JPH11158621A - Production of semiconductor device and producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the thinning of coating thickness on the outer circumferential part of a substrate at the time of producing a semiconductor device by an ionization sputtering method. SOLUTION: The space between a target 10 and a substrate 20 is provided with an induction coil 5, plasma is generated, and sputtering particles (+) released from the target are ionized. A bias electrode 7 surrounding the circumference on the outside of the substrate is provided, and a negative bias is applied by a high frequency power source. By staggering the timing of the bias to be applied to the bias electrode 7 and a stage part 3, the uniformization of the thickness of the coating to be deposited on the substrate is attained. The bias electrode 7 is made movable up and down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing a semiconductor device, and more particularly to a method for forming a thin film using an ionization sputtering apparatus and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in this type of semiconductor device manufacturing apparatus,
A sputtering method is mainly used in which ions such as Ar ⁺ are accelerated in a vacuum and collided with an electrode (target) maintaining a negative potential. These electrode substances are separated from the electrode surface by the energy of Ar ⁺ (sputtering phenomenon), and the protruding substances (sputter particles) are deposited on the substrate to form a thin film.

At this time, as shown in FIG.
An induction coil 5 is provided in a space between the zero and the substrate 20 and connected to a high frequency (RF) power supply 6 to apply a high frequency to the induction coil 5 to positively ionize sputtered particles by plasma formed.

Further, a negative bias is also applied to the substrate 20 by the high-frequency power supply 4 to attract the positively ionized sputtered particles as a component closer to the vertical toward the substrate 20 side, thereby forming a thin film on the substrate. (Ionization sputtering). According to such a method, the sputtered particles can be attracted almost vertically onto the substrate,
A thin film can be formed in a hole having a high aspect ratio, and high coverage in the hole can be expected.

[0005]

In the above-described conventional semiconductor device manufacturing apparatus, not all of the sputtered particles emitted from the target are emitted perpendicularly to the target. The number of sputter particles attracted toward the outer peripheral portion of the substrate is limited as compared with that attracted toward the central portion of the substrate. Therefore, there is a disadvantage that the film thickness at the outer peripheral portion of the substrate is smaller than that at the central portion of the substrate.

When the film thickness at the outer peripheral portion of the substrate is about 200 ° or less, the thin film is peeled off due to friction with the carrier during the process, or is peeled off due to gas attack in a later CVD process. There is a drawback that this may cause the occurrence of.

An object of the present invention is to eliminate a source of particles by preventing a peripheral portion of a substrate from being thinner than a central portion when manufacturing a semiconductor device by ionization sputtering. . It is still another object of the present invention to make the film thickness as uniform as possible over the entire substrate and to expand the effective area of the substrate when manufacturing a semiconductor device.

[0008]

SUMMARY OF THE INVENTION A semiconductor device manufacturing apparatus according to the present invention is an apparatus for forming a thin film on a semiconductor substrate by an ionization sputtering method. A stage portion provided at a position where the semiconductor substrate is mounted,
A power supply for applying a negative bias to the stage, an induction coil provided in a space between the target and the stage, a high-frequency power supply for applying a high frequency to the induction coil, and an outer periphery of the semiconductor substrate And a power supply for applying a negative bias to the bias electrode unit.

It is preferable that the bias electrode section has a moving means for moving the bias electrode section in parallel with the substrate and in a direction perpendicular to the surface of the substrate.

A method for manufacturing a semiconductor device by the semiconductor device manufacturing apparatus of the present invention is characterized in that biases are applied to the stage portion and the bias electrode portion at different timings. That is, the first
After applying a bias to the bias electrode portion to secure formation of a thin film around the semiconductor substrate as a step, a bias is applied to the stage portion to form a thin film over the entire substrate as a second step.

Further, by using the above-described means for moving the bias electrode portion, the bias electrode portion is positioned on the side opposite to the stage portion with respect to the semiconductor substrate mounted on the stage or on the same side as the stage portion. The position and thickness of the film formed on the substrate can be controlled depending on whether the film is positioned or positioned on the side of the stage.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing a configuration of an embodiment of a semiconductor device manufacturing apparatus according to the present invention.

The housing 1 houses a main part of the manufacturing apparatus,
This is a case in which an internal pressure is maintained at a predetermined degree of vacuum by a vacuum generator (not shown), and an inert gas such as Ar is contained. A target 10 is held inside the housing 1. A negative potential is applied to the target 10 to form a cathode. When ions such as Ar ⁺ accelerated in a vacuum collide with the surface of the target, the electrode material of the target receives the energy of Ar ⁺ and separates sputtered particles from the electrode surface by a sputtering phenomenon.

A DC power supply 2 for applying a negative potential to the target 10 is provided outside the housing 1, and its cathode is connected to the target 10.

The stage section 3 is provided to face the target 10 and is a table on which a semiconductor substrate 20 on which a thin film is to be formed is mounted thereon.

A first high-frequency power supply 4 is provided outside the housing 1 and is connected to the stage 3 to apply a negative bias to the substrate 20 mounted on the stage 3.

The induction coil 5 includes the target 10 and the substrate 2
0 and is connected to a second high-frequency power supply 6 provided outside the housing to generate plasma in the middle of the space formed by the target 10 and the substrate 20. This is a device for positively ionizing sputter particles detached from the target 10 by a sputtering phenomenon.

The bias electrode 7 is provided so as to surround the entire periphery of the peripheral portion of the substrate 20 mounted on the stage section 3 (see FIG. 2), and is connected from the first high frequency power supply 4 via a changeover switch 8. , A negative bias is applied. The changeover switch 8 is a changeover switch that can apply a negative bias generated from the first high-frequency power supply 4 to either the stage unit 3 or the bias electrode 7 or simultaneously apply them to both.

Next, the operation of the semiconductor device manufacturing apparatus will be described. After the target 10 is provided inside the housing 1 and the substrate 20 is placed on the stage section 3, the inside of the housing 1 is maintained at a predetermined vacuum pressure and argon gas is supplied. A negative voltage is applied to the target 10 by the DC power supply 2 to serve as a cathode, thereby causing a glow discharge state between the target 10 and the substrate 20. In this state, Ar in the argon gas
⁺ Ions are accelerated, and the target 10 is maintained at a negative potential.
And sputtered particles are detached from the surface.

When a high frequency power is supplied to the induction coil 5 from the second high frequency power supply 6, the sputtered particles are (+) ionized by the plasma generated in the middle of the space formed by the target 10 and the substrate 20. In this state, a negative bias is applied to the bias electrode 7 from the first high-frequency power supply 4 by operating the changeover switch 8 in order to increase the film thickness formed around the substrate. Therefore, the (+) ionized sputtered particles are attracted to the outer peripheral portion of the substrate, and a thin film is formed preferentially on the outer peripheral portion of the substrate.

At this time, the negative bias applied to the bias electrode 7 is
It is necessary that the value be sufficiently weak so as not to attract r ⁺ .

In the method of manufacturing a semiconductor device according to the present invention, it is effective to perform the following two steps. That is, as a first step, the switch 8 is operated to apply a bias from the first high-frequency power supply 4 only to the bias electrode 7, stop applying the bias to the stage 3, and remove the ionized sputter particles from the outer periphery of the substrate. And the film is preferentially deposited on the outer peripheral portion of the substrate.

Next, as a second stage, a bias is applied to only the stage portion 3 without applying a bias to the bias electrode 7 provided on the outer periphery of the substrate, and the (+) ionized sputtered particles are vertically applied to the substrate 20. To form a thin film of the target material on the substrate surface. At this time, the ionized sputtered particles increase the vertical component attracted to the substrate side and decrease the oblique component contributing to film formation on the outer peripheral portion of the substrate. Although the thickness of the thin film is relatively small, the thin film is preferentially formed on the outer peripheral portion of the substrate in the first stage, so that the thickness of the thin film over the entire substrate can be made uniform.

In the above-described process, as a first step, a bias is applied only to the bias electrode 7, and no bias is applied to the stage 3, and a thin film is formed preferentially on the outer peripheral portion of the substrate. By applying a bias to only the stage portion 3 in two stages to form a thin film on the substrate, the film thickness over the entire surface of the substrate was made uniform. However,
The order of the first and second steps can be reversed, and the first and second steps may be performed simultaneously to form a film.

Although the method and apparatus for manufacturing a semiconductor device described above mainly use the ionization sputtering method based on the magnetron method, the method and apparatus of the present invention can also be applied to a parallel plate electrode type apparatus. is there.

In the above embodiment, the sputtering method using a DC power supply has been described. However, the power supply is not limited to a DC power supply, and a high-frequency power supply is used to apply a negative bias. The power supply used for applying the voltage is not limited to the high-frequency power supply.

As a result of the above-described film forming process, the difference in film thickness between the outer peripheral portion and the central portion of the substrate was reduced. That is, the percentage of the difference between the maximum value and the minimum value of the film thickness measured at a plurality of locations on the entire surface of the substrate and the average value of the measured film thickness was 5% in the device according to the related art. In the device according to the invention, this has been reduced to 3%.

Furthermore, as the thickness of the outer peripheral portion of the substrate is formed as thick as that of the central portion, the number of particles generated due to the friction between the substrate and the carrier and the peeling of the film due to the gas attack in the next step is reduced by the conventional technology. The effect of reducing the number of 30 generated on the substrate to 20 on the substrate formed by the apparatus according to the present invention was obtained.

Next, as a second embodiment of the present invention, a device provided with a moving device 9 for moving the bias electrode 7 in a direction perpendicular to the surface of the substrate 20 in addition to the device shown in FIG. 3 is shown. The moving device 9 includes an arm 9 a movable in a direction perpendicular to the surface of the substrate 20, one end of the arm 9 a is connected to the bias electrode 7, and the bias electrode 7 is connected to the substrate 20 with respect to the stage unit 3. Side (a), a position almost directly beside the substrate 20 (b), the substrate 20
Can move continuously to the position (c) on the same side as the stage 3.

In the sputtering state, when a bias is applied to the bias electrode 7, when the bias electrode 7 is at the position (a) with respect to the substrate 20, it is possible to increase the deposition of sputtered particles on the outer peripheral portion of the substrate. When the bias electrode 7 is located at a position (b) almost directly beside the substrate 20, the deposition state of sputter particles mainly on the surface of the substrate 20 is improved, and the bias electrode 7 is located at a position (c) with respect to the substrate 20. In some cases, sputter particles can be deposited at the rounded edge of the substrate edge.

When the film is formed by the two-step process described above, the position of the bias electrode 7 in the first step is set at the position (a) with respect to the substrate to increase the deposition of sputtered particles on the outer periphery of the substrate. Then, applying a bias to the stage portion 3 in the second stage is effective for forming a thin film having a uniform thickness over the entire substrate.

Furthermore, even when a bias is applied to the stage 3 at the same time, the bias electrode 7 located at the position (a) with respect to the substrate selectively deposits sputter particles on the outer periphery of the substrate. This is effective in forming a uniform thin film on the entire surface.

As described above, by moving the bias electrode 7 in the direction perpendicular to the surface of the substrate 20 by the moving device 9, the thickness of the film formed on the substrate 20, particularly the round portion of the outer peripheral portion and the edge of the substrate, is reduced. Since the thickness of the deposited film can be controlled, the thickness of the substrate becomes uniform, and the number of effective chips on the outer peripheral portion of the substrate can be increased.

[0034]

As described above, according to the present invention, in a device for forming a thin film on a semiconductor substrate by ionization sputtering, a bias electrode portion is provided around the outside of the semiconductor substrate, and the bias electrode portion is formed at right angles to the substrate surface. It is possible to improve the thinning at the outer peripheral portion of the substrate because the ionized sputtered particles can be preferentially attracted to the outer peripheral portion of the substrate and the round portion of the peripheral edge of the substrate to form a film preferentially. In addition, since the film thickness is secured at the outer peripheral portion and the round portion of the peripheral edge of the substrate, peeling of the film due to friction with the carrier during the process can be prevented, and the generation of particles can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a semiconductor device manufacturing apparatus of the present invention.

FIG. 2 is a schematic plan view of a bias electrode shown in FIG.

FIG. 3 is a schematic vertical sectional view showing another configuration of the semiconductor device manufacturing apparatus of the present invention.

FIG. 4 is a schematic vertical sectional view of a semiconductor device manufacturing apparatus according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 DC power supply 3 Stage part 4 1st high frequency power supply 5 Induction coil 6 2nd high frequency power supply 7 Bias electrode 8 Changeover switch 9 Moving device 9a Arm 10 Target 20 Substrate

Claims (9)

[Claims] 1. A semiconductor device manufacturing apparatus for forming a thin film on a semiconductor substrate by a sputtering method, comprising: a power supply for discharging sputtered particles from a target; A stage section for mounting, a power supply for applying a negative bias to the stage section, an induction coil provided in a space between the target and the stage section, and applying a high frequency to the induction coil. A semiconductor device manufacturing apparatus, comprising: a high-frequency power supply, a bias electrode portion surrounding the outer periphery of the semiconductor substrate, and a power supply for applying a negative bias to the bias electrode portion. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein a power supply for discharging sputtered particles from said target is a DC power supply. 3. The semiconductor device manufacturing apparatus according to claim 1, wherein the power supply for applying the negative bias is a high-frequency power supply. 4. The semiconductor device according to claim 1, wherein the bias electrode portion disposed around the outside of the semiconductor substrate has a moving unit movable in parallel with the semiconductor substrate and in a direction perpendicular to the surface of the semiconductor substrate. 2. The semiconductor device manufacturing apparatus according to 1. 5. A method for manufacturing a semiconductor device, comprising: when forming a thin film on a semiconductor substrate by the semiconductor device manufacturing apparatus, applying a bias to be applied to each of the stage section and the bias electrode section at a different application timing. 6. When a thin film is formed on a semiconductor substrate by the semiconductor device manufacturing apparatus, a bias is applied to the bias electrode portion before the stage portion to secure formation of the thin film on the outer peripheral portion of the semiconductor substrate. The method of manufacturing a semiconductor device according to claim 5, wherein 7. When forming a thin film on a semiconductor substrate by the semiconductor device manufacturing apparatus, the bias electrode portion disposed around an outer periphery of the semiconductor substrate is provided with the bias electrode portion mounted on the stage portion. A method for manufacturing a semiconductor device, wherein the substrate is provided on a side opposite to the stage with respect to the substrate. 8. When the semiconductor device manufacturing apparatus forms a thin film on a semiconductor substrate, the bias electrode portion disposed around an outer periphery of the semiconductor substrate is provided with the bias electrode portion mounted on the stage portion. A method of manufacturing a semiconductor device, wherein the substrate is provided on the same side as the stage with respect to the substrate. 9. When forming a thin film on a semiconductor substrate by the semiconductor device manufacturing apparatus, the bias electrode portion disposed so as to surround an outer periphery of the semiconductor substrate is disposed on a side of the stage portion. , Semiconductor device manufacturing method.