JP3204527B2 - Planar magnetron sputtering equipment for ITO thin film formation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar magnetron sputter for a non-magnetic material target which can be used to generate a magnetron discharge plasma on the front surface of the target, sputter the target material and generate a thin film on the substrate surface. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a thin film of ITO (indium tin oxide) on a substrate, a poloidal magnetic field is generated by a permanent magnet or an electromagnet, and a magnetron discharge plasma is generated on a front surface of a target disposed on the front surface of the magnet. In addition, a planar magnetron sputtering apparatus that sputters ITO or the like as a target material has been widely used industrially.

FIGS. 16, 17 and 18 of the accompanying drawings show an example of a conventional planar magnetron sputtering apparatus for a non-magnetic target. In the drawings, reference numeral 1 denotes a cathode assembly, which has an elliptical water-cooled packing plate 2 and The elliptical magnet 3 disposed on the rear side of the packing plate and the linear magnet 4 extending along the central axis inside the elliptical magnet 3 are bonded to the front side of the packing plate 2 with indium or the like. And an elliptical target 5 to be formed. An earth shield 6 is arranged around the target 5, a chimney 7 is provided above the earth shield 6, and a substrate 8 is arranged to face the target 5. DC power is normally supplied from the floating power source between the cathode assembly 1 and the chimney 7, and the former is connected to the negative electrode and the latter is connected to the positive electrode. The earth shield 6 is grounded, and the wall of the vacuum vessel containing these components and the substrate 8 are also kept at the ground potential.

In the operation of such a conventional device, the magnets 3 and 4 generate a poloidal magnetic field in front of the target 5 as shown in FIGS. 19 and 20, and the potential difference between the chimney 7 and the target 5 causes An orthogonal electromagnetic field is generated in front of the target 5. Assuming that the surface of the target 5 emits secondary electrons or exoelectrons due to cosmic rays, natural radioactivity, these electrons are generated by the orthogonal electromagnetic field on the surface of the target 5 several times in a direction perpendicular to the orbit. Exercise while drawing. During this time, electrons that have lost some of their energy by colliding with molecules of a carrier gas (usually argon is used) cannot return to the target 5 having a high potential for electrons, and draw a trochoidal orbit in an orthogonal electromagnetic field. It drifts in a racetrack-like poloidal magnetic field. During this time, it collides with the carrier gas and is ionized, generating a pair of electrons and ions (α action). The generated ions are accelerated toward the cathode, that is, the target 5, and collide with the target 5 to sputter the target material and emit secondary electrons (γ action).
The emitted secondary electrons behave similarly to the electrons emitted from the first target described above. In this way, when the plasma grows, the total orbit length of the trochoid trajectory during the 1 cm drift of the electrons drifting in the poloidal magnetic field while trochoidally moving is determined by the ion sheath transition generated near the surface of the target 5. The area is particularly long, usually tens of cm to 200 cm. A racetrack-like plasma is generated on the front surface of the target 5. Carrier gas ions are accelerated toward the target by the sheath voltage between the generated plasma and the target 5, whereby the target material is sputtered to form a thin film on the substrate 8.

[0005]

By the way, in the conventional magnetron sputtering apparatus, electrons that drift E × B while drawing a trochoid trajectory are curved so that the lines of magnetic force become upward as shown in FIG. However, when the electric field is not orthogonal to the sheath or the electric field in the transition region of the sheath, the electron receives a force from the electric field E. In this portion (the region indicated by the symbol A in FIG. 21), the electron concentration becomes highest. Therefore, ions also gather in this region A, and the plasma is most sputtered in this part,
Partially eloaded. As a result, as shown in FIG. 21, a deep V-shaped erosion valley B is formed. As a result, only 10 to 15% of the entire target material is used, so that the target has holes and becomes unusable, resulting in high cost. The efficiency of using the target was very low. The conventional horizontal magnetic field 200
With a ~ 300 gauss cathode, the electrical conductivity of the film formed on the substrate could not be too high when sputtering ITO.
In the case of a non-magnetic target, the vertical component of the magnetic field within the range of 0.5 mm to 2 mm from the surface of the target has a linear portion, a corner portion, and a transition between the linear portion and the corner portion of the oval magnet. In each cross section of the part, rise from more than a few hundred gauss negative, cut the zero line, turn to decrease through the not too large local maximum value, cut again the zero line to become a negative value, the absolute value is too large Turns positive three times through no minimum and reaches a positive hundreds of gauss or
Falling from a few hundred positives, the zero line was cut, the absolute value changed through a not-so-large minimum, and then turned to increase. We have found that we need to cut the zero line three times to reach several hundred gauss negative. Accordingly, the present invention solves such problems associated with the conventional magnetron sputtering apparatus, and can greatly improve the use efficiency of the target and can form a high-quality transparent conductive thin film having high electrical conductivity. It is an object of the present invention to provide a planar magnetron sputtering apparatus for a magnetic material target.

[0006]

According to the present invention, there is provided, in accordance with the present invention, an ITO target mounted on a cathode and to be sputtered, and provided on the back side of the cathode and having a And a poloidal magnetic field generating means for generating a poloidal magnetic field, generating a racetrack-shaped plasma on the surface of the ITO target, and irradiating the ITO target with ions from the plasma to sputter an ITO target material, thereby forming an ITO target material. In a planar magnetron sputtering apparatus for forming an ITO thin film on a substrate arranged opposite to a surface, a poloidal magnetic field generating means includes an elongated central magnet positioned along and parallel to a longitudinal central axis of the ITO target. Provided around the center magnet, the pole of the center magnet An annular outer magnet having the opposite polarity to the central magnet and the outer magnet, positioned along these magnets, and parallel to the ITO target in each cross section of the magnetic field formed near the ITO target. At least one auxiliary magnet for controlling the magnetic field so that the vertical magnetic field component in the plane passes through the zero level three times, and the auxiliary magnet disposed adjacent to the central magnet has a polarity opposite to that of the central magnet. And the horizontal magnetic field component at the point where the vertical magnetic field component first and third times crosses the zero line is 1000
It is characterized in that it is configured to show a value of Gauss or more. The auxiliary magnet may consist of one oval magnet having a polarity opposite to that of the central magnet. In addition, the auxiliary magnet is disposed along one straight line portion outside the long annular magnet having a polarity opposite to the polarity of the central magnet, and the polarity of this long annular magnet is A linear magnet having the opposite polarity may be used, and the elliptical magnet and the linear magnet may have different cross-sectional shapes depending on locations. Alternatively, the auxiliary magnet consists of two oval magnets of different polarities, one of the oval magnets arranged adjacent to the central magnet having a polarity opposite to that of the central magnet, Each of the long annular magnets may be configured to have a different cross-sectional shape depending on the location. In the planar magnetron sputtering apparatus for forming an ITO thin film according to the present invention, preferably, the cross section of the linear portion, the corner portion, and the transition portion between the linear portion and the corner portion of the oval magnet is formed on the ITO target and the ITO section. From 1 mm above the target, the vertical component of the magnetic field in the target falls from more than a few hundred gauss on a line parallel to the ITO target, cuts the zero line, and increases through the negative minimum, which is not too large in absolute value. It can be made to have a magnetic field distribution that again turns off the zero line, turns positive, turns through a not too large local maximum, turns off, turns off the zero line three times, turns negative, and reaches negative hundreds of gauss or more. Instead, in the planar magnetron sputtering apparatus for forming an ITO thin film of the present invention, the vertical component of the magnetic field in the ITO target from 1 mm on the ITO target and from 1 mm on the ITO target is from several hundred gauss or more negative on a line parallel to the ITO target. Stand up, cut the zero line, turn through the positive maximum that is not too large, turn down, turn off the zero line again, turn negative, turn through the minimum, which is not too high in absolute value, turn positive, cut the zero line three times It is also possible to have a magnetic field distribution that turns positive and reaches more than a few hundred gauss.

[0007]

In the planar magnetron sputtering apparatus according to the present invention, the magnetic field generating means is provided along an elongated central axis of the target in parallel with the elongated central magnet, and is provided so as to surround the central magnet. At least one auxiliary magnet is provided along these magnets between the elliptical outer magnets having the opposite polarity to that of the magnets, and is parallel to the target in each section of the poloidal magnetic field formed on the target. Since the vertical magnetic field component on such a plane forms a magnetic field such that the vertical magnetic field component passes through the zero level three times, in most cases, the horizontal magnetic field is minimal at the point where the vertical magnetic field crosses the zero level for the second time. That is, the vertical and horizontal magnetic field components at a position of 1 mm to 0.5 mm on the target are, for example, as shown in FIG.
The distribution is as shown in FIG.

In such a magnetic field distribution, due to the component of the force in the direction of the magnetic field line of the force −eE, the electron that undergoes E × B drifting from the electric field E is bent in the direction of the apex of the curved magnetic field line. The electron concentration is highest in the two peaks, while the electron with E × B drift is -gradB / B
As a result, the force that spreads somewhat in the middle of the two peaks is also received, and the electron concentration is highest in the two peaks of the magnetic field lines and the wide band that fills the gap between them.
Ions also collect in this part, and these ions are accelerated by the sheath voltage and strike the target, and thus a wide U-shaped erosion profile is obtained.

By the way, in this case, since the electrons which trace the trochoid orbit are rotating along the elliptical poloidal magnetic field while performing the E × B drift, even if a part of the elliptical poloidal magnetic field is used as described above, If the magnetic field distribution is not such, the electron concentration is biased at that part, and ions are gathered at that part, not only the target is locally eloaded, but also the electron concentration bias at some part. In the device according to the invention, not only the linear part of the oblong magnet, but also the curved part, between the curved part and the linear part, although it spreads out so that the other parts are also locally unloaded. 6, the magnetic field distribution on the target surface is as shown in FIG. 6, so that a wide U-shaped erosion profile can be obtained over the entire target. .

Further, since the elliptical magnet has a three-dimensional structure, its magnetic field distribution is different from an infinitely long two-dimensional magnet having the same cross-sectional shape even in a linear portion, but has a curved portion and a curved portion. Even if the transition portions between the straight portions have the same cross-sectional shape, they have different magnetic field distributions from the magnetic field distribution of the straight portions. Therefore, by appropriately changing the cross-sectional shape of the auxiliary magnet depending on the location and appropriately changing the strength of the auxiliary magnet depending on the location, a magnetic field distribution as shown in FIG. .

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 schematically show the configuration of a main part of a planar magnetron sputtering apparatus according to one embodiment of the present invention. In these drawings, reference numeral 10 denotes a cathode assembly. The cathode assembly 10 includes an oval-shaped backing plate 11 and a backing plate 11.
, A central magnet 12 linearly extending along the central axis, an outer annular magnet 13, and a central magnet 12, which are arranged around the central magnet 12 at substantially constant intervals.
Oval auxiliary magnets 14 concentrically arranged between the outer magnet 13 and the outer magnet 13, and are arranged in parallel between the oval auxiliary magnet 14 and the outer magnet 13 along the linear portions of these magnets. The center magnet 12 is of polarity S in this embodiment, the polarity of the outer magnet 13 is N,
The polarity of the toroidal auxiliary magnet 14 is N, and the polarity of the linear auxiliary magnet 15 is S. Although the center magnet 12 and the outer magnet 13 have substantially the same height, the center magnet 12 has a larger cross-sectional width than the outer magnet 13. These magnets are erected on a common magnetic pole plate 16.

The annular auxiliary magnet 14 and the linear auxiliary magnet 15 are formed narrower and lower in height than the central magnet 12 and the outer magnet 13. As shown in FIGS. 3, 4 and 5, in the elongated annular auxiliary magnet 14, the straight portion is lower than the curved portion, that is, the corner portion, and the transition portion between the straight portion and the curved portion is a straight line. It is formed stepwise higher than the height of the curved portion and lower than the height of the curved portion.
Therefore, the linear portion, the curved portion, and the transition portion of the elliptical auxiliary magnet 14 have constant cross-sectional areas different from each other. The linear auxiliary magnet 15 extends along the linear portion of the outer magnet 13, and both end portions of the linear auxiliary magnet 15 corresponding to the transition portion of the auxiliary magnet 14 are formed in a step shape lower than the other portions. Therefore, the central portion and both end portions of the linear auxiliary magnet 15 have a constant and mutually different cross-sectional area.

The backing plate 11 has a water-cooled jacket 11a as shown in FIG.
17 is bonded with indium or the like. An earth shield 18 is arranged around the target 17, a chimney 19 is provided above the earth shield 18, and a substrate 20 is arranged to face the target 17. Cathode assembly 10
DC power is supplied from a floating power supply (not shown) between the power supply and the chimney 19, the former being connected to the negative electrode and the latter being connected to the positive electrode. The earth shield 18 is grounded, and the walls of the vacuum vessel (not shown) containing these components and the substrate 20 are also kept at ground potential.

The operation of the illustrated apparatus configured as described above will be described. When each of the center magnet 12, the outer magnet 13, the elliptical auxiliary magnet 14, and the linear auxiliary magnet 15 is magnetized as shown, the linear portion, the curved portion, and the transition between these portions of each magnet. The vertical magnetic field H as shown in FIG. 6 is set at a level of about 0.5 mm to 1 mm above the surface of the target 17 over the entire portion.
v and a horizontal magnetic field Hh are formed. In other words, the distribution of the vertical magnetic field Hv rises from a negative value of several hundred gauss or higher, crosses the zero line, passes through a maximum value that is not too large, turns to decrease, cuts the zero line again, turns negative, and returns a minimum value in which the absolute value is not too large. It turns positive through the value, crosses the zero line three times and turns positive, reaching more than a few hundred gauss positive. In the magnetic field thus formed, the horizontal magnetic field Hh is minimized at a position where the vertical magnetic field Hv crosses the zero almost the second time as can be seen from the drawing.

FIG. 7 schematically shows the form of the lines of magnetic force. In such a magnetic field distribution, the E × B drifted electron is bent in the direction of the vertex of the curved magnetic field line by the force component in the magnetic field line direction of the force −eE received from the electric field E, and the two peaks of the magnetic field line are formed. The part has the highest electron concentration. On the other hand, an electron that drifts by E × B also receives a force proportional to −gradB / B, and thus receives a force that spreads somewhat also between the two peaks. The concentration of electrons is highest at the two peaks of the magnetic field lines and the wide band that fills the gap, and the ions also gather at this point, and are accelerated by the sheath voltage to strike the target 17, and thus have a wide U-shaped erosion. A profile will be obtained.
As described above, since the magnetic field distribution also has the magnetic field distribution as shown in FIG. 6 in the linear portion, the curved portion, and the transition portion between these portions of the magnet, a U-shaped profile is obtained over the entire circumference of the target, Very high target use efficiency can be obtained.

FIG. 8 shows a modified embodiment, and portions corresponding to the embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals. In the embodiment shown in FIG. 8, a groove 21 for receiving upper ends of the center magnet 12 and the outer magnet 13 is provided below the backing plate 11. The upper polarity of each magnet is arranged such that the central magnet 12 has an N pole, the outer magnet 13 has an S pole, the annular auxiliary magnet 14 has an S pole, and the linear auxiliary magnet 15 has an N pole. I have. In this case, the magnetic field has a distribution as shown in the drawing, that is, the vertical magnetic field component Hv falls from several hundred gauss, cuts off the zero line, increases through a negative minimum value that is not too large in absolute value, turns to increase, and returns to zero again. It cuts the line, turns positive, passes through a not-so-large maximum, turns to decrease, and cuts the zero line three times, turns negative, reaching more than a few hundred gauss negative. The lines of magnetic force are the same as in FIG. 7, but the directions are reversed.

FIGS. 9 to 13 show examples in which the vertical component Hv and the horizontal component Hh of the magnetic field actually formed on the target in the configuration shown in FIG. 8 are shown in FIGS. The outward horizontal distance (mm) is shown, the right vertical axis shows the horizontal magnetic field component (Oe), the left vertical axis shows the vertical magnetic field component (Oe), and the triangular points show the vertical component Hv again. Points represent the horizontal component Hh. FIG. 9 is a diagram showing a right lateral direction x from the center O of the target as schematically shown in FIG.
Shows the magnetic field distribution at. FIG. 10 shows a magnetic field distribution at a position corresponding to a transition portion between a straight portion and a curved portion of the magnet assembly. FIG. 11 shows a magnetic field distribution at a position corresponding to the boundary between the curved portion and the transition portion. FIG. 12 shows a magnetic field distribution at a position corresponding to a curved portion at 45 ° from the central axis. FIG. 13 shows a magnetic field distribution at a position corresponding to a curved portion on the central axis. As can be seen from the graphs shown in these figures, the vertical component Hv of the magnetic field at each portion on the target crosses the zero level three times, and the horizontal component Hh shows that the vertical magnetic field component is first and last (third). It shows a value of 1000 Oe or more at the position where the level crosses zero.

FIG. 14 shows the structure of a magnet assembly according to another embodiment of the present invention. This embodiment is different from the embodiment shown in FIGS. 1 to 7 in that both auxiliary magnets are formed in an oblong ring. It is different from the configuration in the example. That is, the annular outer magnets 23 are arranged at regular intervals around the linear central magnet 22, and the central magnet 22 and the annular outer magnet 23 are arranged.
Two auxiliary annular magnets 24 and 25 are disposed between the auxiliary magnets 23 and 23. These auxiliary magnets 24 and 25 can be configured similarly to the elongated annular auxiliary magnet 14 in the embodiment shown in FIGS. The polarities of the magnets are such that they are N-pole, S-pole, N-pole and S-pole in order from the center magnet 22 to the outer annular magnet 23, or conversely S-pole, N-pole, S-pole and N-pole. Can be In the former polarity arrangement, as shown in FIG. 8, the vertical component of the generated magnetic field falls from a few hundred gauss, cuts off the zero line, turns to an increase through a negative minimum value that is not so large in absolute value, and turns to zero again. After turning off the line, turning positive, passing through a not-too-large maximum, turning to decrease, turning off the zero line three times, turning negative, and reaching a negative hundreds of gauss or more. As shown in the figure, the vertical component of the magnetic field rises from more than a few hundred gauss negative, crosses the zero line, passes through a maximal value that is not too large, turns to decrease, crosses the zero line again, turns negative, and a minimal value that does not have a large absolute value. The distribution turns positive through the value, crosses the zero line three times, and turns positive to reach more than a few hundred gauss.

FIG. 15 shows still another embodiment of the present invention, in which one auxiliary magnet is provided. That is, in FIG. 15, one elongated annular auxiliary magnet 28 is concentrically arranged between the linear center magnet 26 and the elongated annular outer magnet 27, and this auxiliary magnet 28 The height is uniform but the width is different. The linear portion of the auxiliary magnet 28 has a uniform width, the curved portion has a uniform width that is wider than the linear portion, and the transition between the linear portion and the curved portion is smaller than the linear portion. Wide and narrower than the curved part. Also in this case, the polarity of each magnet is such that when the center magnet 26 is set to N polarity, the outer magnet 27 is set to S polarity, and the auxiliary magnet 28
When the center magnet 26 is set to S polarity, the outer magnet 27 and the auxiliary magnet 28 are set to N polarity. The magnetic field generated on the target is as shown in FIG. 8 in the former case, and as shown in FIG. 6 in the latter case.
The dimensions of the respective parts of the auxiliary magnet 28, especially the ratio of the width, are determined by the vertical component of the magnetic field formed on the target according to the shapes of the central magnet 26 and the outer magnet 28, their mutual positions, the strength of the generated magnetic field, and the like. Is set to cross the zero level three times in the cross section from the center magnet 26 to the outer magnet 27.

Although the illustrated embodiment is an example in which a rectangular or oval target is used as a target, the concept of the present invention can also be applied to a case in which a rectangular or circular target is used. Of course, the outer magnet around the center magnet and the one or two auxiliary magnets arranged between them can be configured as polygonal or circular magnets arranged in a polygonal or circular shape.

[0021]

As described above, according to the present invention, one or two auxiliary magnets having different cross-sectional areas depending on places are provided between the central magnet and the outer annular magnet along the magnets. 0.5 to above the target in all sections, i.e., all cross sections of the straight sections, curved sections and transitions between these sections of the magnet assembly.
Since the vertical magnetic field distribution in the parallel plane of 1 mm is set to be zero three times, a wide plasma can be generated everywhere on the target, and a wide U-shaped erosion profile is generated. , Very high target use efficiency can be obtained. In fact, the usage efficiency can be increased from 15% to 50% or more, and as a result, the material cost of expensive targets can be reduced.

In the present invention, since the horizontal magnetic field component at the point where the vertical magnetic field component crosses the zero line for the first time and the third time shows a value of 1000 gauss or more, ITO (indium tin tin) is used. Oxide) When an ITO thin film is formed using a target, the discharge electrode can be lowered to a low voltage of 250 volts or less, whereby the oxygen negative electrode generated on the target surface and accelerated to the substrate by the discharge voltage is discharged. It is possible to reduce the energy of ions (O-) incident on the ITO target, thereby reducing the damage to the formed thin film and forming a high-quality transparent conductive thin film having a higher electrical conductivity three times or more than that of the conventional thin film. become able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an essential part taken along line AA in FIG. 2, showing one embodiment of the present invention.

FIG. 2 is a schematic plan view of the apparatus of FIG. 1 as viewed from above a target surface.

FIG. 3 is a schematic perspective view showing a part of the magnet assembly in FIGS. 1 and 2;

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a sectional view taken along line CC in FIG. 3;

FIG. 6 is a schematic diagram schematically showing a magnetic field formed on a target surface of the apparatus of FIG. 1;

FIG. 7 is a schematic diagram schematically showing lines of magnetic force on a target surface of the apparatus of FIG. 1;

FIG. 8 is a schematic sectional view showing a modified embodiment of the present invention.

9 is a graph showing the distribution of a magnetic field in a linear portion actually measured using the apparatus according to the embodiment of FIG.

FIG. 10 is a graph showing a magnetic field distribution in a transition portion actually measured using the apparatus according to the embodiment of FIG. 8;

11 is a graph showing the distribution of a magnetic field at a boundary between a transition portion and a curved portion actually measured using the apparatus according to the embodiment of FIG. 8;

FIG. 12 is a graph showing the distribution of a magnetic field at a boundary portion with a curved portion at 45 ° with respect to a center axis actually measured using the apparatus according to the embodiment of FIG. 8;

FIG. 13 is a graph showing the distribution of a magnetic field at a boundary portion with a curved portion on a central axis actually measured using the apparatus according to the embodiment of FIG. 8;

FIG. 14 is a schematic plan view showing another embodiment of the present invention.

FIG. 15 is a schematic plan view showing still another embodiment of the present invention.

FIG. 16 is a schematic sectional view showing an example of a conventional planar magnetron sputtering apparatus.

17 is a schematic plan view of the apparatus of FIG. 16 as viewed from above a target.

FIG. 18 is a schematic perspective view of the device of FIG.

FIG. 19 is a diagram showing a poloidal magnetic field formed on a target and movement of electrons in the poloidal magnetic field.

FIG. 20 is a view for explaining movement of electrons in an orthogonal electromagnetic field on a target.

FIG. 21 is a view showing a sputtering state of a target in the apparatus shown in FIG. 16;

[Explanation of symbols]

 10 Cathode assembly 11 Oval backing plate 12 Linear central magnet 13 Oval outer magnet 14 Oval auxiliary magnet 15 Linear auxiliary magnet 16 Magnetic pole plate 17 Target 18 Earth shield 19 Chimney 20 Substrate

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21 / 203,21 / 363 C23C 14/35

Claims (6)

(57) [Claims] 1. An ITO target mounted on a cathode and to be sputtered, and an
A poloidal magnetic field generating means for generating a poloidal magnetic field on the surface of the TO target; generating a racetrack-like plasma on the surface of the ITO target;
In a planar magnetron sputtering apparatus which sputters an O target material and forms an ITO thin film on a substrate arranged opposite to the surface of the ITO target, a poloidal magnetic field generating means is parallel to the ITO target along the longitudinal central axis. An elongated central magnet positioned around the central magnet, an annular outer magnet surrounding the central magnet and having a polarity opposite to that of the central magnet, and a magnet between the central magnet and the outer magnet. At least one auxiliary magnet that controls the magnetic field so that the vertical magnetic field component in a plane parallel to the ITO target in each cross section of the magnetic field formed in the vicinity of the ITO target is distributed three times through the zero level. The auxiliary magnet disposed adjacent to the central magnet has a polarity opposite to that of the central magnet, Field components the first and third time planar magnetron sputtering apparatus for ITO film formation in which the horizontal magnetic field component is characterized by being configured to indicate a value of at least 1000 gauss at the point off the zero line. 2. The ITO according to claim 1, wherein the auxiliary magnet is formed of one elongated annular magnet having a polarity opposite to that of the central magnet, and the elongated annular magnet has a different cross-sectional shape depending on a location. Planar magnetron sputtering equipment for thin film formation. 3. A magnet according to claim 1, wherein the auxiliary magnet is arranged along a straight part outside the elliptical magnet, the elliptical magnet having a polarity opposite to the polarity of the central magnet. 2. A planar magnetron sputtering apparatus for forming an ITO thin film according to claim 1, wherein said magnet comprises a linear magnet having a polarity opposite to that of said magnet, and said elliptical magnet and said linear magnet have different cross-sectional shapes depending on locations. . 4. The auxiliary magnet comprises two elongated annular magnets having polarities different from each other, and one of the elongated annular magnets disposed adjacent to the central magnet has a polarity opposite to that of the central magnet. The planar magnetron sputtering apparatus for forming an ITO thin film according to claim 1, wherein each of the annular auxiliary magnets has a different cross-sectional shape depending on a location. 5. The vertical component of the magnetic field in the ITO target from 1 mm above the ITO target and from the 1 mm above the ITO target is I
On the line parallel to the TO target, fall from more than a few hundred gauss positive, cut the zero line, pass through the negative minimum value that is not too large in absolute value, turn to increase, turn off the zero line again, turn positive, and not too large 5. The magnet according to claim 1, wherein the central magnet, the outer magnet and the auxiliary magnet are configured to have a magnetic field distribution which passes through the local maximum value, turns to decrease, cuts the zero line three times, turns negative, and reaches more than a few hundred gauss. The planar magnetron sputtering apparatus for forming an ITO thin film according to claim 1. 6. The vertical component of the magnetic field in the ITO target from 1 mm above the ITO target and from the 1 mm above the ITO target is I
On the line parallel to the TO target, rise from more than a few hundred negative gauss, cut the zero line, pass through the not too large positive maximum, turn to decrease, turn off the zero line again, turn negative, and turn the absolute value into the not too small minimum The central magnet, the outer magnet, and the auxiliary magnet are configured to have a magnetic field distribution which turns positive through a value, cuts a zero line three times, turns positive, and reaches more than a few hundred gauss. A planar magnetron sputtering apparatus for forming an ITO thin film according to claim 1.