JPH09246377A - Manufacture of semiconductor device and semiconductor manufacture device used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an insulating film formed through a high-density plasma CVD method and a metal interconnection film to be surely bonded together. SOLUTION: The surface 2a of a first interconnection layer 2 of tungsten or the like formed on a semiconductor wafer 1 is etched as far as 200Å or so through an argon sputtering method, and the oxidized surface 2a of the first interconnection layer 2 is removed. By this setup, an insulating film 11 is formed after the activated surface 2b of the interconnection layer 2 is exposed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device and a semiconductor manufacturing apparatus used for the method, and more particularly,
High-density plasma CVD (Chemical Vapor)
The present invention relates to a technique effectively applied to the adhesion of an insulating film formed by the deposition and a metal film wiring.

[0002]

2. Description of the Related Art According to a study made by the present inventor, for example, as one of methods for forming a thin film such as an insulating film, CVD is used.
There is a high-density plasma CVD method that introduces plasma chemistry into the technology.

This high-density plasma CVD is a few mtor.
Under a low pressure of r, a high-density plasma having an electron density of about 10 ¹¹ cm ^-3 is generated, and a high frequency bias is applied to the semiconductor wafer to simultaneously perform film formation and sputter etching.

Further, in high density plasma CVD, a semiconductor wafer at about room temperature is transferred to a film forming chamber, and a film is directly formed on a metal wiring such as aluminum formed on the semiconductor wafer.

Incidentally, as an example in which this kind of semiconductor manufacturing apparatus is described in detail, there is "Low Temperature Plasma Material Chemistry" P35-P40 issued by Yoshihito Nagata (published by Sangyo Tosho Co., Ltd.) on March 18, 1994, This document describes a plasma CVD apparatus configuration and method.

[0006]

However, the present inventor has found that the above-mentioned film forming method by high-density plasma CVD has the following problems.

That is, since the semiconductor wafer is heated by the high density plasma during the film formation by the high density plasma CVD, the stage for mounting the semiconductor wafer is equipped with a cooling mechanism, and the semiconductor wafer is film-formed while being cooled. Is being done.

Therefore, the stage is not provided with heating means for heating the semiconductor wafer, and the semiconductor wafer is at about room temperature at the initial stage of film formation, and the reaction is activated to form the film on the semiconductor wafer at about room temperature. However, there is a possibility that the adhesiveness between the silicon oxide film, which is an insulating film, and the metal wiring may not be sufficient.

Further, when the semiconductor wafer is heated by the high density plasma, thermal stress and film stress may be applied to the semiconductor wafer, and the silicon oxide film and the metal wiring may be separated.

As a result, there are problems that a film having a large stress cannot be deposited on the upper layer of the semiconductor wafer and that the yield of semiconductor device production is reduced.

An object of the present invention is to provide a method of manufacturing a semiconductor device and a semiconductor device used therefor, which can reliably bond an insulating film formed by high density plasma CVD and a metal film wiring formed on a semiconductor wafer. To provide a device.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0013]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the semiconductor device manufacturing method of the present invention is to form an insulating film by high density plasma CVD after etching the surface of the metal film wiring formed on the semiconductor wafer.

As a result, by forming an insulating film on the surface of the etched metal wiring film, the surface of the metal wiring film is oxidized at the initial stage of formation of the insulating film and becomes an adhesive layer to bond the metal wiring film and the insulating film. It is possible to significantly improve the sex.

The semiconductor device manufacturing method of the present invention is
The high density plasma C is used to etch the surface of the metal film wiring.
It is carried out in a reaction chamber in which an insulating film is formed by VD.

As a result, the surface of the metal film wiring can be easily etched in a short time, and the high density plasma C
Only the device that performs VD does not require the addition of another device.

Further, in the method for manufacturing a semiconductor device of the present invention, the etching of the surface of the metal film wiring performed in the reaction chamber is performed by ion sputtering using an inert gas.

Since this can be carried out by using the carrier gas at the time of performing the high density plasma CVD, the surface of the metal film wiring can be easily etched at a low cost.

Further, a method of manufacturing a semiconductor device according to the present invention
Before forming an insulating film formed on a semiconductor wafer, the semiconductor wafer is preheated in a vacuum.

As a result, the metal wiring film on the semiconductor wafer can be improved in adhesiveness at the interface between the surface of the metal wiring film and the insulating film by forming the metal wiring film from an active state having thermal energy.

Further, in the method for manufacturing a semiconductor device of the present invention, the semiconductor wafer is preheated in an atmosphere of hydrogen gas or an inert gas before forming the insulating film formed on the semiconductor wafer.

As a result, the surface of the metal wiring film is activated and modified, and an interface serving as an adhesive layer is easily formed during film formation, and the surface serves as an adhesive layer to bond the insulating film and the metal wiring film. It is possible to significantly improve the sex.

Further, the semiconductor manufacturing apparatus of the present invention is provided with a preheating chamber for preheating a semiconductor wafer in the vicinity of a reaction chamber for forming an insulating film by high density plasma CVD.

As a result, after preheating the semiconductor wafer,
The insulating film can be immediately formed by high-density plasma CVD.

As described above, the adhesiveness between the metal wiring film and the insulating film formed by the high density plasma CVD is significantly improved, so that the yield of semiconductor device manufacturing can be improved.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a semiconductor device after formation of an insulating film according to Embodiment 1 of the present invention, and FIGS. 2 and 3 are insulating films according to Embodiment 1 of the present invention. 5 is a process explanatory diagram in the step of forming a film, FIG. 4 is a configuration diagram of a high density plasma CVD apparatus according to the first embodiment of the present invention,
Is a high density plasma CVD according to the first embodiment of the present invention.
FIG. 6 is a process flowchart diagram in the insulating film forming step according to FIG.

In the first embodiment, as shown in FIG. 1, the semiconductor wafer 1 on which the semiconductor device is formed is subjected to, for example, a MOS (Metal Oxide) by a pre-process.
Various semiconductor elements such as a semiconductor transistor T are formed, and the wiring (metal film wiring) 2 which is the first wiring layer is formed of tungsten or the like on these semiconductor elements.

The wiring 2 may be made of a material such as aluminum, aluminum alloy, titanium nitride, or a laminated film thereof, which can form the wiring 2.

Next, the MOS transistor T shown in FIG.
Is an N-type MOS transistor, and diffusion layers 4 and 4a, which are semiconductor regions into which phosphorus or the like is introduced, are formed at predetermined positions in a P-WELL 3 formed on the semiconductor wafer 1.

A gate electrode 6 made of polysilicon or the like is provided above the channel portion located between the diffusion layers 4 and 4a via an insulating film 5 made of silicon dioxide or the like.
And a cap insulating film 7 is formed on the gate electrode 6.

The wiring 2 described above is formed on the diffusion layer 4, and the diffusion layer 4 and the wiring 2 are connected by a predetermined connection hole, and silicon dioxide or the like is formed on the other portions. An insulating film 8 made of is formed.

Further, the formed MOS transistor T
A field insulating film 9 for separating the elements is formed at the end of the channel insulating film 9. Below the field insulating film 9, a channel stopper 10 made of silicon dioxide or the like for electrically insulating adjacent elements is formed. , For example, LOC
OS (Local Oxidation of Sil)
Ionic) method or the like.

On the semiconductor wafer 1 on which various semiconductor elements such as the MOS transistor T and the first wiring layer such as the wiring 2 are formed, an insulating film 11 such as a silicon oxide film is formed.

Further, the high density plasma CVD apparatus (semiconductor manufacturing apparatus) 12 for forming the insulating film 11 which is an insulating film,
Inductive coupling method, helicon wave method or ECR (Ele
stric Cyclotron Resonanc
e) a high-density plasma is generated using one of the methods, and as shown in FIG. 4, the load-lock chamber 13 serving as an unloading / transporting unit of the semiconductor wafer (FIG. 1), and the semiconductor transported to the load-lock chamber 13. It is configured by a transfer chamber 14 for transferring the wafer 1 and a film forming chamber (reaction chamber) 15 for forming a film.

Next, the operation of the present embodiment will be described with reference to FIG.
~ Process explanatory diagram of FIG. 3, high-density plasma CVD of FIG.
This will be described with reference to the block diagram of the device 12 and the process flowchart of FIG.

First, the semiconductor wafer 1 on which various semiconductor elements such as the MOS transistor T shown in FIG. 2 and the first wiring layer such as the wiring 2 are formed is loaded into the load lock chamber 13 and provided in the transfer chamber 14. Film forming chamber 1 provided in the high-density plasma CVD apparatus 12 by the transport mechanism described above.
The sheet is conveyed to No. 5 (step S101).

Then, the semiconductor wafer 1 is transferred to the film forming chamber 15 at a predetermined position, and the film forming chamber 15 is moved several mtor by a vacuum pump provided in the high density plasma CVD apparatus 12.
Vacuuming is performed until the pressure becomes as low as r (step S1).
02).

After that, for example, argon gas is introduced into the film forming chamber 15 and the semiconductor wafer 1 is subjected to RF (Radio).
A power source bias is applied by a frequency power source to generate a high-density plasma having an electron density of about 10 ¹¹ cm ⁻³ , and argon sputter etching for implanting ions into the surface 2 a of the semiconductor wafer 1 is performed by the plasma (step S 103). Wiring 2 in the first wiring layer shown in FIG.
The surface 2a is etched.

The wiring 2 is etched until the surface 2a of the wiring 2 is etched to about 200 Å, and the surface 2a of the wiring 2 is activated, that is, the oxidized surface of the wiring 2 is removed.

Then, the surface 2a oxidized by etching is removed, and the activated surface 2b of the wiring 2 is exposed as shown in FIG.

Next, when the etching of the wiring 2 is completed,
Silane gas and oxygen gas are introduced together with argon gas into the reaction chamber 15 of the high-density plasma CVD apparatus 12 (step S104), and the power source is biased again by the RF power source to generate a high-density plasma with an electron density of about 10 ¹¹ cm ^-3. Are formed to form a film by high-density plasma CVD (step S105), and as shown in FIG. 1, an insulating film 11 is formed on the surface 2b of the wiring 2.

Therefore, the insulating film 11 is formed on the surface 2a of the wiring 2.
Will be formed on the exposed surface 2b.

As a result, according to the first embodiment, the surface 2b of the wiring 2 is oxidized at the initial stage of the formation of the insulating film 11, so that the oxidized surface 2b serves as an adhesive layer.
The adhesiveness between the wiring 1 and the wiring 2 can be significantly improved.

(Embodiment 2) FIG. 6 is a block diagram of a high-density plasma CVD apparatus according to Embodiment 2 of the present invention, and FIGS. 7 and 8 are steps of forming an insulating film according to Embodiment 2 of the present invention. 9A and 9B are process flowcharts in the process of forming an insulating film by high-density plasma CVD according to the second embodiment of the present invention.

In the second embodiment, as shown in FIG. 6, a heating chamber (preheating chamber) 16 for heating the semiconductor wafer 1 is provided adjacent to the transfer chamber 14 in the high density plasma CVD apparatus 12a. There is.

The process flow in the high density plasma CVD apparatus 12a will be described with reference to the process explanatory diagrams of FIGS. 7 and 8 and the process flow chart of FIG.

First, the semiconductor wafer 1 on which various semiconductor elements such as the MOS transistor T shown in FIG. 7 and the first wiring layer such as the wiring 2 are formed is loaded into the load lock chamber 13 and provided in the transfer chamber 14. By the transport mechanism described above, the transport is performed to the heating chamber 16 provided in the high-density plasma CVD apparatus 12a (step S201).

The inside of the heating chamber 16 is 300 ° C. to 3 ° C.
It is heated to about 50 ° C. and is evacuated to a predetermined degree of vacuum by a vacuum pump. Further, an inert gas such as nitrogen gas or argon gas or an annealing gas such as hydrogen gas is introduced into the heating chamber.

Then, the semiconductor wafer 1 transferred to the heating chamber 16 is subjected to the above-mentioned 300 in the annealing gas of a predetermined concentration.
The surface 2a of the wiring 2 is activated by annealing while being heated to a temperature of about [deg.] C. to 350 [deg.] C. (step S202).

Thereafter, the semiconductor wafer 1 whose surface 2a has been activated is again moved by several mtor by the transfer mechanism of the transfer chamber 14.
The film is transferred to the film forming chamber 15 which has a low pressure of about r (step S203).

Next, silane gas and oxygen gas together with argon gas are introduced into the reaction chamber 15 of the high-density plasma CVD apparatus 12a (step S204), and a power source bias is applied by an RF power source to have an electron density of about 10 ¹¹ cm ^-3. The high density plasma is generated to form a film by high density plasma CVD (step S205), and an insulating film 11 such as a silicon oxide film is formed as shown in FIG.

Therefore, the wiring 2 in the semiconductor wafer 1
Is in an active state having thermal energy, and by forming a film from this state, an intermediate layer is formed at the interface between the surface 2a of the wiring 2 and the insulating film 11, and the adhesiveness is improved. Become.

Further, the surface 2a of the wiring 2 is annealed and activated in an atmosphere of an inert gas or a hydrogen gas to modify the surface 2a of the wiring 2 and to form a film in the high density plasma CVD apparatus 12a. It is possible to make a state in which an interface serving as an adhesive layer is easily formed.

As a result, in the second embodiment, the semiconductor wafer 1 is annealed in the heating chamber 16 in the atmosphere of the inert gas or the hydrogen gas, so that the adhesive layer is more easily formed and the surface 2a is bonded. As a layer, the adhesiveness between the insulating film 11 and the wiring 2 can be significantly improved.

The invention made by the present inventor has been specifically described above based on the embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it can be changed.

[0058]

Advantageous effects obtained by typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows.

(1) According to the present invention, the adhesion between the metal wiring film and the insulating film can be significantly improved by forming the insulating film after etching the surface of the metal wiring film.

(2) Further, in the present invention, the surface of the metal film wiring is etched in the reaction chamber where the insulating film is formed by high density plasma CVD, so that the metal film wiring can be easily carried out in a short time with a simple device structure. The surface of the can be etched.

(3) Furthermore, in the present invention, the surface of the wiring and the insulating film are preheated in a vacuum or in an atmosphere of hydrogen gas or an inert gas before forming the insulating film formed on the semiconductor wafer. The adhesiveness of the interface with the can be improved.

(4) According to the present invention, the above (1)
By (3) to (3), the adhesiveness between the metal wiring film and the insulating film formed by high-density plasma CVD is significantly improved, so that the yield of semiconductor device manufacturing can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device after forming an insulating film according to a first embodiment of the present invention.

FIG. 2 is a process explanatory diagram in the insulating film forming step according to the first embodiment of the present invention.

FIG. 3 is a process explanatory diagram in the process of forming the insulating film according to the first embodiment of the present invention.

FIG. 4 is a high-density plasma C according to the first embodiment of the present invention.
It is a block diagram of a VD apparatus.

FIG. 5 is a high-density plasma C according to the first embodiment of the present invention.
It is a process flowchart figure in the formation process of the insulating film by VD.

FIG. 6 is a high-density plasma C according to the second embodiment of the present invention.
It is a block diagram of a VD apparatus.

FIG. 7 is a process explanatory diagram in the process of forming an insulating film according to the second embodiment of the present invention.

FIG. 8 is a process explanatory view in the insulating film forming step according to the second embodiment of the present invention.

FIG. 9 is a high-density plasma C according to the second embodiment of the present invention.
It is a process flowchart figure in the formation process of the insulating film by VD.

[Explanation of symbols]

 1 semiconductor wafer 2 wiring (metal film wiring) 2a surface 2b surface 3 P-WELL 4 diffusion layer 4a diffusion layer 5 insulating film 6 gate electrode 7 cap insulating film 8 insulating film 9 field insulating film 10 channel stopper 11 insulating film 12 high density Plasma CVD apparatus (semiconductor manufacturing apparatus) 12a High density plasma CVD apparatus (semiconductor manufacturing apparatus) 13 Load lock chamber 14 Transfer chamber 15 Film forming chamber (reaction chamber) 16 Heating chamber (preheating chamber) T MOS transistor

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Claims (6)

[Claims] 1. A method of manufacturing a semiconductor device, wherein an insulating film is formed on a semiconductor wafer having metal film wiring formed thereon by high-density plasma CVD, wherein the insulating film is formed immediately after etching the surface of the metal film wiring. A method of manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the surface of the metal film wiring is etched in a reaction chamber where an insulating film is formed by high density plasma CVD. . 3. The method for manufacturing a semiconductor device according to claim 2, wherein the etching of the surface of the metal film wiring performed in the reaction chamber is ion sputtering using an inert gas. Production method. 4. A method of manufacturing a semiconductor device in which an insulating film is formed on a semiconductor wafer on which metal film wiring is formed by high-density plasma CVD, wherein the semiconductor wafer is preliminarily vacuumed before the insulating film is formed. A method for manufacturing a semiconductor device, which comprises heating. 5. A method of manufacturing a semiconductor device, wherein an insulating film is formed on a semiconductor wafer having metal film wiring formed thereon by high-density plasma CVD, wherein the semiconductor wafer is hydrogen gas or inert before forming the insulating film. A method of manufacturing a semiconductor device, comprising preheating in a gas atmosphere. 6. A semiconductor manufacturing apparatus for forming an insulating film on a semiconductor wafer on which metal film wiring is formed by high density plasma CVD, wherein the semiconductor wafer is provided in the vicinity of a reaction chamber where the insulating film is formed by high density plasma CVD. A semiconductor manufacturing apparatus comprising a preheating chamber for preheating.