JPH023538B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a semiconductor device by forming a synthetic film, for example, a Si alloy film, on a substrate to be film-formed by sputtering.

[Prior art]

FIG. 1 shows the cross-sectional structure of a typical MOS transistor. Polycrystalline silicon 72 is used for the gate wiring body on the gate oxide film.
In order to increase the speed of MOS transistors, it is necessary to reduce the resistance of the gate wiring section and improve the operating speed of MOS transistors.

[Purpose of the invention]

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a method for forming an IC wiring pattern in which a synthetic film of a high-quality high-melting point metal and silicon is formed on the surface of a sample substrate by sputtering. It is on offer.

[Summary of the invention]

In order to achieve the above object, the present invention prepares a target flat plate disposed with different types of materials, generates plasma on the target flat plate using a planar magnetron sputtering electrode, and generates a plasma on the target flat plate using a planar magnetron sputtering electrode. This method is characterized in that a composite film is formed with a predetermined composition ratio on a substrate to be film-formed by magnetically moving the position of plasma.
In particular, focusing on the difficulty of preparing an alloy target with a predetermined composition containing a high melting point metal, two types of target flat plate portions of the sputter electrode structure (for example, high melting point metals Mo, Ta, Wo, and Si) were prepared. ,
Cr, Nb, V, Zr, Tc, Ru, Rh, Bf, Ir, Os,
Separately prepare material regions of Re and other metals (Si, Si, etc.) or more, and use sputtering to create synthetic films (e.g., Mo+Si, Ta+Si, Zr+Si, Cr+Si, Wo+Si,
Pt+Si, Pd+Si, Rh+Si, Ir+Si).

In addition, the main point of the present invention is that when magnetic lines of force are generated from a single source of magnetic lines of force, they do not intersect with each other due to their nature;
Considering that the Maxwell stress, which is an attractive force or a force, acts, a single magnetic field line source with multiple magnetic poles is constructed, and the magnetic field lines generated at some of the magnetic poles are controlled to control the magnetic field line distribution emitted to the remaining magnetic poles. By moving the standing position, the position of the plasma is moved, and two or more different material regions are provided as the target plate to be sputtered, and a composite film with an arbitrary composition can be formed by planar magnetron sputtering. It is possible to form a semiconductor device and manufacture a semiconductor device. By the way, MOS
In semiconductor memory, the polySi layer alone results in high wiring resistance, making it impossible to increase the operating speed sufficiently. Therefore, this polySi layer has low resistance.
It is possible to form an Al layer, but the process of impurity diffusion requires heat treatment at around 1000°C, which poses the problem of melting the Al layer. Therefore, if we could form a silicide layer of high-melting point metal on top of the polySi layer, we could reduce the wiring resistance in the gate area and greatly improve the operating speed.
A MOS type semiconductor memory can be obtained. On the other hand, high melting point metals or refractory metals naturally have a high melting point and are therefore difficult to refine, and high melting point metal silicides (intermetallic compounds with silicon) have a high purity, such as 99.999%, which is normally required for semiconductor devices. It is difficult to manufacture a material with such purity as a practical target material, and it has become a major process hurdle in the gate wiring process of MOS semiconductor memory devices that use high-melting point metal silicide.

And speaking of MoSi ₂ alloy targets,
Since scouring by vacuum melting is difficult, it is manufactured using the hot press method (a method in which particles are compression molded under high temperature), but since a binder material is used to promote bonding between _two MoSi particles, purity can be improved. There was a problem that lowered the However, according to the present invention, these problems can be solved, and a MOS type IC memory with greatly improved operating speed can be obtained.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 3 is a conceptual cross-sectional view for explaining part of the principle of the present invention using a conventional planar magnetron type sputtering apparatus. A ring-shaped magnetic pole 23 is magnetically coupled by a yoke 22 to the back surface of a target material flat plate (hereinafter referred to as a target flat plate) 21 in which a plurality of materials 21a and 21b are arranged.
A cylindrical magnetic pole 24 is arranged at the center of the ring-shaped magnetic pole 23 to form a magnetic circuit.
These magnetic poles 23 and 24 create a distribution of magnetic lines of force in the space on the surface side of the target flat plate 21, in other words, a half-cut plane is formed perpendicular to the height direction of the torus, and the half-cut surface becomes the target flat plate 21. A semicircular annular magnetic field distribution parallel to the surface of the magnetic field, commonly known as a tunnel magnetic field distribution 25, is generated. Due to this tunnel-like magnetic field distribution 25, the annular plasma-like ions 30 are confined therein at a high concentration. These plasma ions are further transferred to a high voltage source between the anode 26 and the cathode 27 installed on the back surface of the target flat plate 21.
The target flat plate 21 is accelerated by an electric field (not shown) that is almost perpendicular to the surface of the target flat plate 21, which is generated by the high voltage applied by Vs.
as a result, the target plate 21
The atoms or particles are successively ejected from the surface of the eroded region 28. This erosion area 2
8, as estimated from the following explanation, the degree of erosion progresses as time passes in the sputtering process, but this erosion usually occurs in a specific part of the target flat plate 21 in the target flat plate structure having the configuration shown in FIG. Proceed in a limited area. The erosion region occurs corresponding to a point or region where the magnetic field lines become parallel to the target plate. Although the explanation was delayed,
In the figure, 29 is an insulating plate, and 31 is an inlet/outlet pipe for a medium (for example, water) for cooling the target flat plate 21. 32 is an O-ring for sealing. 33 is an insulating bushing that electrically insulates the anode 26 and the cathode 27.

Next, the sputter electrode structure according to the present invention will be explained. Magnetic poles 23 and 24 are provided so that lines of magnetic force 25 are generated so that plasma 31a is generated across the two substances of target flat plate 21, which is composed of target 21A made of substance A and target 21B made of substance B. For this purpose, a synthetic thin film made of substances A and B, such as an alloy thin film, is formed on the substrate 10 from the erosion part 28a of the target flat plate 21.

FIG. 4 is a schematic cross-sectional view showing one embodiment of a sputter electrode structure according to the present invention. The main components of the sputter electrode are:
A target flat plate 21 composed of a circular target flat plate 21a and annular target flat plates 21b and 21c, a copper backing plate 35 to which the target flat plate 21 is fixed by suitable brazing means and serves as a cathode, A substrate 10 to be film-formed is placed stationary in parallel with a target flat plate 21, and an appropriate strength is generated as a planar magnetron sputter electrode in the hollow space between the substrate 10 to be film-formed and the target flat plate 21. The magnetic poles 36, 37, 38 and these magnetic poles 36, 37,
The yoke 41 is configured with an inner excitation coil 39, an outer excitation coil 40, which are excitation coils for exciting the yoke 38, and these coils 39, 40 and magnetic poles 36, 37, 38 as one magnetic flux generation source.
, terminals 42 for wiring the inner and outer excitation coils, terminals 43 for wiring the outer excitation coils, and an insulating member 4 for insulating and attaching the sputter electrode to the vacuum chamber 44.
5, an O-ring 46 for vacuum sealing, and an electrode body 36 electrically connected to a backing plate 35 for applying an electric field to the target flat plate 21.
There are a lead terminal 37 for wiring from the target plate 21, and a grounded anode 38' which prevents unnecessary discharge from occurring outside the front surface of the target flat plate 21 and which serves as an anode for the sputter electrode.

As mentioned above, the target flat plate 21 includes a disk-shaped first member 21a, an annular second target member 21b surrounding 21a, and an annular third target member 21c further surrounding 21b. It consists of In this embodiment, the first target member 21a is made of Si, and the second target member 21a is made of Si.
b is an annular Cr, and the third target member 21
c is annular Si. These three target members are arranged concentrically.

In the embodiment shown in FIG.
is circular, but this is because the substrate to be film-formed used in this example is circular. When using a rectangular substrate, it is appropriate to prepare a rectangular target flat plate. Will. 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 rectangle, does not depart from the scope of the present invention.

Further, a flow path (not shown) for passing a refrigerant such as water is formed on the back side of the backing plate 35, and a pipe 31 for supplying and discharging the refrigerant from the outside via a magnetic field generating yoke 41 etc. is formed in this flow path. The target flat plate 21 is cooled.

FIG. 5 shows a schematic configuration of the excitation power source for this electrode structure. As a main component of the excitation power supply section, two current supply circuits are incorporated in order to control the inner electromagnetic coil 39 and the outer electromagnetic coil 40 completely separately. The current applied to the excitation power supply section and the inner and outer electromagnetic coils 39 and 40 can be applied completely arbitrarily, that is, a constant current that does not change over time, a rectangular waveform with a constant period, a triangular waveform, an AC waveform, etc. A microprocessor 51 and memory 52 are used so that the current waveform can be set, and information regarding the predetermined current waveform can be provided from a keyboard 53 or a suitable external storage device 50 (eg, magnetic tape, magnetic disk). , the output of the microprocessor 51 is sent to digital-to-analog signal converters 54a, 54b (D
-A converter), this is further connected to the inner and outer electromagnetic coils 3 by current amplifiers 55a and 55b.
9 and 40 to a predetermined intensity sufficient to excite the magnets.

The excitation power supply unit shown in FIG. 5 has the following objects to be controlled:
Since we are dealing with the inner and outer electromagnetic coils 39 and 40,
It is a power source with constant current characteristics, and the output current detecting sections 56a and 56b detect the output current, that is, the current value of each electromagnet, and this is sent to the D/A converter 54.
Current amplifiers 55a and 55
It has a means of returning information to b.

As the high-voltage power supply for supplying discharge power for sputtering, that is, the sputtering power supply, a power supply having an output voltage of about 0 to 800 V and an output current of about 0 to 15 A, as is well known in the past, was used. Furthermore, as is well known, this high voltage power supply has constant current output characteristics in order to control the power input to the glow discharge.

As mentioned above, the eroded region where sputtering occurs on the target plate is located almost directly below the location where the plasma ring is generated. In addition, at sputtering pressures of 1 to 10 mtorr used in ordinary planar magnetrons, the plasma ring is generated in a hollow space above the first main surface of the target flat plate by 10 to 20 mm from the first main surface of the target flat plate. This occurs when a magnetic field vector at a distance of about 100 psi is focused into a region parallel to the first major surface of the target plate.

Therefore, in order to know the location where the erosion region occurs on the target flat plate, it is effective to know the magnetic flux distribution in the hollow space on the first main surface side of the target flat plate.

Therefore, before conducting experiments to determine various characteristics such as the film thickness distribution of the sputtered electrode structure of this example, the magnetic flux distribution in the hollow space on the first main surface of the target flat plate 21 was measured. . A Gauss meter was used to measure the magnetic flux distribution.

6 and 7 show the first main surface 21 of the target flat plate 21 of the sputter electrode structure of this embodiment.
This is an example in which a yoke material having approximately the same size as that of the present example shown in FIG. 5 was manufactured and actually measured in order to simulate the magnetic flux distribution on the first principal surface of the magnetic flux distribution. The difference between the embodiment shown in FIG. 4 and this artificially manufactured yoke is that the grooves in which the outer electromagnetic coils 39 and 40 are embedded are shallower in FIG.

The vertical axes in FIGS. 6 and 7 represent the magnetic pole tips 36,
The height (mm) above 37 and 38, the horizontal axis is the central axis of the sputter electrode part of the sputter electrode structure shown in Fig. 4,
That is, it is the distance (mm) from the central axis of the magnetic pole tip 36 in the outward radial direction. In FIG. 6, the magnetomotive forces of the inner electromagnetic coil 39 and the outer electromagnetic coil 40 are set to be 40:1, respectively. In FIG. 7, the magnetomotive force of the inner electromagnetic coil 39 and the outer electromagnetic coil 40 is set to be 1.5:1. In FIGS. 6 and 7, the directions of the currents flowing through the inner coil 39 and the outer coil 40 are opposite to each other.

As mentioned above, since a plasma ring is generated in the region where the magnetic field vector is parallel to the first main surface of the target flat plate 12, the plasma ring is generated in the regions indicated by 48 and 49 in FIGS. 6 and 7, respectively. occurs.

Therefore, as is clear from FIGS. 6 and 7, by changing the magnetomotive force that urges the inner and outer magnet coils 49 and 50, the location where the plasma ring is generated can be moved.

In the example shown in FIGS. 6 and 7, the magnetomotive force of the inner electromagnetic coil 39 is constant, and the magnetomotive force of the outer electromagnetic coil 40 is reduced from 1/40 to 1/1.5 of the magnetomotive force of the inner electromagnetic coil 39. However, even if the magnetomotive force applied to the outer electromagnetic coil 40 is kept constant and the magnetomotive force applied to the inner electromagnetic coil 39 is changed, the magnetic field vector will not change to the target as in FIGS. 6 and 7. A region parallel to the flat plate 12 can be moved.

Before starting the description of this embodiment, the basic film thickness distribution characteristics of the film formed on the substrate 10 to be formed by the electrode structure shown in FIG. 4 and the drive power system shown in FIG. 5 will be described. In this case, first the target flat plate 21
As mentioned above, the explanation will start from the case where the structure is not a triple ring structure but is simply made of one material.

FIG. 8 shows the diameter D of the annular erosion area 28 generated on the target plate 2.
The substrate 10 to be film-formed is placed parallel to the first main surface of the target flat plate at a distance of 85 mm from the first main surface of the target flat plate.
This is an example of calculating how the above film thickness distribution characteristics change, and explains the first basic technical idea of the present invention. The vertical axis shows the film thickness, taking the film thickness at the center of the substrate to be film-formed as 100%.
The horizontal axis represents the distance (mm) in the outward radial direction from the center of the substrate on which the film is to be formed.

As is clear from FIG. 8, when the diameter D of the annular eroded region 28a is large, the film thickness distribution has a shoulder at a radius of about 100 mm on the substrate to be formed. A bimodal film thickness distribution characteristic is obtained. On the other hand, when D=125φmm or less, this shoulder in the film thickness distribution characteristic disappears, and a so-called unimodal film thickness distribution characteristic with a peak at the center on the substrate to be formed is obtained.

The above discussion is based on the diameter D of the annular erosion region 28a.
As mentioned above, since this eroded region occurs almost directly under the plasma ring, it is safe to consider the diameter of the annular eroded region as the diameter of the plasma ring. Therefore, by controlling the magnetic field distribution characteristics shown in FIGS. 6 and 7, it is possible to arbitrarily obtain various film thickness distribution characteristics by changing the diameter of the plasma ring, as shown in FIG. I can predict that it will be possible.

A curve 61 shown in FIG. 9, for example, allows the current of the inner electromagnetic coil 39 and the current of the outer electromagnetic coil 40 shown in FIG. This is a conceptual diagram of the film thickness distribution characteristic expected to be obtained when the magnetomotive force ratio with the coil 30 is 1:40, and the curve 62 shown in FIG. FIG. 3 is a conceptual diagram of the film thickness distribution characteristics obtained when the diameter of the plasma ring is reduced by setting the ratio of magnetomotive force to the electromagnetic coil 40 to 1.5:1.

During the film formation process on one substrate to be filmed, the magnetomotive force of the inner and outer electromagnets is changed, and the magnetomotive force is changed to 6 as shown in FIG.
If the operation to give a film thickness distribution such as 1 and 62 is performed appropriately, the curve 61 will be formed on the substrate to be film-formed.
As a composite film thickness distribution obtained by adding the curve 62 and the curve 62, it is possible to obtain a uniform film thickness over a wide range on the substrate to be film-formed, as shown by the curve 63 shown in FIG.

Figures 10, 11, 12, and 13 are
This figure shows the basic characteristics of this embodiment, that is, the distribution of the amount of film deposited on the substrate 10 to be deposited when the target flat plate is made of one type of material.

10 to 13 each show the actual film deposition amount distribution when the distance between the first main surface of the target flat plate 21 and the film deposition target substrate 10 is 73 mm,
The target material is Al-2%Si (purity 99.999
%) and Ar (purity 99.999
%) Obtained under conditions of 5.4 mTorr.

The excitation conditions for the excitation coils 39 and 40 are that the outer excitation coil current = 0, and the first
A current is applied to the inner excitation coil so that a magnetic flux density of approximately 200 Gauss is obtained 15 mm above the main surface of the coil, and then a predetermined current is applied to the outer excitation coil with the opposite polarity to the inner excitation coil according to the experimental conditions. did.

FIG. 10 shows the film deposition amount distribution obtained when a current was applied to the outer excitation coil so that the diameter of the plasma ring was approximately 94 mm. The radius of the plasma ring was determined by determining the erosion area 28a after the film forming experiment using a surface roughness meter.

Figure 11 shows that the plasma ring diameter is 150 mm.
This is the film-forming amount distribution characteristic obtained when mm.

Figure 12 shows a plasma ring with a diameter of 122 mm.
This is the film deposition amount distribution characteristic obtained when .

As can be seen from Figures 10 to 12, when the target substrate distance is 73 mm, the plasma ring diameter is
It can be seen that when the thickness is about 122 mm, a flat film can be formed over the widest range.

Figure 13 shows that the plasma ring diameter is 94 mm for 8 seconds, then the plasma ring diameter is 94 mm.
This cycle is repeated 5 times to form a film of approximately 1 μm, with a time of 150 mm being 11 seconds. Plasma ring diameter
It has film formation distribution characteristics that are almost similar to the characteristics shown in FIG. 12 when the thickness is 122 mm. That is, it can be said that almost the same film-forming amount distribution characteristic for a plasma ring of 122 mm can be obtained in a simulated manner by combining the film-forming fractional characteristics obtained for plasma rings with diameters of 94 mm and 150 mm.

Here, the explanation will proceed regarding the case of the triple ring target shown in FIG. Figure 14 shows the same triple annular target with a plasma ring diameter of 94 mm.
This diagram schematically shows the mutual positional relationship when the distance is 150mm. As shown in the figure, the plasma rings 30a', 30a'' actually have widths,
It is considered that erosion regions 28a' and 28a'' occur.

Next, the most remarkable effects of the present invention will be described.
Triple ring target plate 2 with dimensions shown in Figure 14
1 was made of Mo21b', Si21a', and 21c', and the results of actual film formation are shown in FIG. The conditions for the plasma ring in FIG. 15 were the same as in FIG. 13, and this cycle was repeated five times, with the plasma ring diameter being 94 mm for 8 seconds and the plasma ring diameter being 150 mm being 11 seconds.

The vertical axis in FIG. 15 shows the amount of Si at the center of the substrate to be film-formed as 100%, and Mo is shown as an atomic percentage with respect to Si. This composition distribution was investigated using an energy dispersive X-ray analyzer. Approximately on the board
Over 140φmm, the composition of Mo:Si=1:2 is ±5
Protected within %. In this way, Mo and Si each form a thin layered structure and are deposited, but the deposited film cannot yet be called a MoSi ₂ alloy film.
After film formation, the film-formed wafer is alloyed by ion implantation, impurity diffusion, and heat treatment for 1 hour in an Ar atmosphere or _N2 atmosphere at 1000°C, as shown in Figure 2. Actual gate wiring film 7
Can be used as 3. In other words, Figure 2 shows a MOS type IC.
FIG. 3 is a diagram showing a partial cross section of the memory. 70 indicates the ion implantation region, 71 indicates SiO ₂ , and 72 indicates the ion implantation region.
PolySi layer is shown. In this way, wiring only at the gate portion of the PolySi layer 72 results in high resistance, and the MOS
The operating speed of type IC memory could not be improved. However, on this PolySi layer 72, MoSi ₂
Since the alloy film 73 can be formed to a thickness of about 3000 Å,
Similarly, the polySi layer 72 can exist without melting during impurity diffusion, and a high-quality MoSi ₂ alloy film 74 can be formed, and the operation speed can be greatly improved and a highly reliable MOS type IC memory can be created. Obtainable.

However, according to the inventors' experiments, immediately after film formation,
The thin layer structure consisting of Mo and Si has a total of Mo and Si.
If the thickness was about 500 Å, no problem would arise in terms of process. Therefore, as mentioned above, if 3000Å
If a MoSi ₂ film is required, it is considered sufficient to set a cycle of about 10 times.

Next, let us show another remarkable effect of the present invention.
Figure 16 shows plasma ring diameters of 80mm and 164mm.
This is the composition distribution characteristics of Mo and Si when the film was formed while changing the . At this time, first, the time during which the plasma ring diameter was 80 mm was set to 4 seconds, and then the time during which the plasma ring diameter was 164 mm was set to 6.5 seconds, and this cycle was repeated 4 times to form a film on the substrate 10 to be film-formed. . As a result, the composition of Si:Mo=100:9.6 (atomic percentage) was 150φmm on the target substrate.
This has been achieved over a period of time. The point that deserves attention here is that by controlling the diameter of the plasma ring, the resulting film formation can be freely determined while keeping the composition distribution constant over a sufficiently wide range. It is. In other words, in this example, the composition can be controlled by determining the current waveform applied to the outer excitation coil, and this is a completely new and extremely effective method that has never been considered with conventional sputter electrodes. It can be said that it is a degree of freedom.

FIG. 17 shows an example of the current waveform applied to the outer excitation coil 40 when the film deposition amount distribution shown in FIGS. 15 and 16 is obtained. In the figure, T is one period of change in the diameter of the plasma ring, and in Figure 15, T=
19 seconds, and in Figure 16 it is 10.5 seconds. If the time when the plasma ring diameter is large is To, and the time when the plasma ring diameter is small is Ti, then T=To+Ti, and regarding FIG. 15, Ti=8 seconds, To
= 11 seconds, and referring to Figure 16, Ti =
4 seconds, To=6.5 seconds.

In FIG. 17, the current in the outer excitation coil 40 has a rectangular waveform, but of course, even if it has a triangular or sinusoidal waveform, if the amplitude, phase, etc. are considered, the current in FIGS. The film deposition amount distribution characteristics as shown below can be obtained.

Figure 18 shows a step-wave current flowing through the outer excitation coil 4.
This is the waveform when film formation was performed with the flow set to 0. This waveform takes a current value Im′ (Io<Im′<Ii) during Tm′,
The value Ii is taken between Ti, the value Im′ (Io<Im″<Ii) is taken between Tm′, and the value Io is taken between To.

As Tm′+Tm″=Tm, during this time the plasma ring assumes a medium diameter that is larger than the plasma ring diameter given by Ii and smaller than the plasma ring diameter given by Io.Tm′=Tm″ In addition, the current value does not need to be Im′=Im″.

Ti=
4sec, Tm (=Tm′+Tm″)=2sec, To=6.5sec,
Im′=Im'' and Io<Im<Ii.If Tm=0sec, this condition is the same as the film forming condition in FIG. 16, and Ii, Io in FIG. In addition, Im was adjusted to a value such that the plasma ring was exactly on the Mo second target members 21b and 21b' shown in Fig. 4 or Fig. 5.The amount of film formed at this time was The husband characteristics are shown in Figure 19.
The film deposition amount distribution characteristic shown in FIG. 9 is the same as the Si curve shown in FIG. 16, but only the atomic percentage of Mo is increased. That is, this means that
As shown in FIG. 18, it is shown that the composition can be controlled by making the plasma ring take an intermediate value that is neither the maximum value nor the minimum value of the diameter during one cycle during film formation. This second composition control method does not significantly disturb the film thickness distribution even if the plasma ring diameter that allows the widest and flattest film shown in Figure 10 is introduced into a certain plasma ring control cycle. This was derived from this knowledge.

If we further develop this idea, even if we combine the plasma ring diameters before and after this medium plasma ring diameter, as described in Figure 13,
Since it is possible to obtain a deposition amount distribution similar to the deposition amount distribution at the plasma ring diameter which gives the widest and flattest distribution of deposition amount, it is not necessary to have a stepped waveform as shown in FIG. For example, even if the waveform is a continuous waveform such as a triangular wave or a sine wave, this composition control can be performed.

As above, regarding the composition control method, the outer excitation coil 4
0 current waveform, but conversely, assuming the outer excitation coil current is constant, the inner excitation coil 39
It was mentioned earlier that similar control can be performed on the current of . Furthermore, even when controlling both the inner and outer excitation currents, this does not deviate from the technical idea regarding composition control described above.

By the way, if a synthetic material is made of substance A and substance B with a predetermined composition as the target flat plate 21, a synthetic film can be formed on the substrate 10 while the substrates 10 are stationary and facing each other in this way. High melting point metals (Mo, Ta, Wo, Si, Cr, Nb, V,
Zr, Tc, Ru, Ra, Hf, Ir, Os, Re) and other metals (e.g. Mo+Si, Ta+Si, Zr+Si, Cr+
Si, Wo+Si, Pt+Si, Pd+Si, Ra+Si, Ir+
It is not possible to obtain synthetic materials such as Si). However, if the material A 21a and the material B 21b are arranged as the target flat plate 21 as shown in FIG. 20, FIG. 21, or FIG. 22, and sputtering is performed using the sputtering apparatus as described above. , a synthetic film having a predetermined composition is formed on the substrate 10.

In particular, by using a sputtering device equipped with dual magnetron electrodes as shown in Fig. 4, by magnetically moving the position where glow discharge is caused and controlling the stopping time, a synthetic film ( alloy film) can be formed. For example, Figure 20,
Or, as shown in Fig. 21, 21a is Si, 21b is Mo, Ta, Zr, Cr, Wo, Pt, Pd, Ph, Ir.
It is clear that it can be formed by

As explained above, according to the present invention, it is possible to form a composite film of a plurality of materials in a predetermined composition ratio while the planar magnetron sputtering electrode and the substrate to be film-formed are statically opposed to each other. This has the effect of making it possible to obtain a good film by co-sputtering, which was previously impossible to obtain.

125φ under the conditions to obtain the composition distribution shown in Figure 15.
A film deposition rate of 1000 Å/min was obtained on a substrate of 420 V x 4 A. This value is approximately 10 times higher than that obtained with prior art co-sputtering equipment. In the measurement by ESCA, an oxygen peak is detected, but when comparing the film formed by the conventional apparatus and the MoSi ₂ film formed by the co-sputtering electrode according to the present invention under the conditions shown in Figure 15, the peak height is The temperature decreased to about 1/3. This indicates that the above-mentioned entrapment of residual impurity gas was reduced as the film formation rate increased. That is, the reason why such favorable process conditions can be achieved is that the sputtering electrode and film forming method according to the present invention enable co-sputtering with a single electrode.

Further, according to the present invention, co-sputtering can be performed while the substrate 10 to be film-formed is kept stationary.
As shown in FIG.
0, the substrate 10 can be easily heated to 300°C or higher, and parts that do not originally need to be heated, such as the vacuum chamber and mechanical parts, are prevented from being heated. Also, gas release is prevented, and an increase in the partial pressure of residual gases other than Ar gas in the vacuum chamber during film formation is prevented, which has the effect of increasing the film formation rate and obtaining the desired good film quality.

Note that 80 is a substrate holder that holds the substrate 10 to be film-formed. 81, the heat from the heater 64 is applied to the substrate 1.
It is a heat shielded room so that it does not hit anything other than 0.
A water cooling pipe 82 is attached to the heat seed chamber 81 and connected to a water source for cooling the heat seat chamber 81 so that it is not heated.

[Effect of the invention] As explained above, according to the present invention, PolySi
A silicide layer of high melting point metal can be formed on top of the layer.
This has the effect of significantly lowering the wiring resistance of the gate portion and making it possible to manufacture an IC with high operating speed.

[Brief explanation of drawings]

Figure 1 is a diagram showing the cross-sectional structure of a MOS transistor using polycrystalline silicon as the gate wiring material.
Figure 2 is a diagram showing the cross-sectional structure of a MOS transistor in which high melting point metal silicide and polycrystalline silicon are used as a two-layer gate wiring material according to the present invention;
The figure is a schematic cross-sectional view showing a planar magnetron sputtering device for co-sputtering to explain part of the principle of the present invention, and FIG. 5 is a diagram showing a power supply unit used in the electrode shown in FIG. 4; FIG. 6 is a diagram showing the magnetic field distribution of the planar magnetron for co-sputtering shown in FIG. 4. , FIG. 7 is a diagram showing the same magnetic field distribution as FIG. 6, FIG. 8 is a diagram explaining the correlation between the plasma ring diameter and the film-forming amount distribution characteristics, and FIG. 9 is a diagram for co-sputtering according to the present invention. A conceptual diagram illustrating the synthesis of film thickness distribution using a planar magnetron sputter electrode, FIG. 10 is a diagram showing the basic film forming characteristics of the planar magnetron sputter electrode for co-sputtering according to the present invention, FIGS. 11 and 12 , FIG. 13 also shows the basic film formation characteristics in the same way as FIG. 10, and FIG.
The figure is a schematic diagram showing the positional relationship between the target flat plate and the plasma ring diameter according to the present invention, FIGS. 15 and 16 are diagrams showing examples of composition distribution characteristics of molybdenum silicide alloy film formation according to the present invention, 17th
18 and 18 are diagrams showing the excitation current control method, FIG. 19 is a diagram showing the composition distribution characteristics of the molybdenum silicide film obtained by the control method shown in FIG. 18, and FIGS. Figure 22 shows a target plate on which different types of substances are arranged. 70... Ion implantation region, 71... SiO ₂ ,
72...PolySi layer, 73...MoSi ₂ alloy film.

Claims (1)

[Claims] 1. Prepare a target flat plate on which a high melting point metal material and a silicon material are arranged, generate plasma on the target flat plate using a planar magnetron sputtering electrode, and magnetically control the position of the generated plasma. A composite film of the high melting point metal material and silicon material is formed at a predetermined composition ratio on the substrate to be film-formed, and this composite film is heat-treated to form a composite film of the high melting point metal and silicon material. A method for forming an IC wiring pattern, which is characterized by forming an intermediate compound.