JP2001351798A - Plasma treatment device, film-forming device, plasma treatment method, film forming method, and semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment device capable of generating plasma having uniform density distribution. SOLUTION: In this plasma treatment device, performing plasma treatment by introducing helicon waves into a workpiece W arranged inside a treatment vessel 14, the inside of each of vacuum vessels 11a and 11b for generating the helicon wave is divided into a plurality of sections by means of a wall face parallel to a magnetic field direction 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma processing apparatus, a film forming apparatus, a plasma processing method, a film forming method, and a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art With the cost reduction of semiconductor integrated circuits and the like, there is a demand for a technique for manufacturing a semiconductor device with a high yield and a high throughput. As a plasma processing apparatus satisfying such demands, a plasma processing apparatus using a helicon wave has been proposed. The helicon wave is a Heusler wave having a frequency intermediate between the ion cyclotron frequency and the electron cyclotron frequency. By propagating the helicon wave in the direction of the magnetic field, neutral particles can be efficiently ionized and a high-density plasma of about 1013 cm-3 can be generated. Have been. For example, if high-density plasma is generated by using this helicon wave in sputter deposition, a target can be sputtered with high efficiency and the throughput of deposition can be improved. Plasma etching and plasma CV
Also in D, efficient processing can be performed by generating high-density plasma using helicon waves.

[0003]

However, in such a plasma processing method using a helicon wave, the following problems have arisen. The problem arises from the fact that the electric field due to the helicon wave is not uniform in a direction perpendicular to the direction of propagation of the helicon wave. That is, due to the non-uniformity of the electric field, there is a problem that the generated plasma is also biased and the plasma processing is not performed uniformly.
For example, when a helicon wave is generated in a cylindrical vacuum vessel and propagated in the axial direction of the cylinder, the generated plasma has the highest density at the center of the axis, and the density decreases as the distance from the center of the axis decreases. Therefore, when performing the plasma processing using the plasma thus generated, the plasma processing reflecting the non-uniformity is performed.
The present invention has been made to solve such problems, and a plasma processing apparatus and a plasma processing method capable of performing uniform plasma processing, and a film forming apparatus and a film forming method capable of performing uniform film formation It is another object of the present invention to provide a method for manufacturing a semiconductor device which improves the throughput.

[0004]

According to the present invention, there is provided a processing container for accommodating an object to be processed, a vacuum container communicating with the processing container, and an inside of the vacuum container. A helicon wave generating means for generating a helicon wave, and a magnetic field generating means for generating a magnetic field in the vacuum vessel and propagating the helicon wave along the direction of the magnetic field, In a plasma processing apparatus that introduces a wave into the processing container and generates plasma in the processing container to perform plasma processing on the object to be processed, a wall parallel to a direction of the magnetic field is formed inside the vacuum container. Is provided. Further, in the plasma processing apparatus, the magnetic field generating means generates a magnetic field in the processing chamber as well as in the vacuum chamber. In addition, a processing vessel provided with a cathode for holding a sputtering target and a high-frequency bias voltage disposed opposite to the cathode, which can be applied, and a substrate electrode capable of holding a film-forming object, A vacuum container communicating with the processing container, a helicon wave generating means for generating a helicon wave in the vacuum container, and a magnetic field generated in the vacuum container, wherein the helicon wave is generated along the direction of the magnetic field. A magnetic field generating means for transmitting the helicon wave into the processing vessel by the propagation, generating plasma in the processing vessel, and forming a film on the object to be processed. In the apparatus, a wall surface parallel to the direction of the magnetic field may be provided inside the vacuum vessel.

Further, a helicon wave generating step of generating a helicon wave in a vacuum vessel, a magnetic field is generated in the vacuum vessel, and the helicon wave is propagated in the direction of the magnetic field, thereby converting the helicon wave into the vacuum. A magnetic field generation step to be introduced into a processing vessel that is in communication with the vessel, and generating plasma by the helicon wave in the processing vessel,
In the plasma processing method of performing plasma processing on an object to be processed disposed in the processing container, the introduction of the helicon wave into the processing container may be such that the electric field intensity distribution in the magnetic field direction has two or more peaks. Wherein the helicon wave is introduced into the plasma processing method. Further, in the plasma processing method, two or more vacuum vessels are provided. Further, the magnetic field generating step includes:
In the plasma processing method, a magnetic field may be generated in the processing container as well as in the vacuum container.
A helicon wave generating step of generating a helicon wave in the vacuum vessel, and a magnetic field being generated in the vacuum vessel, and the helicon wave communicating with the vacuum vessel by propagating the helicon wave in the direction of the magnetic field. And a step of introducing a gas in the processing container into plasma by the helicon wave, and introducing cations generated by the plasma. In a film forming method in which the target particles disposed on the cathode side in the processing container are caused to collide with each other and target particles struck out by the collision are formed on the surface of the object to be formed, the introduction step includes: The introduction of the wave into the processing container is characterized in that the helicon wave is introduced such that the electric field intensity distribution in the magnetic field direction has two or more peaks. Is a film forming method.

Further, a film forming step of forming a thin film on the surface of a wafer placed in a processing container, a resist coating step of coating a resist on the surface of the formed wafer, and a wafer coated with the resist A semiconductor device manufacturing method comprising: an exposure step of performing patterning on the substrate; and a step of performing etching on the patterned wafer to form the thin film in a predetermined pattern. A method for manufacturing a semiconductor device, characterized by using a film formation method.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG.
1 shows a film forming apparatus 10 according to the embodiment. The film forming apparatus 10 includes vacuum vessels 11a and 11b, an antenna 12a serving as a helicon wave generating means for generating a helicon wave in the vacuum vessel 11a, and an RF generator 13a.
An antenna 12b and an RF generator 13b, which are helicon wave generating means for generating a helicon wave in the vacuum vessel 11b, a processing vessel 14 communicated with the vacuum vessels 11a and 11b, and are disposed in the processing vessel 14. An upper electrode 15 for holding the target T, a DC power supply 16 for applying a negative potential to the upper electrode 15,
A substrate electrode 17 for holding the workpiece W disposed in the processing container 14, an RF power source 18 for applying an RF bias voltage to the substrate electrode 17, a vacuum container 11a,
11b and solenoid coils 19a and 19b which are magnetic field generating means for generating a magnetic field in the processing chamber 14. Hereinafter, each component will be described. FIG. 2A is a perspective view of the vacuum container 11a, and FIG.
(B) has shown the top view of the vacuum container 11a. As shown in FIG. 2, the vacuum container 11a is, for example, about 5 cm ×
It has a rectangular parallelepiped shape of 5 cm × 20 cm, and one side surface thereof communicates with the processing container 14 through the opening 21. The vacuum vessel 11a is equally divided into four spaces by three wall surfaces 22. This wall surface 22 is substantially parallel to the direction of the magnetic field generated by the solenoid coils 19a and 19b. The vacuum vessel 11a is made of quartz glass which is a dielectric. The vacuum vessel 11b has the same shape and communicates with the processing vessel 14 in the same manner.

[0008] The RF generator 13a
a and 13.56 MH on the antenna 12a.
A voltage of z is applied. As shown in FIG. 2A, the antenna 12a is wound one turn around the outer circumference of about 5 cm from the end surface of the vacuum vessel 11a. Also, the antenna 12a
Generates a helicon wave inside the vacuum vessel 11a by applying a voltage from the RF generator 13a. Similarly, the RF generator 13b applies a high-frequency voltage to the antenna 12b wound around the outer periphery of the vacuum vessel 11b. The side surfaces of the processing container 14 are vacuum containers 11a and 11b.
The gas introduced into the processing chamber 14 is turned into plasma by the helicon wave introduced from the opening 21. The processing vessel 14 includes an upper electrode 15 and a substrate electrode 17. Upper electrode 15
Is provided on a wall surface (for example, a ceiling) of the processing container 14 and has a function of holding the target T. The upper electrode 15 is electrically connected to a DC power supply 16, and a negative potential is applied to the ground. Substrate electrode 17
Is provided on a wall surface (for example, a bottom surface) of the processing container 14 so as to face the upper electrode 15, and has a function of holding the workpiece W by, for example, an electrostatic chuck. An RF bias voltage is applied to the substrate electrode 17 by an RF power supply 18.

The solenoid coils 19a and 19b have a function of generating a magnetic field in the processing vessel 14 and in the vacuum vessels 11a and 11b. As shown in FIG. 1, the solenoid coils 19a, 1b are provided around the vacuum vessels 11a, 11b.
9b, the arrow 20 in FIG.
, That is, in a direction parallel to the wall surface dividing the inside of the vacuum vessels 11a and 11b. Also, in the processing chamber 14, the direction of the magnetic field is substantially horizontal, so that it is substantially perpendicular to the direction connecting the substrate electrode 17 and the upper electrode 15. With the above configuration, the function of film formation will be described. First, the target T is set on the upper electrode 15. As the target T, for example, Ti is used. An object W to be formed is set on the substrate electrode 17. The workpiece W is, for example, a semiconductor wafer. Subsequently, the inside of the processing container 14 and the inside of the vacuum containers 11a and 11b communicating therewith are evacuated by a vacuum pump (not shown) communicating with the side surface of the processing container 14. Then, argon gas is introduced into the processing container 14 and the vacuum container 11a by a gas supply unit (not shown) communicating with the side surface of the processing container 14. The internal pressure at this time is about 1 ×
10-3 torr. And the solenoid coil 19
a, and a current flows through 19b. This current forms a magnetic field that penetrates the processing container 14 and the vacuum containers 11a and 11b substantially horizontally. Further, the DC power supply 16 applies a negative voltage to the upper electrode 15, and the RF power supply 18 applies a high-frequency bias voltage to the substrate electrode 17. Film formation is performed under the above initial settings.

First, a 13.56 MHz high frequency voltage is applied to the antenna 12a by the RF generator 13a. The application of this voltage generates a helicon wave inside the vacuum vessel 11a. Since a magnetic field is generated in a substantially horizontal direction inside the vacuum chamber 11a, the helicon wave propagates substantially horizontally toward the processing container 14 along the magnetic field. Now, the vacuum vessel 11a has four walls 22 formed in parallel to the direction 20 of the magnetic field shown in FIG.
Is divided into two spaces. Therefore, the four helicon waves generated in each space are parallel to the processing vessel 14 respectively.
In the direction of. Generally, the electric field strength in the direction of the magnetic field, that is, the propagation direction of the helicon wave contributes to plasma generation, and the higher the electric field strength, the higher the density of plasma generated. Now, the electric field strength in this magnetic field direction is
It has a relatively small value in the vicinity, and has a larger value as the distance from the wall surface 22 increases. The solid line in the graph of FIG. 3B shows the electric field intensity distribution of the helicon wave in the direction of the magnetic field on AA ′ shown in FIG. 3A, and each peak has a peak near the center of the divided space. It has a small value near the wall surface. Similarly, a high-frequency voltage is applied to the antenna 12b by the RF generator 13b, and a helicon wave is generated inside the vacuum vessel 11b. This helicon wave propagates toward the processing container 14.
For reference, FIG. 3B shows the distribution of the electric field strength in the magnetic field direction of the helicon wave when no wall surface is provided by a dotted line.

Since the helicon wave propagates along the magnetic field, it travels horizontally within the processing vessel 14 without spreading so much, and ionizes the argon gas to generate plasma. This helicon wave has a peak of the electric field strength in the magnetic field direction for each of the four divided spaces. The electric field strength in the direction of the magnetic field contributes to plasma generation. Therefore, as shown by the dotted line in FIG. 4B, the plasma density on BB ′ shown in FIG. 4A has four peaks. For reference, FIG. 4B shows the plasma density distribution in the case where there is no wall with a solid line. On the other hand, the ionized argon ions sputter the target T of the upper electrode 15. Since the sputtered particles are ionized by the helicon wave, the substrate electrode 1 biased by the RF power supply 18 is used.
It will be drawn while accelerating to the 7 side. The ionized sputtered particles are deposited almost vertically on the surface of the workpiece W to form a film. A film was formed by the above-described operation. A conventional electric field intensity distribution in the propagation direction of a helicon wave has a peak at the center of a vacuum vessel, and becomes weaker as the distance from the center increases. The electric field strength in this propagation direction contributes to plasma generation. Therefore, conventionally, a plasma having one peak at the center and having a smaller density as being away from the center has been generated. However, in the present invention, the vacuum vessel for propagating the helicon wave is divided into a plurality of spaces in a direction parallel to the magnetic field. Therefore, a helicon wave having a plurality of peaks propagated in the vacuum vessel. Therefore, a peak of the plasma density exists for each of these peaks. For this reason, it is possible to generate plasma with small variations in density. Therefore, a uniform film can be formed.

Further, since the helicon wave is propagated in parallel between the target and the object to be processed, it is possible to form a film without exposing the object to plasma. In the present embodiment, helicon waves are propagated from both sides using two vacuum vessels, so that more uniform plasma can be generated. As shown in FIG. 5A, the antenna 12c may be wound by dividing the vacuum vessel 11c into a lattice shape, and the number of divisions is not limited to four. Further, as shown in FIG. 5B, a plurality of vacuum vessels 11d are provided, and the plurality of vacuum vessels 11d are provided.
A helicon wave may be generated in each vacuum vessel 11d by winding the antenna 12d around d. The case where a plurality of separable vacuum vessels is provided inside the antenna in this way is also included in "providing the wall surface inside the vacuum vessel" in the present invention. Further, as shown in FIG. 6, the antenna 12e may be penetrated inside the vacuum vessel 11e. In this case, if the material of the target and the material of the antenna are the same, the influence of the deposition can be reduced. Further, as shown in FIG.
The part that generates the 1f helicon wave is a common space, and the antenna 12f is wound around the position of the common space,
The path through which the helicon wave propagates is defined by a wall 2 parallel to the direction of the magnetic field.
The division may be performed by providing 2f. Further, the number of turns of the antenna for generating the helicon wave is not limited to one turn. In addition, as a method of winding the antenna, a method of spirally winding, a method of branching, and other various methods can be applied.

In this embodiment, the case where the direction of the magnetic field is substantially orthogonal to the straight line connecting the object to be processed and the target has been described. However, the present invention can be applied to the case where the direction is parallel. The target and gas substances can be variously modified. For example, contact holes may be formed using silicon as a target and a mixed gas of argon gas and nitrogen gas as a gas. In this embodiment, a film forming apparatus is described, but the present invention is also applicable to a plasma CVD apparatus, a plasma etching apparatus, and other plasma processing apparatuses using plasma. Various other modifications are possible for the same purpose. (Second Embodiment) The second embodiment relates to a method for manufacturing a MOS transistor. In the process of manufacturing an N-type MOS transistor, the film forming apparatus described in the first embodiment is used to form an aluminum wiring in a contact hole on a wafer. The outline of the manufacturing process of the MOS transistor up to the stage before the film formation will be described below. First, as shown in FIG.
After a silicon oxide film 32 is grown on the surface of a 00 mm P-type silicon wafer 31 using a thermal oxidation method, a silicon nitride film 33 is grown using a vapor phase growth method. Thereafter, as shown in (b), after applying a photoresist 34 on the surface, the mask pattern is transferred. By this transfer, a mask pattern that is masked other than the portion where the field oxide film 35 is formed is formed. Then RI
Etching is performed by the E method to remove the silicon nitride film 33 and the silicon oxide 32 at portions not covered with the mask. Thereafter, as shown in (c), the field oxide film 35 is selectively formed only on the portion where the silicon nitride film 33 is not formed by using the thermal oxidation method.

The silicon nitride film is removed by etching using phosphoric acid, and then the underlying silicon oxide film is removed by etching using hydrofluoric acid. Through the above steps, only the field oxide film 35 remains on the silicon wafer 31 as shown in FIG. Next, as shown in FIG. 9A, a gate insulating film 36 is grown on the surface of the silicon wafer 31 exposed by the thermal oxidation method. Further, a polycrystalline silicon film 37 is deposited on the entire surface of the silicon wafer 31. As shown in FIG. 9B, a gate electrode pattern is formed on the polycrystalline silicon film 37 by patterning and etching. Next, arsenic is ion-implanted into the silicon wafer 31 to form a source region 38 and a drain region 39. Next, as shown in FIG. 9C, an interlayer insulating film 40 is deposited on the entire surface of the silicon wafer 31 by using a vapor phase growth method. A contact hole for extracting an electrode is formed on the interlayer insulating film 40 by patterning and etching. Thereafter, a film is formed on the silicon wafer 31 by using sputtering. This film formation is performed as follows using the film formation apparatus described in the first embodiment. The same components as those used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

First, the silicon wafer 31 is placed in the processing container 14.
Set inside. Aluminum as the target T is supported by the upper electrode 15 in advance. After the argon gas is introduced into the processing container 14, a helicon wave is generated in the vacuum containers 11a and 11b and a magnetic field is generated, and the helicon wave is propagated along the magnetic field. As described in the first embodiment, since the vacuum vessels 11a and 11b are divided into four spaces, the electric field intensity distribution of the helicon wave introduced into the processing vessel 14 in the magnetic field direction has four peaks. . And this helicon wave ionizes argon gas,
A plasma having a uniform density distribution is generated. Argon ions generated by the plasma collide with the target T, and aluminum atoms are knocked out. The beaten-out aluminum atoms are exposed to plasma and ionized, and then are attracted while being accelerated toward the biased substrate electrode 17. Thus, aluminum is deposited on the silicon wafer 31 almost vertically. Therefore, the aluminum film 41 is also formed inside the contact hole having a high aspect ratio. FIG. 10A shows a schematic diagram after the film formation. After film formation,
Aluminum wiring 41 'is formed by photolithography. Thereafter, the protective film 42 is vapor-phase grown, and FIG.
An N-type MOS transistor is manufactured as shown in FIG.

As described above, the N-type MOS transistor was manufactured. Since the silicon wafer 31 has a shape with a large diameter and a high aspect ratio, the embedding property is not sufficient in the related art, and sufficient film formation may not be performed at a position away from the center of the silicon wafer 31. Was. However, in the film formation in this embodiment, plasma having a uniform density distribution can be generated.
Film formation can be performed uniformly. Therefore MOS
It is possible to improve the yield of transistor manufacture. It is needless to say that the present embodiment is not limited to the manufacture of a MOS transistor, but can be variously applied to other semiconductor devices.

[0017]

According to the present invention, a plasma which enables uniform plasma processing by dividing a helicon wave path by providing a wall surface substantially parallel to a magnetic field for propagating the helicon wave inside the vacuum vessel in which the helicon wave is generated. A processing apparatus and a plasma processing method can be provided. In addition, by providing a plurality of vacuum vessels that generate helicon waves, a plasma processing apparatus and a plasma processing method capable of performing uniform plasma processing can be provided. In addition, a film forming apparatus and a film forming method capable of forming a uniform film can be provided. In addition, a method for manufacturing a semiconductor device which improves the yield can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a film forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a vacuum vessel according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an energy intensity distribution of a helicon wave in the first embodiment of the present invention.

FIG. 4 is a diagram showing a distribution of a plasma density in the first embodiment of the present invention.

FIG. 5 is a view showing a modified example of the vacuum vessel according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 7 is a diagram showing a modification of the first embodiment of the present invention.

FIG. 8 is a diagram showing a manufacturing process of the MOS transistor according to the second embodiment of the present invention.

FIG. 9 is a diagram showing a manufacturing process of the MOS transistor according to the second embodiment of the present invention.

FIG. 10 is a diagram showing a manufacturing process of the MOS transistor according to the second embodiment of the present invention.

[Explanation of symbols]

Vacuum container 11a, 11b, antenna 12a, 12
b, processing container 14, solenoid coil 19a, 19
b.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/285 H01L 21/285 Z 21/3065 21/302 BF Term (Reference) 4G075 AA24 AA30 BC02 BC04 BC06 BD14 CA05 CA25 CA42 CA47 CA63 EB42 EC09 EE12 4K029 AA06 AA24 BD01 CA13 DC00 DC43 4M104 AA01 BB01 BB02 BB14 CC01 DD38 DD39 GG09 HH20 5F004 AA01 BA20 BB07 BB13 DA23 5F045 AA08 AE15 EH02 EH11 EH05

Claims (8)

[Claims] 1. A processing container for storing an object to be processed, a vacuum container communicating with the processing container, a helicon wave generating means for generating a helicon wave in the vacuum container, and the vacuum container A magnetic field generating means for generating a magnetic field therein, and propagating the helicon wave along the direction of the magnetic field, introducing the helicon wave into the processing container by the propagation, and generating plasma in the processing container. A plasma processing apparatus for generating and performing plasma processing on the object to be processed, wherein a wall parallel to a direction of the magnetic field is provided inside the vacuum vessel. 2. The plasma processing apparatus according to claim 1, wherein said magnetic field generating means generates a magnetic field not only in said vacuum vessel but also in said processing vessel. 3. A process comprising a cathode for holding a sputtering target and a substrate electrode arranged opposite to the cathode, to which a high-frequency bias voltage can be applied and which can hold a film-forming object. A vessel, a vacuum vessel in communication with the processing vessel, a helicon wave generating means for generating a helicon wave in the vacuum vessel, a magnetic field in the vacuum vessel, Magnetic field generating means for propagating along the direction, introducing the helicon wave into the processing vessel by the propagation, generating plasma in the processing vessel, and forming a film on the object to be processed. In the film forming apparatus, a wall surface parallel to a direction of the magnetic field is provided inside the vacuum vessel. 4. A helicon wave generating step of generating a helicon wave in a vacuum vessel, and generating a magnetic field in the vacuum vessel, and propagating the helicon wave in the direction of the magnetic field, thereby converting the helicon wave into the vacuum. A magnetic field generating step of introducing the magnetic field into a processing vessel communicated with the vessel, generating plasma by the helicon wave in the processing vessel, and performing plasma processing on an object to be processed disposed in the processing vessel. Wherein the introduction of the helicon wave into the processing container is performed by providing a plurality of propagation paths of the helicon wave by a wall surface substantially parallel to a direction of the magnetic field provided in the vacuum container. Plasma treatment method. 5. The plasma processing method according to claim 4, wherein two or more vacuum vessels are provided. 6. The plasma processing method according to claim 4, wherein the magnetic field generating step generates a magnetic field not only in the vacuum chamber but also in the processing chamber. 7. A helicon wave generating step of generating a helicon wave in a vacuum vessel, and generating a magnetic field in the vacuum vessel, and propagating the helicon wave in the direction of the magnetic field, thereby converting the helicon wave into a vacuum. A step of introducing a gas into the processing container into a plasma by the helicon wave; and introducing the gas into the processing container in which the film is formed. In a film forming method in which ions collide with a target disposed on the cathode side in the processing container and target particles beaten out by the collision are formed on the surface of the film-forming object, the introduction step includes: A film forming method, wherein a plurality of propagation paths of the helicon wave are provided and introduced by a wall surface substantially parallel to a direction of the magnetic field provided in the vacuum vessel. 8. A film forming step of forming a thin film on a surface of a wafer placed in a processing container, a resist applying step of applying a resist on a surface of the formed wafer, and a wafer coated with the resist 8. A method for manufacturing a semiconductor device, comprising: an exposure step of performing patterning on a substrate; and a step of performing etching on the patterned wafer to form the thin film into a predetermined pattern. A method of manufacturing a semiconductor device, characterized by using the film forming method of (1).