JPH093642A - Sputtering device and sputtering method using the sputtering device - Google Patents

Abstract

PURPOSE: To provide a sputtering device and a sputtering method in which no segregation is present, no remainder is left in the subsequent machining, or no short circuit is generated, or no inconveniences such as increase in resistance is generated even when the material to be formed by the sputtering consists of the main component (base metal) and added elements (impurities). CONSTITUTION: When the material is formed on a substrate 3 by the sputtering of a semiconductor wafer, etc., a mechanism which is provided with two or more stages 1, 2 to support a base body of different set temperature in the same sputtering chamber 10, and switches loading base bodies at need is used. For example, one stage is set to a temperature at which the added element is completely solved to the base metal, and the other stage is set to a temperature at which the degree of solid solution of the added element to the base metal is <=0.1%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus and a sputtering method using the sputtering apparatus. The present invention is, for example, an electronic material (semiconductor device, etc.)
It can be used when forming a material on various substrates during formation, for example, sputter film formation, and for example, forming a wiring or the like.

[0002]

2. Description of the Related Art In various fields using sputtering technology, products are being miniaturized and integrated, and, for example, in the field of semiconductor devices, electrical integration between elements has been accompanied by high integration of ULSI and the like. The miniaturization is progressing also in the wiring connected to. As a result, higher reliability is required for fine wiring. Regarding the wiring material, Al alloy wiring in which Al is a base material and impurities such as Cu, Si, and Ti are added is generally used. However, these additional elements are generally solid-dissolved in Al at the device ambient temperature. It is added more than once. For example, C
When u is added, electromigration (EM)
In order to increase the resistance, an addition amount of 0.3 wt% or more is necessary, and in the case of Si addition, an addition amount of 1 wt% or more is necessary to suppress mutual diffusion with the Si substrate.

Therefore, the following problems occur when the wiring is formed by sputtering. That is, as described above, A
Impurities that exist in supersaturation in the base metal such as l are A due to the temperature history (usually slow cooling) received immediately after sputtering.
The film segregates as nodules in the film and forms a residue during etching. If the amount of this residue is large, a short circuit between wirings may occur.

In addition, when Si is added, Si nodules are formed, and when this occurs in the contact portion, the contact resistance increases, and in some cases, ohmic contact cannot be made.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the material to be formed by sputtering is
Even when the main component (base material) is composed of additional elements or impurities, there is no segregation of additional elements or impurities, there is no problem of residue or short circuit due to this during later processing, or there is a problem such as resistance increase. An object of the present invention is to provide a sputtering apparatus that does not have such a problem, and a sputtering method using the sputtering apparatus.

[0006]

The sputtering apparatus of the present invention is a sputtering apparatus for forming a material on a substrate by sputtering, and has two or more substrate supporting stages having different set temperatures in the same sputtering chamber. It is a sputtering device.

The sputtering method of the present invention is a sputtering method for forming a material on a substrate by sputtering, using a sputtering apparatus having two or more substrate supporting stages having different set temperatures in the same sputtering chamber. Is placed on a stage to carry out sputtering, thereby performing sputtering at different substrate temperatures.

In the sputtering apparatus of the present invention, the temperature of the above stage is set to a temperature at which one element completely dissolves in the base metal of the material to be formed on the substrate, and The two stages can be configured as a sputtering apparatus in which the solid solubility of the additive element in the base metal is set to 0.1% or less.

The sputtering apparatus of the present invention first forms the material on the substrate by the sputtering method at the temperature above the temperature at which the additive element completely forms a solid solution in the base metal of the material to be formed on the substrate, and immediately after the completion of sputtering, It is possible to adopt a configuration having a mechanism for remounting the substrate on a stage set to a temperature at which the solid solubility of the additive element in the base metal is 0.1% or less. In the description of the present invention, the indication of% means wt% unless otherwise specified.

In the sputtering method of the present invention, the temperature of the above stage is set to a temperature above the temperature at which one element completely forms a solid solution with the base metal of the material to be formed on the substrate, and The two stages are set to a temperature at which the solid solubility of the additive element in the base metal is 0.1% or less, and the temperature at which the additive element completely forms a solid solution in the base metal of the material to be formed on the substrate. As described above, the material is formed on the substrate by the sputtering method, and immediately after the completion of the sputtering, the substrate is remounted on the stage whose temperature is set so that the solid solubility of the additive element in the base metal is 0.1% or less. The structure of a sputtering device that performs sputtering can be used.

That is, the basic structure of the present invention is to have a structure having two stages having different set temperatures in the same chamber.

In a preferred specific embodiment, the stage is a heater stage, and the temperature of the heater stage is set to a temperature above the temperature at which the additive element is completely solid-dissolved in the base metal such as the wiring material to be formed. The other stage is set to a temperature at which the solid solubility of the additive element in the base metal is 0.1% or less.

Further, at the heater stage temperature, a wiring layer is first formed by a sputtering method at a temperature above the temperature at which the additive element is completely solid-soluted in the base metal of the wiring material, and immediately after the completion of sputtering, the addition to the base metal is performed. It is assumed that a mechanism is provided for repositioning the substrate on a stage set to a temperature at which the solid solubility of the element is 0.1% or less.

Further, the base metal of the wiring material is Al,
It is a preferred embodiment to be selected from Cu, Ag, Au and W.

[0015]

According to the present invention, since two or more substrate supporting stages having different set temperatures are provided in the same sputtering chamber, the substrate is mounted on each stage having a desired temperature, and sputtering at different substrate temperatures is sequentially performed. It can be carried out.

By using the present invention, segregation of impurities (additional elements) can be prevented, and the disadvantages associated therewith can be eliminated. The mechanism by which the segregation of impurities can be prevented by using the sputtering apparatus of the present invention having two heater stages having different set temperatures in the same chamber will be described as follows.

For example, when Cu is added as an impurity to Al, the solid solubility at a certain temperature is Al-Cu shown in FIG.
It can be known from the equilibrium diagram of. For example, 0.5w
A temperature of about 350 ° C. is required to completely dissolve t% of Cu. When sputtering at this temperature,
Immediately after the end of the sputter discharge, Cu was in a completely solid solution state in Al, but in the process of returning to room temperature, it was cooled slowly in a normal device (see FIG. 9), and therefore supersaturated Cu was precipitated at room temperature. You can see the phenomenon. By quenching from 350 ° C. to 200 ° C., where Cu has a solid solubility of about 0.1%, Cu in Al can be returned to room temperature in a state of almost solid solution, so that an AlCu film that does not generate Cu nodules Is obtained.

Similarly, when Si is added to the Al film, from the equilibrium diagram shown in FIG. 8, the solid solution temperature at a predetermined Si concentration is rapidly cooled to a temperature at which the solid solubility becomes 0.1% or less. By doing so, it can be seen that Si nodules can be prevented.

For example, with Al-1 wt% Si, 520 ° C.
Completely forms a solid solution in a certain degree (equilibrium phase diagram (Al-S
See (i)), so that the Si nodules can be improved by quenching from this temperature.

[0020]

Embodiments of the present invention will be described below in detail. However, as a matter of course, the present invention is not limited to the following examples.

Example 1 An apparatus having a mechanism for rotating two heaters in combination will be described below with reference to FIGS. 1 to 3 as an example of the embodiment of the sputtering apparatus and the sputtering method using the same according to the present invention. .

As shown in FIGS. 1 to 3, the sputtering apparatus of this embodiment uses a substrate 3 by sputtering.
A sputtering apparatus for forming a material on a (here, a semiconductor wafer) having two or more (here, two) substrate supporting stages 1 and 2 having different set temperatures in the same sputtering chamber 10. .

In the present embodiment, the temperature of the above-mentioned stage is such that in one stage 1, the additive element (here, Cu) is completely solid-dissolved in the base metal (here, Al) of the material to be formed on the substrate 3. The temperature of the second stage 2 is set to be equal to or higher than the temperature for which the solid solubility of the additive element (here, Cu) to the base metal is 0.1% or less.

In this embodiment, first, the material is formed on the substrate 3 by the sputtering method by the stage 1 at the temperature at which the additive element is completely solid-solved in the base metal of the material to be formed on the substrate 3, and the sputtering is completed. Immediately after that, there is a mechanism for remounting the substrate on the stage 2 whose temperature is set so that the solid solubility of the additive element in the base metal is 0.1% or less (FIG. 1).
(See FIG. 2 in which transfer is changed by rotating 4 ').

In the present invention, there is provided a sputtering method for forming a material on the substrate 3 by sputtering, wherein the same sputtering chamber 10 has two or more substrate supporting stages 1 and 2 having different set temperatures. By using the
Then, the substrate is replaced with a new one, and the sputtering is performed at different substrate temperatures.

At this time, the temperature of the above stage is set to a temperature above the temperature at which the additive element is completely solid-dissolved in the base metal of the material to be formed on the base in one stage, and
The other stage is set to a temperature at which the solid solubility of the additive element in the base metal is 0.1% or less, and the additive element is completely solid-solved in the base metal of the material to be formed on the substrate. A material is formed on the substrate by a sputtering method at a temperature equal to or higher than the temperature, and immediately after the completion of the sputtering, the solid solubility of the additive element in the base metal is 0.1.
The substrate is placed on a stage whose temperature is set to be not more than%, and sputtering is performed.

The metal serving as the base material is Al here, but other metals selected from Cu, Ag, Au and W can be preferably used.

This embodiment will be described in more detail with reference to the drawings. FIG. 1 is a schematic view of the inside of the sputtering apparatus of this embodiment. In the figure, the heater stage 1,
2 is back-to-back, and has a mechanism that rotates about a rotation shaft 4 and a vertical mechanism 5 (shown by an arrow).
The wafer, which is the substrate 3, is supported by lift pins 5 while the stages 1 and 2 are rotating and moving up and down. Of the two stages, Stage 1 is 350 ° C (Depositio
n, that is, sputter deposition temperature), and the stage 2 is set to room temperature (Cool down, that is, cooling temperature).

First, the wafer, which is the substrate 3, is placed on the heater stage 1 at 350 ° C., and Al is heated at a temperature of 350 ° C.
-0.5 wt% Cu film is formed by sputtering. Immediately after the end of the sputtering, as shown in FIG. 2, the heater stages 1 and 2 are rotated about the rotation axis 4 as shown by the arrow 4 ', and the substrate 3 (wafer) is set on the stage 2 set to room temperature.
Cool down is performed (FIG. 3).

As a result, the substrate 3 (wafer) is 350
It is rapidly cooled from 0 ° C., and Cu in Al is returned to room temperature while forming a solid solution in supersaturation. The Al thus formed by this apparatus
In the Cu film, since Cu nodules are not generated in the film,
A residue is not generated during etching processing, and accurate processing is possible.

In this apparatus, the cooling rate after sputtering was 200 ° C./min.

Heating during sputtering is performed from the rear surface of the heater by Ar.
It is carried out by a gas heating method in which the gas is flown. In addition, cooling (Coo
Similarly, in the case of 1 down, the cooling is performed by flowing Ar from the back surface of the wafer.

The process and formation conditions for forming AlCu using this apparatus are shown below. In this embodiment,
The following steps 1 to 3 are performed. A substrate wafer, which is the substrate 3, is transferred into the chamber 10. It is installed on the heater stage 1 at 350 ° C (Fig. 1). AlCu is deposited as a wiring material by sputtering. Reference numeral 7 is a target, and 8 is plasma. After the end, the heater stages 1 and 2 are rotated around the rotation shaft 4. The rotation at this time is shown by reference numeral 4 '(FIG. 2). The substrate 3 is placed on the room temperature heater stage 2 (FIG. 3). Perform cool down. Substrate 3 after sputtering film formation from chamber 10
Take out (wafer).

In this embodiment, the AlCu forming conditions are as follows:
It was as follows.

AlCu forming conditions (conditions during sputter deposition) Gas Ar = 100 SCCM Pressure 5 mTorr DC Power 13 kW Temperature 350 ° C.

Cool-down (cooling) conditions Gas Ar = 30 SCCM Pressure 1 mTorr Temperature 25 ° C.

According to this embodiment, the following concrete effects can be obtained. (1) Immediately after forming an alloy film such as Al-Cu by sputtering,
It becomes possible to cool rapidly, and the generation of Cu nodules can be suppressed. (2) When a Cu-added Al film formed by this method is dry-etched, Cu residue is not generated, and accurate wiring processing is possible.

Example 2 As another example of the sputtering apparatus of the present invention, an apparatus having a parallel moving mechanism by combining two heaters will be described below.
This will be described with reference to FIGS. 4 to 6. Here, the case of AlCu sputter film formation will be particularly described as in the first embodiment.

FIG. 4 is a schematic view of the inside of the sputtering apparatus of this embodiment. In the figure, heater stages 1 and 2
Can move in parallel (left and right in the figure), and further has a vertical movement mechanism. The wafer, which is the substrate 3, is supported in the air by lift pins 6 while the stages 1 and 2 are moving (FIG. 5). The two stages 1 and 2 are
As in Example 1, 350 ° C. (Deposition),
Each is set to room temperature (Cool down).

First, the wafer, which is the substrate 3, is placed on the heater stage 1 at 350 ° C., and Al is heated at a temperature of 350 ° C.
-0.5 wt% Cu film is formed by sputtering. Immediately after the end of sputtering, the heater stages 1 and 2 are moved in parallel as shown in FIG. This made stage 2 set to room temperature
The substrate 3 (wafer) is placed on the substrate and cool down is performed (FIG. 6).

As a result, the substrate 3 (wafer) is 350
It is rapidly cooled from 0 ° C., and Cu in Al is returned to room temperature while forming a solid solution in supersaturation. Since Cu nodules are not generated in the AlCu film formed by this apparatus, no residue is generated during the etching process, and accurate processing is possible.

In this apparatus, the cooling rate after sputtering was 200 ° C./min.

Heating during sputtering is performed from the rear surface of the heater by Ar.
It is carried out by a gas heating method in which the gas is flown. In addition, cooling (Coo
Similarly, in the case of 1 down, the cooling is performed by flowing Ar from the back surface of the wafer.

The process and conditions for forming AlCu using this apparatus are shown below. In this embodiment,
The following steps 1 to 3 are performed. A substrate wafer, which is the substrate 3, is transferred into the chamber 10. It is set on the heater stage 1 at 350 ° C. (FIG. 4). AlCu is deposited as a wiring material by sputtering. After completion, the heater stages 1 and 2 are moved in parallel (Fig. 5). The substrate is placed on the room temperature heater stage 2 (FIG. 6). Perform cool down. Substrate 3 after sputtering film formation from chamber 10
Take out (wafer).

In this embodiment, the AlCu forming conditions are as follows:
It was as follows.

Conditions for forming AlCu (conditions during sputter deposition) Gas Ar = 100 SCCM Pressure 5 mTorr DC power 13 kW Temperature 350 ° C.

Cool-down condition Gas Ar = 30 SCCM Pressure 1 mTorr Temperature 25 ° C.

This embodiment also has the same effect as that of the first embodiment.

Example 3 This example is an example of forming Al—Si using the sputtering apparatus used in Example 2.

FIG. 4 is a schematic view of the inside of the sputtering apparatus used in this embodiment. In the figure, the heater stages 1 and 2 can be moved in parallel (left and right directions in the figure), and further have a vertical movement mechanism. The wafer, which is the substrate 3, is supported in the air by lift pins 6 while the stages 1 and 2 are moving (FIG. 5). Two stages 1,
Here, 2 is set to 550 ° C. (Deposition) and room temperature (Cool down), respectively.

First, the wafer as the film-forming substrate 3 is set to 55.
It is placed on the heater stage 1 at 0 ° C., and an Al-1 wt% Si film is sputtered at a temperature of 550 ° C. Immediately after completion of sputtering, as shown in FIG.
Is translated. As a result, the substrate 3 (wafer) is placed on the stage 2 set to room temperature and cool down is performed (FIG. 6).

As a result, the substrate 3 (wafer) is 550
It is rapidly cooled from 0 ° C., and Si in Al is returned to room temperature while forming a solid solution in supersaturation. Since the AlSi film formed by this apparatus has no Si nodules in the film, no residue is generated during the etching process, and the process can be performed with high accuracy.

In this apparatus, the cooling rate after sputtering was 200 ° C./min.

Heating during sputtering is performed from the rear surface of the heater by Ar.
It is carried out by a gas heating method in which the gas is flown. In addition, cooling (Coo
Similarly, in the case of 1 down, the cooling is performed by flowing Ar from the back surface of the wafer.

The process and conditions for forming AlSi using this apparatus are shown below. In this embodiment,
The following steps 1 to 3 are performed. A substrate wafer, which is the substrate 3, is transferred into the chamber 10. It is installed on the heater stage 1 at 550 ° C. (FIG. 4). AlSi is deposited as a wiring material by sputtering. After completion, the heater stages 1 and 2 are moved in parallel (Fig. 5). The substrate is placed on the room temperature heater stage 2 (FIG. 6). Perform cool down. Substrate 3 after sputtering film formation from chamber 10
Take out (wafer).

In this embodiment, the AlSi formation conditions are as follows:
It was as follows.

Conditions for forming AlSi (conditions during sputter deposition) Gas Ar = 100 SCCM Pressure 5 mTorr DC power 13 kW Temperature 550 ° C.

Cool-down (cooling) conditions Gas Ar = 30 SCCM Pressure 1 mTorr Temperature 25 ° C.

According to the present embodiment, it is possible to suppress the generation of Si nodules and to prevent an increase in contact resistance and the inconvenience associated therewith.

[0060]

According to the sputtering apparatus of the present invention and the sputtering method using the sputtering apparatus,
The material to be formed by sputtering is the main component (base material)
In addition, even if it is composed of an additive element or an impurity, there is no segregation of the additive element or impurity, and there is no residue such as a short circuit due to a residue during subsequent processing, or there is no inconvenience such as an increase in resistance. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration and an operation of a sputtering apparatus according to a first embodiment.

FIG. 2 is a diagram showing a configuration and an operation of a sputtering apparatus according to a first embodiment.

FIG. 3 is a diagram showing a configuration and an operation of a sputtering apparatus according to a first embodiment.

FIG. 4 is a diagram showing a configuration and an operation of a sputtering apparatus according to a second embodiment.

FIG. 5 is a diagram showing a configuration and an operation of a sputtering apparatus according to a second embodiment.

FIG. 6 is a diagram showing a configuration and an operation of a sputtering apparatus according to a second embodiment.

FIG. 7 shows an AlCu phase diagram.

FIG. 8 shows an AlSi phase diagram.

FIG. 9 is a diagram showing the background of the invention, in which Al-0.5 wt%
It is a figure which shows the thermal history at the time of sputtering of Cu.

[Explanation of symbols]

 1 Substrate Support Stage (1) 2 Substrate Support Stage (2) 3 Substrate (Wafer) 7 Target 8 Plasma

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C23F 4/00 C23F 4/00 A H01L 21/203 H01L 21/203 S

Claims (7)

[Claims] 1. A sputtering device for forming a material on a substrate by sputtering, comprising two or more substrate supporting stages having different set temperatures in the same sputtering chamber. 2. A material to be formed on a substrate is composed of a base metal and an additive element contained in the base metal, and the temperature of the above stage is such that the additive element is completely dissolved in the base metal in one stage. The temperature is set to a temperature higher than the above, and the other stage is that the solid solubility of the additive element in the base metal is 0.1%.
The sputtering apparatus according to claim 1, wherein the following temperatures are set. 3. A material is first formed on a base material by a sputtering method at a temperature at which the additive element is completely solid-soluted in the base metal of the material to be formed on the base material, and immediately after the completion of the sputtering, the addition to the base material metal. The sputtering apparatus according to claim 2, further comprising a mechanism for repositioning the substrate on a stage set to a temperature at which the solid solubility of the element is 0.1% or less. 4. The base metal is Al, Cu, Ag, A
The sputtering apparatus according to claim 2, wherein the sputtering apparatus is selected from u and W. 5. A sputtering method for forming a material on a substrate by sputtering, wherein a sputtering apparatus having two or more substrate supporting stages having different set temperatures in the same sputtering chamber is used and the substrate is placed on the stage. The sputtering method is configured to perform sputtering at different substrate temperatures by performing sputtering with different temperatures. 6. A material to be formed on a substrate is composed of a base metal and an additive element contained therein, and the temperature of the above stage is such that in one stage, the additive element is completely dissolved in the base metal. The temperature is set to a temperature higher than the above, and the other stage is that the solid solubility of the additive element in the base metal is 0.1%.
The temperature is set as follows, and the material is formed on the base material by the sputtering method at a temperature above the temperature at which the additive element is completely solid-soluted in the base metal of the material to be formed on the base material. The sputtering method according to claim 5, wherein the substrate is remounted on the stage set to a temperature at which the solid solubility of the additive element is 0.1% or less and sputtering is performed. 7. The base metal is Al, Cu, Ag, A
The sputtering method according to claim 5, wherein the sputtering method is selected from u and W.