JP2012001761A - Device and method for forming film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for forming a film excelling in coverage when forming a metal layer on a side face and a bottom face in a minute structure of a high aspect ratio formed on a substrate surface.SOLUTION: The device 1 for forming a film is used for forming, by sputtering, a metal layer on a substrate surface 4 formed with a minute structure. The device 1 for forming a film includes at least: a chamber 2 having an internal space for storing both a substrate 4 and a target 5 forming a base material of the metal layer therein by facing them to each other; an exhaust unit to reduce the pressure in the chamber 2; a gas introduction unit to introduce sputtering gas into the chamber 2; a first magnetic field generation unit 6 to generate a magnetic filed in front of a sputtering surface 5a of the target 5; a D.C. power source 7 for applying a negative D.C. voltage to the target 5; and a second magnetic field generation unit 10 to generate a magnetic field B in a direction from the target 5 toward the substrate 4.

Description

  The present invention relates to a film forming apparatus and a film forming method for forming a metal layer by sputtering on a substrate surface on which a fine structure is formed. More particularly, the present invention relates to a film forming apparatus and a film forming method for forming a metal layer on the side and bottom surfaces in a fine structure by sputtering while generating a magnetic field toward the substrate surface on which the fine structure is formed. .

When forming a metal layer on the side and bottom surfaces of a fine structure such as a fine hole (via), fine groove (trench), or through-hole formed in a silicon substrate or the like that constitutes a semiconductor device, CVD, sputtering, or the like is used. A membrane method is used (see Patent Document 1).
With the recent miniaturization of wiring patterns and the like in semiconductor devices, the depth and width ratio (aspect ratio) can be deposited with good coverage on the side and bottom surfaces in a high aspect ratio fine structure exceeding 5, There is a strong demand for improved coverage.
When the film is formed by CVD, the coverage is excellent, but there is a problem that the cost becomes high. On the other hand, when forming a film by lower cost sputtering, there is a problem that coverage is inferior. Particularly in a fine structure with a high aspect ratio, a decrease in coverage is a problem. For this reason, development of the film-forming method by sputtering excellent in coverage is strongly desired.

JP 2010-1505 A

  The present invention has been made in view of the above circumstances, and a film forming apparatus and a composition excellent in coverage when a metal layer is formed on a side surface and a bottom surface in a high aspect ratio microstructure formed on a substrate surface. It is an object to provide a membrane method.

The film forming apparatus according to claim 1 of the present invention is a film forming apparatus that forms a metal layer by sputtering on a substrate surface on which a fine structure is formed, and is a target that forms a base material of the substrate and the metal layer. And a chamber having an internal space for accommodating both, an exhaust means for decompressing the inside of the chamber, a gas introduction means for introducing a sputtering gas into the chamber, and a magnetic field in front of the sputtering surface of the target. First magnetic field generating means for generating, a DC power source for applying a negative DC voltage to the target, and second magnetic field generating means for generating a magnetic field in a direction from the target toward the substrate are provided. Features.
According to a second aspect of the present invention, there is provided the film forming apparatus according to the first aspect, wherein the second magnetic field generating means is installed on the side of the chamber, closer to the target side than the midpoint of the target and the substrate. It is characterized by being.
According to a third aspect of the present invention, there is provided a film forming apparatus according to the first or second aspect, further comprising a high frequency power source for applying high frequency power to the substrate.
A film forming method according to a fourth aspect of the present invention uses a film forming apparatus according to any one of the first to third aspects, and a magnetic field of 30 to 600 Gauss by the second magnetic field generating means. The metal layer is formed on the side surface and the bottom surface in the microstructure formed on the surface of the substrate by sputtering the target while generating.

According to the film forming apparatus and the film forming method of the present invention, the sputtered particles can be directed to the substrate by a magnetic field (lines of magnetic force) generated by the second magnetic field generating unit in a direction from the target toward the substrate. it can. As a result, the sputtered particles can reach the deep side surfaces and the bottom surface in the high aspect ratio microstructure formed on the substrate surface, and a metal layer with good coverage can be formed. Furthermore, since the second magnetic field generation means is installed on the side of the chamber of the film forming apparatus closer to the target than the midpoint of the target and the substrate, a gradient of the magnetic field strength is generated. The sputtered particles are more easily diffused to the substrate side, and the sputtered particles easily reach the side and bottom surfaces of the deep portion of the fine structure having a high aspect ratio, so that a metal layer with better coverage can be formed.
When the film forming apparatus of the present invention includes a high-frequency power source that applies high-frequency power to the substrate, bias sputtering can be performed. By bias sputtering, sputtered particles and charged particles of inert gas can be directed to the substrate. As a result, the orientation of sputtered particles by the magnetic field can be further accelerated. Furthermore, by resputtering the film formed on the bottom surface in the microstructure by self-bias by applying high frequency power, the coverage of the metal layer formed on the side surface and bottom corner in the microstructure is further improved. Can be.
In the film forming method of the present invention, a metal layer having excellent coverage can be formed even when the fine structure formed on the substrate surface is a fine hole or fine groove having an aspect ratio of 5 or more.

(a) Schematic sectional view showing an example of a film forming apparatus according to the present invention, (b) Schematic plan view showing an example of a film forming apparatus system provided with the film forming apparatus of (a). The schematic cross section which shows the metal layer formed using the film-forming apparatus of this invention. FIG. 4 is a schematic cross-sectional view showing another example of a film forming apparatus according to the present invention. It is a SEM image which shows the metal layer formed using the film-forming apparatus of this invention, (a) shows the coverage of 17.4% of the side part of the micropore of aspect ratio 5, (b) The coverage of the bottom of the hole is 17.1%. It is a SEM image which shows the metal layer formed using the film-forming apparatus of a comparative example, (a) shows the coverage of 3.7% of the side part of the micropore of aspect ratio 5, (b) The coverage of the bottom of the hole is 3.5%. The graph which shows an example of the relationship between the magnetic field intensity of the 2nd magnetic field generation means in the film-forming apparatus of this invention, and the coverage of the formed metal layer. The schematic cross section which shows the metal layer formed using the film-forming apparatus of a comparative example. The graph which shows an example of the relationship between the magnetic field intensity of the 2nd magnetic field generation means in the film-forming apparatus of this invention, and the coverage of the formed metal layer.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the present invention. is there.

  FIG. 1A is a schematic cross-sectional view showing an example (first embodiment) of a film forming apparatus 1 according to the present invention. The film forming apparatus 1 according to the first embodiment is a so-called magnetron sputtering apparatus, and includes a chamber 2 that is a processing chamber that can be decompressed. The shape in particular of the chamber 2 is not restrict | limited, For example, substantially cylindrical shape is mentioned. On the ceiling portion of the chamber 2, a cathode 3 having a target placement portion is disposed. A target 5 made of a material appropriately selected according to the composition of the metal layer to be formed on the surface of the substrate 4 to be processed is attached to the target mounting portion. A first magnetic field generating means 6 for generating a tunnel-like magnetic field is arranged on the upper portion of the cathode 3 in front of the sputtering surface 5 a of the target 5.

The chamber 2 has an exhaust pump (not shown) such as a turbo molecular pump or a rotary pump as an exhaust means for decompressing the inside, and is adjusted to a desired degree of vacuum. The chamber 2 is connected to a gas pipe (not shown) communicating with a gas source controlled by a mass flow controller as a gas introduction means for introducing a sputtering gas into the chamber 2, and introduces a desired sputtering gas. Can do. Examples of the sputtering gas include an inert gas such as Ar gas and a process gas such as N ₂ gas.

The shape of the target 5 is not particularly limited, and can be set to a desired shape (for example, a disk shape) so that the area of the sputtering surface 5a is larger than the surface area of the substrate 4 in accordance with the shape of the substrate 4 to be processed. .
As the material of the target 5, that is, the material of the metal layer formed on the surface of the substrate 4, a material according to the purpose may be selected. For example, Ti, Cu, W, Ni, Ta, Cr, Mo, Al, and These metal alloys are mentioned.
The target 5 and the cathode 3 are connected to a DC power source 7, and a predetermined negative potential is applied.

  The first magnetic field generating means 6 is arranged on the side opposite to the sputtering surface 5a (upper side), the yoke 6a arranged in parallel to the target 5, and the polarity on the target 5 side on the lower surface of the yoke 6a alternately. The magnets 6b and 6c are arranged. The shape and number of the magnets 6b and 6c are appropriately selected according to the magnetic field to be formed in front of the target 5 from the viewpoint of the stability of discharge and the use efficiency of the target 5 and the like. The first magnetic field generating means 6 may be configured to reciprocate or rotate on the back side of the target 5.

  A stage 8 is disposed at the bottom of the chamber 2 so as to face the target 5 so that the substrate 4 can be positioned and held. A high frequency power source 9 (RF power source) that applies high frequency power to the substrate 4 is connected to the stage 8.

  On the side wall 2 a of the chamber 2, the second magnetic field generating means 10 is disposed so as to surround the chamber 2. The second magnetic field generating means 10 is not particularly limited as long as it can generate a magnetic field B having a magnetic force line x in a direction from the target 5 toward the substrate 4. For example, a solenoid coil may be used. The number of the solenoid coils, the diameter of the conductive wire, and the number of turns are, for example, the size of the target 5, the distance between the target 5 and the substrate 4, the current value of the power supply device connected to the solenoid coil, and the strength of the magnetic field to be generated. It is set appropriately according to

  A dotted line in the chamber 2 in FIG. 1A indicates the approximate shape of the magnetic force lines x generated by the second magnetic field generating means 10. As for the direction of the magnetic force line x represented by the dotted line, either the upper or lower direction may be the N pole or the S pole, but FIG. 1A shows the case where the upper side is the N pole and the lower side is the S pole. The vector B indicates the direction of the magnetic field B formed by the plurality of magnetic field lines x. Since the second magnetic field generating means is arranged so as to be line symmetric with respect to the center line connecting the target 5 and the substrate 4, the magnetic field B to be formed is line symmetric with respect to the center line. Therefore, the magnetic field B can be represented by a vector B from the target 5 toward the substrate 4.

  The second magnetic field generating means 10 in FIG. 1A is installed on the side of the target 5 with respect to the midpoint V between the target 5 and the substrate 4 on the side wall 2 a of the chamber 2. With this arrangement, an inclination of the magnetic field strength from the target to the substrate direction is generated, and this inclination further facilitates diffusion of sputtered particles. Thereby, the coverage of the metal layer formed on the side surface and the bottom surface in the microstructure on the surface of the substrate 4 can be improved. Although this mechanism is not necessarily clear, it is presumed that it is important that the maximum point G of the lines of magnetic force in the chamber 2 is separated from the substrate 4 by a predetermined distance or more.

  Accordingly, the second magnetic field generation means 10 is arranged such that the center of the second magnetic field generation means 10 (the maximum point G of the magnetic force lines x generated by the second magnetic field generation means) is from the midpoint V between the target 5 and the substrate 4. Is preferably on the target 5 side, and more preferably on the target 5 side than the trisection point on the target 5 side among the points for dividing the target 5 and the substrate 4 into three (divided points). .

  On the other hand, as an example in which the center of the second magnetic field generating means 10 (the maximum point G of the magnetic force line y) is on the midpoint V, there is a film forming apparatus 100 (second embodiment of the present invention) shown in FIG. The same components as those of the film forming apparatus 1 shown in FIG. The approximate shape of the lines of magnetic force y in the magnetic field B generated by the second magnetic field generating means 10 of the film forming apparatus 100 is represented by dotted lines. Since the maximum point G of the line of magnetic force y is located at the midpoint between the target 5 and the substrate 4, the film forming property (the side surface in the microstructure and The coverage of the metal layer formed on the bottom surface is inferior. That is, the film forming apparatus 1 according to the first embodiment of the present invention is superior in film forming properties.

As a reason for this, in the film forming apparatus 1 of the first embodiment of the present invention, as described above, the maximum point G is set closer to the target 5 than the middle point V, and the diffusion of sputtered particles is promoted. This is thought to be due to the occurrence of a gradient of the magnetic field strength. For this reason, it is considered that the sputtered particles easily reach the bottom surface of the fine structure formed on the substrate surface, and the coverage is further improved.
Therefore, the arrangement of the second magnetic field generating means 10 in the film forming apparatus 1 of the first embodiment is more preferable than the arrangement of the second magnetic field generating means 10 in the film forming apparatus 100 of the second embodiment.

  FIG. 1B shows a schematic plan view of the film forming apparatus system 30. The film forming system 30 includes a substrate 4 (wafer) transfer chamber T, a load / unload chamber (L / UL chamber), an etching chamber (E2 chamber), a first sputtering chamber (S3 chamber), and a second sputtering chamber. (Room S4). The film forming apparatus 1 is installed in each of the S3 and S4 rooms.

  The L / UL chamber, the E2 chamber, the S3 chamber, and the S4 chamber are separated from the transfer chamber T by the partition wall W, and the inside can be made a vacuum atmosphere. Thus, for example, when the substrate is transferred from the E2 chamber to the S3 chamber, the substrate can be exposed to the atmosphere.

  The handler H0 provided in the partition wall W rotates while holding the substrate, and conveys the substrate between the E2, S3, S4, and L / UL chambers. The transfer machine in the transfer chamber T includes a handler H1 and substrate (wafer) cassettes C1 and C2. The handler H1 moves while holding the substrate, carries the substrate set in the cassette into the L / UL chamber, carries out the sputtered substrate from the L / UL chamber, and returns it to the cassette.

  Next, a film forming method using the film forming apparatus system 30 including the film forming apparatus 1 will be described. The substrate 4 shown in FIG. 2 has micropores 11 with an aspect ratio of 5 (depth / width ratio) formed on the surface. This substrate 4 is set in the transfer machine cassette C1, and is carried into the L / UL chamber by the handler H1. Subsequently, it is carried into the E2 chamber by the handler H0, and the oxide layer on the substrate surface is removed by etching. Thereafter, the handler H0 is placed on the stage 8 of the film forming apparatus 1 in the S3 chamber for positioning. The stage 8 is driven by the drive unit M so as to be movable up and down, and after placing the substrate 4, the substrate 4 is placed in the chamber 2.

The exhaust means of the chamber 2 is operated to evacuate to a predetermined vacuum level (for example, 10 ⁻⁵ Pa level). A solenoid coil that is the second magnetic field generating means 10 is operated to generate a magnetic field B from the target 5 toward the substrate 4. While introducing argon gas (sputtering gas) or the like into the chamber 2 at a predetermined flow rate, a predetermined negative potential is applied (powered on) to the target 5 from the DC power source 7 to form a plasma atmosphere in the chamber 2. Further, electrons ionized in front of the sputtering surface 5a and secondary electrons generated by sputtering are captured by the magnetic field from the first magnetic field generating means 6, and plasma is generated in front of the sputtering surface 5a.

  Further, when the magnetic field B is generated by the second magnetic field generating means 10, the plasma in front of the sputtering surface 5a can be made high in density, and ionization efficiency can be increased. Argon ions in the plasma collide with the sputtering surface 5 a and the sputtering surface 5 a is sputtered, and Ti atoms and Ti ions are scattered from the Ti target 5 toward the substrate 4 from the sputtering surface 5 a. Sputtered particles composed of argon ions, Ti ions, and Ti atoms fly along the magnetic field lines from the target 5 of the magnetic field B to the substrate 4 by the second magnetic field generating means 10 and are guided in the direction of the substrate 4. That is, the straight lines of the sputtered particles in the depth direction of the fine holes 11 are enhanced by the lines of magnetic force. As a result, the metal layer 12 made of Ti having excellent coverage can be formed by reaching the surface 4a of the substrate 4 and the side surface 11a and bottom surface 11b of the deep portion in the microhole 11. Here, since the lines of magnetic force have an appropriate inclination with respect to the surface of the substrate 4, the sputtered particles have higher straightness, and therefore the coverage of the bottom surface 11 b can be improved.

  At the time of this sputtering, it is preferable to apply high frequency (RF) power to the substrate 4 from the high frequency power source 9 for bias sputtering. Ar can be prevented from being occluded in the metal layer 12 made of Ti to improve the properties of the metal layer, and the resputtering effect (sputtered particles on which the metal layer is formed can be struck out of the metal layer temporarily. By forming the metal layer again), the coverage of the side surface 11a and the bottom surface 11b in the microhole 11 can be improved.

“Coverage” in this specification is defined as (the thickness of the metal layer formed on the side surface 11a or the bottom surface 11b in the micropore 11 / the thickness of the metal layer 12 formed on the substrate surface 4a) × 100%. Is done.
Hereinafter, (the thickness of the metal layer formed on the side surface 11a in the microhole 11 / the thickness of the metal layer 12 formed on the substrate surface 4a) × 100% may be referred to as side coverage. Among the side coverage, in particular, (the thickness of the metal layer formed in the vicinity of the bottom surface (corner portion) of the side surface 11a in the microhole 11 / the thickness of the metal layer 12 formed on the substrate surface 4a) × 100% , May be called corner coverage.
Further, (the thickness of the metal layer formed on the bottom surface 11b in the microhole 11 / the thickness of the metal layer 12 formed on the substrate surface 4a) × 100% may be referred to as bottom coverage.

The intensity (Gauss) of the magnetic field B by the second magnetic field generating means is preferably 30 to 600 Gauss, more preferably 150 to 550 Gauss, and further preferably 350 to 500 Gauss.
Coverage can be made favorable as it is more than the lower limit of the said range. Further, if it is at least the upper limit of the above range, the substrate is charged up by charged particles supplied by the magnetic field, which may cause abnormal discharge and increase in the substrate temperature.

The cause of the above relationship between the intensity of the magnetic field B and the coverage is considered as follows.
In general, charged particles (electrons, ionized sputtered particles) rotate along a magnetic field B (lines of magnetic force), but small and light electrons are immediately magnetized in a weak magnetic field (several gauss). However, sputtered particles that are larger and heavier than electrons are magnetized at several tens of gausses. From this, it is considered that a magnetic field to the extent that ionized sputtered particles are magnetized is necessary to improve coverage.

  For example, relatively light sputtered particles such as aluminum (Al) and alloys thereof (for example, Al-Si series) are considered to have an effect of magnetization at about several tens of gausses. Therefore, when light sputtered particles are used, the strength of the magnetic field B by the second magnetic field generating means is preferably about 30 to 300 gauss, more preferably 60 to 200 gauss, and further preferably 80 to 150 gauss.

  On the other hand, for example, relatively heavy sputtered particles such as titanium (Ti), nickel (Ni), copper (Cu), thallium (Ta), and tungsten (W) are considered to have an effect of magnetization at about several hundred gauss. . Therefore, when heavy sputtered particles are used, the strength of the magnetic field B by the second magnetic field generating means is preferably about 150 to 600 gauss, more preferably 250 to 550 gauss, and even more preferably 350 to 500 gauss.

Note that “magnetization” is defined as a state in which a charged particle rotates along a magnetic field one or more times while colliding with other particles.
[References]
Title: Introduction to Tohoku University Basic Electronics Engineering, Volume 4 Gas Discharge Author: Yoshinori Hatta Publisher: Toyosaku Kanayama Publisher: Modern Science Co., Ltd. Section 3.14.2 Influence of external magnetic field on plasma

  After forming the metal layer 12 made of Ti in the S3 chamber, the stage 8 is lowered and separated from the chamber 2, and placed on the stage 8 of the film forming apparatus 1 in the S4 chamber by the handler H0 and positioned. The target 5 in the film forming apparatus 1 in the S4 chamber is made of copper. A metal layer 14 made of copper can be laminated on the metal layer 12 made of Ti in the film forming apparatus 1 in the aforementioned S3 chamber (FIG. 2). The metal layer 14 made of copper can be formed by the same film forming method as that for the metal layer 12 made of Ti.

  The coverage of the metal layers 12 and 14 thus formed (FIG. 2) is that of the metal layer 13 (FIG. 7) formed using a film forming apparatus (comparative example) that does not include the second magnetic field generator. Obviously better than coverage.

Example 1
Using the above-described film forming apparatus system 30 provided with the film forming apparatus 1 of the present invention, a silicon substrate 4 in which fine holes 11 having a depth of 100 μm and a width of 20 μm (aspect ratio of 5) are formed is used. Specific examples of the film forming method are shown below.

  The silicon substrate 4 was transferred to the L / UL chamber by the transfer machine in the transfer chamber T, and the oxide layer on the substrate surface was removed by etching with argon gas in the E2 chamber. Thereafter, the silicon substrate 4 was moved to the S3 chamber, placed on the stage 8 of the film forming apparatus 1, and set in the chamber 2. At this time, the distance between the Ti target 5 and the silicon substrate 4 was set to 100 mm to 200 mm.

  The pressure in the chamber 2 is set to about 0.1 to 0.5 Pa using argon gas, the input power of the DC power source 7 connected to the cathode 3 is set to about 1.0 to 8.0 kW, and the second magnetic field A magnetic field was generated in the depth direction of the microhole 11 by passing a current of about 20 to 60 A through the coil conductor as the generating means. Further, the high frequency power source 9 applied about 100 to 500 W to the silicon substrate 4 to generate a self-bias.

  In this way, the metal layer 12 made of Ti was formed on the surface of the silicon substrate 4 and on the side surface 11 a and the bottom surface 11 b in the microhole 11. FIG. 4 shows an SEM image of a cross section of the metal layer 12 formed when the magnetic field generated by the second magnetic field generating means is 600 gauss, and the metal layer formed when the magnetic field generated by the second magnetic field generating means is 0 gauss. An SEM image of 12 cross sections is shown in FIG. FIG. 6 shows changes in the coverage {the coverage of the side surface 11a (corner portion) and the coverage of the bottom surface 11b (bottom portion)} when the magnetic field generated by the second magnetic field generating unit is changed from 0 to 600 gauss.

From the above results, it is clear that by applying a magnetic field in the depth direction of the fine holes 11, the straightness of the sputtered particles can be improved and the amount of film deposited and the coverage inside the fine holes 11 can be improved. Furthermore, by applying a bias voltage to the silicon substrate 4, the metal layer 12 formed on the side surface 11 a and the bottom surface 11 b of the microhole 11 is re-sputtered, and the peripheral portion of the bottom surface 11 b of the microhole 11 (most metal layer is It is clear that the film deposition amount and coverage at the corner portion, which is generally said to be difficult to form, can be improved. It can also be seen that the ionization rate of the sputtered particles is increased by the magnetic field, and the efficiency of resputtering by the electric field applied to the substrate side is increased.
From FIG. 6, it is clear that when the magnetic field intensity by the second magnetic field generating means is 150 gauss or more, both the coverage of the corner portion and the bottom coverage are rapidly improved, and the improvement of the coverage reaches a peak at 500 to 600 gauss. is there.

(Example 2)
The same procedure as in Example 1 was performed except that the target 5 was changed to Al and the magnetic field generated by the second magnetic field generating means was changed from 0 to 105 gauss. A metal layer 12 made of Al was formed on the side surface 11a and the bottom surface 11b.
FIG. 7 shows changes in coverage {coverage of the side surface 11a (corner portion) and coverage of the bottom surface 11b (bottom portion)} in this case.

  From FIG. 8, it is clear that the coverage sharply improves when the magnetic field intensity by the second magnetic field generating means is 30 Gauss or more. In particular, the improvement in the coverage at the corner is remarkable.

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus, 2 ... Chamber, 2a ... Side wall, 3 ... Cathode, 4 ... Substrate, 4a ... Substrate surface, 5 ... Target, 5a ... Sputtering surface, 6 ... First magnetic field generation means, 6a ... Yoke, 6b ... Magnet: 6c: Magnet, 7: DC power supply, 8: Stage, M: Drive unit, x: Magnetic field line, y: Magnetic field line, G: Maximum point of magnetic field line, 9: High frequency power supply, 10: Second magnetic field generating means (solenoid coil) ), 11... Fine hole, 11 a... Side surface of the fine hole, 11 b. Bottom surface of the fine hole, 12... Metal layer (Ti layer), 13 ... Metal layer, 14 ... Metal layer (Cu layer), 30. , T ... transfer chamber, L / UL ... load / unload chamber, E2 ... etching chamber, S3 ... first sputter chamber, S4 ... second sputter chamber, H0 ... handler, H1 ... handler, W ... partition, C1 ... transfer Loading machine cassette, C2 ... Transfer machine cassette.

Claims (4)

A film forming apparatus for forming a metal layer by sputtering on a substrate surface on which a fine structure is formed,
A chamber having an internal space for accommodating both of the substrate and the target that forms the base material of the metal layer,
An exhaust means for decompressing the inside of the chamber;
Gas introduction means for introducing sputtering gas into the chamber;
First magnetic field generating means for generating a magnetic field in front of the sputtering surface of the target;
A DC power supply for applying a negative DC voltage to the target;
Second magnetic field generating means for generating a magnetic field in a direction from the target toward the substrate;
A film forming apparatus comprising:   2. The film forming apparatus according to claim 1, wherein the second magnetic field generating unit is installed on the side of the chamber, closer to the target side than the midpoint between the target and the substrate.   The film forming apparatus according to claim 1, further comprising a high frequency power source that applies high frequency power to the substrate. Using the film forming apparatus according to any one of claims 1 to 3,
By sputtering the target while generating a magnetic field of 30 to 600 Gauss (Gauss) by the second magnetic field generating means,
A film forming method comprising forming the metal layer on a side surface and a bottom surface in a microstructure formed on a surface of the substrate.