JP2008047661A - Deposition device and method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deposition device capable of speeding up the deposition rate without lowering a coverage. <P>SOLUTION: The depostition device of the present invention comprises: a stage 14 with a semiconductor susbtrate 1 mounted on its surface; a first sputtering target 34 positioning over the stage 14 and arranged on the surface of the stage 14 approximately parallel; and a second sputtering target 36 positioning obliquely over the stage 14 and arranged obliquely to the surface of the stage 14. In this deposition device, the particle of the substance to be deposited comes flying from not only the first sputtering target 34 but also the second sputtering target 36. A part of an incident density of the particle to the inclined plane of a concave and convexity is thereby larger than conventional incident rate even if there is irregularity on the surface of the substrate with the film formed thereon. the coverage of the film in the irregularity part is not lowered and the deposition rate can be quicker than the conventional deposition rate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a film forming apparatus and a method for manufacturing a semiconductor device. In particular, the present invention relates to a film forming apparatus and a semiconductor device manufacturing method capable of increasing a film forming speed without reducing coverage.

  FIG. 4 is a plan view for explaining the structure of a conventional film forming apparatus, and FIG. 5 is a cross-sectional view for explaining the structure of an Al alloy film formed by the film forming apparatus shown in FIG. . A conventional method for forming an Al alloy film serving as an Al alloy wiring on the silicon substrate 100 will be described with reference to FIGS.

  First, a plurality of silicon substrates 100 are carried into the transfer chamber 110 through the carry-in port 11. In the silicon substrate 100, an interlayer insulating film 102 and a connection hole 102a are formed in advance. Next, the silicon substrate 100 is carried into the first sputtering chamber 120 and sputtering is performed. Thereby, a barrier metal film 103 is formed on the interlayer insulating film 102 and in the connection hole 102a.

  Next, the silicon substrate 100 is transferred from the first sputtering chamber 120 to the second sputtering chamber 131, and the Al alloy film 104 a is formed on the barrier metal film 103 using the second sputtering chamber 131. At this time, the silicon substrate 100 is not heated and the deposition rate is decreased so that the coverage of the Al alloy film 104a is improved inside the connection hole 102a.

  Next, the silicon substrate 100 is transferred from the second sputtering chamber 131 to the third sputtering chamber 132, and the Al alloy film 104 b is formed on the Al alloy film 104 a using the third sputtering chamber 132. At this time, the silicon substrate 100 is heated and the deposition rate is increased as compared with the case where the Al alloy film 104a is formed.

  Next, the silicon substrate 100 is transferred from the third sputtering chamber 132 to the fourth sputtering chamber 140, and the antireflection film 105 is formed on the Al alloy film 104 b using the fourth sputtering chamber 140. A technique similar to this technique is disclosed in Patent Document 1.

  In each of the first to fourth sputtering apparatuses described above, the sputtering target is disposed above the silicon substrate 100 in parallel with the silicon substrate 100 (not shown).

Japanese Patent Laying-Open No. 2001-176862 (fourth paragraph, FIG. 6)

  In the above steps, the time required for forming the barrier metal film and the time required for forming the antireflection film are sufficiently shorter than the time required for forming the Al alloy film. For this reason, if the deposition rate of the Al alloy film is increased to shorten the time required for deposition, the production efficiency of the semiconductor device is improved. However, a connection hole is formed in the interlayer insulating film, and in order to increase the coverage of the Al alloy film in the connection hole, it has been conventionally necessary to reduce the initial film formation rate of the Al alloy film.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a film forming apparatus and a semiconductor device manufacturing method capable of increasing the film forming speed without reducing the coverage. It is in.

In order to solve the above problems, a film forming apparatus according to the present invention includes a stage on which a semiconductor substrate is placed,
A first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage;
A second sputtering target positioned obliquely above the stage and disposed obliquely with respect to the surface of the stage.

  According to this film forming apparatus, the particles of the substance to be a film fly not only from the first sputtering target but also from the second sputtering target. For this reason, even if the surface of an object (for example, an interlayer insulating film) on which a film is formed has irregularities, the incident density of particles with respect to the inclined surface of the irregularities is higher than in the past. Therefore, the film formation speed on the sloped portion of the concavo-convex portion is faster than the conventional one, and the difference from the film formation rate on the portion without the concavo-convex portion is smaller than the conventional one. For this reason, it is possible to increase the deposition rate as compared with the conventional one without reducing the coverage of the film on the slope portion of the uneven portion.

Three or more second sputtering targets are provided, and an angle formed by two straight lines connecting the centers of the two second sputtering targets located next to each other and the center of the stage is any of the 2 Even if two second sputtering targets are selected, it is preferable that they are all substantially equal.
The first and second sputtering targets are, for example, Al alloy targets.

Another film forming apparatus according to the present invention includes a transfer chamber,
A first processing chamber connected to the transfer chamber;
A plurality of second processing chambers connected to the transfer chamber;
Comprising
Each of the plurality of second processing chambers includes:
A stage on which a semiconductor substrate is placed;
A first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage;
A second sputtering target located obliquely above the stage and disposed obliquely with respect to the surface of the stage.

According to this film forming apparatus, the processing time in the second processing chamber can be shortened without reducing the coverage. The semiconductor substrate is transferred to the second processing chamber after being processed by the first processing chamber, and the processing time in the first processing chamber is shorter than the processing time in the second processing chamber (for example, In the case of half or less, the processing time in the film forming apparatus can be shortened by operating the plurality of second processing chambers in parallel.

In the method for manufacturing a semiconductor device according to the present invention, a first sputtering target is disposed substantially parallel to the surface of the stage above a stage on which a semiconductor substrate is placed.
The second sputtering target is disposed obliquely with respect to the surface of the stage obliquely above the stage,
A step of placing a semiconductor substrate on the surface of the stage and forming a film on the semiconductor substrate by sputtering using the first and second sputtering targets;

  In this method of manufacturing a semiconductor device, the first and second sputtering targets are, for example, Al alloy targets, and the semiconductor substrate includes, for example, an interlayer insulating film and a connection hole formed in the interlayer insulating film. In this case, an Al alloy film to be a wiring of the semiconductor device is formed on the interlayer insulating film and in the connection hole by the sputtering. In this case, the thickness of the Al alloy film is, for example, 2000 nm or more.

Another method of manufacturing a semiconductor device according to the present invention includes a transfer chamber,
A first processing chamber connected to the transfer chamber;
A stage on which a semiconductor substrate is mounted; a first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage; and positioned obliquely above the stage and A second sputtering target disposed obliquely with respect to the surface of the stage, and a plurality of second processing chambers connected to the transfer chamber;
A sputtering apparatus comprising:
Sequentially processing a plurality of semiconductor substrates using the first processing chamber;
The plurality of semiconductor substrates processed in the first processing chamber are processed in parallel using the plurality of second processing chambers, thereby forming the same film on each of the plurality of semiconductor substrates.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view for explaining the configuration of a film forming apparatus according to an embodiment of the present invention. This film forming apparatus is an apparatus for forming an Al alloy film serving as an Al alloy wiring on a silicon substrate, and includes a first sputtering chamber 20 for forming a barrier metal film, and a plurality of second layers for forming an Al alloy film. Each of the sputtering chamber 30 and the third sputtering chamber 40 for forming the antireflection film is connected to the transfer chamber 10 through the slit valve 12. A plurality of silicon substrates are carried into and out of the transfer chamber 10 from the carry-in port 11.

  In the prior art described above, an Al alloy film is formed on one silicon substrate using two sputtering apparatuses. On the other hand, in this embodiment, since each of the second sputtering chambers 30 forms an Al alloy film on different silicon substrates, a plurality of silicon substrates are processed in parallel using the plurality of second sputtering chambers 30. be able to.

  2A and 2B are a schematic plan view and a longitudinal sectional view for explaining the configuration of the second sputtering chamber 30, respectively. An exhaust pump 16 is connected to the second sputtering chamber 30.

  In the second sputtering chamber 30, a stage 14 on which the silicon substrate 1 is placed, a sputtering target 34, and a plurality of sputtering targets 36 (three in this example) are arranged. The sputtering target 34 is positioned above the stage 14 and is disposed substantially parallel to the surface of the stage 14. The sputtering target 34 is located obliquely above the stage 14 and is disposed obliquely with respect to the surface of the stage 14. The angles formed by the two straight lines connecting the centers of the two sputtering targets 36 located adjacent to each other and the center of the stage 14 are substantially equal regardless of which two sputtering targets 36 are selected. That is, when the stage 14 is the center, the plurality of sputtering targets 36 are arranged at equal intervals. The distance from each sputtering target 34 to the stage 14 can be adjusted independently of each other.

  The sputtering target 34 is held on an electrode 38a, and the plurality of sputtering targets 36 are held on different electrodes 38b. The inputs of the electrode 38a and the plurality of electrodes 38b can be controlled independently of each other.

  In the example shown in the figure, the diameter of the sputtering target 34 is larger than the diameter of the sputtering target 36, but is not limited to this. The angles of the surfaces of the plurality of sputtering targets 36 with respect to the surface of the stage 14 may be the same or different from each other.

  Next, a method for forming an Al alloy film to be an Al alloy wiring using the film forming apparatus according to the present embodiment will be described with reference to FIGS. On the silicon substrate 1, an interlayer insulating film 2 and a connection hole 2a are formed in advance. The connection hole 2a is formed using, for example, wet etching and dry etching together, but may be formed only by dry etching.

  First, the silicon substrate 1 is transferred to the first sputtering chamber 20 and sputtering is performed. As a result, as shown in FIG. 3A, a barrier metal film 3 is formed on the interlayer insulating film 2, the inner wall of the connection hole 2a, and the silicon substrate 1 exposed at the bottom of the connection hole 2a. . The barrier metal film 3 is a film in which, for example, a Ti film is laminated on a TiN film, and the thickness thereof is, for example, 50 nm. The processing time in the first sputtering chamber 20 is shorter than the processing time in the second sputtering chamber 30 described later, for example, half or less.

  Next, the silicon substrate 1 is transferred to any one of the second sputtering chambers 30. Next, sputtering is performed without heating the silicon substrate 1. At this time, it is preferable that the distance between each of the sputtering targets 34 and 36 and the silicon substrate 1 is 200 mm or more. Thereby, as shown in FIG. 3B, the Al alloy film 4 is formed thin (for example, 400 nm) on the barrier metal film 3. In this step, the Al alloy particles fly not only from the sputtering target 34 but also from the sputtering target 36. For this reason, the incident density of the particles of the Al alloy with respect to the inner wall of the connection hole 2a is increased as compared with the conventional case. Therefore, the deposition rate of the Al alloy film 4 on the inner wall of the connection hole 2a is faster than the conventional one, and the difference from the deposition rate of the Al alloy film 4 on the interlayer insulating film 2 is smaller than the conventional one. For this reason, the deposition rate of the Al alloy film 4 can be increased compared with the conventional one without reducing the coverage of the Al alloy film 4 in the connection hole 2a.

  Thereafter, the silicon substrate 1 is heated to, for example, 400 ° C. while continuing the sputtering in the second sputtering chamber 30. At this time, the distance between the sputtering targets 34 and 36 and the silicon substrate 1 is not shortened. Thereby, as shown in FIG. 3C, the thickness of the Al alloy film 4 is increased. And after the unevenness | corrugation of the Al alloy film 4 surface resulting from the inside of the connection hole 2a becomes small, the input for sputtering is raised and the deposition rate of the Al alloy film 4 is made quick.

  Also in these steps, since the Al alloy particles come from the sputtering targets 34 and 36, respectively, the deposition rate of the Al alloy film 4 should be increased as compared with the prior art without reducing the coverage of the Al alloy film 4. Can do. Finally, the thickness of the Al alloy film 4 is set to 2000 nm or more, for example.

  Further, since the film formation rate is faster than the conventional one, the heat load applied to the Al alloy film 4 is smaller than the conventional one. For this reason, the grain size of the Al alloy film 4 is smaller than that of the prior art. In addition, since the Al alloy film 4 is formed in the second sputtering chamber 30, it is necessary to transfer the silicon substrate 1 to the transfer chamber 10 having a low degree of vacuum during the formation of the Al alloy film as in the prior art. Absent. Therefore, the surface state of the Al alloy film 4 becomes better than the conventional one.

  As described above, the Al alloy films 4 can be formed in parallel on the plurality of silicon substrates 1 by processing the plurality of silicon substrates 1 in parallel using the plurality of second sputtering chambers 30. Further, as described above, the deposition rate of the Al alloy film 4 can be increased as compared with the conventional one. Accordingly, the production efficiency of the semiconductor device can be improved.

  Further, there is no need to transport the silicon substrate 1 while the Al alloy film is being formed as in the prior art. For this reason, the production efficiency of the semiconductor device can be further improved since the time for transporting the silicon substrate 1 becomes unnecessary.

  Next, the silicon substrate 1 is transferred to the third sputtering chamber 40 and sputtering is performed. Thereby, an antireflection film 5 is formed on the Al alloy film 4 as shown in FIG. The antireflection film 5 is, for example, a TiN film, and the thickness thereof is, for example, 40 nm. The processing time in the third sputtering chamber 40 is shorter than the processing time in the second sputtering chamber 30 and is, for example, half or less.

  Thereafter, a photoresist film (not shown) is formed on the antireflection film 5, and this photoresist film is exposed and developed. As a result, a resist pattern is formed on the antireflection film 5. Next, the antireflection film 5, the Al alloy film 4, and the barrier metal film 3 are etched using this resist pattern as a mask. As a result, the antireflection film 5, the Al alloy film 4, and the barrier metal film 3 are selectively removed, and an Al alloy wiring is formed.

  As described above, since the grain size of the Al alloy film 4 is smaller than the conventional one, the surface state of the Al alloy film 4 is improved, and it is easy to focus in the step of exposing the photoresist film. Therefore, the development residue of the resist pattern decreases, and the etching residue of the antireflection film 5, the Al alloy film 4, and the barrier metal film 3 decreases.

  As described above, according to the embodiment of the present invention, since the sputtering target 34 and the plurality of sputtering targets 36 (three in the example of this figure) are arranged in the second sputtering chamber 30, the coverage of the Al alloy film 4 can be increased. Without lowering, the deposition rate of the Al alloy film 4 can be increased compared to the conventional one. Moreover, since the grain size of the Al alloy film 4 is reduced, the surface state of the Al alloy film 4 is improved.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the example of FIG. 3, the case where an Al alloy film is formed on the first interlayer insulating film is shown, but the connection holes formed on the interlayer insulating film after the second layer and in this interlayer insulating film. The present invention can also be applied when an Al alloy film is formed inside. Further, instead of the Al alloy film, a Cu film to be a Cu wiring may be formed by a sputtering method.

The top view for demonstrating the structure of the film-forming apparatus which concerns on embodiment of this invention. (A) And (B) is the plane schematic and longitudinal cross-sectional view for demonstrating the structure of the sputtering chamber 30, respectively. Each drawing is a cross-sectional view for explaining a method of forming an Al alloy film to be an Al alloy wiring. The top view for demonstrating the structure of the conventional film-forming apparatus. Sectional drawing for demonstrating the structure of Al alloy film formed into a film by the film-forming apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 ... Silicon substrate, 2,102 ... Interlayer insulation film, 2a, 102a ... Connection hole, 3,103 ... Barrier metal film, 4,104a, 104b ... Al alloy film, 5,105 ... Antireflection film, 10, DESCRIPTION OF SYMBOLS 110 ... Transfer chamber, 11 ... Insertion port, 12 ... Slit valve, 14 ... Stage, 16 ... Exhaust pump, 20, 30, 40, 120, 131, 132, 140 ... Sputtering chamber, 34, 36 ... Sputtering target, 38a, 38b ... Electrode

Claims (9)

A stage on which a semiconductor substrate is placed;
A first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage;
A second sputtering target located obliquely above the stage and disposed obliquely with respect to the surface of the stage;
A film forming apparatus comprising: Comprising three or more second sputtering targets;
The angles formed by the two straight lines connecting the centers of the two second sputtering targets positioned next to each other and the center of the stage are substantially the same regardless of which of the two second sputtering targets is selected. The film-forming apparatus of Claim 1 which is equal.   The film forming apparatus according to claim 1, wherein the first and second sputtering targets are Al alloy targets. A transfer chamber;
A first processing chamber connected to the transfer chamber;
A plurality of second processing chambers connected to the transfer chamber;
Comprising
Each of the plurality of second processing chambers includes:
A stage on which a semiconductor substrate is placed;
A first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage;
A second sputtering target located obliquely above the stage and disposed obliquely with respect to the surface of the stage;
A film forming apparatus. The semiconductor substrate is processed by the first processing chamber and then transferred to the second processing chamber.
The film forming apparatus according to claim 4, wherein a processing time in the first processing chamber is shorter than a processing time in the second processing chamber. Above the stage on which the semiconductor substrate is placed on the surface, the first sputtering target is disposed substantially parallel to the surface of the stage,
The second sputtering target is disposed obliquely with respect to the surface of the stage obliquely above the stage,
A method for manufacturing a semiconductor device, comprising: placing a semiconductor substrate on a surface of the stage; and forming a film on the semiconductor substrate by sputtering using the first and second sputtering targets. The first and second sputtering targets are Al alloy targets,
The semiconductor substrate comprises an interlayer insulating film and a connection hole formed in the interlayer insulating film,
The method of manufacturing a semiconductor device according to claim 6, wherein an Al alloy film to be a wiring of the semiconductor device is formed on the interlayer insulating film and in the connection hole by the sputtering.   The method of manufacturing a semiconductor device according to claim 7, wherein the thickness of the Al alloy film is 2000 nm or more. A transfer chamber;
A first processing chamber connected to the transfer chamber;
A stage on which a semiconductor substrate is mounted; a first sputtering target positioned above the stage and disposed substantially parallel to the surface of the stage; and positioned obliquely above the stage and A second sputtering target disposed obliquely with respect to the surface of the stage, and a plurality of second processing chambers connected to the transfer chamber;
A sputtering apparatus comprising:
Sequentially processing a plurality of semiconductor substrates using the first processing chamber;
A plurality of semiconductor substrates processed by the first processing chamber are processed in parallel using the plurality of second processing chambers, thereby forming the same film on each of the plurality of semiconductor substrates. Production method.

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