JPS583976A - Method and device for formation of film by sputtering - Google Patents

Abstract

PURPOSE:To make the distributions of deposited film thicknesses uniform by flowing electric currents of prescribed periods to electromagnets, and changing the magnetic induction forces energized in the inside and outside electromagnet coils thereby changing the diameter of plasma rings. CONSTITUTION:A packing plate 22 to serve as the cathode is provided to a target flat plate 21, and a yoke 23 which generates prescribed magnetic flux distributions in the hollow space 29 over the 1st plane of the plate 21, inside, outside electromagnet coils 24, 25, a central magnetic pole terminal 26, inside, outside magnetic pole terminals 27, 28, an electrode support 30, and an O-ring 31 are provided. A shield 32 to serve as the anode is provided via an insulation spacer. When sputtering is effected by applying a high voltage power source, plasma rings are generated in the space 29 over the plate 21. If the difference in the magnetic induction forces to be applied upon the coils 24, 25 is decreased to decrease the diameter of the plasma rings, the thickness distributions of the formed films of a curve 62 are obtained. If the difference is increased, a curve 61 is obtained, and the synthetic films of a curve 63 are distributed on a substrate 20 to be formed with films, whereby the uniform thickness of the formed films is obtained.

Description

[Detailed description of the invention] The present invention is used in a sputtering device for thin film materials.

This invention relates to a film forming method and apparatus using planar magnetron sputtering, which aims to increase the length of the target plate and control the thickness distribution of the deposited film on the sample surface. 1° sputtering technology uses low pressure atmospheric gas.

It causes a glow discharge and becomes ionized (plasma-like), creating Yin and Yang 1! A high voltage applied between the electrodes accelerates the plasma-like ions and causes them to collide with a plate of target material placed at the cathode.

This is a technique in which atoms or particles constituting the target material ejected by the collided ions are deposited on a substrate provided near the anode to form a thin film of the target material.

In this case, the purpose of deposition is to confine the ions generated by the glow discharge in a space at a high density and to effectively transport them onto the target material flat plate.

This is important for improving speed and reducing substrate damage caused by electrons.

For this purpose, the above-mentioned ions are transferred to the target material P1. (It is effective to achieve high density confinement in the spatial region on the plate surface. Then, the magnetic field configuration was studied.

It's coming.

In recent years, V-type planar magnetron sputtering equipment has reached a level where its deposition rate is comparable to that of conventional resistance heating type and vacuum evaporation equipment, and has recently been used to form thin films for thin film integrated circuits and semiconductor devices.

As a device, it has come to be widely used in the film forming process for production.

FIG. 1 is a conceptual explanatory cross-sectional view showing the structure near a target material flat plate of a well-known conventional plate 211 magnetron type sputtering apparatus. Target material flat plate (hereinafter referred to as tarp).

A magnet is attached to the back surface of the flat plate (referred to as a flat plate) 1 by a yoke 6.

An air-coupled ring-shaped magnetic pole 2 and its ring-shaped 5 magnetic poles 2
A cylindrical magnet 5 is arranged at the center of the magnetic circuit to form a magnetic circuit. Target 1 by these magnetic poles 2°6
0 surface side (Fig. 1).

In other words, the distribution of magnetic lines of force is in the space of the torus (7'
aruz) is cut in half along a plane perpendicular to the height direction, and the half-cut plane is parallel to the surface of the target flat plate 10 by 1°.

A semicircular annular magnetic field distribution, commonly known as tunnel magnetism.

A field distribution 11 is generated. This tunnel-like magnetic field distribution.

11, the plasma-like ions are confined therein at a high concentration (not shown). This 1° plasma-like ion is even more positive! , 10 and the cathode 7 installed on the back surface of the target flat plate 1 with an insulating spacer 8 interposed therebetween.

The atoms or particles are accelerated by an electric field substantially perpendicular to the surface of the target flat plate 10 and collide with the surface of the target flat plate 1, and as a result, the atoms or particles are sequentially ejected from the target 1 surface and invade the eroded area.

A region 12 is formed.

Note that 5 is a water cooling mechanism. This erosion area 12 is.

As you can guess from the above explanation, it's spat.

The degree of erosion progresses with the passage of time and I& during the process.

This erosion is the target of the structure shown in Figure 1.

In flat plate structures, the erosion is effectively confined to a specific area of the target plate.

It is said that only the volume of the area can be used. 1,1 Therefore, the initial value is the desired uniform film thickness.

Even if no distribution is obtained, the target material is further ejected due to the formation of such erosion areas.

Because the direction and amount of atoms ejected change,
The 1° distribution of the thickness of the thin film to be deposited on the surface of the sample substrate changes over time, and the distribution of the allowable film thickness becomes large. Rather, there is a drawback that the lifetime of the target material is determined by deterioration of the film thickness distribution over time.

7, it is impossible to perform a long sputtering process if you want to continuously deposit a film on a large number of substrates or perform a long sputtering process, which is considered to be the limit of the conventional sputtering process. .

It is. Thereafter, in order to eliminate this defect, the etching region 12 is formed over a wide area on the surface of the target flat plate 1.

The magnetic field distribution 11 is changed so that the magnetic field distribution 11 is generated.

was proposed (JP-A-51-86085; JP-A-53-
17586).

What is the theoretical background or technical philosophy behind this technology?

2nd page of JP-A-51-86085, lower right column.

From line 19 to page 3, top left column, line 2, it says, ``The greatest target erosion is caused by magnetic field lines.

In an area aligned with and lying below the above point or area parallel to the target plate.

Therefore, Japanese Patent Application Laid-Open No. 1983-1980
In Japanese Patent No. 86083, as stated in the first claim of the patent, an auxiliary variable magnetic field is generated in the direction perpendicular to the source for the first magnetic field means, A town.

A second magnet means metal fitting 1j that changes the variable magnetic field and continuously moves f to such an extent that the resultant lines of magnetic force become parallel to the source.
4 of the drawings as a specific technique.
An actual example in which the electromagnets shown in the figure are arranged in isolation is disclosed. Others Tokukai Akira.

In 55-7586, the technique is straightforward.

In other words, the magnetic means itself is moved mechanically.

Even if it's something you do.

However, the inventors of the present invention are among the above-mentioned known series.

The technical idea was also reexamined in light of the experimental facts of the inventor of the present application, and the effect was further improved than the technical means shown in the above-mentioned publicly known series.

Furthermore, we have achieved a new technology that allows almost arbitrary control of the thickness and distribution of the deposited thin film.
).

An object of the present invention is to provide a method and apparatus for forming a film by planar magnetron sputtering, which eliminates the drawbacks of the prior art described above, provides a uniform copying distribution, and can be put to practical use.

The main point of the present invention is that when magnetic flux lines are generated from a negative magnetic flux source, the magnetic fluxes do not interlink with each other due to their nature, and an attractive or repulsive force called maxraalt stress acts on the magnetic flux lines. It has at least three magnetic pole faces.

- constitutes a magnetic flux source and is generated on some of its magnetic pole faces.

control the amount of magnetic flux that is emitted to the other remaining magnetic pole faces.

A planar magnetron system in which the amount of magnetic flux and the position of its distribution, that is, the area where plasma stands, can be easily and widely moved.

A sputtering device, in which an electromagnet provided in a part of the magnetic pole body is rotated a predetermined period during the sputtering process.

A current that changes with time is passed through this place at the same time.

The sputtering power is increased or decreased in synchronization with a predetermined period to reduce the annular plasma generation region at a predetermined period.

The film is formed by increasing and decreasing the amount of sputtering while moving both of the annular plasmas one or more times, and synthesizing the film thicknesses observed in each annular plasma generation area.

Hereinafter, the present invention will be explained based on the embodiments shown in the drawings. (( Explain physically.

FIGS. 2 and 3 are schematic cross-sectional views of one embodiment of an electrode portion of a sputtered electrode structure according to the present invention.

The main component of the electrode portion is a target flat plate 21 (254 χ am, thickness.

20, Al-2% S1), the target plate 21 is fixed by suitable brazing means, for example, and serves as a cathode.

Backing plate 22 (made of copper), the target flat plate 2
A predetermined magnetic flux is applied to the hollow space on the first main surface of 1.

Yoke 1゜23 for generating magnetic field, which is a means for generating distribution
, inner electromagnetic coil 24, outer electromagnetic coil 25, center pole tip 26, inner pole tip 27. Outer pole tip 28° electrode support 30. Rolling 51, shield 32 serving as an anode. and an insulating spacer 55.

In the example shown in FIG. 2, the target flat plate 21 is circular, but this is because the substrate to be film-formed used in this example is circular. When using a rectangular substrate, a rectangular target flat plate is prepared. It would be appropriate to do so. That is, the circular electrode part of the electrode structure described in this embodiment is one example, and the shape of the electrode part, such as a rounded rectangle, does not deviate from the present invention.

Further, a flow path 34 for passing a refrigerant such as water is formed on the back side of the backing plate 22, and a vibrator 35, 56 for supplying and discharging the refrigerant from the outside via the magnetic field generating yoke 23 etc. is provided in this flow path 34. ,.

Wt is used to cool the target flat plate 21.

Figure 4 is a schematic diagram of a power source for excitation of a one-electrode structure.

This shows the configuration. The main part of the excitation power supply section.

As for the components, the inner electromagnet coil 24 and the outer electromagnet coil 25 are controlled completely separately.

Two current supply circuits are incorporated. The current applied to the excitation power source and the inner and outer electromagnetic coils 24 and 25 can be applied completely arbitrarily, that is, a constant current that does not change from time to time, or a rectangular waveform, triangular waveform, alternating current waveform, etc. with a constant period. A microprocessor 41 and a memory 42 are used so that the current waveform can be set to the current waveform of the keyboard 43. Alternatively, information regarding a predetermined current waveform may be provided from a suitable external storage device 40 (e.g., magnetic tape, magnetic disk), and the output of the microprocessor 41 may be digitally converted.
In addition to analog signal converters 44g and 44b (DJ converters), current amplifiers 45α and 45hVC are also installed.
The power is amplified to a predetermined strength sufficient to excite the inner and outer electromagnet 5 coils 24,25.

The excitation power supply unit in FIG. 4 handles the inner and outer electromagnetic coils 24, 25 as control objects, so it is a power supply with constant current characteristics, and the output current detection units 1) 46a and 46A That is, the current amplifier 4 detects each electromagnet current value, compares it with a predetermined current value given by the v/i converters 44a, 44, and performs correction.
5a, I have the means to return information to 454.
Release 1 to perform 1° sputtering! High-voltage power supply for supplying electric power, that is, sputter power supply.

As is well known, it ranges from 0 to 800.

It has a thigh output voltage and an output current of about 0 to 15.4.

I used something. Also, as is well known, 4□, 1
To control the power input to glow discharge.

This high voltage power supply has constant current output characteristics.

As mentioned above, the eroded region I-F plasma ring is generated where sputtering occurs on the target flat plate.

It is located almost directly below the place where it occurs. In addition, the generation of plasma rings is caused by
At the sputtering pressure inside and outside 1Q rntorr, the magnetic field vector in the hollow space on the first main surface of the target flat plate at a distance of about 10 to 1120 mm from the first main surface of the target flat plate is the first It is focused and occurs in a region parallel to the principal plane of the plane.

Therefore, in order to know the occurrence position of the erosion area on the target flat plate, it is necessary to know the magnetic flux distribution in the hollow space on the first main 15 side of the target flat plate.

It is a powerful tool.

Therefore, the sputter power supply structure according to this embodiment.

To obtain various properties such as the film thickness distribution due to the corpse, the magnetic flux distribution in the hollow space 29 on the first main surface 1 of the target flat plate 21 was measured before conducting the experiment.

A glass meter was used to measure the magnetic flux distribution. 5 and 6 are similar to the embodiment shown in FIG. 2 in order to simulate the magnetic flux distribution on the first main surface of the target flat plate 1 of the sputter electrode structure of this embodiment. This is 11, which was actually measured by manufacturing yoke materials of almost the same size. The difference between the embodiment shown in FIG. 2 and this simulated yoke is that the groove in which the outer electromagnetic coils 24 and 25 are embedded is shallower. ■5th
The vertical axis in the figures and FIG. From the central axis of the extremes 26, radially outward.

distance to ←). The magnetic force I5 of the outer electromagnetic coil 25 was set to be 40:1. No.

Figure 6 shows the inner electromagnet coil 24 and the outer electromagnet.

The magnetomotive force of the coil 25 was set to be 1.5:1.

5 and 6, the inner coil 24 and the outer coil 2
In Fig. 5, the directions of the currents flowing through the terminals are opposite to each other.
As described above, a plasma ring is generated in the area where the magnetic field vector is parallel to the first main surface of the target flat plate 21, so that the inner electromagnetic coil 24 and the plasma ring in FIGS. A plasma ring is generated in the area indicated by 54.

Therefore, as is clear from FIGS. 5 and 6, the inner and outer magnet coils 24, 25 are energized.

The generation location of the plasma ring can be moved by changing the magnetomotive force generated by the plasma ring. In the example shown in FIGS. The magnetomotive force of the outer electromagnetic coil 25 is equal to the magnetomotive force of the inner electromagnetic coil 24. However, even if the magnetomotive force applied to the outer magnet coil 25 is kept constant and the magnetomotive force 15 applied to the inner electromagnetic coil 24 is changed, the result is the same as in FIGS. 5 and 6. The region where the magnetic field vector is parallel to the target flat plate 21 can be moved.

Next, the film thickness distribution characteristics of the deposited film in this example will be described. Fig. 7 shows an image of a target plate parallel to the first principal surface of the target plate at a distance of 85° from the first principal surface of the target plate with respect to the diameter of the annular erosion region. This is an example of calculating by division whether the film thickness distribution characteristic on the substrate 2G to be film-formed placed on the film-forming target substrate 2G changes from L4 to L4, and explains the first basic technical idea of the present invention. It is something.

The vertical axis shows the film thickness with the film thickness at the center of the target substrate as 100%, and the horizontal axis shows the thickness of the nucleic acid film in the outward radial direction from the center of the target substrate on the target substrate. The distance R (orchid) is shown. 1 ((As is clear from FIG. 7, if the diameter of the circular mound-shaped erosion area is large, the surface of the film-forming target substrate.

The ceiling, which has a shoulder in the thickness distribution of the deposited film at a radius of about 100 m, has a double eye-shaped film thickness distribution characteristic of 1%.

On the other hand, in Dj6125-F and above, the debris in the thickness distribution of the deposited film disappears, resulting in a so-called unimodal deposited film thickness distribution with a mountain in the center on the substrate to be deposited. Get out of your sexuality.

The above discussion was about the diameter of the annular eroded region, but as mentioned earlier, this eroded region occurs almost directly below the 1° plasma ring, so the diameter of the annular eroded region is the same as the diameter of the plasma ring. You can think of it as the diameter. Therefore, by controlling the magnetic field distribution characteristics shown in Figures 5 and 6, the diameter of the plasma ring can be changed.
Various film thickness distribution characteristics as shown in FIG.

can be expected to be obtained arbitrarily.

The curve 61 shown in FIG. 8, for example, as shown in FIG. The magnetomotive force with the electromagnetic coil 24 was set to 1:40.

8 is a conceptual diagram of the film thickness distribution characteristic expected to be obtained when the film is formed, and the curve 62 shown in FIG.

For example, the inner electromagnetic coil 24 and the outer electromagnetic coil 1° coil 2
plasma with a magnetomotive force ratio of 1.5:1.

The film thickness that can be reduced when the ring diameter is made smaller.

It is a detailed diagram of distribution characteristics.

During the film formation process on one film formation target substrate, the magnetomotive force of the inner and outer electromagnets is changed, and 7. as shown in FIG. ) curve 61.6
If the operation to give a film thickness distribution like 2 is performed appropriately, the curve 1lli161 and curve 6 will be formed on the target substrate.
As a synthetic film thickness distribution obtained by adding up 2, a curve 65 shown in FIG. 8 shows a nucleic acid.

A uniform film thickness can be obtained over a wide range on the target surface.

FIG. 9 shows an example of the film thickness distribution characteristics of the film formed in this example.
The inner electromagnetic coil 24 generates approximately 20
This is when a magnetic field strength of about 0 glass can be obtained on the target. Also, in song 71, the ratio of the magnetomotive force between the inner electromagnetic coil 24 and the outer electromagnetic coil 25 is 5:
L7 shows the film thickness distribution characteristics when the film thickness is set to 1.

Curves 71 and 72 in FIG. 9, the Talget flat plate 21,
.

The distance from the main surface of No. 1 to the substrate to be film-formed was 80 fi.

Argon with a purity of 99,999% was used as the sputtering gas.

The sputtering gas was obtained at a sputtering gas pressure of 5.4 mtorr.

The vertical axis of FIG. 9 shows the film formation 2. 1 speed, and the 4R axis is the speed of this example.

radially outward from the central axis of the IL+D portion of the sputtering electrode body, distance # on the substrate to be film-formed.
It is 1 (-).

As shown in Figure 9, the outer electromagnetic coil 2
By increasing the magnetomotive force applied to the inner electromagnetic coil 24 and relatively decreasing the difference between it and the magnetomotive force applied to the inner electromagnetic coil 24, the diameter of the plasma ring becomes smaller, resulting in the formation as shown by the curve 62 in FIG. The film thickness distribution characteristics are obtained, and conversely, the outside 1
By reducing the electromotive force applied to the 111 electromagnetic coil 251 (l), the diameter of the plasma ring becomes larger, and the 8th
A groove film thickness distribution characteristic as shown by the curve 61° in the figure is obtained.

Even if the magnetomotive force of the outer electromagnetic coil 5 is changed to obtain the thickness distribution of 71.72 in Figure 9, the thickness distribution will be 15%.
Although the plasma ring moves, the discharge impedance of the glow discharge, ie, rp-ge.

The voltage applied to the target 1. There is no change of more than ±5% in the current flowing through the current, and as mentioned above, the star current output characteristics of this embodiment V are also different. There is almost no change in the spacing power applied to .

For this reason, under the conditions of this embodiment in which a constant sputtering power is applied, when the diameter of the plasma ring is made small, the area of the plasma ring, that is, the first principal surface v on the target flat plate is Since the area of the region that is eroded by sputtering becomes smaller, the force per unit area on the first main surface of the target flat plate 21 increases. Prerna, as it is well known.

In Macnetron sputtering VC, B,p = eroded region V on the target flat plate.The film formation rate on the substrate to be filmed is approximately proportional to the applied power per unit area. Therefore, when the plasma ring diameter is small, the film formation rate in the center region of the substrate to be film-formed is higher than when the plasma ring diameter is large, as shown in FIG. .

The monomodal and bimodal film thicknesses shown in FIG.

In order to synthesize a custom-made cloth and achieve as uniform a film thickness distribution as possible over a wide area, it is important to keep the plasma ring diameter small during the deposition process on a single target substrate. It is necessary to select a ratio of 5 to the time during which the diameter is increased. As mentioned above, when the plasma ring diameter is small, the film formation rate at the center is higher than when the plasma ring diameter is large. If you do not make the ratio of "the time when the radius is a dog" to 1 or less 11), @1. Appropriate film thickness distribution characteristics cannot be achieved on the target substrate.

Furthermore, per unit area on the target flat plate, sputter (according to the force input, its erosion).

It is thought that the amount of erosion in the area where the target plate is exposed, that is, the progress of erosion in the thickness direction of the target flat plate, is proportional.

Therefore, the amount of erosion in the area on the target plate corresponding to the position where the plasma ring diameter is small.

This tar is compatible with TIU as the plasma ring diameter is large.

Match the amount of erosion in the area on the target plate. .

That's good. This is because the amount of erosion is unbalanced.

If so, the erosion depth in one of the eroded areas reaches the thickness of the target flat plate first, and the erosion progresses uniformly in both eroded areas during the life of the target flat plate.

It can be said that the life of the target flat plate is shorter than that in the case where the target plate is used.

FIG. 10 shows typical synthetic film thickness distribution characteristics obtained by actually forming a film and synthesizing the film thickness distribution characteristics shown by curves 71 and 72 in FIG. 9. Curves 71 and 72 in Fig. 9 are calculated and synthesized to allow a film thickness deviation of 15% and obtain a uniform film thickness over the widest area 0, and from the conditions, the most A film was formed by selecting one that had a small diameter and took a long time. 1st
The circle mark in Figure 0 is a plot obtained by calculation from the film thickness distribution characteristic 5 shown in Figure 9. It shows good agreement.

The film forming conditions of curve 81 in FIG. 10 are those of FIG.

This is the same as that used to determine the film thickness distribution characteristics. 2゜The excitation conditions for the inner and outer electromagnetic coils are that the magnetomotive force of the inner electromagnet coil 24 is constant at 10,000 ampere turns via the D/A converter 44m and the current amplifier 4511 according to the command from the vpμ41, and Coil nPu41
The D/A converter 446 is operated by a command from the D/A converter 446.

As shown in FIG. 9, the magnetomotive force of the magnetomotive force of the current amplifier is determined by the time T when the plasma ring diameter is at its maximum due to the rectangular wave pulse current.
1 for 10 seconds and 20007 unbear.

The time T2 for the turn and the minimum plasma ring diameter is 2.
The cycle was repeated 11,110 times with a period TO of 12 seconds.

The time of T1 may be a current or a negative current.

As mentioned above, including the experimental results, the film formation described in Figs. 7 and 8 was performed from the two viewpoints of achieving a uniform film thickness distribution and not shortening the life of the target flat plate. The first basic technical idea of the present invention, which is to synthesize the film thickness distribution, is that under the condition that the input sputtering power is 1 U, [time when the plasma ring diameter is small] + "time when the plasma ring diameter is large" So that the ratio is less than 1,
The purpose is to change the respective magnitudes of the inner and outer electromagnet currents, and conversely, to excite each electromagnet so that the above-mentioned time ratio is less than 1, while improving the utilization efficiency or lifespan of the target flat plate. Flat film thickness distribution.

There are conditions under which this can be improved.

In the prior art planar magnetron electrode with a fixed magnetic field, as local erosion of the target flat plate progresses, a valley is formed within the target flat plate (in other words, the cross-sectional shape is R-shaped). It has already been mentioned that as this V-shaped valley formation progresses, the film thickness distribution deteriorates and the "C" progresses. As shown in Figure 12 <h>, the method of scattering of the target plate material by sputtering is based on the cosine law (curve 1).
01), and the particles sputtered in a relatively wide solid angle range are scattered.

On the other hand, the r-shaped valley mentioned above is the target flat.

As it is formed on the plate, the scattering direction distribution shown in FIG. 12(A) narrows the solid angle of the V as shown by curve 111 in FIG. 13(A).Curve The outline of the film thickness distribution corresponding to curve 101 and curve 111 is shown in Fig. 112 (
a) and curves 102 and 112 in FIG. 13 (σ), the film thickness increases due to the formation of V-shaped valleys.

The distribution becomes uneven and the film thickness distribution deteriorates.

FIG. 14 shows the change over time in the film thickness distribution when the magnetomotive force of the inner and outer electromagnetic coils is the same in the embodiment of the present invention shown in FIGS. 2 and 5. It is something that Curve 121, sputtering power 6KI#1 constant,
After 0 hours of use, 122 for 10 hours, 125 for 20 hours,
124 is the film thickness distribution characteristic after 30 hours of use. In addition, the maximum erosion depths at curves 121, 122, 5123, and 124, that is, the depth of the bottom of the V-shaped valley, are 0 and 124, respectively.
It was 2.4.6m.

As is clear from FIG. 14, when the maximum erosion depth reaches 6-i, the thickness of the film formed on the substrate is 0150 cm.

3. The distribution characteristics exceed the range of ±5 inches (+10 inches in curve 123 in FIG. 12), which is considered to be practical.

FIG. 15 shows the second basic idea of the present invention and the most remarkable effect.

FIG. 15 shows the composite film thickness distribution shown in FIG. 10.

In other words, the plasma ring diameter is made smaller or larger at a ratio of 1:5 before film formation.

This figure shows the change over time in the film thickness distribution characteristic when the film was continuously deposited, and as in % Fig. 14, it was assumed that the vine growth rate of 6 Kam was constant. Curve 131 is 0 hours, curve 152 is 29° hours,
133 and 154 are the film thickness distribution characteristics when the target plate was consumed for 40 hours and 60 hours, respectively.

Ru.

What is clear by comparing Figures 14 and 15.

If the eroded area of the target flat plate is expanded by periodically changing the size of the plasma ring, the formation of the V-shaped valley will be slowed down.

Alternatively, as the apex angle of the V-shaped valley becomes large, the change in the film thickness distribution over time occurs only to the extent that it hardly poses a problem in practice.

, 24 The above can also be confirmed from Fig. 16.

FIG. 16 shows the actual measurement of the cross-sectional shape of the eroded area of the target plate 21 when the target was consumed for 30 hours under the conditions shown in FIGS. 14 and 15. Curve 141 corresponds to the condition shown in FIG. 14, that is, when the size of the plasma ring is constant, and curve 142 corresponds to the condition shown in FIG. 15, that is, when the size of the plasma ring is changed periodically. . It can be confirmed that the V-shaped valley of the curve 141 has a narrower apex angle than the curve 142 (1), and a larger amount of debris is collected in terms of the film thickness distribution characteristics.

The embodiment shown in FIG. 2 has been described above, and as shown in FIG. 10, a substrate having a pi of about 50- is used for film formation. However, the present invention can also be applied to film formation on a substrate with a larger area.

As can be seen from the curve 142 in FIG. 16, 01aO
For substrates the size of a strawberry, the erosion area does not have to be large in amplitude to provide a sufficient film thickness.

Cloth properties can be obtained. However, in the present invention, when forming a film on a horizontal substrate using a sputtering electrode that requires 1°, the size of the target flat plate 210 must be adjusted to match the substrate.
It has to be bigger.

In this case, the above-mentioned eight methods of simply controlling the generation location of the plasma ring to only two positions do not result in a continuous erosion area as shown by the curve 142 in FIG. 16. In other words, annular eroded regions such as the curve 141 in FIG. 16 are formed on the target flat plate 21 in two spaces, and the material utilization efficiency of the target flat plate 21 is reduced.

Therefore, by forming a single or multiple eroded area in the area of the surface of this 2M annular eroded area, it is possible to improve the material usage efficiency. In this case, digital from HPμ41.

An example of the current waveform that is converted into an analog signal by the D/A converter 44h according to the command signal and applied to the current amplifier 45hI/the outer electromagnetic coil 251+1 is shown in the 17th example.
As shown in the figure.

Plasma phosphorus was applied for the time shown in Fig. 17.

The diameter of the plug is the largest, and the next 12, TI and plastic,! L
The diameter of the summaring becomes smaller, takes the middle size again, and returns to the initial 1υ' state. If the time sound T2 is when the plasma ring diameter is medium 1q, then 7x
= 72 10T'. Under the condition of constant sputtering force V, as described above, the erosion depth of the target flat plate 21 is the same in the ζ small erosion area corresponding to each plasma ring diameter, and the target flat plate is In order for a wide area to wear out uniformly, TI>72>Tg
The condition of u; is necessary.

In both of the plasma ring diameter control methods shown in FIGS. 11 and 17, sputtering electrons are used.

Under conditions of constant force, plasma phosphorus.

When the plasma ring diameter is longer than the plasma ring diameter, the plasma ring diameter is longer than the plasma ring diameter.

Time to maintain a smaller plasma IJ ring diameter.

The basic technology of the present invention is to maintain the target plate for a longer period of time by uniformly wearing out the target flat plate over as wide an area as possible and depositing a film with a uniform thickness on the substrate to be formed. This is a philosophy.

In the embodiment of FIG. 2 according to the present invention, in order to change the size of the plasma ring diameter, it is possible to change the relative strength of the magnetomotive force by the inner electromagnetic coil and the magnetomotive force by the outer electromagnetic coil 5. I mentioned this before.

Furthermore, it is easy to configure the excitation power supply section of the electromagnet.

In this case, it is advantageous to change the size of the plasma ring diameter by changing only the current applied to the coil of either the outer or inner electromagnet, as shown in FIG.
In the control method shown in FIG. 17, the outer electromagnetic coil 2
The explanation was given by taking as an example the control of the current value applied to 5.

In yet another embodiment of the present invention, as shown in FIG.

If the constant strength magnetic flux generating means, that is, the permanent magnet 2001 in FIG. 18 is replaced, and only the current applied to the outer electromagnetic coil 25° has a waveform as shown in FIG. 11 to FIG. Examples and.

Similarly, it is possible to control the diameter of the plasma ring.

As another embodiment of the VC of the present invention, as shown in FIG.
If the -5 part or the entire part of the permanent magnet 2002 in FIG. 9 is replaced by one, and only the current applied to the inner electromagnetic coil 24 has a waveform as shown in FIGS. 11 to 17, the result will be as shown in FIG. Implementation shown in .

As in the example, it is possible to control the size of the plasma ring diameter. However, in the case of the 10th embodiment shown in FIG. 19, if the current value applied to the inner electromagnetic coil 4 is made smaller, the plasma ring diameter becomes smaller, and conversely, the current/current applied to the inner electromagnetic coil 4 becomes smaller. If the value is set to dog, the plasma ring diameter will be large.

Therefore, the main point of the present invention is that the plasma phosphorus takes a long time when the diameter of the plasma is large.

VC (
a, For example, Fig. 17 is the excitation aI of the inner electromagnetic coil 24°.
If the current waveform is T, contrary to the case of the outer electromagnetic coil,
The condition of 1〈T2〈Tj is indispensably 2°.

As described above, as an embodiment related to the present invention, the target flat plate 2
1 and the backing plate 22, the sputtering force supplied to the electrode support 30 on the h-shaped plate is independent of the position of the plasma ring.

Although we have described the control method when the sputtering force is constant, it is also possible to form a film with a uniform thickness by combining this sputtering force with controlling the diameter of the plasma ring.

This will be explained in detail below. 2.1 In order to obtain a uniform thick film over as large a surface as possible, as mentioned above, under the condition that the sputtering power is constant, [time when the plasma ring diameter is small] + 1 when the plasma ring diameter is small time] had to be 1 or less.

For example, the excitation waveform of the outer electromagnetic coil 25 as shown in FIG. 11 is changed to a waveform (181) as shown in FIG. The command synchronized with D
/A converter is set to the same length as the time when the A converter is small.

Furthermore, as shown in FIG. 4, a command synchronized with the signal given from the MPU 41 to the D//i converter 44b is given to the D//(converter 47). The power amplified by the amplifier 48 and supplied to the electromagnetic support 50 is generated in a rectangular waveform as shown at 182 in FIG. 20(A), and is synchronized with the excitation waveform of the outer electromagnetic force coil 25 shown in FIG. i.e. the outer electromagnetic coil 25
When the excitation current of . Therefore, when the plasma ring diameter is large, the signal given from MpH 41 to the power amplifier 4B is increased and the sputtering is supplied to the electrode support 50.

MP when increasing power and plasma ring diameter is small
By lowering the signal given from U41 to the power amplifier 4 and reducing the sputtering power supplied to the electrode support 50, a uniform film droplet distribution can be obtained.

I can do it.・(
)1 to -F, by increasing or decreasing the sputtering power supplied to the electrode support 50 according to the diameter of the plasma ring, the composite film formation distribution shown in FIG. 10 can be obtained.

Figures 21 (q) and (h) are a further development of the idea described above, in which the current amplifier 45b is activated by a command from the MPU 41.
This is an example in which the outer excitation current 191 is increased or decreased sinusoidally through the power amplifier 48, synchronized with this waveform by a command from the MPU 41, and the power is changed sinusoidally through the power amplifier 48. In this way, it is possible to obtain exactly the same effect as in the method of controlling the outer electromagnet coil current shown in FIG. 11.

Furthermore, as shown in FIG. 17, the diameter of the plasma ring is changed stepwise two or more times.

The above technical idea can also be applied when adopting a control method, and an example of this is shown in FIG. 22(a) IA).

Reference numeral 201 shown in FIG. 22 (α) is the excitation current waveform of the outer electromagnetic coil 25, where Tl'=Tffi'-71. , 1°202, 201i/ This shows the control waveform of the sputtering power supplied from the synchronized power amplifier 47 to the electrode support 3a, which has a stepped waveform like 201. In the example of Fig. 22, −T2==Tl is used, but the way to take these values is free within the practical range.
The control waveform of the sputtering power is combined with the excitation waveform of the outer electromagnetic coil 25 to obtain optimal film forming characteristics.

In the above example, only the excitation control of the outer electromagnetic coil 25 was taken as an example, but when changing the excitation 111 magnetic current of the inner electromagnetic coil 24, the current waveform is exactly reversed. , similar effects can be achieved.

The output power detection section 49 is a circuit that feeds the power amplifier 48 so that the power supplied from the power amplifier 48 to the electrode support 30 does not fluctuate by 1-2 instantaneously.

Further, the shield 32 is grounded, and sputtering power is applied between the upper end of the shield 32 and the target flat plate 21. Therefore, when the sputtering power applied between the target flat plate 21 and the shield 62 increases, the amount of glow discharge 4r colliding with the target flat plate 21 increases,
The amount of spatter increases.

As described above, according to the planar magnetron sputtering method of the present invention, it is possible to greatly oscillate the plasma generation region in the shape of the substrate and increase or decrease the sputtering power in synchronization with the oscillation, thereby achieving a uniform distribution of the deposited film thickness. This provides an effect that can be obtained and put to practical use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of a conventional planar magnetron sputter electrode, FIG. 2 is a sectional view of a planar magnetron sputter electrode according to the present invention, and FIG. 3 is a perspective view of FIG. 4 is a diagram showing the configuration of a driving device that drives the electromagnet shown in FIGS. 2 and 6, FIGS. 5 and 6 are diagrams showing an example of measuring the magnetic field on the sputter electrode according to the present invention, and FIG. The figure shows an example of the change in film thickness distribution characteristics obtained by calculation, Figure 8 is a diagram conceptually showing the synthesis of film thickness distribution characteristics, and Figure 9 shows the film thickness distribution according to an embodiment of the present invention. Figure 10, which is a diagram showing the characteristics, shows an example of the composite film thickness distribution completely synthesized from the film thickness distribution shown in Figure 9. In the figure shown in Figure 11, in order to improve the composite film thickness distribution shown in Figure 10, the magnetomotive force of the inner electromagnetic coil is kept constant, and the magnetomotive force of the outer electromagnetic coil is periodically controlled. Figures 12 and 13 show current waveforms when controlling
The figure is a conceptual diagram explaining the change f in the film thickness distribution characteristic due to the progress of target erosion VC.
Figure 15 shows the change over time in the film thickness distribution characteristics when the magnetomotive forces of the inner and outer electromagnetic coils are the same, as in the present invention. A diagram showing the change over time in the film thickness distribution characteristics when the synchronous current waveform shown in Figure 11 is applied to the electromagnetic coil, and Figure 16 shows the state of wear of the target flat plate in Example 5 of the present invention. FIG. 17 is a diagram showing an example of the current control waveform applied to the outer electromagnetic coil in order to deposit a film on a larger area substrate, and FIG. Figure 19 shows an example in which the outer magnetic pole is replaced with a permanent magnet in the present invention, and Figure 20 (a) shows the waveform of the current flowing through the outer electromagnetic coil. Figure 2 showing an example of
0 (b) shows the waveform of the sputtering power supplied to the electrode support; FIG. 1 (a) shows another embodiment different from FIG. 20 (a); ) is a diagram showing the sputtering power waveform corresponding to FIG. 21(a),
Figure (a) shows a further different current waveform, and Figure 22 (
A) corresponds to FIG. 22(a). FIG. 1°20
... Substrate to be film-formed 21 ... Target flat plate 2
2...Backing plate 23...Yoke for magnetic field generation 24...Inner electromagnetic coil 25...Outer electromagnetic coil 1"160...'α4pe support 32...Shield 41...Microprocessor 42...Memory 45
...Keyboard 44a, 44h...D/l converter 45a, 45A...Current amplifier 46...Detection section
,! 116 47... D/A converter 48... Power amplifier 49... Detection unit fee J'' Susuki EB, J. Figure 4 [

Claims (1)

[Claims] 1. It has at least three magnetic poles and at least 52 magnetic field generating means, and at least one of the magnetic field generating means
Using a planar magnetron's pole equipped with a dipping electromagnet, a current is passed through the electromagnet at a predetermined period, and at the same time, at the predetermined period. The sputtering power is increased/decreased in synchronization with the above, and the annular 1° plasma generation region is moved at least once or more in the above-described predetermined period while increasing/decreasing the amount of sputtering to form a film in each annular plasma generation region. Special feature is to synthesize the thickness and form a film. A film formation method using sputtering. 1゜2
The magnetic field generating means has at least three magnetic poles and at least two magnetic field generating means. At least one of them is provided with a planar magnetron sputtering magnetic pole equipped with an electromagnet, and means for applying a current to the electromagnet at a predetermined period is provided. A sputtering power applying means for applying increasing or decreasing power to the target is provided, and the sputtering is performed by the sputtering power applying means while moving the plasma generation region at least once at a predetermined period by the means and the magnetic field generating means. A film forming apparatus P using sputtering that is patented in that it is configured to increase or decrease the amount of plasma in each plasma generation area and synthesize the film thickness.
i0