JP2002083783A - Rf-sputtering device and manufacturing method for semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an RF sputtering device and a manufacturing method for semiconductor device, with which the release of a coating film on a stage can be suppressed in RF sputtering. SOLUTION: This RF sputtering device is a device for applying RF sputtering to a wafer 21. This RF sputtering device is provided with a stage 22, which is located inside an RF chamber, for placing the wafer 21 and a material film 24, with which the outer periphery of the upper surface of this stage is coated, having resistance to RF sputtering and to be positioned on the outer periphery of the wafer, when the wafer is placed on the upper surface of the stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RF sputtering apparatus for performing an RF sputtering process on an object to be processed and a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art A conventional RF sputtering apparatus will be described below. A wafer stage is arranged in an RF sputtering chamber of the RF sputtering device. The RF sputtering apparatus removes a natural oxide film attached to an Al alloy wiring in a via hole (connection hole) by RF sputtering.

[0003] An alumina plate is arranged on the upper surface of the wafer stage. The alumina plate is arranged so as to be located below the wafer when the wafer to be processed is placed on the wafer stage. Alumina is coated on the upper surface of the wafer stage and the outer peripheral portion of the aluminum plate.

Next, a procedure for processing a wafer by an RF sputtering apparatus will be described. The wafer is placed on the wafer stage. At this time, the alumina coated on the outer peripheral portion of the upper surface of the wafer stage is in an exposed state.

After that, the wafer is subjected to an RF sputtering process in an RF sputtering apparatus. That is, by introducing Ar gas into the RF sputtering chamber, applying RF, and pulling Ar ions to the negative-polar wafer stage,
A is applied to the Al alloy wiring exposed in the via hole of the wafer.
RF sputtering is performed by bombarding r ions. Thereby, the natural oxide film in the via hole is removed. At this time,
RF sputtering is also performed on the alumina coating on the outer peripheral portion of the upper surface of the wafer stage.

[0006]

As described above, if RF sputtering is also performed on the alumina coating, the coated alumina is peeled off, and the peeled alumina causes particles. When the peeling of the coated alumina on the wafer stage progresses, the wafer stage is reused by coating the wafer stage again with alumina.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an RF sputtering apparatus and a method of manufacturing a semiconductor device which can suppress the peeling of a coating film on a stage during RF sputtering. It is in.

[0008]

An RF sputtering apparatus according to the present invention is an RF sputtering apparatus for performing an RF sputtering process on an object to be processed, and includes a stage disposed in an RF chamber for mounting the object to be processed. And a material film coated on the outer periphery of the upper surface of the stage and having resistance to RF sputtering positioned on the outer periphery of the object when the object is placed on the upper surface of the stage. Features.

In the RF sputtering apparatus according to the present invention, the material film is preferably a polyimide film or a SiC film.

According to the RF sputtering apparatus, the material film coated on the outer peripheral portion of the upper surface of the stage has resistance to RF sputtering. Therefore, RF
Even when RF sputtering is performed on a material film during sputtering, the material film can be prevented from being peeled.

A method of manufacturing a semiconductor device according to the present invention includes the steps of forming a first Al alloy wiring above a semiconductor substrate, forming an insulating film on the first Al alloy wiring,
Forming a connection hole located on the first Al alloy wiring in the insulating film; placing a semiconductor substrate on the upper surface of a stage in an RF chamber; Removing a native oxide film attached to the first Al alloy wiring exposed on the substrate, and forming a second Al alloy wiring in the connection hole and on the insulating film,
The outer periphery of the upper surface of the stage is coated with a material film having resistance to RF sputtering, and this material film is located on the outer periphery of the semiconductor substrate when the semiconductor substrate is mounted on the upper surface of the stage. It is characterized by.

In the method for manufacturing a semiconductor device according to the present invention, the material film is preferably a polyimide film or a SiC film.

According to the method of manufacturing a semiconductor device, the material film coated on the outer peripheral portion of the upper surface of the stage has resistance to RF sputtering. Therefore, even if RF sputtering is performed on the material film in the step of removing the natural oxide film attached to the first Al alloy wiring exposed in the connection hole, the material film is prevented from being peeled. Can be.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram schematically showing a wafer processing apparatus provided with an RF sputtering apparatus according to an embodiment of the present invention. FIG. 2A is a plan view showing a wafer stage on which a wafer to be processed is placed in the RF sputtering apparatus shown in FIG. 1, and FIG.
FIG. 2 is a sectional view taken along line 2b-2b shown in FIG.

The wafer processing apparatus has a transfer chamber 11 for transferring a wafer. A loader (not shown) for setting a wafer to be processed and an unloader (not shown) for holding a processed wafer are arranged on the outer periphery of the transfer chamber 11. Further, an RF sputtering apparatus 1 is provided on the outer periphery of the transfer chamber 11.
2 and first to fourth sputtering apparatuses 13 to 16 are arranged. Thereby, it is possible to continuously perform the sputtering process on the wafer.

A wafer stage 22 shown in FIG. 2 is arranged in the RF sputtering chamber of the RF sputtering apparatus 12. The RF sputtering device 12 removes a natural oxide film attached to an Al alloy wiring in a via hole (connection hole) by RF sputtering (reverse sputtering). The first sputtering device 13 is for forming a Ti film on a wafer, the second sputtering device 14 is for forming a TiN film on a wafer, and the third sputtering device 15 is for forming an Al film. The fourth sputtering apparatus 16 forms a cap TiN film.

As shown in FIGS. 2A and 2B, an alumina plate 23 is disposed on the upper surface of the wafer stage 22. The alumina plate 23 is arranged so as to be located below the wafer 21 when the wafer 21 is placed on the wafer stage 22. An upper surface of the wafer stage 22 and an outer peripheral portion of the aluminum plate 23 are coated with a material film 24 having excellent resistance to RF sputtering (a material film having excellent etching resistance). As the material film 24, it is preferable to use a polyimide film, a SiC film, or the like. When the wafer 21 is placed on the wafer stage 22, the material film 24 is located on the outer peripheral portion of the wafer 21.

Various methods can be used to coat the outer peripheral portion of the upper surface of the wafer stage 22 with a polyimide film, and examples thereof include potting. Various methods can be used to coat the outer peripheral portion of the upper surface of the wafer stage 22 with the SiC film. For example, CVD (Chemic)
al Vapor Deposition) method.

Next, a procedure for processing a wafer by the wafer processing apparatus shown in FIG. 1 will be described with reference to FIG. FIG. 3A is a cross-sectional view showing a main part of the wafer before being processed by the wafer processing apparatus shown in FIG. 1, and FIG.
FIG. 2 is a cross-sectional view showing a main part of the wafer after being processed by the wafer processing apparatus shown in FIG. 1.

As shown in FIG. 3A, a first insulating film 32 is deposited on a silicon substrate (wafer) 21, and a contact hole (connection hole) 32a is formed in the first insulating film 32. Next, a barrier metal film 33 is deposited in the contact hole 32a and on the first insulating film 32, and a first A is formed on the barrier metal film 33 and in the contact hole 32a.
An 1 alloy film 34 is deposited. Thereafter, the first Al alloy film 3
By patterning the barrier metal film 4 and the barrier metal film 33, a first Al alloy wiring 34 is formed in the contact hole 32a and on the first insulating film 32. Next, the first
A second insulating film 35 is deposited on the entire surface including the Al alloy wiring 34, and a via hole 35a is formed in the second insulating film 35.

Thereafter, the wafer 21 is set on a loader in the wafer processing apparatus shown in FIG. Next, the wafer in the loader is transferred into the RF sputtering chamber of the RF sputtering apparatus 12 via the transfer chamber 11, and the wafer 2
1 is placed on a wafer stage 22 shown in FIG. At this time, as shown in FIG. 2A, the material film 24 coated on the outer peripheral portion of the upper surface of the wafer stage 22 is exposed.

Thereafter, the wafer is subjected to an RF sputtering process in an RF sputtering apparatus. That is, an Ar gas is introduced into the RF sputtering chamber, RF is applied, and Ar ions are pulled to the negative wafer stage 22, thereby being exposed in the via hole 35a of the wafer 21 shown in FIG. RF sputtering (reverse sputtering) is performed by bombarding the first Al alloy wiring 34 with Ar ions. Thereby, the natural oxide film in the via hole is removed. At this time, RF sputtering is also performed on a material film 24 such as a polyimide film on the outer peripheral portion of the upper surface of the wafer stage 22. Since the material film 24 is a film having resistance to RF sputtering as described above, the conventional alumina coating is used. In this case, the material film 24 can be prevented from being peeled off by reverse sputtering of Ar ions.

Next, the first to fourth sputtering devices 13 to 1
In step 6, a sputtered film is continuously formed on the wafer 21.

That is, the wafer of the RF sputtering apparatus 12 is transferred into the first sputtering apparatus 13 via the transfer chamber 11 and subjected to a sputtering process, so that, as shown in FIG. A Ti film is formed in the via hole 35 a and on the second insulating film 35. Thereafter, the wafer of the first sputtering device 13 is transferred into the second sputtering device 14 via the transfer chamber 11 and subjected to a sputtering process to form a TiN film on the Ti film and in the via hole 35a. Film. The TiN film and the Ti film become the barrier metal film 36.

Next, the wafer of the second sputtering device 14 is transferred into the third sputtering device 15 via the transfer chamber 11 and subjected to a sputtering process, so that the wafer is placed on the TiN film and in the via hole 35a. The second Al alloy film 37 is formed. Thereafter, the wafer of the third sputtering device 15 is transferred into the fourth sputtering device 16 via the transfer chamber 11,
A cap TiN film 38 is formed on the second Al alloy film 37 by performing a sputtering process.

Thereafter, the wafer of the fourth sputtering apparatus 16 is transferred to the unloader via the transfer chamber 11, and the processed wafer 21 is stored in the unloader. Thus, the wafer processing is performed in the wafer processing apparatus.

According to the above embodiment, the material film 24 coated on the outer peripheral portion of the upper surface of the wafer stage 22
It has resistance to F sputtering. For this reason, even if the material film 24 is also subjected to RF sputtering during RF sputtering, the material film 24 can be prevented from being peeled off, whereby particles can be reduced. Therefore, it is possible to suppress the occurrence of a connection failure due to particles entering the via hole 35a.

Further, in the present embodiment, as described above, since the material film 24 is not easily peeled off during RF sputtering, the wafer stage 22 from which the material film 24 has been peeled is reused. The number of times of recoating the material film 24 (maintenance frequency) can be reduced as compared with the conventional stage. Therefore, the maintenance time can be extended, and the maintenance cost can be reduced.

The present invention is not limited to the above embodiment, but can be implemented with various modifications. For example,
In the above embodiment, a polyimide film as the material film 24,
Although the SiC film is described, other material films may be used as long as they have resistance to RF sputtering.

[0030]

As described above, according to the present invention, the outer peripheral portion of the upper surface of the stage is coated with a material film having resistance to RF sputtering. Therefore, RF
It is possible to provide an RF sputtering apparatus and a method for manufacturing a semiconductor device, which can suppress peeling of a coating film on a stage during sputtering.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a wafer processing apparatus provided with an RF sputtering apparatus according to an embodiment of the present invention.

2A is a plan view showing a wafer stage on which a wafer to be processed is placed in the RF sputtering apparatus shown in FIG. 1, and FIG. 2B is a line 2b-2b shown in FIG. FIG.

FIG. 3A is a cross-sectional view illustrating a main part of a wafer before being processed by the wafer processing apparatus illustrated in FIG. 1, and FIG.
FIG. 2 is a cross-sectional view illustrating a main part of the wafer after being processed by the wafer processing apparatus illustrated in FIG. 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Transfer chamber 12 ... RF sputtering apparatus 13 ... First sputtering apparatus 14 ... Second sputtering apparatus 15 ... Third sputtering apparatus 16 ... Fourth sputtering apparatus 21 ... Wafer (silicon substrate) 22 ... Wafer stage 23 ... Alumina plate 24 ... Material film having resistance to RF sputtering 32 ... First insulating film 32a ... Contact hole (connection hole) 33, 36 ... Barrier metal film 34 ... First Al alloy wiring (first Al alloy film) 35: second insulating film 35a: via hole (connection hole) 37: second Al alloy film 38: cap TiN film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01L 21/768 H01L 21/90 A F term (Reference) 4K029 AA06 BA17 BA60 BB02 BD01 CA05 DC00 JA01 4M104 DD23 HH16 HH20 5F004 AA14 BB18 BB23 BB30 BC08 DA23 5F031 CA02 HA02 HA03 MA04 MA29 NA04 PA06 PA26 5F033 HH08 HH33 JJ00 JJ08 KK08 MM12 MM13 QQ92 QQ94 XX00

Claims (4)

[Claims] 1. An RF for performing an RF sputtering process on an object to be processed.
A sputtering apparatus, comprising: a stage arranged in an RF chamber, on which an object to be processed is mounted; and a coating coated on an outer periphery of an upper surface of the stage. An RF sputtering apparatus, comprising: a material film located on an outer periphery of a processing body and having resistance to RF sputtering. 2. The method according to claim 1, wherein the material film is a polyimide film or SiC.
The RF sputtering apparatus according to claim 1, wherein the RF sputtering apparatus is a film. Forming a first Al alloy wiring above the semiconductor substrate; forming an insulating film on the first Al alloy wiring; forming a first Al alloy wiring on the first Al alloy wiring; Forming a connection hole located on the substrate; placing the semiconductor substrate on the upper surface of the stage in the RF chamber; and performing RF sputtering to adhere to the first Al alloy wiring exposed in the connection hole. A step of removing a natural oxide film; and a step of forming a second Al alloy wiring in the connection hole and on the insulating film. A material film having resistance to RF sputtering is formed on the outer periphery of the upper surface of the stage. A method of manufacturing a semiconductor device, wherein the material film is coated and is located on the outer periphery of the semiconductor substrate when the semiconductor substrate is mounted on the upper surface of the stage. 4. The material film is a polyimide film or SiC.
4. The method according to claim 3, wherein the semiconductor device is a film.