JP2902822B2 - Planar magnetron sputter electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a planar magnetron <br/> Nsupatta electrodes, in particular, sputtering <br/> suitable planar mug <br/> the deposition rate improved in the thin film formation on the substrate It relates to a netron sputter electrode.

[0002]

2. Description of the Related Art A magnetron sputter electrode forms a region where a magnetic field and an electric field are orthogonal to each other on a target surface in a low-pressure gas atmosphere, confines electrons, generates a high electron density, and is generated by glow discharge. By confining the gas ions in this region, the ion concentration is increased, and the deposition rate of the target material on the substrate is improved.
This is to reduce the flow of electrons into the substrate. However, the region where the magnetic field and electric field in which electrons are confined is orthogonal to the surface of the target is limited, and in the region, the sputtered material is locally eroded due to the difference in the local magnetic field strength. Usage efficiency is very poor. In particular, the final target use efficiency when a magnetic target is used is about 7% to less than 9%. In addition, there is an essential problem that the film formation rate on the substrate is locally different depending on the difference in the target erosion state.

In the prior art, in order to suppress the aforementioned local erosion of the target, for example, Japanese Patent Application Laid-Open No.
By controlling the position of a magnet used to generate a magnetic field from the back surface of the target, as described in Japanese Patent No. 2215771, the magnetic field intensity distribution on the target surface is changed to disperse the portion where the ion concentration is concentrated. ,
The method of avoiding local erosion is mainly used.
However, in this case, the change in the magnetic field intensity on the target surface due to the temporal change of the target shape due to the erosion is not sufficiently considered, and the ideal erosion shape has not been achieved. The present inventors have studied the position control of the magnet used to generate a magnetic field from the back surface of the target according to the above-mentioned known example. As a result, the final target use efficiency in the case where the magnetic target is used is shown. Is about 15% to 20%
%.

[0004]

In the above-mentioned prior art, no matter how the position of the magnet installed on the back surface of the target is controlled, the erosion of the target is locally performed at a location where the magnetic field intensity always exists on the surface of the target. Speed increases,
The impedance decreases. As a result, the magnetic field vector is further concentrated on this portion, so that the ion concentration is concentrated, local erosion of the target is promoted, and the target material cannot be uniformly eroded. In particular, the final target utilization efficiency when using a magnetic target was about 15% to 20%.

[0005] This means that when a thin film is formed using a magnetron sputter electrode, the efficiency of use of a target material required from the viewpoint of cost reduction, productivity improvement, and continuous processing are considered. This is clearly disadvantageous in terms of reducing the frequency of changing the required target material.

An object of the present invention is to generate a high-density plasma in order to solve the above-mentioned problems of the prior art.
In the case of forming one annular tunnel magnetic field, the erosion area of the target material is expanded to make the target material uniform and the utilization efficiency of the target material is increased , and at the same time, the space for the substrate is increased.
It is possible to achieve a uniform deposition rate
To provide a planar magnetron sputtering electrode.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a magnetic head having a centrally disposed magnetic pole and peripherally disposed magnetic poles.
An annular tunnel magnetic field between the poles
Magnetic field forming means for forming
The surface within the single annular tunnel magnetic field
The target material made of a sputtered substance is
Where the horizontal magnetic field strength is maximum in the tunnel magnetic field
On the outside of the central annular target provided in
The outer annular target provided and inside the part
Electrically connected to the inner ring target provided
Insulated and divided, the central annular target
The outer and inner annular
Increase the power supplied to the target and apply
Utilization efficiency of target material in annular tunnel magnetic field
Power supply means for improving
It is a laner magnetron sputter electrode .

[0008]

[0009]

According to the above construction, the magnetic field is formed by the magnetic field forming means.
Surface in a single annular tunnel magnetic field
The target material made of the putter substance is
In the part where the horizontal magnetic field strength in the tunnel magnetic field becomes maximum
The central annular target provided and the
And the inside of said part
Electrically isolated from each other with the inner annular target
Separated and configured to supply to the center annular target
Outer and inner annular targets for power
The power to be supplied to the
Emission per unit emitted from an annular target
Emit from outer and inner annular targets relative to number
Increases the electron density by increasing the number of electrons emitted per unit
Target in a single annular tunnel magnetic field
Radially expand a uniform erosion area to improve target material
Sputtering on substrates while improving efficiency
The film deposition rate can be made uniform .

[0010]

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Parts corresponding to those in the conventional example of FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. Embodiment 1 FIG. 1 is a cross-sectional view of a magnetron sputter electrode according to one embodiment of the present invention, FIG. 2 is an erosion cross-sectional shape of a target when the electrode of FIG. 1 is used, and FIG.
Front view of a circular planar magnetron sputter electrode using the above sputter electrode structure, FIG. 6 is a cross-sectional view of a conventional magnetron sputter electrode, and FIG. 7 is an erosion cross-sectional shape view of a target when the electrode of FIG. 6 is used. is there.

FIG. 1 shows a cross section of a case where the present invention is implemented as a circular planar electrode with the center of the target being O. In this drawing, a sputtering target 6 divided into a plurality (three in this example) of flat target materials is disposed.
a, 6b, 6c are divided backing plates 4
a, 4b, and 4c, which are made of the same material.
The backing plates 4a, 4b, 4c are, for example,
It is electrically insulated by a spacer 3 made of an electrically insulating material such as Teflon or alumina.

The backing plates 4a, 4b, 4
Magnetic field straddling c (see leakage magnetic field lines 5 shown in FIG. 1)
A permanent magnet 2 according to a magnetic field forming means that generates a magnetic field is disposed, and a yoke 1 is used for magnetically coupling the two. In addition, DC power sources 7a, 7b, and 7b of the sputtering targets 6a, 6b, and 6c can apply individual power to the electrically insulated sputtering targets.
7c is provided.

According to this embodiment, the applied power is set to be lower for a portion where the target erosion is fast, and to be higher for a portion where the target erosion is slow.
By controlling the applied power independently depending on the erosion shape, an erosion region as shown by hatching in FIG. 1 is formed, and the sputtering targets 6a, 6b, and 6c existing in the magnetic field for confining electrons are high targets. The utilization efficiency becomes possible.

Thus, the electrode structure according to the embodiment of FIG.
The conventional electrode structure shown in FIG.
The comparison is made according to the erosion cross-sectional shape when used for the e target (target thickness: 4 mm). The magnetron sputtering electrode shown in FIG. 6 has an undivided sputtering target 6 held on a backing plate 4, a permanent magnet 2 for generating a magnetic field having a shape straddling the sputtering target 6, and a yoke 1. Are combined.

FIG. 7 shows an erosion cross-sectional shape when a conventional electrode is used. When the center of the target is O, the position in the left and right cross-section cutting direction is shown on the horizontal axis, and the target erosion shape is shown on the vertical axis. The erosion of the target is concentrated on the portion where the horizontal magnetic field intensity is maximum, and shows a steep shape. The target utilization efficiency was about 7% to 9%. The discharge conditions here are a constant power of 4 kW and an argon gas pressure in the chamber of 2 mTorr.

FIG. 2 shows an erosion cross-sectional shape when the electrode according to the present embodiment is used. It can be seen that the erosion of the target has a peak at the portion where the horizontal magnetic field intensity is maximum, but the half width of the erosion region is 6 times or more as compared with FIG. The utilization efficiency of the target was 50% or more, and a higher value than the conventional value could be obtained. The discharge conditions here are as follows: constant power: 4 kW to DC power supplies 7a and 7c in FIG. 1, power: 0 kW to 1 kW to DC power supply 7b, and argon gas pressure in the chamber: 2 mTorr. Further, an electrically insulated target 6 for sputtering is used.
A gap of 1 mm is provided between a, 6b, and 6c.

FIG. 3 is a front view of the circular planar magnetron sputtering electrode used in the above embodiment. In this embodiment, the flat plate targets 6a, 6b, 6c for sputtering are electrically insulated from each other. , And a magnet 2 installed on the back surface thereof.

According to the present embodiment, the use efficiency of the target can be improved as compared with the related art by providing a distribution of power applied to the target in a magnetic field for confining the electrons generated on the target surface of the magnetron sputtering electrode. In addition, the cost for forming a thin film can be reduced, and the frequency of replacing spatter materials can be reduced. Further, since the local erosion is suppressed, the film formation rate on the substrate facing the target can be made uniform.

Embodiment 2 FIG. 4 is a front view of an elliptic planar magnetron sputtering electrode according to another embodiment of the present invention. In this example, since the sputtering target has a rectangular shape, based on the structure shown in FIG. 3, the sputtering flat plate targets 6A, 6B, and 6C which are elongated in a track shape, and the magnet 2A installed on the back surface thereof. It is configured. Also in the case of the example of FIG. 4, the target use efficiency was 50% or more.

Embodiment 3 FIG. 5 is a sectional view of a magnetron sputtering electrode according to still another embodiment of the present invention. In the figure, components having the same reference numerals as those in FIG. 1 are the same as those in the embodiment of FIG. The embodiment of FIG. 5 is an example using only one DC power supply 7A. Electrically insulated sputtering targets 6a, 6b, 6
The variable resistors 8a, 8b, and 8c are connected in parallel to the DC power supply 7A for each c, and the applied power to each target is controlled by changing each resistance value.

In this embodiment, the output of the DC power supply 7A is 12
In order to make the output to the flat plate targets for sputtering 6a and 6c 4 kW, the variable resistor 8a is set to 0Ω, and the cathode voltage 4 to each of the sputtering targets 6a and 6c is set to 4 kW.
Data of 20 V and current of 9.5 A were obtained. On the other hand, with respect to the sputtering target 6b, the variable resistor 8b was set to 2Ω and the variable resistor 8c was set to 50Ω to obtain a cathode voltage of 400V and a current of 1.5A in order to output 0.6 kW. Other discharge conditions were the same as in Example 1. In each of the above embodiments, a permanent magnet is used as the magnetic field forming means. However, the present invention is not limited to this, and a magnetic field forming means using an electromagnet may be used.

[0023]

According to the present invention, the magnetic field forming means
The surface in one formed annular tunnel magnetic field is
The target material made of the material to be sputtered is
Where the horizontal magnetic field strength is maximum in a tunnel-like magnetic field
The center annular target provided on the outside of the part
The outer annular target provided on the inside of said part
To the inner annular target provided on the
Insulated and divided into a central annular target
The outer and inner annular targets
Since the power to be supplied to the unit is increased and applied,
Target uniformity in a single annular tunnel magnetic field
Radius of the erosion area, and the efficiency of target material utilization
Film formation by sputtering on the substrate
There is an effect that the speed can be made uniform .

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetron sputter electrode according to one embodiment of the present invention.

FIG. 2 is an erosion cross-sectional view of a target when the electrode of FIG. 1 is used.

FIG. 3 is a front view of a circular planar magnetron sputter electrode using the sputter electrode structure of FIG. 1;

FIG. 4 is a front view of an elliptical planar magnetron sputtering electrode according to another embodiment of the present invention.

FIG. 5 is a sectional view of a magnetron sputtering electrode according to still another embodiment of the present invention.

FIG. 6 is a sectional view of a conventional magnetron sputter electrode.

FIG. 7 is an erosion cross-sectional view of a target when the electrode of FIG. 6 is used.

[Explanation of symbols]

2, 2A permanent magnet 3 Spacer 4a, 4b, 4c Backing plate 6a, 6b, 6c, 6A, 6B, 6C Flat plate target for sputtering 7a, 7b, 7c, 7A DC power supply 8a, 8b, 8c Variable resistance

Continuation of front page (72) Inventor Katsuo Abe 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Hitachi Manufacturing Co., Ltd. (56) References JP-A-3-61367 (JP, A) JP-A-2- 225666 (JP, A) Japanese Utility Model 62-75063 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 14/00-14/58 H01L 21/203, 21/285

Claims (1)

(57) [Claims] 1. A magnetic pole disposed at a center and a magnetic pole disposed at a peripheral part.
An annular tunnel magnetic field between the magnetic poles
Magnetic field forming means for forming
Surface in a single annular tunnel magnetic field
The target material made of the putter substance is
In the part where the horizontal magnetic field strength in the tunnel magnetic field becomes maximum
The central annular target provided and the
And the inside of said part
Electrically isolated from each other with the inner annular target
The edge is divided and configured, and the center annular target is
For the power supplied, the outer and inner annular taps
The power supplied to the target is increased and applied to the one ring.
Efficiency of target material in a tunnel-like magnetic field
Pre characterized in that a power supply means for improving
Toner magnetron sputter electrode.