substrate 10 is covered with a semiconductor element such as a transistor or a diffusion layer 11 on the semiconductor substrate 10 or is covered with an element isolation insulating film formed on the semiconductor substrate 10. A base insulating film 20 made of silicon oxide formed by a plasma CVD method or the like is formed. The upper layer of the base insulating film 20 is formed, for example, by a normal pressure CVD method or the like, and contains 100 to 500 n containing 0 to 4.5% by weight of phosphorus.
m silicon oxide film (PSG film) 21a, for example, 0.2 to 20 atm formed by a low pressure CVD method or the like.
A silicon nitride film 21b having a thickness of 50 to 150 nm containing m% of hydrogen and a hydroxyl group (water) of 0.5 to 10% by weight formed by a CVD method using, for example, O ₃ and TEOS as raw materials. A lower coating insulating film 21, which is a laminated insulating film of a silicon oxide film 21c having a thickness of 50 to 150 nm, is formed.

A contact hole CH which penetrates the above-described base insulating film 20 and lower coating insulating film 21 and reaches diffusion layer 11 is opened, and is made of, for example, polysilicon containing a conductive impurity such as phosphorus, or A plug 12 made of a laminate of an adhesion layer such as titanium nitride and a conductive layer such as tungsten is embedded.

An electrode-coating conductive layer (barrier metal layer) 30 a made of titanium nitride, titanium oxynitride, or the like formed by sputtering or the like so as to be connected to the plug 12, on the lower coating insulating film 21. For example, a first electrode 30 formed of a laminate of electrode layers 30b made of a conductive material such as platinum or iridium formed by a sputtering method or the like is formed. The above-mentioned first electrode 30
, For example, tantalum oxide (Ta ₂ O ₅ ), BST
(Barium strontium titanate) or STO
(A strontium titanate) or a high dielectric constant film or a capacitor insulating film 2 made of a ferroelectric film such as Y1
2 are formed. An electrode layer 3 made of a conductive material such as platinum or iridium formed on the capacitor insulating film 22 by, for example, a sputtering method.
1a, for example, titanium nitride or titanium oxynitride formed by a sputtering method or the like;
The second electrode 31 is formed of a laminate of the electrode coating conductive layer 31b having a thickness of 0 nm. As described above, a capacitor element having a structure in which a pair of electrodes face each other with a capacitor insulating film interposed therebetween is formed.

The above-mentioned capacitor element is coated and has a hydroxyl group (moisture) content of 0.5 to 10% by weight formed by, for example, a CVD method using O ₃ and TEOS as raw materials.
A silicon oxide film 23a having a thickness of 00 to 500 nm, for example, 1 to 20 atoms formed by a catalytic CVD method or the like.
% Hydrogen-containing silicon nitride film 23b having a thickness of 50 to 150 nm, and a phosphorus-containing silicon oxide film (PSG film) formed by, for example, a normal pressure CVD method or the like.
An upper coating insulating film 23 which is a laminated insulating film of 23c is formed.

For example, O ₃ is formed on the upper insulating film 23.
Or IC using TEOS and TEOS as raw materials
It is made of silicon oxide formed by a high-density plasma CVD method such as a P-type plasma CVD method, an ECR-type plasma CVD method, or a helicon wave plasma CVD method,
A planarization insulating film 24 that has been planarized by a CMP process or the like is formed. Further, an upper insulating film 25 made of silicon oxide formed by, for example, a plasma CVD method using TEOS as a raw material is formed thereon. For example, the plasma CVD
Silicon nitride film (SiN _x : H film)
A passivation film 26 is formed.

The semiconductor device having the structure shown in FIG. 5 is substantially the same as the semiconductor device having the structure shown in FIG. 1, and the water contained in the insulating film covering the capacitor element is similar to the above. (Hydroxyl group), hydrogen, etc. are prevented from moving to the capacitor insulating film, and the device characteristics are stabilized (for example,
This is a semiconductor device having a capacitor element in which an increase in leakage current is reduced, a decrease in capacitance value is reduced, a deterioration in breakdown voltage is reduced, and a frequency characteristic on a high frequency side is prevented from deteriorating.

Second Embodiment FIG. 6 is a sectional view of a semiconductor device according to this embodiment.
The semiconductor device according to the present embodiment is substantially the same as the semiconductor device according to the first embodiment, and has a capacitor element portion having the same configuration as that of the first embodiment. Is PSG (phosphorus-containing silicon oxide) film 2
1a and a silicon nitride film 21b (not including the O ₃ -TEOS film 21c of the first embodiment), and the upper cover insulating film 23 is a silicon nitride film 23b and an upper PSG film. 23C (not having the O ₃ -TEOS film 23a in the first embodiment).

The method of manufacturing the semiconductor device according to the present embodiment is substantially the same as the method of manufacturing the semiconductor device according to the first embodiment, and includes a step of forming the lower coating insulating film 21 and the upper coating insulating film 23. In each, O ₃ -TEOS
The film can be formed by omitting the manufacturing process of the film.

As in the first embodiment, the capacitor having the above structure prevents water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element from moving to the capacitor insulating film. The device characteristics of the capacitor can be stabilized.

Third Embodiment FIG. 7 is a sectional view of a semiconductor device according to the third embodiment .
The semiconductor device according to the present embodiment is substantially the same as the semiconductor device according to the first embodiment, and has a capacitor element portion having the same configuration as that of the first embodiment. Is PSG (phosphorus-containing silicon oxide) film 2
1a and a silicon nitride film 21b (not including the O ₃ -TEOS film 21c of the first embodiment), and the upper covering insulating film 23 has a single-layer structure of the silicon nitride film 23b. (Not having the O ₃ -TEOS film 23a and the PSG film 23c in the first embodiment).

The method of manufacturing the semiconductor device according to the present embodiment is substantially the same as the method of manufacturing the semiconductor device according to the first embodiment, and the steps of forming the lower coating insulating film 21 and the upper coating insulating film 23 are performed. In each, O ₃ -TEOS
The film can be formed by omitting the film manufacturing process and omitting the PSG film manufacturing process in the process of forming the upper covering insulating film 23.

As in the first embodiment, the capacitor having the above structure prevents water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element from moving to the capacitor insulating film. The device characteristics of the capacitor can be stabilized.

Fourth Embodiment FIG. 8 is a sectional view of a semiconductor device according to the fourth embodiment .
The semiconductor device according to the present embodiment is substantially the same as the semiconductor device according to the first embodiment, and has a capacitor element portion having the same configuration as that of the first embodiment. Are the silicon nitride film 21b and the O ₃ -TEOS film 2
1c (PS of the first embodiment)
G (does not have a phosphorus-containing silicon oxide) film 21a), and the upper covering insulating film 23 is made of O ₃ -TEO.
It is different in that it is composed of a stacked body of an S film 23a and a silicon nitride film 23b (having no PSG film 23c in the first embodiment).

The method for fabricating the semiconductor device according to the present embodiment is substantially the same as the method for fabricating the semiconductor device according to the first embodiment, and includes a step of forming the lower covering insulating film 21 and the upper covering insulating film 23. Can be formed by omitting the manufacturing steps of the respective PSG films.

In the capacitor having the above structure, water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element is prevented from moving to the capacitor insulating film, as in the first embodiment. The device characteristics of the capacitor can be stabilized.

Fifth Embodiment FIG. 9 is a sectional view of a semiconductor device according to the fifth embodiment .
The semiconductor device according to this embodiment is substantially the same as the semiconductor device according to the fourth embodiment, and has a capacitor element portion having the same configuration as that of the fourth embodiment. Is a single-layer structure of the silicon nitride film 21b (having no O ₃ -TEOS film 21c of the fourth embodiment).

The method of manufacturing a semiconductor device according to the present embodiment is substantially the same as the method of manufacturing a semiconductor device according to the fourth embodiment. In the step of forming the lower covering insulating film 21, O ₃ -TEOS The film can be formed by omitting the manufacturing process of the film.

In the capacitor having the above structure, as in the fourth embodiment, water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element is prevented from moving to the capacitor insulating film. The device characteristics of the capacitor can be stabilized.

Sixth Embodiment FIG. 10 is a sectional view of a semiconductor device according to the sixth embodiment . The semiconductor device according to the present embodiment is substantially the same as the semiconductor device according to the fifth embodiment, and has a capacitor element portion having the same configuration as that of the fifth embodiment. The difference is that the silicon nitride film 23b has a single-layer structure (does not include the O ₃ -TEOS film 23a of the fifth embodiment).

The method of manufacturing the semiconductor device according to the present embodiment is substantially the same as the method of manufacturing the semiconductor device according to the fifth embodiment. In the step of forming the lower covering insulating film 23, O ₃ -TEOS The film can be formed by omitting the manufacturing process of the film.

In the capacitor having the above structure, similarly to the fifth embodiment, water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element is prevented from moving to the capacitor insulating film. The device characteristics of the capacitor can be stabilized.

Seventh Embodiment FIG. 11 is a sectional view of a semiconductor device according to the present embodiment. The semiconductor device according to the present embodiment is substantially the same as the semiconductor device according to the second embodiment. In the capacitor element according to the second embodiment, the second electrode has an electrode coating conductive layer such as titanium nitride. Except for the fact that the conductive layer has a single-layer structure, the rest is substantially the same as the second embodiment. However, the difference is that the upper coating insulating film 23 has a single-layer structure of the silicon nitride film 23b (does not include the O ₃ -TEOS film 23a of the fifth embodiment).

For example, a semiconductor element (not shown) such as a transistor is formed in an active region (not shown) of the semiconductor substrate 10 separated by an element isolation insulating film formed by the LOCOS method or the like. A semiconductor element such as a transistor on the semiconductor substrate 10 is coated on the semiconductor substrate 10 or an element isolation insulating film formed on the semiconductor substrate 10 is coated on the semiconductor substrate 10. A base insulating film 20 made of silicon oxide formed by a CVD method or the like is formed. On the upper layer of the base insulating film 20, for example, 100 to 5 containing 0 to 4.5% by weight of phosphorus formed by a normal pressure CVD method or the like.
A silicon oxide film (PSG film) 21a having a thickness of 00 nm
And, for example, from 0.2 to
A lower covering insulating film 21, which is a stacked insulating film of a silicon nitride film 21b having a thickness of 50 to 150 nm and containing 20 atom% of hydrogen, is formed.

An upper layer of the lower covering insulating film 21 is made of titanium nitride, titanium oxynitride, or the like formed by a sputtering method or the like so as to be connected to a not-shown buried plug made of, for example, tungsten or polysilicon. A first electrode 30 formed of a laminate of an electrode-coated conductive layer (barrier metal layer) 30a and an electrode layer 30b formed of a conductive material such as platinum or iridium formed by, for example, a sputtering method is formed. On the upper layer of the first electrode 30, for example, tantalum oxide (Ta ₂ O ₅ )
BST (barium strontium titanate) or S
A high dielectric constant film such as TO (strontium titanate) or a compound group called Y1 such as SBT (SrBi ₂ Ta ₂ O ₉ ) (US Pat. No. 5,519,234) or PZT
A capacitor insulating film 22 made of a ferroelectric film such as (PbZrO ₃ ) is formed. On the upper layer of the capacitor insulating film 22, a second electrode 31 made of an electrode layer made of a conductive material such as platinum or iridium formed by, for example, a sputtering method is formed. As described above, a capacitor element having a structure in which a pair of electrodes face each other with a capacitor insulating film interposed therebetween is formed.

The above-mentioned capacitor element is coated, and for example, 1 to 20 atom% formed by a catalytic CVD method or the like.
Hydrogen-containing silicon nitride film 23b having a thickness of 50 to 150 nm, and a phosphorus-containing silicon oxide film (PSG film) 2 formed by, for example, a normal pressure CVD method or the like.
An upper covering insulating film 23, which is a laminated insulating film of 3c, is formed.

For example, O ₃ is formed on the upper coating insulating film 23.
Or IC using TEOS and TEOS as raw materials
It is made of silicon oxide formed by a high-density plasma CVD method such as a P-type plasma CVD method, an ECR-type plasma CVD method, or a helicon wave plasma CVD method,
A planarization insulating film 24 that has been planarized by a CMP process or the like is formed. Further, an upper insulating film 25 made of silicon oxide formed by, for example, a plasma CVD method using TEOS as a raw material is formed thereon. For example, the plasma CVD
Silicon nitride film (SiN _x : H film)
A passivation film 26 is formed.

The method for manufacturing a semiconductor device according to the present embodiment is substantially the same as the method for manufacturing a semiconductor device according to the second embodiment. It can be formed by omitting the layer process.

The capacitor having the above structure suppresses the movement of water (hydroxyl group), hydrogen, and the like contained in the insulating film covering the capacitor element to the capacitor insulating film, as in the second embodiment. The device characteristics of the capacitor can be stabilized.

The semiconductor device and the method of manufacturing the same according to the present invention are not limited to the above embodiments. For example, the shape of the capacitor can be applied to various shapes such as a planar type, a cylinder type, a stack type, a fin type, and a trench type. Also, as the capacitor, DRAM
For example, a capacitor in which a first electrode and a second electrode face each other via a capacitor insulating film in a semiconductor device, such as a memory capacitor in a VRAM or the like. Further, the semiconductor element formed on the substrate is not particularly limited, such as a transistor. In addition, various changes can be made without departing from the gist of the present invention.

[0102]

According to the present invention, in a capacitor element having a high dielectric constant capacitor insulating film, such as a DRAM memory capacitor, water (hydroxyl group) or hydrogen contained in the insulating film covering the capacitor element is provided. Thus, it is possible to provide a semiconductor device having a capacitor having stabilized device characteristics and a method of manufacturing the same, by suppressing the movement of the semiconductor device to the capacitor insulating film.

[Brief description of the drawings]

FIG. 1 is a sectional view of a semiconductor device according to a first embodiment.

FIGS. 2A and 2B are cross-sectional views illustrating a manufacturing process of a method for manufacturing a semiconductor device according to a first embodiment. FIG. 2A illustrates a process until a process of forming a silicon oxide (PSG film) containing phosphorus.
(B) shows up to a step of forming a silicon oxide film using O ₃ and TEOS as raw materials, and (c) shows up to a step of forming a layer to be a second electrode.

FIG. 3 shows a step subsequent to that of FIG. 2; (d) shows up to a patterning step of the capacitor element; and (e) shows up to a step of forming a silicon nitride film.

4 shows a step subsequent to that of FIG. 3; FIG. 4 (f) shows a step up to a step of forming an insulating film for flattening, and FIG. 4 (g) shows a step up to the flattening step.

FIG. 5 is a cross-sectional view of a semiconductor device having another structure according to the first embodiment.

FIG. 6 is a sectional view of a semiconductor device according to a second embodiment.

FIG. 7 is a sectional view of a semiconductor device according to a third embodiment.

FIG. 8 is a sectional view of a semiconductor device according to a fourth embodiment.

FIG. 9 is a sectional view of a semiconductor device according to a fifth embodiment.

FIG. 10 is a sectional view of a semiconductor device according to a sixth embodiment.

FIG. 11 is a sectional view of a semiconductor device according to a seventh embodiment.

FIG. 12 is a sectional view of a semiconductor device according to a first conventional example.

FIG. 13 is a sectional view of a semiconductor device according to a second conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Semiconductor substrate, 11 ... Diffusion layer, 12 ... Plug, 20
... Base insulating film, 21 ... Lower covering insulating film, 21a ... PSG
Film, 21b: silicon nitride film, 21c: O ₃ -TEOS
Film, 22: capacitor insulating film, 23: upper cover insulating film,
23a: O ₃ -TEOS film, 23b: silicon nitride film,
23c PSG film, 24 flattening insulating film, 25 upper insulating film, 26 passivation film, 30 first electrode, 3
0a: Electrode-coated conductive layer (barrier metal layer), 30b: Electrode layer, 31: Second electrode, 31a: Electrode layer, 31b: Electrode-coated conductive layer, CH: Contact hole.

Claims (52)

[Claims] A capacitor element having a first electrode formed on a substrate, a capacitor insulating film formed on the first electrode, and a second electrode formed on the capacitor insulating film. A semiconductor device in which a film for preventing permeation of hydrogen is formed on at least an upper surface of the second electrode. 2. The semiconductor device according to claim 1, wherein a conductive film for preventing permeation of hydrogen is formed on a surface portion of an upper surface of said second electrode. 3. A conductive film containing at least one of titanium nitride, titanium oxynitride film, and iridium oxide is formed as a conductive film formed on a surface portion of the upper surface of the second electrode to prevent permeation of hydrogen. Claim 2
13. The semiconductor device according to claim 1. 4. The semiconductor device according to claim 1, wherein a film for preventing permeation of hydrogen is formed on a lower surface of said first electrode. 5. The semiconductor device according to claim 4, wherein a conductive film for preventing permeation of hydrogen is formed on a surface portion of a lower surface of said first electrode. 6. A conductive film formed on a surface portion of a lower surface of said first electrode and containing at least one of titanium nitride, titanium oxynitride film and iridium oxide is formed as a conductive film for preventing permeation of hydrogen. Claim 5
13. The semiconductor device according to claim 1. 7. The semiconductor device according to claim 1, wherein a covering insulating film including an insulating film for preventing permeation of moisture is formed on at least one of an upper layer of said second electrode and a lower layer of said first electrode. 8. The semiconductor device according to claim 7, wherein a covering insulating film including an insulating film for preventing moisture permeation is formed on both sides of an upper layer of said second electrode and a lower layer of said first electrode. 9. The semiconductor device according to claim 7, wherein said insulating film for preventing permeation of moisture is an insulating film containing at least a silicon nitride film or a silicon oxynitride film. 10. An insulating film for preventing the permeation of moisture, and an insulating film for preventing the permeation of water, the insulating film being disposed on at least one of the upper layer of the second electrode and the lower layer of the first electrode, opposite to the capacitor element. 8. The semiconductor device according to claim 7, further comprising a coating insulating film including a laminated insulating film with the insulating film that stores moisture formed in the semiconductor device. 11. An insulating film for preventing the permeation of moisture, on both sides of an upper layer of the second electrode and a lower layer of the first electrode, and an insulating film for preventing the permeation of water formed on the opposite side of the capacitor element. The semiconductor device according to claim 10, wherein a covering insulating film including a laminated insulating film with the insulating film that stores the moisture is formed. 12. The semiconductor device according to claim 10, wherein said insulating film for storing moisture is an insulating film including a silicon oxide film containing at least phosphorus. 13. An insulating film for preventing permeation of moisture, and an insulating film for preventing permeation of moisture is formed on at least one of the upper layer of the second electrode and the lower layer of the first electrode. 8. The semiconductor device according to claim 7, wherein a coating insulating film including a laminated insulating film with the formed insulating film having a reduction preventing function is formed. 14. An insulating film for preventing permeation of moisture and an insulating film for preventing permeation of moisture, on both sides of an upper layer of the second electrode and a lower layer of the first electrode, on the capacitor element side of the insulating film for preventing permeation of the water. 14. The semiconductor device according to claim 13, wherein a covering insulating film including a laminated insulating film with an insulating film having a reduction preventing function is formed. 15. The insulating film having a reduction preventing function is an insulating film containing at least a silicon oxide film.
13. The semiconductor device according to claim 1. 16. An insulating film for preventing the permeation of moisture, and an insulating film for preventing the permeation of moisture, on at least one of the upper layer of the second electrode and the lower layer of the first electrode, opposite to the capacitor element from the insulating film for preventing the transmission of moisture. And a covering insulating film including a laminated insulating film of an insulating film formed to accumulate moisture and an insulating film having a function of preventing reduction formed on the capacitor element side of the insulating film preventing transmission of the moisture. Claim 7
13. The semiconductor device according to claim 1. 17. An insulating film for preventing permeation of moisture, on both sides of an upper layer of said second electrode and a lower layer of said first electrode, and an insulating film for preventing permeation of said water on an opposite side of said capacitor element. And a covering insulating film including a laminated insulating film of an insulating film that accumulates the formed moisture and an insulating film having a function of preventing reduction formed on the capacitor element side of the insulating film that prevents the transmission of the moisture. The semiconductor device according to claim 16. 18. The semiconductor device according to claim 16, wherein said insulating film for storing moisture is an insulating film including a silicon oxide film containing at least phosphorus. 19. The insulating film having a reduction preventing function is an insulating film containing at least a silicon oxide film.
13. The semiconductor device according to claim 1. 20. A capacitor element comprising: a first electrode formed on a substrate; a capacitor insulating film formed on the first electrode; and a second electrode formed on the capacitor insulating film. An insulating film for preventing the transmission of moisture and an insulating film for preventing the transmission of moisture are formed on at least one of the upper layer of the second electrode and the lower layer of the first electrode on the opposite side of the capacitor element from the insulating film for preventing the transmission of the moisture. A semiconductor device in which a covering insulating film including a laminated insulating film with an insulating film that accumulates moisture is formed. 21. An insulating film for preventing permeation of moisture, on both sides of an upper layer of the second electrode and a lower layer of the first electrode, and an insulating film for preventing permeation of the water on the opposite side of the capacitor element. 21. The semiconductor device according to claim 20, wherein a covering insulating film including a laminated insulating film with the insulating film that stores the moisture is formed. 22. The semiconductor device according to claim 20, wherein said insulating film for preventing permeation of moisture is an insulating film containing at least a silicon nitride film or a silicon oxynitride film. 23. The semiconductor device according to claim 20, wherein said insulating film for storing moisture is an insulating film including a silicon oxide film containing at least phosphorus. 24. A method comprising the steps of: forming a first electrode on a substrate; forming a capacitor insulating film on the first electrode; and forming a second electrode on the capacitor insulating film. A method of manufacturing a semiconductor device, wherein the steps after the step of forming the second electrode include the step of forming a film for preventing permeation of hydrogen on at least the upper surface of the second electrode. 25. In the step of forming the second electrode,
25. The method of manufacturing a semiconductor device according to claim 24, wherein a conductive film for preventing permeation of hydrogen is formed on a surface portion of the upper surface of the second electrode. 26. The step of forming a conductive film for preventing permeation of hydrogen, which is formed on a surface portion of the upper surface of the second electrode, includes at least one of titanium nitride, titanium oxynitride film, and iridium oxide. The method for manufacturing a semiconductor device according to claim 25, wherein a conductive film to be formed is formed. 27. The method according to claim 24, wherein the step before the step of forming the first electrode further includes the step of forming a film for preventing permeation of hydrogen on the lower surface of the first electrode. 28. In the step of forming the first electrode,
28. The method of manufacturing a semiconductor device according to claim 27, wherein a conductive film for preventing permeation of hydrogen is formed on a surface portion of a lower surface of the first electrode. 29. The step of forming a conductive film for preventing permeation of hydrogen formed on a surface portion of a lower surface of the first electrode includes at least one of titanium nitride, titanium oxynitride film, and iridium oxide. The method for manufacturing a semiconductor device according to claim 28, wherein a conductive film to be formed is formed. 30. A covering insulating film including an insulating film for preventing moisture permeation is formed at least before the step of forming the second electrode or after the step of forming the first electrode. The method for manufacturing a semiconductor device according to claim 24, further comprising a step. 31. A step of forming a covering insulating film including an insulating film for preventing moisture permeation both before the step of forming the second electrode and after the step of forming the first electrode. 31. The method of manufacturing a semiconductor device according to claim 30, further comprising: 32. Before the step of forming the first electrode, an insulating film including at least a silicon nitride film is formed by a low pressure CVD (chemical vapor deposition) method as the insulating film for preventing the permeation of moisture. The method for manufacturing a semiconductor device according to claim 30. 33. The semiconductor device according to claim 30, wherein an insulating film containing at least a silicon nitride film or a silicon oxynitride film is formed by plasma CVD (chemical vapor deposition) as the insulating film for preventing the permeation of moisture. Manufacturing method. 34. A semiconductor device according to claim 30, wherein an insulating film containing at least a silicon nitride film or a silicon oxynitride film is formed by catalytic CVD (chemical vapor deposition) as the insulating film for preventing the permeation of moisture. Manufacturing method. 35. After the step of forming the second electrode, an upper insulating film including an insulating film for preventing permeation of moisture and an insulating film for accumulating moisture on an upper layer of the insulating film for preventing permeation of the water. 31. The method of manufacturing a semiconductor device according to claim 30, further comprising a step of forming a semiconductor device. 36. A lower covering insulating film including an insulating film for storing moisture and an insulating film for preventing the transmission of moisture in an upper layer of the insulating film for storing the moisture before the step of forming the first electrode. 31. The method of manufacturing a semiconductor device according to claim 30, further comprising a step of forming a semiconductor device. 37. The insulating film for accumulating moisture, comprising CV
36. The method for manufacturing a semiconductor device according to claim 35, wherein an insulating film including a silicon oxide film containing at least phosphorus is formed by a D (chemical vapor deposition) method. 38. The insulating film for accumulating moisture, comprising: CV
37. The method of manufacturing a semiconductor device according to claim 36, wherein an insulating film including a silicon oxide film containing at least phosphorus is formed by a D (chemical vapor deposition) method. 39. After the step of forming the second electrode, an upper covering insulating film including an insulating film having a reduction preventing function, and an insulating film for preventing the permeation of moisture in an upper layer of the insulating film having the reducing preventing function. 31. The method according to claim 30, further comprising the step of:
The manufacturing method of the semiconductor device described in the above. 40. Prior to the step of forming the first electrode, an insulating film for preventing permeation of water and a lower side including an insulating film having a function of preventing reduction of an upper layer of the insulating film for preventing permeation of the water. 31. The method according to claim 30, further comprising a step of forming a coating insulating film.
The manufacturing method of the semiconductor device described in the above. 41. The method of manufacturing a semiconductor device according to claim 39, wherein an insulating film including at least a silicon oxide film is formed by a CVD (chemical vapor deposition) method as said insulating film having a reduction preventing function. 42. The method of manufacturing a semiconductor device according to claim 40, wherein an insulating film containing at least a silicon oxide film is formed by a CVD (chemical vapor deposition) method as said insulating film having a reduction preventing function. 43. A step of forming a first electrode on a substrate; a step of forming a capacitor insulating film on the first electrode; a step of forming a second electrode on the capacitor insulating film; A semiconductor device comprising, as an upper layer of two electrodes, a step of forming an upper covering insulating film including an insulating film for preventing the transmission of moisture and an insulating film for storing the moisture in the upper layer of the insulating film for preventing the transmission of the moisture; Manufacturing method. 44. A semiconductor device according to claim 43, wherein an insulating film containing at least a silicon nitride film or a silicon oxynitride film is formed by plasma CVD (chemical vapor deposition) as said insulating film for preventing the transmission of moisture. Manufacturing method. 45. A semiconductor device according to claim 43, wherein an insulating film including at least a silicon nitride film or a silicon oxynitride film is formed by catalytic CVD (chemical vapor deposition) as the insulating film for preventing the permeation of moisture. Manufacturing method. 46. An insulating film for accumulating moisture, comprising CV
44. The method of manufacturing a semiconductor device according to claim 43, wherein an insulating film including a silicon oxide film containing at least phosphorus is formed by a D (chemical vapor deposition) method. 47. Prior to the step of forming the first electrode, an insulating film for preventing the transmission of moisture, and an insulating film for accumulating moisture below the insulating film for preventing the transmission of the moisture are provided on the substrate. The method of manufacturing a semiconductor device according to claim 43, further comprising a step of forming a lower coating insulating film including: 48. A step of forming a lower covering insulating film including an insulating film for accumulating moisture on a substrate, and an insulating film for preventing the transmission of moisture in an upper layer of the insulating film for accumulating the moisture; A semiconductor device comprising: forming a first electrode on an upper layer of a covering insulating film; forming a capacitor insulating film on an upper layer of the first electrode; and forming a second electrode on the upper layer of the capacitor insulating film. Manufacturing method. 49. The method of manufacturing a semiconductor device according to claim 48, wherein an insulating film including at least a silicon nitride film is formed by a low pressure CVD (chemical vapor deposition) method as said insulating film for preventing permeation of moisture. 50. A semiconductor device according to claim 48, wherein an insulating film containing at least a silicon nitride film or a silicon oxynitride film is formed by plasma CVD (chemical vapor deposition) as said insulating film for preventing the transmission of moisture. Manufacturing method. 51. A semiconductor device according to claim 48, wherein an insulating film containing at least a silicon nitride film or a silicon oxynitride film is formed by catalytic CVD (chemical vapor deposition) as said insulating film for preventing the permeation of moisture. Manufacturing method. 52. The insulating film for accumulating moisture, comprising: CV
49. The method of manufacturing a semiconductor device according to claim 48, wherein an insulating film including a silicon oxide film containing at least phosphorus is formed by a D (chemical vapor deposition) method.