JP2000183052A - Manufacture of electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance an organic dielectric film in adhesion to a work by a method wherein the work is inversely sputtered so as to be provided with dangling bonds on its surface, and then the organic dielectric film is formed thereon. SOLUTION: Dangling bonds are formed on the surface of a work 10 by inverse sputtering. By inverse sputtering, active sites are formed on the surface of the work 10, so that an organic dielectric film 12 is enhanced in adhesion to the work 10 by chemical bonding. Inverse sputtering is carried out by the use of rare gas such as He, Ar, Xe, Kr or the like. Reducing gas such as H2, SiH4 or the like may be added to these rare gases. Inverse sputtering is carried out in the same film forming chamber where an inorganic dielectric film 11a is formed, or an inverse sputtering is carried out in an inverse sputtering- dedicated pre-treatment chamber. In this case, a pre-treatment chamber and a film forming chamber are continuously connected through a vacuum gate valve, and a metal wiring provided on a work is prevented from being oxidized again while the work is trarsferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an electronic device, and more particularly, to a method for manufacturing an electronic device with improved adhesion when an organic dielectric film is formed on a substrate to be processed.

[0002]

2. Description of the Related Art ULSI (Ultra Large Scale Integrate)
As the degree of integration of semiconductor devices such as d circuits increases, the wiring width and the wiring pitch need to be finer. The reduction of the wiring width and the wiring pitch simultaneously increases the aspect ratio of the wiring cross section and the aspect ratio of the space between wirings. As a result, the burden is concentrated on the etching technology for processing fine and high-aspect-ratio wiring and the technology for embedding the fine and high-aspect-ratio wiring space with an interlayer insulating layer, which complicates the manufacturing process and reduces the number of processes. It is increasing.

At the same time as miniaturization, in order to meet the demands for low power consumption and high operating speed of various semiconductor devices, especially high speed logic semiconductor devices, an interlayer insulating film having a low dielectric constant is required. Along with the materials, selection of a low-resistance electrode wiring material and its process technology are becoming increasingly important as elemental technologies. This is also an important problem in various high-frequency fine electronic devices other than semiconductor devices.

Conventionally, aluminum-based metals such as Al-Si and Al-Si-Cu, which have relatively low resistance, have been used as electrode wiring materials for semiconductor devices and the like. However, as a next-generation electrode wiring material, Cu, which has a lower specific resistance than Al and has excellent electromigration and stress migration resistance, is considered to be promising. The specific resistance of Cu is 1.72 μΩ-cm, and the specific resistance of Al is 2.
It is about 60% of 7 μΩ-cm. Cu film formation methods include sputtering and CVD (Chemical Vapor Deposition).
In addition to the method and the like, an electrolytic plating method can also be applied.

As one low dielectric constant interlayer insulating film, SiOF in which fluorine is introduced into conventional SiO ₂ (dielectric constant: 4) is known. SiOF constitutes a SiO ₂ Si-
By terminating the O-Si bond with F atoms, the density is reduced, and the polarizability of the Si-F bond and the OF bond is small, so that a dielectric constant lower than that of SiO ₂ is achieved. Since this SiOF is similar to the conventional SiO ₂ in the process of film formation and etching, it can be easily adopted even in a current manufacturing apparatus. Also, since it is an inorganic material, it has excellent heat resistance. However, the relative dielectric constant of SiOF is only about 3.7 to 3.2.

[0006] As a low dielectric constant interlayer insulating layer, an organic dielectric film material containing carbon atoms is also known. That is, organic S
OG (Spin On Glass), polyaryl ether, polyimide, polyparaxylylene (trade name: parylene), benzocyclobutene, polynaphthalene, etc., having a relative dielectric constant of 2.5 to
It is an organic polymer material of about 3.5. The density of these materials is reduced by containing carbon atoms, and a low dielectric constant is achieved by reducing the polarizability of the molecule (monomer) itself. Also, by introducing a siloxane bond, an imide bond, or a benzene ring or a naphthalene ring,
Has some heat resistance.

[0007] These hydrocarbon-based organic dielectric film materials include:
In addition, fluorocarbon polymers with fluorine atoms introduced
With a relative dielectric constant of about 1.5 to 2.5, further lowering of the dielectric constant and improvement of heat resistance can be obtained. As the organic material of such a fluororesin, perfluoro group-containing polyimide, fluorinated polyarylether, Teflon (trade name), Flare (trade name) and the like are known. These organic low dielectric constant materials are described, for example, in "Nikkei Micro Devices" magazine, July 1995.
It is introduced on pages 105-112 of the monthly issue.

As a process for applying these low-resistance electrode wiring materials and low-dielectric-constant interlayer insulating films to semiconductor devices and the like, Damascene or Dual Damascene is used.
There is a method called. In these, a metal wiring material is embedded in a wiring groove or a wiring groove and a connection hole previously formed in an interlayer insulating film by a reflow sputtering method, an electrolytic plating method, or the like, and a CMP (Chemical mechanical polishing) method is used.
This is a technique for flattening the surface by a method. The Damascene or Dual Damascene process does not require high-aspect-ratio interconnects to be patterned by etching, nor does the space between interconnects need to be filled with interlayer dielectrics. Therefore, this process contributes to the reduction rate of the number of manufacturing steps as the wiring aspect ratio increases and the number of wiring layers increases.

[0009]

The organic dielectric film has a significantly different film quality from the conventional inorganic dielectric film. Especially 0.18
An organic dielectric film containing fluorine having a relative dielectric constant of 2.5 or less, which is being considered for introduction into a semiconductor device having a minimum design rule of μm, is required to have improved adhesion with an underlayer or an upper layer.

The organic dielectric film generally has poor reactivity at the interface, and therefore has poor adhesion, leaving a problem of separation from the inorganic dielectric film and the metal wiring material. In particular, in the manufacturing process of a semiconductor device, mechanical stress, CMP, etc. from an underlayer, an inorganic dielectric film or metal wiring formed as an upper layer,
(Chemical Mechanical Polishing) or other mechanical processes, or CVD (Chemical Vapor Depos).
There are many opportunities to apply various stresses such as thermodynamic stress in the ition) process.

As a method for improving the adhesion of the organic dielectric film, there is a technique of forming an interface reinforcing layer such as a silane coupling agent on the surface of the underlayer or the surface of the organic dielectric film as an adhesion layer. However, it is known that in the manufacturing process of a semiconductor device, peeling prevention cannot be completely achieved only by forming such an adhesion layer.

The present invention has been made in view of such problems of the prior art. That is, an object of the present invention is to solve the problem of adhesion when forming an organic dielectric film and to provide a highly reliable method for manufacturing an electronic device.

[0013]

All of the conventional methods for improving the adhesion rely on only the intermolecular force at the interface, that is, the van der Waals force. In the present invention,
Further, high adhesion is intended to be obtained by utilizing the chemical bonding force at the interface.

That is, a method of manufacturing an electronic device according to the present invention is a method of manufacturing an electronic device having a step of forming an organic dielectric film on a substrate to be processed. The method is characterized by comprising a step of forming a dangling bond on the surface and a step of forming an organic dielectric film on the substrate to be processed on which the dangling bond is formed.

Further, another method of manufacturing an electronic device according to the present invention is as follows.
What is claimed is: 1. A method for manufacturing an electronic device, comprising: forming an organic dielectric film on a substrate to be processed.
An inorganic dielectric film of any one of O ₂ , Si ₃ N ₄ and SiO ₂ / Si ₃ N ₄ solid solution;
At least at the interface with the organic dielectric film, a step of forming an inorganic dielectric film rich in Si from the stoichiometric composition of the inorganic dielectric film, and forming an organic dielectric film on the inorganic dielectric film And a process.

Still another method of manufacturing an electronic device according to the present invention is a method of manufacturing an electronic device having a step of forming an organic dielectric film on a substrate to be processed.
Forming an inorganic dielectric film of any one of SiO ₂ , Si ₃ N ₄ and SiO ₂ / Si ₃ N ₄ solid solution; reverse sputtering the inorganic dielectric film to form a dangling bond on its surface; And forming an organic dielectric film on the inorganic dielectric film on which the dangling bonds are formed.

The electronic devices to which the present invention is applied include a highly integrated semiconductor device employing an organic dielectric film as an insulating film, a thin-film magnetic head device, a thin-film coil, a thin-film inductor and a micromachine.

[Operation] By reverse sputtering the surface of the substrate to be processed, which is the base for forming the organic dielectric film,
The chemical bond of the base material layer is cut, and an unpaired bond, that is, a dangling bond is formed. Dangling bonds are chemically active and exist as reaction sites on the surface of the substrate to be treated. On the other hand, the organic dielectric film is generally formed by a coating method such as spin coating, but the polymer in the coating solution has a reaction site to be cross-linked, and chemically bonds to the reaction site on the substrate to be treated, thereby firmly adhering. I do. Even when the organic dielectric film is formed by a plasma CVD method or the like, there is a reaction site in the precursor at the stage when the monomer is polymerized, and the chemical site is also chemically bonded to the reaction site on the side of the substrate to be processed, and firmly adheres.

On the other hand, SiO ₂ , Si ₃
An inorganic dielectric film such as a solid solution of N ₄ and SiO ₂ / Si ₃ N ₄ is formed, and at least an interface between the inorganic dielectric film and the organic dielectric film is Si-rich from the stoichiometric composition of the inorganic dielectric film. When formed as a simple inorganic dielectric film composition,
Also in this case, an active dangling bond is formed at the interface, and the adhesion to the organic dielectric film is improved.

[0020] SiO _2, Si ₃ N ₄ on the substrate to be processed
And an inorganic dielectric film such as a SiO ₂ / Si ₃ N ₄ solid solution. In this case, the inorganic dielectric film may have a stoichiometric composition. Thereafter, the same effect can be obtained by reverse sputtering this inorganic dielectric film and performing dangling bonding. In any case, the adhesion due to the formed chemical bond is almost equal to the tensile strength of the organic dielectric film itself, and can almost satisfy the adhesion required in the semiconductor device manufacturing process.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-integration semiconductor device will be described below as an example of an electronic device. A laminated structure of an organic dielectric film / an inorganic dielectric film, or an inorganic dielectric film / an organic dielectric film /
A process for forming an interlayer insulating film having a laminated structure of an inorganic dielectric film will be described as an example. The electronic device is not limited to a semiconductor device, but may be a thin film magnetic head, a magnetoresistive head,
The present invention can be applied to various electronic devices such as a thin film inductor, a thin film coil, and a micro machine.

FIG. 1 is a schematic cross-sectional view schematically showing a main part of a semiconductor device to which an electronic device manufacturing method according to the present invention is applied.
That is, in FIG. 1A, an organic dielectric film 12 and an inorganic dielectric film 11a are formed on a substrate 10 to be processed. 1B, an inorganic dielectric film 11a, an organic dielectric film 12, and an inorganic dielectric film 11b are formed on the substrate 10 to be processed.

The structure shown in FIG. 1 is a schematic cross-sectional view showing only the main parts related to the present invention.
0 and the upper structure on the inorganic dielectric film 11a are not shown. Also, the dimensions of each component are not proportional to the actual semiconductor device.

The substrate 10 to be processed is a semiconductor substrate itself on which a MOS transistor or the like is formed, or a substrate on which an interlayer insulating film and a lower wiring are formed. Among them, the interlayer insulating film is generally formed of a silicon oxide based insulating film. Silicon oxide based insulating film
For example, low pressure CVD using SiH ₄ and O ₂ gas as source gas
It is formed by a plasma CVD method using TEOS (Tetraethyl Orthosilicate) as a source gas. The interlayer insulating film may be formed of a low dielectric constant insulating film or a laminate of the low dielectric constant insulating film and an inorganic dielectric film such as SiO ₂ . By adopting a laminated structure with an inorganic dielectric film, a low-dielectric-constant insulating film generally having low mechanical strength can be reinforced, and the reliability of a semiconductor device can be improved. Of course, by employing a low dielectric constant insulating film, the capacitance between wirings can be reduced.

The lower wiring may be a trench wiring or a contact plug with an impurity diffusion layer formed in the semiconductor substrate. Further, a structure in which the groove wiring and the contact plug are integrated may be employed. In the case of a contact plug, a via contact plug facing the lower layer wiring may be used. For the lower wiring, a high melting point metal such as an Al alloy or W, a high melting point metal polycide, or Cu is generally employed. These may be barrier metal structures, in which case T
A laminated structure of aN and Cu, a laminated structure of Ta and Cu, a laminated structure of TiN and an Al—Cu alloy, or the like is employed. If Cu is used, a low-resistance wiring is obtained, and if an Al-Cu alloy is used, relatively low-resistance and low-cost wiring can be provided.

The substrate 10 to be processed is a CMP (Chemical Mec).
The surface is desirably formed flat by a hanical polishing method or the like.

The organic dielectric film 12 is made of an organic SOG (Spin O
n glass), polyaryl ether, polyimide, polyparaxylylene (trade name: parylene), polyquinoline, benzocyclobutene, polynaphthalene, fluororesin, a mixture thereof, or the like. Any organic dielectric film has a problem in adhesion with the inorganic dielectric film,
Usually, by applying an adhesive layer such as a silane coupling agent, a certain degree of adhesiveness is ensured. In the present invention, these adhesion layers may be used in combination.

In the present invention, in the example of the structure shown in FIG. 1A, a dangling bond is formed on the surface of the substrate 10 to be processed by reverse sputtering. By the reverse sputtering process, active sites are generated on the surface of the substrate 10 to be processed, and the adhesion to the organic dielectric film 12 by chemical bonding is ensured. Reverse sputtering is He, A
A rare gas such as r, Xe, Kr or Ne is used.
A reducing gas such as H ₂ or SiH ₄ may be added to these rare gases.

The reverse sputtering may be performed in the same film forming chamber as the apparatus for forming an inorganic dielectric film, but may be performed in a pretreatment chamber dedicated to reverse sputtering. In this case, the pre-processing chamber and the film forming chamber are connected by a vacuum gate valve to prevent re-oxidation in the middle of transfer when metal wiring is provided on the substrate to be processed.

In the structure shown in FIG. 1B, an organic dielectric film 12 is formed on an inorganic dielectric film 11a. This inorganic dielectric film 11a is made of SiO ₂ , Si ₃ N ₄
Alternatively, it is made of a SiO ₂ / Si ₃ N ₄ solid solution or the like. The surface of the inorganic dielectric film 11a is richer in Si than the stoichiometric composition of these inorganic dielectric films, and the dangling bonds are also formed, so that the adhesion to the organic dielectric film 12 is improved. ing. The inorganic dielectric film 11a may have a normal stoichiometric composition. In this case, since there is no active site, it is necessary to perform reverse sputtering.

The upper inorganic dielectric film 11b is also made of Si
It is made of O ₂ , Si ₃ N ₄ or SiO ₂ / Si ₃ N ₄ solid solution. The inorganic dielectric film 11b is formed to protect the surface of the organic dielectric film 12 and improve mechanical strength.
The inorganic dielectric film 11b also has low adhesion to the organic dielectric film 12. Therefore, it is desirable to reverse-sputter the surface of the organic dielectric film 12 before forming the inorganic dielectric film 11b. Alternatively, it is desirable that at least the interface of the inorganic dielectric film 11b in contact with the organic dielectric film 12 has a composition richer than that of the stoichiometric composition. The reason is that the lower inorganic dielectric film 11a and the organic dielectric film 1
This is the same as the relationship with 2.

As a method for forming the inorganic dielectric films 11a and 11b, a vapor phase growth method such as a plasma CVD method or a sputtering method which can be formed at a low temperature is employed. The sputtering method is SiO ₂ , Si ₃ N ₄ or SiO ₂ / Si ₃ N ₄
In addition to the method using a solid solution as a target, a reactive sputtering method using silicon as a target and adding N ₂ , NH ₃ or O ₂ to Ar is employed. At this time, N ₂
By controlling the amount of addition of NH ₃ or O ₂ ,
The composition of the inorganic dielectric films 11a and 11b can be controlled.

The inorganic dielectric films 11a and 11b can also be formed by a plasma CVD method. When a plasma CVD apparatus having a high-density plasma generation source capable of obtaining an electron density of about 1 × 10 ¹⁰ / cm ³ or more is used as a plasma generation source for uniformity or when metal wiring is provided on a substrate to be processed. It is preferable from the viewpoint of preventing oxidation. High density plasma C
The VD apparatus can generate plasma at a high degree of vacuum of about 1 × 10 ⁻³ Torr, and has good consistency with the ultimate vacuum degree of the turbo molecular pump (about 1 × 10 ⁻⁶ Torr). These high-density plasma CVD devices include ECR (Electr
on Cyclotron Resonance) Plasma CVD equipment, ICP
(Inductively Coupled Plasma) CVD apparatus, helicon wave plasma CVD apparatus and the like are exemplified. Further, it is desirable to use a plasma CVD apparatus capable of independently controlling a power supply for generating plasma and a power supply for applying a substrate bias. Thus, reverse sputtering can be performed in the same film forming chamber. As the plasma CVD apparatus, an ordinary parallel plate type plasma CVD apparatus can be used.

The semiconductor device shown in the schematic cross-sectional view of FIG. 1 is in the process of being manufactured. If necessary, an upper metal wiring or an interlayer insulating film is formed, and finally a passivation film or the like is formed. Complete the device.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing an electronic device according to the present invention will be described.
2 to 4 taking a method of manufacturing a highly integrated semiconductor device as an example.
The embodiment will be described in more detail with reference to FIG.
However, this embodiment is merely an example, and the present invention is not limited to this embodiment.

Embodiment 1 In this embodiment, a substrate to be processed is reverse-sputtered to form a dangling bond, and an organic dielectric film is formed on the substrate to be formed with the dangling bond by a coating method. This is an example of forming and improving adhesion.

FIG. 2A: Substrate 10 shown here
Is formed by forming a first-layer interlayer insulating film 5, a first-layer wiring 6, a second-layer interlayer insulating film 7, a second-layer wiring 8, and the like on a semiconductor substrate 1 of Si or the like. These first interlayer insulating film 5, second
The interlayer insulating film 7, the first-layer wiring 6, the second-layer wiring 8, and the like can be manufactured by a known semiconductor device manufacturing process. Second-layer interlayer insulating film 7 and second-layer wiring 8
Is desirably planarized. The planarization can be performed by a CMP (Chemical Mechanical Polishing) process in the Damascene or Dual Damascene process. STI (Sh
allow Trench Isolation (MOS) and MOS (Metal Oxide Semiconducto)
r) An impurity diffusion layer 3, a gate electrode 4, and the like formed by a process or the like are formed.

FIG. 2 (b): The substrate 10 shown in FIG. 2 (a) is replaced with a substrate bias applying type ECR (Electron Cyc
The substrate is carried into a plasma CVD apparatus, and silicon nitride is formed to have a thickness of 100 nm as the inorganic dielectric film 11a. This silicon nitride has a stoichiometric composition of Si
Having a Si-rich composition as compared to the ₃ N _4.

Inorganic dielectric film 11a Plasma CVD conditions SiH ₄ 25 to 50 sccm N ₂ 25 to 50 sccm Pressure 1 to 10 mTorr Microwave power 1 to 3 kW Temperature 200 to 400 ° C. The film forming conditions are SiH ₄ and N _2. Is, for example, 1: 1.
However, the range of about 1: 0.5 to 1: 2.0 is selected. Thus, a silicon nitride-based insulating film having a higher Si content than the stoichiometric composition of Si ₃ N ₄ is formed. The film formation rate is about 100 nm / min, and the film thickness control is relatively easy.

The film may be formed over the entire thickness of the inorganic dielectric film 11a under these film forming conditions, but only in the range of about 5 to 50 nm in the vicinity of the interface with the organic dielectric film to be formed as the upper layer, the Si-rich film is formed. It may be changed depending on the film forming conditions. That is,
Since the portion not in contact with the organic dielectric film does not directly affect the adhesion, this portion may form stoichiometric Si ₃ N ₄ . Plasma CVD of stoichiometric Si ₃ N ₄
Conditions, for example, a flow rate ratio of SiH ₄ and N ₂ 1: 2~1:
It is about 10. NH ₃ or N as a nitriding agent in place of N _2
2 H ₃ may be used. However, these have a nitriding action of N ₂
Since it is stronger, it is desirable to use N ₂ when a metal wiring which is easily nitrided is formed on the substrate 10 to be processed.

Thereafter, an upper organic dielectric film may be formed immediately. However, in this embodiment, the inorganic dielectric film 11a is further formed.
Is subjected to reverse sputtering to remove a film thickness of about 1 nm to 10 nm. By this reverse sputtering process, dangling bonds are more reliably formed on the surface of the inorganic dielectric film 11a. Ar 100 to 300 sccm Pressure 1 to 10 mTorr μ wave power 1 to 3 kW Bias power 500 W Temperature Room temperature to 400 ° C. In addition to Ar, a rare gas such as Ne, Xe, Kr or an inert gas such as N ₂ is used. You may.

FIG. 3C: Next, an organic dielectric film 12 is formed to a thickness of 500 nm by a usual spin coater. As a material for the organic dielectric film 12, a coating solution of a polyaryl ether is applied to the inorganic dielectric film 11 shown in FIG.
a. Drop about 3cc-5cc on a, 2000rpm-4
Spread evenly at 000 rpm. After this, 50 ° C to 250 ° C
For 1 to 3 minutes, and curing is performed at 300 ° C. to 450 ° C. in a nitrogen gas atmosphere under reduced pressure or normal pressure.

Polyaryl ether is an organic dielectric film having a low dielectric constant but poor adhesion. However, in the present example, since dangling bonds were formed on the surface of the underlying inorganic dielectric film 11a, strong adhesion due to chemical bonding was obtained. Of course, it is also effective to treat the surface of the underlying inorganic dielectric film 11a with a normal interface reinforcing agent such as a silane coupling agent.

FIG. 3D: Thereafter, the substrate shown in FIG. 3C is carried into a parallel plate type plasma CVD apparatus, and a silicon oxynitride film is formed on the organic dielectric film 12 as an inorganic dielectric film 11b. It was formed to a thickness of 50 nm. Inorganic dielectric film 11b Plasma CVD conditions SiH ₄ 50 to 150 sccm NH ₃ 0 to 100 sccm N ₂ O 500 to 1500 sccm Pressure 0.5 to 1.5 Torr RF power 0.5 to 1 kW Temperature 200 to 350 ° C.

This plasma CVD condition is a plasma CVD condition in a reducing atmosphere using N ₂ O as an oxynitriding agent. If the flow rates of N ₂ O and NH ₃ are reduced at the initial stage of the formation of the inorganic dielectric film 11 b to form a Si-rich oxynitride film, the adhesion to the organic dielectric film 12 is improved. Alternatively, before the inorganic dielectric film 11b is formed, the organic dielectric film 12 may be subjected to reverse sputtering to improve the adhesion.

Higher order silanes such as Si ₂ H ₅ may be used instead of SiH ₄ . As the oxidizing gas, a weak oxidizing agent such as H ₂ O can be used. As a nitriding agent, N ₂ H
₄ or N ₂ may be used, but these nitriding agents need not always be added. As the inorganic dielectric film 11b, in addition to silicon oxynitride, silicon oxide or silicon nitride may be used. In the case of silicon nitride, since the dielectric constant is high, the capacitance between wirings increases.

FIG. 4 (e): The subsequent steps are the inorganic dielectric film 11b, the organic dielectric film 12, and the inorganic dielectric film 11a.
A semiconductor device is completed through a step of forming a wiring groove or via hole, a step of forming a third layer wiring 9, and finally a step of forming a final passivation film and a pad electrode. The third layer wiring 9 is desirably formed of low-resistance Cu.

Embodiment 2 In this embodiment, a substrate to be processed is reverse-sputtered to form a dangling bond, and an organic dielectric film is formed on the substrate on which the dangling bond is formed by a plasma CVD method. This is an example in which the adhesion is improved. This step will be described with reference to FIGS.

FIG. 2A: The substrate 10 to be processed is formed on the semiconductor substrate 1 of Si or the like, as in the first embodiment, on the first-layer interlayer insulating film 5, the first-layer wiring 6, and the second-layer interlayer insulating film. 7, the second layer wiring 8 and the like are formed. The first-layer interlayer insulating film 5, the second-layer interlayer insulating film 7, the first-layer wiring 6, the second-layer wiring 8, and the like can all be manufactured by a known semiconductor device manufacturing process. It is desirable that the surfaces of the second-layer interlayer insulating film 7 and the second-layer wiring 8 be flattened. Planarization is performed by CMP (Chemical Mechanical Polish) in Damascene or Dual Damascene process.
ing). The semiconductor substrate 1 includes
An element isolation region 2 formed by an STI (Shallow Trench Isolation) process or the like, a MOS (Metal Oxide Se
An impurity diffusion layer 3, a gate electrode 4, and the like formed by a semiconductor process or the like are formed.

FIG. 2 (b): The substrate to be processed 10 shown in FIG. 2 (a) is mounted on a substrate bias applying type ECR (Electron Cyclo).
(Tron Resonance) The substrate is carried into a plasma CVD apparatus, and silicon oxynitride is formed in a thickness of 100 nm as the inorganic dielectric film 11a. This silicon oxynitride has a Si-rich composition as compared with the stoichiometric composition SiO ₂ / Si ₃ N ₄ .

Inorganic dielectric film 11a Plasma CVD conditions SiH ₄ 25 to 50 sccm N ₂ O 25 to 50 sccm Pressure 1 to 10 mTorr μ wave power 1 to 3 kW Temperature 200 to 400 ° C. The film forming conditions are SiH ₄ and N The flow ratio of ₂ O is, for example, 1:
1, but a range of about 1: 0.5 to 1: 2.0 is selected. Thus, a silicon oxynitride-based insulating film having a higher Si content than the stoichiometric composition of SiO ₂ / Si ₃ N ₄ is formed. The film formation rate is about 100 nm / min, and the film thickness control is relatively easy.

The film may be formed over the entire thickness of the inorganic dielectric film 11a under these film forming conditions, but only in the range of about 5 to 50 nm in the vicinity of the interface with the organic dielectric film to be formed as an upper layer, the Si-rich layer is formed. It may be changed depending on the film forming conditions. That is,
Since the portion not in contact with the organic dielectric film has no direct relation to the adhesion, this portion has a stoichiometric composition of SiO ₂ / Si ₃ N
₄ may be formed. Stoichiometric SiO ₂ / Si ₃
The plasma CVD conditions for the N ₄ solid solution are SiH ₄ and N ₂ O
Is, for example, about 1: 2 to 1:10.

As the inorganic dielectric film 11a, silicon oxide or silicon nitride may be used instead of silicon oxynitride. In the case of silicon oxide, O ₂ may be used instead of N ₂ O. However, since O ₂ is oxidizing action is stronger than N ₂ O, if prone metal wire is oxidized to the processed substrate 10 is formed using the N ₂ O, it is desirable that the silicon oxynitride.

Thereafter, an upper organic dielectric film may be formed immediately, but in this embodiment, the inorganic dielectric film 11a is further formed.
Is subjected to reverse sputtering to remove a film thickness of about 1 nm to 10 nm. By this reverse sputtering process, dangling bonds are more reliably formed on the surface of the inorganic dielectric film 11a. Ar 100 to 300 sccm Pressure 1 to 10 mTorr μ wave power 1 to 3 kW Bias power 0.3 to 1 kW Temperature Room temperature to 400 ° C. In addition to Ar, rare gases such as Ne, Xe, Kr, and N ₂ An active gas may be used.

FIG. 3C: Next, in this embodiment, the organic dielectric film 12 is formed by the plasma CVD method. FIG.
The sample in the state of (b) is carried into an ECR plasma CVD apparatus, and a fluororesin-based organic dielectric film is deposited under the following conditions.
It was formed to a thickness of 0 nm. Organic dielectric film 12 plasma CVD conditions _{C 4 F 8 100 sccm C 2} H 2 0~10 sccm C 2 H 4 0~10 sccm Pressure 1 to 10 mTorr mu wave power 0.5 to 2 kW bias power 0.5 3 kW temperature normal temperature

Under these plasma CVD conditions, the fluororesin-based organic dielectric film 12 is formed. In order to enhance the adhesion to the inorganic dielectric films 11a and 11b, C ₄ F is used in the initial stage and the latter stage of the film formation. ₈ supply stopped, C ₂ H ₂ and C
It is desirable to perform plasma CVD only with ₂ H ₄ . In this case, 50 sccm each of C ₂ H ₂ and C ₂ H ₄
Flow rate.

FIG. 3D: Thereafter, the substrate shown in FIG. 3C was carried into a parallel plate type plasma CVD apparatus, and a silicon oxynitride film having a thickness of 50 nm was formed as the inorganic dielectric film 11b. Inorganic dielectric film 11b Plasma CVD conditions SiH ₄ 50 to 150 sccm NH ₃ 0 to 100 sccm N ₂ O 500 to 1500 sccm Pressure 0.5 to 1.5 Torr RF power 0.5 to 1 kW Temperature 200 to 350 ° C.

This plasma CVD condition is a plasma CVD condition in a reducing atmosphere using N ₂ O as an oxynitriding agent. If the flow rates of N ₂ O and NH ₃ are reduced at the initial stage of the formation of the inorganic dielectric film 11 b to form a Si-rich oxynitride film, the adhesion to the organic dielectric film 12 is improved. Alternatively, before the inorganic dielectric film 11b is formed, the organic dielectric film 12 may be subjected to reverse sputtering to improve the adhesion.

Higher order silanes such as Si ₂ H ₆ may be used instead of SiH ₄ . As the oxidizing gas, a weak oxidizing agent such as H ₂ O can be used. As a nitriding agent, N ₂ H
₄ or N ₂ may be used, but these nitriding agents need not always be added. As the inorganic dielectric film 11b, in addition to silicon oxynitride, silicon oxide or silicon nitride may be used. In the case of silicon nitride, since the dielectric constant is high, the capacitance between wirings increases.

FIG. 4E: Subsequent processes are performed for the inorganic dielectric film 11b, the organic dielectric film 12, and the inorganic dielectric film 11a.
A semiconductor device is completed through a step of forming a wiring groove or via hole, a step of forming a third layer wiring 9, and finally a step of forming a final passivation film and a pad electrode. The third layer wiring 9 is preferably formed of low-resistance Cu.

According to the present embodiment, it is possible to enhance the adhesion of the organic dielectric film formed by the plasma CVD method.

Although the present invention has been described with reference to the two embodiments, reverse sputtering is performed in addition to Ar, Ne, Kr, Xe,
A rare gas such as Rn, an inert gas such as N ₂ , or a mixed gas thereof can be used. The reverse sputtering apparatus has an ECR plasma generation source and an IC
Various devices such as a P generation source, a helicon wave plasma generation source, and a parallel plate type plasma processing apparatus can be used.

The present invention is particularly suitably applied to an electronic device employing an organic dielectric film having a low dielectric constant as an interlayer insulating film. In addition to the examples, polyimide, organic SOG, benzocyclobutene, polynaphthalene, Good results can be obtained by applying to all known organic dielectric films such as polyparaxylylene, Teflon (trade name) and Cytop (trade name). These are all low dielectric constant materials that are desirable as insulating films for highly integrated electronic devices.

The method of manufacturing an electronic device according to the present invention is suitably used in the step of forming an interlayer insulating film of a highly integrated semiconductor device. The present invention is effective when applied to a method of manufacturing various electronic devices such as a magnetoresistive head, a thin film inductor, a thin film coil, and a micromachine.

[0065]

As is apparent from the above description, according to the method for manufacturing an electronic device of the present invention, the adhesion which is a problem when forming an organic dielectric film as an interlayer insulating film is improved, and the peeling is improved. It is possible to provide a highly reliable electronic device without fear.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view schematically showing a main part of a semiconductor device to which an electronic device manufacturing method according to the present invention is applied.

FIG. 2 is a schematic cross-sectional view showing a manufacturing process of a highly integrated semiconductor device as an example of a method of manufacturing an electronic device according to the present invention.

FIG. 3 is a schematic cross-sectional view showing a manufacturing process of a highly integrated semiconductor device as an example of a method of manufacturing an electronic device of the present invention;
3 shows a step that follows the step of FIG.

FIG. 4 is a schematic cross-sectional view showing a manufacturing process of a highly integrated semiconductor device as an example of a method of manufacturing an electronic device according to the present invention;
4 shows a step that follows the step of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor base, 2 ... Element isolation region, 3 ... Diffusion layer, 4 ... Gate electrode, 5 ... First interlayer insulating film, 6 ... First
Layer wiring, 7: Second layer interlayer insulating film, 8: Second layer wiring, 9 ...
Third layer wiring, 10: substrate to be processed, 11a, 11b: inorganic dielectric film, 12: organic dielectric film

Continued on front page F-term (reference) BF29 BF30 BH20 BJ02

Claims (3)

[Claims] 1. A method for manufacturing an electronic device, comprising a step of forming an organic dielectric film on a substrate to be processed, wherein the substrate to be processed is reverse-sputtered to form a dangling bond on the surface of the substrate to be processed. And on the substrate to be processed on which the dangling bond is formed,
Forming an organic dielectric film. 2. A method for manufacturing an electronic device, comprising a step of forming an organic dielectric film on a substrate to be processed, wherein SiO ₂ , Si ₃ N ₄ and Si are formed on the substrate to be processed.
An inorganic dielectric film of any one of O ₂ / Si ₃ N ₄ solid solution, and at least at the interface with the organic dielectric film, which is Si-richer than the stoichiometric composition of the inorganic dielectric film A method for manufacturing an electronic device, comprising: a step of forming an inorganic dielectric film; and a step of forming an organic dielectric film on the inorganic dielectric film. 3. A method of manufacturing an electronic device, comprising a step of forming an organic dielectric film on a substrate to be processed, comprising: forming SiO ₂ , Si ₃ N ₄ and Si on the substrate to be processed.
Forming an inorganic dielectric film of any one of O ₂ / Si ₃ N ₄ solid solution; reverse sputtering the inorganic dielectric film to form a dangling bond on the surface of the inorganic dielectric film; Forming an organic dielectric film on the inorganic dielectric film on which the dangling bonds have been formed.