JPH09260355A - Magnetron discharge type plasma surface treatment equipment and its treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable performing uniform treatment on a substratum to be treated, by installing a second magnetic member which generates a magnetic field symmetrical to the magnetic field in a vacuum container which is generated by a magnetic member contained in a bearing which rotates and moves a magnetic field generating means along the periphery of the vacuum container. SOLUTION: A vacuum container 1 having an electrode 5 on which a substratum 3 to be treated is mounted and a process gas introducing inlet 11 for introducing process gas in the vacuum container 1 are installed. A high frequency electric power source 7 which generates discharging phenomenon in the vacuum container 1 and makes the inside process gas a plasma state, and a dipole ring magnet 19 generating a magnetic field in the vacuum container 1 are installed. A bearing containing a magnetic member 21 which bearing rotates and moves the dipole ring magnet 19 along the periphery of the vacuum container 1, and an auxiliary magnetic member 23 which generates a magnetic field symmetrical to the magnetic field which is generated by the magnetic member 21 in the vacuum container 1 are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma surface processing apparatus such as a plasma etching apparatus and a plasma CVD apparatus, and more particularly to one using magnetron discharge.

[0002]

2. Description of the Related Art FIG. 10 shows a conventional magnetron discharge type R.
It is a schematic block diagram of an IE apparatus. As shown in FIG.
Inside the process chamber 1, an electrode 5 on which the wafer 3 is placed is provided. The electrode 5 is connected to a high frequency power source 7, and high frequency power is applied. A process gas inlet 11 for introducing a process gas is provided in a portion of the housing 9 forming the chamber 1 facing the electrode 5. The portion of the housing 9 that faces the electrode 5 is a counter electrode 13 that is grounded. By applying high frequency power to the electrode 5, a discharge phenomenon occurs between the electrode 5 and the electrode 13. When the discharge phenomenon occurs between the electrode 5 and the electrode 13, the process gas introduced into the chamber 1 is turned into plasma. The line indicated by reference numeral 15 is a line of electric force generated between the electrode 5 and the electrode 13. The RIE device disclosed herein is a magnetron discharge type. Inside the chamber 1, magnetic force lines 17 that are substantially orthogonal to the electric force lines 15 are generated. A dipole ring magnet 19 is installed outside the cylindrical portion B of the housing 9 in order to generate the magnetic field lines 17.

FIG. 11 is a plan view of a dipole ring magnet. Details of the dipole ring magnet are described in, for example, 1993 Patent Application No. 233930. The dipole ring magnet 19 rotates horizontally along the circumference of the housing 9 in the magnetic field line. In order to rotate the ring magnet 19 horizontally to the magnetic field line, the ring magnet 19 is installed on the flat portion A of the housing 9 via a bearing 21. The ring magnet 19 slides on the housing 9 by a bearing 21 and rotates around the cylindrical portion B of the housing 9.

[0004]

The process uniformity of the magnetron discharge type plasma surface treatment apparatus shown in FIG. 10 is good. However, considering future miniaturization of semiconductor devices,
Further processing uniformity is required.

However, in the magnetron discharge type plasma surface treatment apparatus shown in FIG. 10, there is a problem to be solved in that the uniformity of treatment is not improved as expected. Therefore, we made one assumption that the magnetic field generated in the chamber 1 may be disturbed by the rotation of the ring magnet 19.

FIG. 12 is a diagram showing the theoretical distribution of the magnetic field generated in the chamber 1 of the magnetron discharge type RIE apparatus. As shown in FIG. 12, the ring magnet 19 generates a magnetic field in the chamber 1 between the south pole of one magnet element 19-1 and the north pole of the other magnet element 19-2. Magnet element 19-1
On the X axis connecting the center of the magnetic field and the center of the magnet element 19-2, the magnetic force lines 17 are straight (parallel magnetic field). Hereafter, this part
It is called the center of the magnetic field. The process surface of the wafer 1 is set to come to the center of this magnetic field, and the surface of the wafer 1 is subjected to RIE processing in a parallel magnetic field. The Z axis is an axis orthogonal to the X axis, and is the direction of the electric force line 15 shown in FIG. 10 in this specification.

[0007] Furthermore, as a cause of the disturbance of the magnetic field, we
Focusing on the bearing 21. The bearing 21 is made of iron (F
This is because it is a magnetic substance containing e). FIG. 13 is a diagram showing a distribution of a magnetic field generated in the chamber 1 by the ring magnet 19 and the bearing 21.

As shown in FIG. 13, when a bearing 21 made of a magnetic material is present near the ring magnet 19, the magnetic force line 17 which should be straight along the X-axis causes the bearing 2 to move.
It turned out that it was curved in a concave shape toward 1.

As described above, it was thought that the surface of the wafer 1 might have been subjected to the RIE treatment in the parallel magnetic field, but in reality, the magnetic field curved concavely toward the bearing 21. In the inside, RIE processing was performed. If the magnetic field has a component in the Z-axis direction, the distribution of electron density becomes non-uniform on the process side during discharge, which affects the uniformity of processing.

The present invention has been made in view of the above circumstances, and an object thereof is a magnetron discharge type plasma surface treatment apparatus in which a magnetic field generator is rotated along the circumference of a vacuum container, and is uniformly applied to a substrate to be treated. It is an object of the present invention to provide a magnetron discharge type plasma surface treatment apparatus capable of performing various treatments. Another object is to provide a magnetron discharge type plasma surface treatment method capable of uniformly treating a substrate to be treated.

[0011]

In order to achieve the above object, in a magnetron discharge type plasma surface treatment apparatus according to the present invention, a vacuum vessel provided with an electrode on which a substrate to be treated is installed, and an inside of the vacuum vessel A process gas introduction means for introducing a process gas into the vacuum container, a plasma generating means for generating a discharge phenomenon inside the vacuum container to plasmanize the process gas inside the vacuum container, and a magnetic field inside the vacuum container. Magnetic field generating means for generating a magnetic field, and rotating the magnetic field generating means along the circumference of the vacuum container.
And a second magnetic body for generating a magnetic field symmetrical to the magnetic field generated by the first magnetic body inside the vacuum container inside the vacuum container. It is characterized by having.

Further, the center of the magnetic field generated by the magnetic field generating means is matched with the process surface of the substrate to be processed. Further, the magnetic field emitted by the first magnetic body and the magnetic field emitted by the second magnetic body are substantially equal to each other.

The first magnetic body is a sliding body for rotating and sliding the magnetic field generating means, and the second magnetic body is a rotating slide body and a rotary motion transmitting body for generating a magnetic field substantially equal to that of the rotating slide body. It is characterized by being either.

Further, the rotary sliding body is a bearing, and the rotary motion transmitting body is a gear. Further, the processing method is such that an electric discharge phenomenon is generated inside the vacuum container, the process gas inside the vacuum container is turned into plasma, and a magnetic field is generated inside the vacuum container to generate inside the vacuum container. In the magnetron discharge type plasma surface treatment method of rotating a magnetic field, the mechanism for rotating the magnetic field includes a magnetic body, at least the disturbance of magnetic lines of force inside the vacuum container due to the magnetic body, It is characterized in that the magnetic field lines on the process surface are subjected to plasma surface treatment while being corrected by providing another magnetic body so as to be horizontal to the process surface.

[0015]

Embodiments of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a magnetron discharge type RIE device according to a first embodiment of the present invention.

As shown in FIG. 1, an electrode 5 on which a wafer 3 is set is provided inside the process chamber 1. The electrode 5 is connected to a high frequency power source 7, and high frequency power is applied. A process gas inlet 11 for introducing a process gas is provided in a portion of the housing 9 forming the chamber 1 facing the electrode 5. The portion of the housing 9 that faces the electrode 5 is a counter electrode 13 that is grounded. By applying high frequency power to the electrode 5, a discharge phenomenon occurs between the electrode 5 and the electrode 13. When the discharge phenomenon occurs between the electrode 5 and the electrode 13, the process gas introduced into the chamber 1 is turned into plasma. The line indicated by reference numeral 15 is a line of electric force generated between the electrode 5 and the electrode 13. The RIE device disclosed herein is a magnetron discharge type. Inside the chamber 1, magnetic force lines 17 that are substantially orthogonal to the electric force lines 15 are generated. A dipole ring magnet 19 is installed outside the cylindrical portion B of the housing 9 in order to generate the magnetic field lines 17.

FIG. 2 is a plan view of the dipole ring magnet 19. As shown in FIG. 2, the dipole ring magnet 19
Is arranged so as to surround the cylindrical portion B concentrically.
It is composed of individual magnet elements 100a to 100p.
Hereinafter, the magnetization direction of the magnet element 100 will be described.

First, 16 magnet elements 100a-100
One of p, the magnet element 1 magnetized in the direction H '
Focus on 00a. The magnet element 100i located at a position facing the magnet element 100a through the center point o is magnetized in the direction H ', like the magnet element 100a. Also,
The magnet element 100b located at a position rotated from the magnet element 100a by the angle θ around the center point o is magnetized in the direction H ″ rotated by the angle 2θ from the direction H ′.
The magnet element 100j located at a position facing the magnet element 100b through the center point o is similar to the magnet element 100b.
It is magnetized in the direction H ″. The 16 magnet elements 100 are annularly arranged by repeating such a relationship.

Further, the dipole ring magnet 19 rotates along the circumference of the cylindrical portion B of the housing 9. In order to rotate the ring magnet 19, the ring magnet 19 is installed on the flat portion A of the housing 9 via a bearing 21. The ring magnet 19 slides on the housing 9 by means of a bearing 21, and the cylindrical portion B of the housing 9
Rotate around. A magnetic material is used for the bearing 21. The housing 9 is made of a non-magnetic material (eg, aluminum alloy, stainless steel, etc.). Further, an auxiliary magnetic body 23 that causes the chamber 1 to generate a magnetic field symmetrical to the magnetic field generated by the bearing 21 in the chamber 1 is provided.

FIG. 3 shows a ring magnet 19 and a bearing 21.
7 is an exploded view showing the auxiliary magnetic body 23 in an exploded manner. FIG.
As shown in FIG. 3, the auxiliary magnetic body 23 includes the ring magnet 19
Is provided on the surface opposite to the bearing 21. The auxiliary magnetic body 23 has almost the same magnetic force as the bearing 21. Preferably, it is the same as the bearing 21.

FIG. 4 shows a ring magnet 19 and a bearing 21.
3 is a diagram showing a distribution of a magnetic field generated by the auxiliary magnetic body in the chamber 1. FIG. As shown in FIG. 4, the ring magnet 19
Is the south pole of one magnet element 19-1 and the other magnet element 19-1.
A magnetic field is generated in the chamber 1 between the −2 north pole. At the same time, the auxiliary magnetic body 23 is symmetrical with the magnetic field generated by the bearing 21 in the chamber 1 with the X axis connecting the center of the magnet element 19-1 and the center of the magnet element 19-2, that is, the center of the magnetic field as a boundary. A strong magnetic field is generated in the chamber 1.

As described above, in order for the auxiliary magnetic body 23 to generate a magnetic field in the chamber 1 that is symmetrical with respect to the magnetic field generated in the chamber 1 by the bearing 21, the magnet element 19-1.
At the X axis connecting the center of the magnetic field and the center of the magnet element 19-2, that is, the center of the magnetic field, the magnetic force line 17 becomes straight (parallel magnetic field).
The process surface of the wafer 1 is set so as to come to the center of this magnetic field, and RIE is performed on the surface of the wafer 1 in a parallel magnetic field.
Processing is performed. The Z axis is an axis orthogonal to the X axis, and is the direction of the electric force line 15 shown in FIG. 1 in this embodiment.

Next, a silicon oxide film (SiO 2) is formed using the magnetron discharge type RIE device according to the first embodiment.
₂ ) The results of etching will be explained. FIG. 5 is a diagram showing the relationship between the position on the wafer surface and the etching rate of the silicon oxide film.

The etching conditions are HBr: 150scc
m, O ₂ : 4 sccm, NF ₃ : 10 sccm, pressure 1
00mTorr, Applied power 1300W, Applied magnetic field strength 2
00G, etching time is 5 minutes.

As shown in FIG. 5, since the magnetic field distribution in the chamber 1 is more uniform than in the device without the auxiliary magnetic material, the silicon oxide film can be uniformly etched in the wafer surface.

Next, the characteristics of the MOS diode formed in the RIE process using the magnetron discharge type RIE device according to the first embodiment will be described. FIG.
It is a figure which shows the breakdown voltage distribution of an OS diode, (a) figure is R
In the IE process, a breakdown voltage distribution of a MOS diode formed by using the magnetron discharge type RIE device according to the first embodiment is shown. FIG. 7B is a magnetron discharge type device in which no auxiliary magnetic material is used in the RIE process. It is a figure which shows the withstand voltage distribution of the MOS diode formed using the RIE apparatus.

In the RIE process, in the MOS type diode formed by using the device without the auxiliary magnetic material, as shown in FIG. 6 (b), it is recognized that it is destroyed by the applied electric field in the range of 0 to 10 MV / cm. To be

On the other hand, in the RIE process, the MOS diode formed by using the device according to the first embodiment is destroyed by an applied electric field of 15 MV / cm or more as shown in FIG. 6 (a). As a result, the breakdown voltage is improved.

This is because the Z-axis direction component of the magnetic field almost disappeared, and the distribution of the electron density became uniform on the process side during discharge. That is, the insulator (S
It is considered that the amount of electrons contained in iO ₂ ) became uniform on the wafer surface, and the quality and characteristics of the MOS capacitor were improved.

As described above, in the device according to the first embodiment, not only the etching can be made uniform, but also the quality of the manufactured semiconductor device is improved. Further, as a method of preventing the breakdown voltage deterioration in a device without an auxiliary magnetic body, a method of intentionally shifting the wafer installation position from the center of the magnetic field can be considered.

However, comparing the manufacturing method with the manufacturing method using the apparatus according to the first embodiment, it is theoretically possible to completely straighten the magnetic force lines (parallel magnetic field). Considering only the line connecting the center of the N pole and the center of the S pole of the magnet, and the surface obtained by rotating this line, the device according to the first embodiment is superior.

FIG. 7 is an exploded view of the main part of the magnetron discharge type RIE device according to the second embodiment of the present invention. As shown in FIG. 7, in the device according to the second embodiment, the rotary sliding mechanism 32 including the bearing 21 is the same as the rotary sliding mechanism 30 for rotating and sliding the ring magnet 19.
Are symmetrically installed with the ring magnet 19 as a boundary. The bearing 34 included in the rotary sliding mechanism 32 is the same as the bearing 21.

Even with such a device, the bearing 2
Since the magnetic field generated by 1 and the magnetic field generated by the bearing 34 can be made substantially equal to each other, the same effect as that of the first embodiment can be obtained.

FIG. 8 is an exploded view of the main part of the magnetron discharge type RIE device according to the third embodiment of the present invention. As shown in FIG. 8, in the device according to the third embodiment, the gear 40 for transmitting the rotational motion to the ring magnet 19 is provided on the surface of the ring magnet 19 opposite to the rotation sliding mechanism 30 and the installation surface.
And the gear 40 is made of a magnetic material.

Even with such a device, the bearing 2
By making the magnetic field generated by No. 1 and the magnetic field generated by the gear 40 substantially equal to each other, it is possible to obtain the same effect as that of the first and second embodiments.

9A and 9B are views showing the magnet elements of the ring magnet 19, FIG. 9A is a perspective view showing an example of a magnet, and FIG. 9B is a perspective view showing an example of a coil. The magnetic element of the ring magnet 19 for generating a magnetic field inside the chamber 1 is (a)
As shown in the figure, a normal magnet (for example, a permanent magnet) 100
In addition, the electromagnet 1 including a coil as shown in FIG.
02 may be used.

In the magnetron discharge type RIE apparatus described in the first to third embodiments, the bearing 21 made of a magnetic material is provided near the ring magnet 19 for generating lines of magnetic force in the chamber 1. Even chamber 1
Since it is possible to obtain a portion where the magnetic force lines 17 are straight (parallel magnetic field), it is possible to perform uniform processing on the wafer 3. Then, by aligning the center of the magnetic field generated by the ring magnet 19 with the process surface of the wafer 3,
The wafer 3 can be uniformly processed.

Further, since the amount of electrons taken into the process surface during processing can be made uniform, a semiconductor device having stable quality can be manufactured. Further, as described in this specification, it was found that the bearing 21 disturbs the magnetic field generated by the ring magnet 19 and impairs uniform processing. It has been considered that the bearing 21 itself is made of a non-magnetic material at the expense of increasing the replacement frequency of the mechanism 30.

However, according to the present invention, since uniform processing can be performed and maintainability is not impaired,
We were able to resolve the above concerns. Regarding the material and material of the auxiliary magnetic body 23, it is not always necessary to use the same material and material as the bearing 21, and at least a magnetic field symmetrical to the magnetic field generated by the bearing 21 inside the chamber 1 of the chamber 1 is generated. It only needs to be generated internally.

Further, magnetron discharge type plasma RIE
Not only equipment, but also magnetron discharge plasma CVD
The present invention can also be applied to devices and the like. Further, in the device according to the above-described embodiment, the ring magnet 19 is rotated horizontally with respect to the plane perpendicular to the electric force lines in order to generate the magnetic force lines that are substantially orthogonal to the electric force lines. ing. This may be rotated horizontally with respect to a plane that obliquely intersects the lines of electric force.

[0041]

As described above, according to the present invention, in the magnetron discharge type plasma surface treatment apparatus in which the magnetic field generator is rotated along the circumference of the vacuum vessel, the substrate to be treated is uniformly treated. It is possible to provide a magnetron discharge type plasma surface treatment apparatus capable of performing the above, and a magnetron discharge type plasma surface treatment method capable of uniformly treating a substrate to be treated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetron discharge type RIE device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a dipole ring magnet.

FIG. 3 is an exploded view of a main part of the magnetron discharge type RIE device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a distribution of a magnetic field generated in the chamber 1 of the magnetron discharge type RIE device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a position on a wafer surface and an etching rate of a silicon oxide film.

FIG. 6 is a diagram showing a breakdown voltage distribution of a MOS diode, and FIG. 6A is an M diagram formed by using the magnetron discharge type RIE device according to the first embodiment in an RIE process.
The figure showing the breakdown voltage distribution of the OS diode, (b) is RI
Magnetron discharge type RIE without auxiliary magnetic material in E process
FIG. 6 is a diagram showing a breakdown voltage distribution of a MOS diode formed by using the device.

FIG. 7 is an exploded view of a main part of a magnetron discharge type RIE device according to a second embodiment of the present invention.

FIG. 8 is an exploded view of a main part of a magnetron discharge type RIE device according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a magnet element of a ring magnet,
FIG. 3A is a perspective view showing an example of a magnet, and FIG. 3B is a perspective view showing an example of a coil.

FIG. 10 is a configuration diagram of a conventional magnetron discharge type RIE device.

FIG. 11 is a plan view of a dipole ring magnet.

FIG. 12 is a diagram showing a theoretical distribution of a magnetic field generated in a chamber 1 of a magnetron discharge type RIE device.

FIG. 13 is a diagram showing a distribution of a magnetic field generated in a chamber 1 of a conventional magnetron discharge type RIE device.

[Explanation of Codes] 1 ... Process chamber, 3 ... Wafer, 5 ... Electrode, 7 ...
High frequency power source, 9 ... Housing, 11 ... Process gas inlet, 13 ... Counter electrode, 15 ... Electric force line, 17 ... Magnetic force line, 19 ... Dipole ring magnet, 21 ... Bearing made of magnetic material, 23 ... Auxiliary magnetic material, 30 ... Rotating and sliding mechanism,
32 ... Rotating and sliding mechanism, 34 ... Bearing made of magnetic material,
40 ... Gear, 50 ... Coil.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H05H 1/46 H05H 1/46 L

Claims (6)

[Claims] 1. A vacuum container provided with an electrode on which a substrate to be processed is installed, a process gas introducing unit for introducing a process gas into the vacuum container, and a discharge phenomenon generated in the vacuum container. A plasma generating means for converting the process gas inside the vacuum vessel into a plasma, a magnetic field generating means for generating a magnetic field inside the vacuum vessel; and rotating the magnetic field generating means along the circumference of the vacuum vessel, A rotation moving means including a first magnetic body, and a second magnetic body generating a magnetic field symmetrical to a magnetic field generated inside the vacuum vessel by the first magnetic body inside the vacuum vessel. A magnetron discharge type plasma surface treatment apparatus comprising a body. 2. The magnetron discharge type plasma surface treatment apparatus according to claim 1, wherein the center of the magnetic field generated by the magnetic field generating means is matched with the process surface of the substrate to be processed. 3. The magnetron discharge according to claim 1, wherein the magnetic field generated by the first magnetic body and the magnetic field generated by the second magnetic body are substantially equal to each other. Type plasma surface treatment equipment. 4. The first magnetic body is a slide body for rotating and sliding the magnetic field generating means, and the second magnetic body is a rotary slide body and a rotary motion transmitting body for generating a magnetic field substantially equal to that of the rotary slide body. 4. The magnetron discharge type plasma surface treatment apparatus according to claim 3, wherein the surface treatment apparatus is a magnetron discharge type plasma surface treatment apparatus. 5. The magnetron discharge type plasma surface treatment apparatus according to claim 4, wherein the rotary sliding body is a bearing, and the rotary motion transmitting body is a gear. 6. A magnetic field generated inside the vacuum container by causing an electric discharge phenomenon inside the vacuum container to turn the process gas inside the vacuum container into plasma and generating a magnetic field inside the vacuum container. A magnetron discharge type plasma surface treatment method of rotating a magnetic field, wherein when a magnetic body is included in the mechanism for rotating the magnetic field, the magnetic body is prevented from disturbing at least the magnetic field lines inside the vacuum container. A magnetron discharge type plasma surface treatment method, wherein a plasma surface treatment is performed on the process surface while another magnetic body is provided so as to correct the magnetic field lines on the surface so as to be horizontal to the process surface.