WO1997001185A1

WO1997001185A1 - Method and apparatus for film formation

Info

Publication number: WO1997001185A1
Application number: PCT/JP1996/001690
Authority: WO
Inventors: Yuji Kubo; Shinji Tokumaru
Original assignee: Nippon Steel Corporation
Priority date: 1995-06-21
Filing date: 1996-06-19
Publication date: 1997-01-09
Also published as: JPH0969498A

Abstract

A thin film is formed by sputtering on a substrate having holes while gas ions are emitted to the substrate at an angle α (0° < α ≤ tan-1 (1/aspect ratio) + 10°), depending on the aspect ratio of the hole, with respect to the perpendicular of the substrate at 30 to 500 eV. In this way, the gas ions are caused to impinge against the sputtered particles adhering to the side wall portion of the hole during the formation of the thin film so that the particles on the side wall may be sputtered again.

Description

Description Film forming method and film forming equipment

The present invention relates to a film forming method and a film forming apparatus. More specifically, the present invention relates to a sputtering method and a sputtering apparatus for forming wiring and the like of a semiconductor device, and more particularly, to a thin film having a good coating property for holes such as contact holes and through holes. The present invention relates to a sputtering method and a sputtering apparatus that can be formed.

Background art

In recent years, as semiconductor devices such as ULSI (Ultra LSI) have become more highly integrated, component sizes have become finer, and problems in the manufacturing process have been increasing. For example, technology for embedding a wire material (a contact layer made of Ti, TiW, etc., a barrier layer made of TiN, etc.) into holes such as contact holes, through holes, and via holes In the above, there is a problem caused by an increase in the aspect ratio of the hole (for example, the depth z diameter of a cylindrical hole) because the opening diameter of the hole is further reduced by miniaturization of the component size. Is happening.

Conventionally, the sputtering method shown in FIG. 1 has been mainly used as the embedding technique. According to this method, particles sputtered from the target 5 are emitted toward the substrate 6 with a certain angular distribution (for example, on the cosine side). As a result, it is difficult to form the thin film 4 on the bottom of the hole 1 having a high aspect ratio because the ratio of particles deposited on the bottom of the hole 1 is small and the particles are easily deposited on the opening of the hole 1. It is. The ratio of the thickness of the thin film composed of particles deposited on the bottom of the hole to the thickness of the thin film composed of particles deposited on the outside of the hole (hereinafter referred to as the “top”) (bottom-force barrier) is increased. In order to achieve this, it is known that “collimation 'sputtering”, in which only sputtered particles whose emission direction is close to the perpendicular of the substrate, is selectively deposited on the substrate, is effective. As shown in Fig. 2, the collimated film is formed by combining a collimated plate 14 having microscopic holes arranged in a honeycomb shape with a substrate 6 and a target 5, for example. By inserting the particles between them, only the particles that have passed through these fine holes (that is, particles having a velocity component close to the perpendicular to the substrate 6) are deposited on the substrate 6, thereby forming the particles on the substrate 6. Improved bottom coverage of the thin film 4.

However, the collimation / spring method has the following problems.

(1) Since a large number of particles that have been packed are trapped by the collimator, a reduction in throughput is inevitable.

(2) Frequent cleaning of the collimator is necessary because particles adhere to the pores of the collimator and cause clogging of the pores.

(3) Dust that separates from the collimator adheres to the substrate.

Although it is known to devise a collimator to solve these problems (for example, Japanese Patent Application No. 6-1365652), other than particles having a velocity component close to the perpendicular to the substrate The principle of blocking particles is the same, and it is not a fundamental solution to the fact that particles adhere to the collimator.

There is also a negative effect due to the shadow effect (see HJ Leamy: Current Topics in Material Science 16 (1980) 309) caused by the sputtered particles having a velocity component that is substantially parallel to the side wall of the hole. For example, when a TiN film is formed using a collimator, a partial force with an extremely small film thickness is generated on the side wall near the opening of the hole, and the film may be peeled off from the partial force. Proceedings of the Integrated Circuit Technology Symposium 46th, p. 92-97, 1994.) Also, the thin film formed on the side wall of the hole tends to be columnar, and the barrier property is reduced. Also, there is a possibility that a problem may occur that the resistance of the wiring is increased.

Disclosure of the invention

An object of the present invention is to provide a film forming technique for forming a film on a substrate having holes having a large aspect ratio by sputtering, in which a decrease in throughput is small and a bottom force, a barrier, a barrier property and electric characteristics are large. An object of the present invention is to provide a film forming method and a film forming apparatus capable of forming a buried wiring.

The film forming method of the present invention is a film forming method in which a thin film is formed on a substrate having holes formed thereon by a sputtering method, wherein the thin film is formed in accordance with an aspect ratio of the holes with respect to a perpendicular to the substrate. The substrate is irradiated with ions at an angle α.

Further, the film forming method of the present invention is a film forming method for forming a thin film on a substrate on which holes are formed by a sputtering method,

Irradiation angle (0 ° a ≤ t an — '(1 / aspect ratio) + 10 °) with respect to the perpendicularity of the substrate according to the aspect ratio of the hole and 30 eV or more 500 The thin film is formed while irradiating the substrate with gas ions with the irradiation energy of eV, and during the formation of the thin film, the sputter particles adhering to the side wall of the hole are subjected to the gas erosion. Then, the sputtered particles are re-sputtered.

The film forming apparatus according to the present invention includes: a vacuum chamber in which a substrate in which holes are formed and a target are arranged so as to face each other; a unit configured to rotate the substrate about a perpendicular line of the substrate as a central axis; Means for irradiating the substrate with an ion beam at an angle α corresponding to an aspect ratio (depth / diameter) of the hole with respect to a perpendicular to the substrate.

Further, the film forming apparatus of the present invention is a film forming apparatus for forming a thin film on a substrate on which holes are formed by a sputtering method,

Means for applying a predetermined bias voltage to the substrate;

Irradiation at an irradiation angle (0 ° <α ≤ tan- ¹ (1 / aspect ratio) + 10 °) with respect to the perpendicular line of the substrate and 30 eV or more and 500 eV Means for irradiating the substrate with gas ions with energy;

Means for generating an electric or magnetic field parallel to the film-forming surface of the substrate,

Means for rotating the substrate about a perpendicular to the substrate as a central axis,

With

Irradiating the gas ions uniformly on the entire side wall of the hole to re-spark sputtered particles attached to the side wall of the hole during the formation of the thin film.

Here, it is necessary to set the ion irradiation angle α so that the ions collide with the side wall of the hole and the re-sputtered particles are directed to the bottom of the hole. This ion irradiation angle α should be in the range of 0 ° <a ≤ tan — '(1 / aspect ratio) + 10 ° with respect to the normal to the substrate. The energy of the ions must be in a range that causes re-sputtering and does not damage the thin film, and the range is 30 eV or more and 500 eV or less. The film forming method and the film forming apparatus of the present invention are characterized in that the film is formed while irradiating the thin film growing on the side wall of the hole with ions. Irradiation angles and respattering occur where ions collide with a wide area of the side wall of the hole and re-spatter particles deposited on the side wall of the hole. By setting the ion irradiation conditions to an energy that does not cause damage, the particles that have once adhered to the side wall of the hole are re-sparked and re-adhered to the bottom of the hole. This improves bottom coverage without significantly reducing productivity. In addition, by rotating the substrate, the side wall of the hole can be uniformly irradiated with ions, and the thickness of the thin film deposited in the hole can be made uniform.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram for explaining a conventional sputtering method.

FIG. 2 is a diagram for explaining a conventional collimator 'sputtering method. FIG. 3 is a schematic diagram for explaining the basic principle of the film forming method of the present invention. FIG. 4 is a view for explaining a first embodiment of the film forming method and the film forming apparatus of the present invention.

FIG. 5 is a view showing a shape of a mask for describing a first embodiment of a film forming method and a film forming apparatus of the present invention.

FIG. 6 is a view for explaining a second embodiment of the film forming method and the film forming apparatus of the present invention.

FIG. 7 is a diagram showing a configuration example of the trapping electrode shown in FIG.

FIG. 8 is a view for explaining a third embodiment of the film forming method and the film forming apparatus of the present invention.

FIG. 9 is a view for explaining a third embodiment of the film forming method and the film forming apparatus of the present invention.

FIG. 10 is a view for explaining a third embodiment of the film forming method and the film forming apparatus of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings. First, the basic principle of the film forming method of the present invention will be described with reference to FIG. When depositing sputtered particles 3 over the entire surface of substrate 6 in which hole 1 was formed to form thin film 4, the sputtered particles 3 were perpendicular to substrate 6 so as to collide with sputtered particles 3 attached to the side wall of hole 1. On the other hand, the substrate 2 is irradiated with the ions 2 at an angle corresponding to the aspect ratio (depth / diameter) of the hole 1. At this time, the sputtered particles 3 that have once adhered to the side wall of the hole 1 are resputtered by the collision of the ions 2 and adhere again to the bottom of the hole 1. As a result, the thickness of the thin film 4 formed at the bottom of the hole 1 increases.

Next, a first embodiment of the film forming method and the film forming apparatus of the present invention will be described with reference to FIG.

The film forming apparatus according to the present embodiment includes a vacuum chamber 7, first and second electrodes 8, 8 provided in the vacuum chamber 7 to face each other, and a second electrode of the first electrode 8. 8 and target 5 provided on the _two opposing to the surface, provided on the outside of the vacuum chamber 7, the first and second electrode 8, the first and second for supplying a DC voltage, respectively 8 DC voltage sources 2 1, 2 1 are provided. Hole 1 (not shown) Force << formed substrate 6 is tilted at an angle to target 5 and perpendicular to substrate 6 on the surface of _second electrode 82 facing the first electrode, It is provided so that it can rotate as a central axis. The second DC voltage source 2 1 ₂ is to the second electrode 8 can be supplied a direct current voltage of one 3 0 V to one 5 0 0 V. In this film forming apparatus, sputtering is performed by using the target 5 as a cathode to generate plasma near the target 5. For example, when using the A r gas as and a discharge gas with a T i target as target 5, with a substantially energy of the same voltage component as the voltage applied to the _second electrode 2 8, to the perpendicular of the substrate 6 Ar ion in the plasma collides with the substrate 6 from an oblique direction only at an angle.

When the Ar ⁺ ions collide with the substrate 6 as described above, the sputtered particles that once adhered to the side wall of the hole 1 are re-sputtered and adhere again to the bottom of the hole 1. As a result, the thickness of the thin film formed at the bottom of the hole 1 increases. Further, by rotating the substrate 6, Ar ⁺ ions are uniformly irradiated on the entire side wall of the hole 1, and the thickness of the thin film formed in the hole 1 can be made uniform.

At this time, the angle α is 0 ° <α≤tan— ¹ (1Z 10 °), preferably ta η ″ ′ (1 aspect ratio) -1 10 ° ≤ α≤ ta η ″ ′ (1 / aspect ratio) +5. Should be within the range. In particular, the effect is significant when the aspect ratio is 4 or less.

The same applies to the case where nitrogen gas is used as the discharge gas for forming the TiN film.

Using the film forming apparatus of the present embodiment, a DC magnetron sputtering apparatus having a magnet disposed on the back surface of the target 5 was configured, and the substrate 6 was not tilted and the substrate 6 was tilted by an angle H = 15 °. A comparative experiment was performed with the case. Note that the distance between the substrate 6 and the target 5 when the substrate 6 is inclined is 65 mm, and the substrate 6 and the target 5 when the substrate 6 is inclined by an angle of 15 °. The distance between them was 50 mm. In each case, the substrate 6 was rotated. However, in this comparative experiment, instead of forming a thin film inside the hole 1 formed in the substrate 6, instead of forming a thin film on the substrate 6, as shown in FIG. Simulate embedding of the thin film 4 using a mask 13 having holes 1 2

In the first experiment, after forming the thin film 4 on the substrate 6 on which the mask 13 with the holes 12 formed was placed, the mask 13 was removed from the substrate 6 and the mask 13 of the substrate 6 was not attached. The thickness of the thin film 4 formed on the portion (top portion) and the hole 12 (bottom portion) of the mask 13 of the substrate 6 is measured with a surface roughness meter to measure the force barrier. Was.

Here, a silicon wafer was used as the substrate 6, and a glass plate having a thickness of 2 mm and a hole 12 having a diameter of lmm was used as the mask 13. In this case, the aspect ratio of the hole 12 is “2”. The thin film 4 is formed by depositing a Ti thin film so that the thickness at the top becomes 0.3 m, and then applying a TiN so that the thickness at the top becomes 3 μm. This was done by depositing a thin film on the Ti film. Deposition of T i thin film, for all samples, using the A r as a discharge gas, pressure 4 XI 0 ³ To rr, was carried out under the condition that the target voltage 380 V and target current 2 A. Further, the deposition of the T i N thin film, a mixed gas of A r and N ₂ as the discharge gas (flow ratio of 1: 1) using a pressure ^{4 X 1 (T 3 To rr} , evening per target voltage 500 V The test was performed under the conditions of a target current of 3 A and a bias voltage applied to the sample and the substrate for 6 mm.

The performance comparison was performed by comparing the bottom coverage of the TiN thin film. Table 1 shows an example of performance comparison. Table 1. Performance comparison

When the substrate 6 is not tilted (that is, when the angle α is 0 °), the bottom coverage is about 8% regardless of whether or not the bias voltage is applied. The value is almost the same as in the case where is formed (see monthly semiconductor world, 1994, 12, p. 190). When the substrate 6 was tilted but no bias voltage was applied, the bottom 'coverage was almost the same as when the substrate 6 was not tilted. When the substrate 6 was tilted and a bias voltage was applied, the bottom 'coverage was almost twice as large as when the substrate 6 was not tilted. Even when a 1 mm thick stainless steel plate having a hole 12 with a diameter of 0.5 mm is used as the mask 13 (the aspect ratio of the hole 12 is "2"). The same results as in Table 1 were obtained.

Next, as a second experiment, a 1.5-μm thick silica film (hereinafter, referred to as “1 μm”) formed by doping with boron (B) and phosphorus (P) was formed. A thin film was formed on a silicon 'wafer, called a “BPSG film”) in the same manner as in the first experiment, and the cross section of the hole was observed by SEM (scanning electron microscope). The thin film is formed by depositing a Ti thin film so that the thickness at the top becomes 0.1 μm, and then forming a Ti thin film so that the thickness at the top becomes 0.7 μm. N thin film This was done by depositing on a Ti thin film. Then, the shape of the thin film formed inside the hole was determined by using the normal sputtering method and the above-mentioned experiment to form the bottom film with the highest coverage (the angle = 15 ° and the bias voltage = -200 V). The comparison was made with the shape of the thin film 4 embedded in the hole 1 having an aspect ratio of 1.5. As a result, the bottom coverage of the thin film formed in this experiment was improved to about twice, and the film thickness did not become extremely small near the opening of the hole. The film formation rate was 480 angstroms / min in ordinary sputtering, but was 450 angstroms Z, and the decrease in productivity was small.

Next, as a third experiment, the same experiment as the above-mentioned second experiment was performed for a case where only a Ti thin film was deposited so that the thickness at the top portion was 0.7 μm. A comparison was made between the case of the Ti thin film forming conditions shown in the first experiment and the case of tilting the substrate by 15 ° and applying a bias voltage of 100 V under these film forming conditions. As a result, in the latter case, the bottom 'coverage is about twice as large as that in the former case, and the film forming rate is 120 Å / min for ordinary sputtering. 880 angstroms, and the decrease in productivity was small. Further, in the latter case, observation by SEM revealed that the thin film deposited on the side wall of the hole was densified. These facts suggest that the present invention is effective for improving the bottom coverage regardless of the type of the material of the thin film. Further, according to the present invention, the improvement of the barrier property by densification of the thin film and This suggests that it is possible to reduce the resistance of the wiring.

Next, a second embodiment of the film forming method and the film forming apparatus of the present invention will be described with reference to FIG.

The film forming apparatus of the present embodiment includes a vacuum chamber 7, first and second electrodes 8, 8 ₂ provided opposite to each other in the vacuum chamber 7, and a second electrode 8 of the first electrode 8. a target 5 provided on the surface facing the electrode _82, provided on the outside of the vacuum chamber 7, the first and second electrode 8, the first and second for supplying respectively a DC voltage to ₈₂ 2 DC voltage sources 2 1, 2 1 ₂ . The substrate 6 in which the hole 1 (not shown) is formed is placed on the surface of the _second electrode 82 facing the first electrode, parallel to the target 5 and centered on the perpendicular of the substrate 6. It is provided so that it can rotate. Second DC Voltage source 2 1 ₂ to the second electrode 8 - 3 0 V~- 5 is capable supplying 0 0 V DC voltage. In this film forming apparatus, the target 5 is used as a force source to generate plasma near the target 5 and perform sputtering.

Film-forming apparatus of this embodiment, a pair of auxiliary electrodes 9 provided across the substrate 6, 9 _2, provided on the outer vacuum chamber 7, a pair of auxiliary electrodes 9, a DC voltage between 9 ₂ And a third DC voltage source 21 for supplying the DC voltage. Third DC voltage source 2 1 from the pair auxiliary electrodes 9, 9 by a predetermined DC voltage is applied to the _2, parallel to the electric field and the deposition surface of the substrate 6 occurs. As a result, the ions collide with the substrate 6 from an oblique direction at an angle α with respect to the normal to the substrate 6.

Although the substrate 6 is set in parallel with the target 5 in the film forming apparatus of the present embodiment, the substrate 6 may be set to be inclined at a predetermined angle with respect to the target 5. In addition, in the film forming apparatus of the present embodiment, the substrate 6 is rotated, but as shown in FIG. 7, a predetermined number of auxiliary electrodes 9 are arranged around the substrate 6, and half of the auxiliary electrodes 9 are used. If the polarity of the auxiliary electrode 9 is controlled so as to sequentially change in the circumferential direction of the substrate 6 so as to be a negative potential, the substrate 6 does not need to be rotated. Further, by using a magnet or an electromagnet instead of the pair of auxiliary electrodes 9, 9 ₂ to generate a magnetic field parallel to the film-forming surface of the substrate 6, ions can be formed only at an angle with respect to the perpendicular to the substrate 6. It can collide with the substrate 6 from an oblique direction.

Using the film forming apparatus shown in FIG. 6, an experiment of embedding into the substrate 6 having the holes 1 having an aspect ratio of 1.5 was performed, and the cross section of the holes 1 was observed by SEM. The thin film is formed by depositing a Ti thin film so that the thickness at the top becomes 0.1 m, and then forming a Ti N thin film so that the thickness at the top becomes 0.7 μm. This was done by depositing on a Ti thin film. Deposition of T i thin film, for all samples, using the A r as a discharge gas, pressure ^{4 X 1 0- 1 3 T orr} , that other one rodents G Voltage 3 8 0 V and data one g e t preparative current 2 A Performed under conditions. Further, the deposition of the T i N thin film with the all samples, a gas mixture of A r and N ₂ as the discharge gas (flow ratio of 1: 1) using a pressure ^{4 X 1 0- 1 3 T orr} , target And the bias voltage applied to the substrate 6 was 200 V, and the voltage applied to the pair of auxiliary electrodes 9 was 50 V. As a result, the bottom of the thin film formed in this experiment The diameter was improved about twice, and the film thickness did not become extremely small near the opening of the hole.

Next, a third embodiment of the film forming method and the film forming apparatus of the present invention will be described with reference to FIGS.

As shown in FIG. 8, the film forming apparatus of the present embodiment includes a vacuum chamber 7, an electrode 8 provided in the vacuum chamber 7, and a target 5 provided on a surface of the electrode 8 facing the substrate 6. A DC voltage source 21 provided outside the vacuum chamber 7 for supplying a DC voltage to the electrode 8; and a radiation angle of the ion can be set to an arbitrary angle with respect to a perpendicular line of the substrate 6 and acceleration of the ion. An assist ion gun 10 capable of setting the speed to 30 V to 500 V is provided. The substrate 6 in which the hole 1 (not shown) is formed is provided so as to be parallel to the target 5 and rotatable about a perpendicular line of the substrate 6 as a center axis.

In the film forming apparatus shown in FIG. 8, sputtering is performed by using the target 5 as a force source to generate plasma near the target 5. However, instead of the electrode 8 and the DC voltage source 21, a sputtering ion gun 11 is provided in the vacuum chamber 7 as shown in FIG. 9 to collect the ion beam emitted from the sputtering ion gun 11. Sputtering may be performed on the target 5. In this case, the installation position and the installation angle of the sputtering ion gun 11 with respect to the target 5 are adjusted so that the flux of the particles sputtered from the target 5 increases in the direction perpendicular to the substrate 6.

In the film forming apparatus shown in FIG. 8 or the film forming apparatus shown in FIG. 9, sputtering is performed using, for example, a Ti target as a target 5 and Ar ⁺ ions are emitted from the assist ion gun 10. However, when depositing a thin film on the deposition surface of the substrate 6, Ar ^ ions generated in the assisting ion gun 10 are emitted with the energy of the voltage applied to the acceleration electrode, and maintain almost the same energy. Collision is made obliquely to the perpendicular direction of the substrate 6 by the inclination angle of the assisting ion gun 10. The same phenomenon occurs when nitrogen ions are used to deposit the TiN film.

In both the film forming apparatus shown in FIG. 8 and the film forming apparatus shown in FIG. 9, the following method for increasing the flux of sputtered particles in the direction perpendicular to the substrate 6 is also used. By using this, it is possible to improve the larger bottom coverage.

(1) How to increase the distance between substrate 6 and target 5 (see NIKKEI MICRO-DEVIC ES, October 1994, October, p.58)

(2) Method using a target with a collimator integrated on the front (see JP-A-6-136527)

After forming a BPSG film with a thickness of 1 μm (an aspect ratio = 0.5) on which a hole with a diameter of 2 tzm was formed on the substrate 6, while rotating the substrate 6, the results are shown in Fig. 9. A thin film was formed on the BPSG film and inside the hole using the film forming apparatus. The thin film is formed by depositing a Ti thin film so that the thickness at the top becomes 0.02〃m, and then forming a TiN so that the thickness at the top becomes 0.3〃m. This was done by depositing a thin film on the Ti film. The deposition of the Ti thin film was performed using a sputter ion gun 11 at an acceleration voltage of 1 000 V and a current density of 5.1 mA / cm ² under a pressure of 1.4 x 10 Torr for all samples. The Ti target was sputtered with Ar ⁺ ions. The incident angle of the sputtered particles with respect to the perpendicular to the substrate 6 was constant for all samples. However, when depositing the TiN thin film, the substrate 6 was irradiated with N ₂ (N) ⁺ ions having an accelerating voltage of 300 V and a current density of 0.17 mAZcm ² by the assisting ion gun 10, and the perpendicular of the substrate 6. The irradiation angle of the assist ion was varied depending on the sample. The bottom coverage was measured by observing the cross section of the hole by SEM, and the bottom coverage was compared for each TiN thin film deposition condition. Table 2 shows the comparison results. Table 2. Comparison results (Ion 'assist conditions and bottom coverage)

When the ion irradiation angle is 0 ° and the ion acceleration voltage is 300 V, the bottom cover Redge is almost the same as without ion assist. This seems to be due to the fact that the ions do not collide with the side wall of the hole and do not resputter atoms attached to the side wall. On the other hand, when the ions are irradiated obliquely, the bottom force coverage is improved, and when the irradiation angle is 40 ° and the irradiation energy is 300 eV, the bottom 'coverage is not ion'. More than doubled.

In this experiment, the sputter ion gun 11 and the target 5 were provided so that the sputtered particles were incident at a large angle with respect to the perpendicular to the substrate 6, so that the thin film force was applied to the bottom of the hole having a high aspect ratio. Not formed. However, if the arrangement of the sputtering ion gun 11 and the target 5 is adjusted so that the flux of the sputtered particles is maximized in a direction close to the perpendicular to the substrate 6, the thin film can be embedded in the holes having a high aspect ratio. Even in that case, the bottom and the coverage are improved as well as the effect of this experiment.

In the film forming apparatus shown in FIG. 8, when the diameter of the ion beam emitted from the assisting ion gun 10 is small, in order to improve the uniformity of the ion irradiation amount on the film forming surface of the substrate 6, FIG. As shown in FIG. 10, the assist ion gun 10 is provided on the XYZ tilt table 31, and the assist ion gun 10 is moved horizontally by the control device 32 for the XYZ tilt table 31. The ion beam applied to the substrate 6 may be scanned by controlling the angle of the ion gun 10 for use. If the assist ion gun 10 cannot be adjusted to an appropriate angle, the substrate 6 is inclined or a pair of auxiliary electrodes 9 with the substrate 6 interposed therebetween, as shown by the broken line in FIG. ,, 9 ₂ pair of auxiliary electrodes 9 a suitable voltage provided, and or applied between 9 _2, may adjust the irradiation angle of the ion beam. The irradiation angle of the ion beam may be adjusted by using both the inclination of the substrate 6 and the installation of the pair of auxiliary electrodes 9, 9 2. Note that a pair of auxiliary electrodes 9! Instead of generating an electric field in a direction parallel to the film-forming surface of the substrate 6 using the first and the _second , a permanent magnet or an electromagnet may be used to generate a magnetic field in a direction parallel to the film-forming surface of the substrate 6.

As is clear from the above description, the present invention does not use a method of selecting and depositing only particles having a velocity component close to the direction perpendicular to the substrate, so that the side near the opening of the hole is not used. There is no portion where the film thickness becomes extremely thin on the wall, and ions are irradiated to the side wall of the hole, so that the thin film is densified and the barrier properties and the electrical characteristics can be expected to be improved. Therefore, the present invention eliminates the problems associated with the embedding of the thin film material according to the prior art, has a small decrease in throughput, and has a great effect in obtaining a wiring having a large bottom coverage, a high barrier property, and a large electric characteristic. can get.

Claims

The scope of the claims

1. A film forming method for forming a thin film on a substrate having holes by a sputtering method,

5 With respect to the perpendicular to the substrate, the irradiation angle (0 ° a ≤ t an — ¹ (1 / aspect ratio) + 10 °) according to the aspect ratio of the hole and 30 eV or more 50,000 e The thin film is formed while irradiating the substrate with gas ions with V irradiation energy, and the gas ions are applied to sputtered particles attached to the side wall of the hole during the formation of the thin film. The method of impinging and re-spacing the sputtered particles.

Ten.

2. A film forming apparatus for forming a thin film on a substrate having holes formed by a sputtering method,

The angle between the vertical line of the substrate and the vertical axis is the irradiation angle a (0 ° ≤ t an — '(1 nos ratio) + 10 °) according to the aspect ratio of the hole. Means for inclining the substrate as described above,

15 means for applying a predetermined bias voltage to the substrate, and irradiating the substrate with gas ions by an irradiation energy of 30 eV or more and 500 eV;

With

The apparatus for uniformly irradiating the gas ions on the entire side wall of the hole to resputter sputtered particles adhered to the side wall of the hole during the formation of the thin film.

3. A film forming apparatus for forming a thin film on a substrate having holes formed by a sputtering method,

Means for applying a predetermined bias voltage to the substrate;

Irradiation angle (0 ° <α≤

Means for irradiating the substrate with gas ions at an irradiation energy of 25 tan— ¹ (1 / aspect ratio) + 10 °) and 30 eV or more and 500 eV;

Means for generating an electric or magnetic field parallel to the film forming surface of the substrate,

With The apparatus for uniformly irradiating the entire side wall portion of the hole with the gas ions to re-pack the sputtered particles attached to the side wall portion of the hole during the formation of the thin film.

4. The film forming apparatus according to claim 3, wherein

The irradiating means may have an irradiation angle (0 ° <≤tan- ¹ (1Z aspect ratio) +10.) According to an aspect ratio with respect to a perpendicular to the substrate. Said apparatus comprising means for tilting the substrate.

5. A film forming apparatus for forming a thin film on a substrate having holes formed by a sputtering method,

Irradiation angle α (0 ° ≤ tan— '(1 / aspect ratio) + 10 °) with respect to the perpendicular line of the substrate according to the aspect ratio of the hole and 30 eV or more and 500 ° means for irradiating the substrate with gas ions at an irradiation energy of eV,

With

The apparatus for uniformly irradiating the entire surface of the hole with the gas ions to resputter sputtered particles attached to the side wall of the hole during the formation of the thin film.

6. The film forming apparatus according to claim 5, wherein

The irradiating means tilts the substrate so that an irradiation angle a (0 ° altan ¹ (1 aspect ratio) + 10 °) corresponding to an aspect ratio with respect to a perpendicular line of the substrate is obtained. The apparatus comprising at least one of: a means for generating a magnetic field and a means for generating an electric field or a magnetic field parallel to a film forming surface of the substrate.

7. The film forming apparatus according to claim 5, wherein

The apparatus, wherein the irradiating unit includes a unit configured to scan the gas / ion on the film forming surface of the substrate while maintaining the irradiation angle.

8. The film forming apparatus according to claim 6, wherein

The apparatus, wherein the irradiating unit includes a unit configured to scan the film surface of the substrate with the gas ions while maintaining the irradiation angle.

9. The film forming apparatus according to claim 5, wherein

The apparatus, wherein the irradiating means includes means for irradiating the substrate with the gas ions while changing the irradiation angle.

10. The film forming apparatus according to claim 6, wherein

The apparatus, wherein the irradiating means includes a means for irradiating the substrate with the gas ions while changing the irradiation angle α.